Abort pgbench if script end is reached with an open pipeline

[pgsql.git] / src / bin / pgbench / pgbench.c

/*
 * pgbench.c
 *
 * A simple benchmark program for PostgreSQL
 * Originally written by Tatsuo Ishii and enhanced by many contributors.
 *
 * src/bin/pgbench/pgbench.c
 * Copyright (c) 2000-2024, PostgreSQL Global Development Group
 * ALL RIGHTS RESERVED;
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for any purpose, without fee, and without a written agreement
 * is hereby granted, provided that the above copyright notice and this
 * paragraph and the following two paragraphs appear in all copies.
 *
 * IN NO EVENT SHALL THE AUTHOR OR DISTRIBUTORS BE LIABLE TO ANY PARTY FOR
 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
 * LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
 * DOCUMENTATION, EVEN IF THE AUTHOR OR DISTRIBUTORS HAVE BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * THE AUTHOR AND DISTRIBUTORS SPECIFICALLY DISCLAIMS ANY WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
 * ON AN "AS IS" BASIS, AND THE AUTHOR AND DISTRIBUTORS HAS NO OBLIGATIONS TO
 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
 *
 */

#if defined(WIN32) && FD_SETSIZE < 1024
#error FD_SETSIZE needs to have been increased
#endif

#include "postgres_fe.h"

#include <ctype.h>
#include <float.h>
#include <limits.h>
#include <math.h>
#include <signal.h>
#include <time.h>
#include <sys/time.h>
#include <sys/resource.h>               /* for getrlimit */

/* For testing, PGBENCH_USE_SELECT can be defined to force use of that code */
#if defined(HAVE_PPOLL) && !defined(PGBENCH_USE_SELECT)
#define POLL_USING_PPOLL
#ifdef HAVE_POLL_H
#include <poll.h>
#endif
#else                                                   /* no ppoll(), so use select() */
#define POLL_USING_SELECT
#include <sys/select.h>
#endif

#include "common/int.h"
#include "common/logging.h"
#include "common/pg_prng.h"
#include "common/string.h"
#include "common/username.h"
#include "fe_utils/cancel.h"
#include "fe_utils/conditional.h"
#include "fe_utils/option_utils.h"
#include "fe_utils/string_utils.h"
#include "getopt_long.h"
#include "libpq-fe.h"
#include "pgbench.h"
#include "port/pg_bitutils.h"
#include "portability/instr_time.h"

/* X/Open (XSI) requires <math.h> to provide M_PI, but core POSIX does not */
#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif

#define ERRCODE_T_R_SERIALIZATION_FAILURE  "40001"
#define ERRCODE_T_R_DEADLOCK_DETECTED  "40P01"
#define ERRCODE_UNDEFINED_TABLE  "42P01"

/*
 * Hashing constants
 */
#define FNV_PRIME                       UINT64CONST(0x100000001b3)
#define FNV_OFFSET_BASIS        UINT64CONST(0xcbf29ce484222325)
#define MM2_MUL                         UINT64CONST(0xc6a4a7935bd1e995)
#define MM2_MUL_TIMES_8         UINT64CONST(0x35253c9ade8f4ca8)
#define MM2_ROT                         47

/*
 * Multi-platform socket set implementations
 */

#ifdef POLL_USING_PPOLL
#define SOCKET_WAIT_METHOD "ppoll"

typedef struct socket_set
{
        int                     maxfds;                 /* allocated length of pollfds[] array */
        int                     curfds;                 /* number currently in use */
        struct pollfd pollfds[FLEXIBLE_ARRAY_MEMBER];
} socket_set;

#endif                                                  /* POLL_USING_PPOLL */

#ifdef POLL_USING_SELECT
#define SOCKET_WAIT_METHOD "select"

typedef struct socket_set
{
        int                     maxfd;                  /* largest FD currently set in fds */
        fd_set          fds;
} socket_set;

#endif                                                  /* POLL_USING_SELECT */

/*
 * Multi-platform thread implementations
 */

#ifdef WIN32
/* Use Windows threads */
#include <windows.h>
#define GETERRNO() (_dosmaperr(GetLastError()), errno)
#define THREAD_T HANDLE
#define THREAD_FUNC_RETURN_TYPE unsigned
#define THREAD_FUNC_RETURN return 0
#define THREAD_FUNC_CC __stdcall
#define THREAD_CREATE(handle, function, arg) \
        ((*(handle) = (HANDLE) _beginthreadex(NULL, 0, (function), (arg), 0, NULL)) == 0 ? errno : 0)
#define THREAD_JOIN(handle) \
        (WaitForSingleObject(handle, INFINITE) != WAIT_OBJECT_0 ? \
        GETERRNO() : CloseHandle(handle) ? 0 : GETERRNO())
#define THREAD_BARRIER_T SYNCHRONIZATION_BARRIER
#define THREAD_BARRIER_INIT(barrier, n) \
        (InitializeSynchronizationBarrier((barrier), (n), 0) ? 0 : GETERRNO())
#define THREAD_BARRIER_WAIT(barrier) \
        EnterSynchronizationBarrier((barrier), \
                                                                SYNCHRONIZATION_BARRIER_FLAGS_BLOCK_ONLY)
#define THREAD_BARRIER_DESTROY(barrier)
#else
/* Use POSIX threads */
#include "port/pg_pthread.h"
#define THREAD_T pthread_t
#define THREAD_FUNC_RETURN_TYPE void *
#define THREAD_FUNC_RETURN return NULL
#define THREAD_FUNC_CC
#define THREAD_CREATE(handle, function, arg) \
        pthread_create((handle), NULL, (function), (arg))
#define THREAD_JOIN(handle) \
        pthread_join((handle), NULL)
#define THREAD_BARRIER_T pthread_barrier_t
#define THREAD_BARRIER_INIT(barrier, n) \
        pthread_barrier_init((barrier), NULL, (n))
#define THREAD_BARRIER_WAIT(barrier) pthread_barrier_wait((barrier))
#define THREAD_BARRIER_DESTROY(barrier) pthread_barrier_destroy((barrier))
#endif


/********************************************************************
 * some configurable parameters */

#define DEFAULT_INIT_STEPS "dtgvp"      /* default -I setting */
#define ALL_INIT_STEPS "dtgGvpf"        /* all possible steps */

#define LOG_STEP_SECONDS        5       /* seconds between log messages */
#define DEFAULT_NXACTS  10              /* default nxacts */

#define MIN_GAUSSIAN_PARAM              2.0 /* minimum parameter for gauss */

#define MIN_ZIPFIAN_PARAM               1.001   /* minimum parameter for zipfian */
#define MAX_ZIPFIAN_PARAM               1000.0  /* maximum parameter for zipfian */

int                     nxacts = 0;                     /* number of transactions per client */
int                     duration = 0;           /* duration in seconds */
int64           end_time = 0;           /* when to stop in micro seconds, under -T */

/*
 * scaling factor. for example, scale = 10 will make 1000000 tuples in
 * pgbench_accounts table.
 */
int                     scale = 1;

/*
 * fillfactor. for example, fillfactor = 90 will use only 90 percent
 * space during inserts and leave 10 percent free.
 */
int                     fillfactor = 100;

/*
 * use unlogged tables?
 */
bool            unlogged_tables = false;

/*
 * log sampling rate (1.0 = log everything, 0.0 = option not given)
 */
double          sample_rate = 0.0;

/*
 * When threads are throttled to a given rate limit, this is the target delay
 * to reach that rate in usec.  0 is the default and means no throttling.
 */
double          throttle_delay = 0;

/*
 * Transactions which take longer than this limit (in usec) are counted as
 * late, and reported as such, although they are completed anyway. When
 * throttling is enabled, execution time slots that are more than this late
 * are skipped altogether, and counted separately.
 */
int64           latency_limit = 0;

/*
 * tablespace selection
 */
char       *tablespace = NULL;
char       *index_tablespace = NULL;

/*
 * Number of "pgbench_accounts" partitions.  0 is the default and means no
 * partitioning.
 */
static int      partitions = 0;

/* partitioning strategy for "pgbench_accounts" */
typedef enum
{
        PART_NONE,                                      /* no partitioning */
        PART_RANGE,                                     /* range partitioning */
        PART_HASH,                                      /* hash partitioning */
} partition_method_t;

static partition_method_t partition_method = PART_NONE;
static const char *const PARTITION_METHOD[] = {"none", "range", "hash"};

/* random seed used to initialize base_random_sequence */
int64           random_seed = -1;

/*
 * end of configurable parameters
 *********************************************************************/

#define nbranches       1                       /* Makes little sense to change this.  Change
                                                                 * -s instead */
#define ntellers        10
#define naccounts       100000

/*
 * The scale factor at/beyond which 32bit integers are incapable of storing
 * 64bit values.
 *
 * Although the actual threshold is 21474, we use 20000 because it is easier to
 * document and remember, and isn't that far away from the real threshold.
 */
#define SCALE_32BIT_THRESHOLD 20000

bool            use_log;                        /* log transaction latencies to a file */
bool            use_quiet;                      /* quiet logging onto stderr */
int                     agg_interval;           /* log aggregates instead of individual
                                                                 * transactions */
bool            per_script_stats = false;       /* whether to collect stats per script */
int                     progress = 0;           /* thread progress report every this seconds */
bool            progress_timestamp = false; /* progress report with Unix time */
int                     nclients = 1;           /* number of clients */
int                     nthreads = 1;           /* number of threads */
bool            is_connect;                     /* establish connection for each transaction */
bool            report_per_command = false; /* report per-command latencies,
                                                                                 * retries after errors and failures
                                                                                 * (errors without retrying) */
int                     main_pid;                       /* main process id used in log filename */

/*
 * There are different types of restrictions for deciding that the current
 * transaction with a serialization/deadlock error can no longer be retried and
 * should be reported as failed:
 * - max_tries (--max-tries) can be used to limit the number of tries;
 * - latency_limit (-L) can be used to limit the total time of tries;
 * - duration (-T) can be used to limit the total benchmark time.
 *
 * They can be combined together, and you need to use at least one of them to
 * retry the transactions with serialization/deadlock errors. If none of them is
 * used, the default value of max_tries is 1 and such transactions will not be
 * retried.
 */

/*
 * We cannot retry a transaction after the serialization/deadlock error if its
 * number of tries reaches this maximum; if its value is zero, it is not used.
 */
uint32          max_tries = 1;

bool            failures_detailed = false;      /* whether to group failures in
                                                                                 * reports or logs by basic types */

const char *pghost = NULL;
const char *pgport = NULL;
const char *username = NULL;
const char *dbName = NULL;
char       *logfile_prefix = NULL;
const char *progname;

#define WSEP '@'                                /* weight separator */

volatile sig_atomic_t timer_exceeded = false;   /* flag from signal handler */

/*
 * We don't want to allocate variables one by one; for efficiency, add a
 * constant margin each time it overflows.
 */
#define VARIABLES_ALLOC_MARGIN  8

/*
 * Variable definitions.
 *
 * If a variable only has a string value, "svalue" is that value, and value is
 * "not set".  If the value is known, "value" contains the value (in any
 * variant).
 *
 * In this case "svalue" contains the string equivalent of the value, if we've
 * had occasion to compute that, or NULL if we haven't.
 */
typedef struct
{
        char       *name;                       /* variable's name */
        char       *svalue;                     /* its value in string form, if known */
        PgBenchValue value;                     /* actual variable's value */
} Variable;

/*
 * Data structure for client variables.
 */
typedef struct
{
        Variable   *vars;                       /* array of variable definitions */
        int                     nvars;                  /* number of variables */

        /*
         * The maximum number of variables that we can currently store in 'vars'
         * without having to reallocate more space. We must always have max_vars
         * >= nvars.
         */
        int                     max_vars;

        bool            vars_sorted;    /* are variables sorted by name? */
} Variables;

#define MAX_SCRIPTS             128             /* max number of SQL scripts allowed */
#define SHELL_COMMAND_SIZE      256 /* maximum size allowed for shell command */

/*
 * Simple data structure to keep stats about something.
 *
 * XXX probably the first value should be kept and used as an offset for
 * better numerical stability...
 */
typedef struct SimpleStats
{
        int64           count;                  /* how many values were encountered */
        double          min;                    /* the minimum seen */
        double          max;                    /* the maximum seen */
        double          sum;                    /* sum of values */
        double          sum2;                   /* sum of squared values */
} SimpleStats;

/*
 * The instr_time type is expensive when dealing with time arithmetic.  Define
 * a type to hold microseconds instead.  Type int64 is good enough for about
 * 584500 years.
 */
typedef int64 pg_time_usec_t;

/*
 * Data structure to hold various statistics: per-thread and per-script stats
 * are maintained and merged together.
 */
typedef struct StatsData
{
        pg_time_usec_t start_time;      /* interval start time, for aggregates */

        /*----------
         * Transactions are counted depending on their execution and outcome.
         * First a transaction may have started or not: skipped transactions occur
         * under --rate and --latency-limit when the client is too late to execute
         * them. Secondly, a started transaction may ultimately succeed or fail,
         * possibly after some retries when --max-tries is not one. Thus
         *
         * the number of all transactions =
         *   'skipped' (it was too late to execute them) +
         *   'cnt' (the number of successful transactions) +
         *   'failed' (the number of failed transactions).
         *
         * A successful transaction can have several unsuccessful tries before a
         * successful run. Thus
         *
         * 'cnt' (the number of successful transactions) =
         *   successfully retried transactions (they got a serialization or a
         *                                      deadlock error(s), but were
         *                                      successfully retried from the very
         *                                      beginning) +
         *   directly successful transactions (they were successfully completed on
         *                                     the first try).
         *
         * A failed transaction is defined as unsuccessfully retried transactions.
         * It can be one of two types:
         *
         * failed (the number of failed transactions) =
         *   'serialization_failures' (they got a serialization error and were not
         *                             successfully retried) +
         *   'deadlock_failures' (they got a deadlock error and were not
         *                        successfully retried).
         *
         * If the transaction was retried after a serialization or a deadlock
         * error this does not guarantee that this retry was successful. Thus
         *
         * 'retries' (number of retries) =
         *   number of retries in all retried transactions =
         *   number of retries in (successfully retried transactions +
         *                         failed transactions);
         *
         * 'retried' (number of all retried transactions) =
         *   successfully retried transactions +
         *   failed transactions.
         *----------
         */
        int64           cnt;                    /* number of successful transactions, not
                                                                 * including 'skipped' */
        int64           skipped;                /* number of transactions skipped under --rate
                                                                 * and --latency-limit */
        int64           retries;                /* number of retries after a serialization or
                                                                 * a deadlock error in all the transactions */
        int64           retried;                /* number of all transactions that were
                                                                 * retried after a serialization or a deadlock
                                                                 * error (perhaps the last try was
                                                                 * unsuccessful) */
        int64           serialization_failures; /* number of transactions that were
                                                                                 * not successfully retried after a
                                                                                 * serialization error */
        int64           deadlock_failures;      /* number of transactions that were not
                                                                         * successfully retried after a deadlock
                                                                         * error */
        SimpleStats latency;
        SimpleStats lag;
} StatsData;

/*
 * For displaying Unix epoch timestamps, as some time functions may have
 * another reference.
 */
pg_time_usec_t epoch_shift;

/*
 * Error status for errors during script execution.
 */
typedef enum EStatus
{
        ESTATUS_NO_ERROR = 0,
        ESTATUS_META_COMMAND_ERROR,

        /* SQL errors */
        ESTATUS_SERIALIZATION_ERROR,
        ESTATUS_DEADLOCK_ERROR,
        ESTATUS_OTHER_SQL_ERROR,
} EStatus;

/*
 * Transaction status at the end of a command.
 */
typedef enum TStatus
{
        TSTATUS_IDLE,
        TSTATUS_IN_BLOCK,
        TSTATUS_CONN_ERROR,
        TSTATUS_OTHER_ERROR,
} TStatus;

/* Various random sequences are initialized from this one. */
static pg_prng_state base_random_sequence;

/* Synchronization barrier for start and connection */
static THREAD_BARRIER_T barrier;

/*
 * Connection state machine states.
 */
typedef enum
{
        /*
         * The client must first choose a script to execute.  Once chosen, it can
         * either be throttled (state CSTATE_PREPARE_THROTTLE under --rate), start
         * right away (state CSTATE_START_TX) or not start at all if the timer was
         * exceeded (state CSTATE_FINISHED).
         */
        CSTATE_CHOOSE_SCRIPT,

        /*
         * CSTATE_START_TX performs start-of-transaction processing.  Establishes
         * a new connection for the transaction in --connect mode, records the
         * transaction start time, and proceed to the first command.
         *
         * Note: once a script is started, it will either error or run till its
         * end, where it may be interrupted. It is not interrupted while running,
         * so pgbench --time is to be understood as tx are allowed to start in
         * that time, and will finish when their work is completed.
         */
        CSTATE_START_TX,

        /*
         * In CSTATE_PREPARE_THROTTLE state, we calculate when to begin the next
         * transaction, and advance to CSTATE_THROTTLE.  CSTATE_THROTTLE state
         * sleeps until that moment, then advances to CSTATE_START_TX, or
         * CSTATE_FINISHED if the next transaction would start beyond the end of
         * the run.
         */
        CSTATE_PREPARE_THROTTLE,
        CSTATE_THROTTLE,

        /*
         * We loop through these states, to process each command in the script:
         *
         * CSTATE_START_COMMAND starts the execution of a command.  On a SQL
         * command, the command is sent to the server, and we move to
         * CSTATE_WAIT_RESULT state unless in pipeline mode. On a \sleep
         * meta-command, the timer is set, and we enter the CSTATE_SLEEP state to
         * wait for it to expire. Other meta-commands are executed immediately. If
         * the command about to start is actually beyond the end of the script,
         * advance to CSTATE_END_TX.
         *
         * CSTATE_WAIT_RESULT waits until we get a result set back from the server
         * for the current command.
         *
         * CSTATE_SLEEP waits until the end of \sleep.
         *
         * CSTATE_END_COMMAND records the end-of-command timestamp, increments the
         * command counter, and loops back to CSTATE_START_COMMAND state.
         *
         * CSTATE_SKIP_COMMAND is used by conditional branches which are not
         * executed. It quickly skip commands that do not need any evaluation.
         * This state can move forward several commands, till there is something
         * to do or the end of the script.
         */
        CSTATE_START_COMMAND,
        CSTATE_WAIT_RESULT,
        CSTATE_SLEEP,
        CSTATE_END_COMMAND,
        CSTATE_SKIP_COMMAND,

        /*
         * States for failed commands.
         *
         * If the SQL/meta command fails, in CSTATE_ERROR clean up after an error:
         * (1) clear the conditional stack; (2) if we have an unterminated
         * (possibly failed) transaction block, send the rollback command to the
         * server and wait for the result in CSTATE_WAIT_ROLLBACK_RESULT.  If
         * something goes wrong with rolling back, go to CSTATE_ABORTED.
         *
         * But if everything is ok we are ready for future transactions: if this
         * is a serialization or deadlock error and we can re-execute the
         * transaction from the very beginning, go to CSTATE_RETRY; otherwise go
         * to CSTATE_FAILURE.
         *
         * In CSTATE_RETRY report an error, set the same parameters for the
         * transaction execution as in the previous tries and process the first
         * transaction command in CSTATE_START_COMMAND.
         *
         * In CSTATE_FAILURE report a failure, set the parameters for the
         * transaction execution as they were before the first run of this
         * transaction (except for a random state) and go to CSTATE_END_TX to
         * complete this transaction.
         */
        CSTATE_ERROR,
        CSTATE_WAIT_ROLLBACK_RESULT,
        CSTATE_RETRY,
        CSTATE_FAILURE,

        /*
         * CSTATE_END_TX performs end-of-transaction processing.  It calculates
         * latency, and logs the transaction.  In --connect mode, it closes the
         * current connection.
         *
         * Then either starts over in CSTATE_CHOOSE_SCRIPT, or enters
         * CSTATE_FINISHED if we have no more work to do.
         */
        CSTATE_END_TX,

        /*
         * Final states.  CSTATE_ABORTED means that the script execution was
         * aborted because a command failed, CSTATE_FINISHED means success.
         */
        CSTATE_ABORTED,
        CSTATE_FINISHED,
} ConnectionStateEnum;

/*
 * Connection state.
 */
typedef struct
{
        PGconn     *con;                        /* connection handle to DB */
        int                     id;                             /* client No. */
        ConnectionStateEnum state;      /* state machine's current state. */
        ConditionalStack cstack;        /* enclosing conditionals state */

        /*
         * Separate randomness for each client. This is used for random functions
         * PGBENCH_RANDOM_* during the execution of the script.
         */
        pg_prng_state cs_func_rs;

        int                     use_file;               /* index in sql_script for this client */
        int                     command;                /* command number in script */

        /* client variables */
        Variables       variables;

        /* various times about current transaction in microseconds */
        pg_time_usec_t txn_scheduled;   /* scheduled start time of transaction */
        pg_time_usec_t sleep_until; /* scheduled start time of next cmd */
        pg_time_usec_t txn_begin;       /* used for measuring schedule lag times */
        pg_time_usec_t stmt_begin;      /* used for measuring statement latencies */

        /* whether client prepared each command of each script */
        bool      **prepared;

        /*
         * For processing failures and repeating transactions with serialization
         * or deadlock errors:
         */
        EStatus         estatus;                /* the error status of the current transaction
                                                                 * execution; this is ESTATUS_NO_ERROR if
                                                                 * there were no errors */
        pg_prng_state random_state; /* random state */
        uint32          tries;                  /* how many times have we already tried the
                                                                 * current transaction? */

        /* per client collected stats */
        int64           cnt;                    /* client transaction count, for -t; skipped
                                                                 * and failed transactions are also counted
                                                                 * here */
} CState;

/*
 * Thread state
 */
typedef struct
{
        int                     tid;                    /* thread id */
        THREAD_T        thread;                 /* thread handle */
        CState     *state;                      /* array of CState */
        int                     nstate;                 /* length of state[] */

        /*
         * Separate randomness for each thread. Each thread option uses its own
         * random state to make all of them independent of each other and
         * therefore deterministic at the thread level.
         */
        pg_prng_state ts_choose_rs; /* random state for selecting a script */
        pg_prng_state ts_throttle_rs;   /* random state for transaction throttling */
        pg_prng_state ts_sample_rs; /* random state for log sampling */

        int64           throttle_trigger;       /* previous/next throttling (us) */
        FILE       *logfile;            /* where to log, or NULL */

        /* per thread collected stats in microseconds */
        pg_time_usec_t create_time; /* thread creation time */
        pg_time_usec_t started_time;    /* thread is running */
        pg_time_usec_t bench_start; /* thread is benchmarking */
        pg_time_usec_t conn_duration;   /* cumulated connection and disconnection
                                                                         * delays */

        StatsData       stats;
        int64           latency_late;   /* count executed but late transactions */
} TState;

/*
 * queries read from files
 */
#define SQL_COMMAND             1
#define META_COMMAND    2

/*
 * max number of backslash command arguments or SQL variables,
 * including the command or SQL statement itself
 */
#define MAX_ARGS                256

typedef enum MetaCommand
{
        META_NONE,                                      /* not a known meta-command */
        META_SET,                                       /* \set */
        META_SETSHELL,                          /* \setshell */
        META_SHELL,                                     /* \shell */
        META_SLEEP,                                     /* \sleep */
        META_GSET,                                      /* \gset */
        META_ASET,                                      /* \aset */
        META_IF,                                        /* \if */
        META_ELIF,                                      /* \elif */
        META_ELSE,                                      /* \else */
        META_ENDIF,                                     /* \endif */
        META_STARTPIPELINE,                     /* \startpipeline */
        META_ENDPIPELINE,                       /* \endpipeline */
} MetaCommand;

typedef enum QueryMode
{
        QUERY_SIMPLE,                           /* simple query */
        QUERY_EXTENDED,                         /* extended query */
        QUERY_PREPARED,                         /* extended query with prepared statements */
        NUM_QUERYMODE
} QueryMode;

static QueryMode querymode = QUERY_SIMPLE;
static const char *const QUERYMODE[] = {"simple", "extended", "prepared"};

/*
 * struct Command represents one command in a script.
 *
 * lines                The raw, possibly multi-line command text.  Variable substitution
 *                              not applied.
 * first_line   A short, single-line extract of 'lines', for error reporting.
 * type                 SQL_COMMAND or META_COMMAND
 * meta                 The type of meta-command, with META_NONE/GSET/ASET if command
 *                              is SQL.
 * argc                 Number of arguments of the command, 0 if not yet processed.
 * argv                 Command arguments, the first of which is the command or SQL
 *                              string itself.  For SQL commands, after post-processing
 *                              argv[0] is the same as 'lines' with variables substituted.
 * prepname             The name that this command is prepared under, in prepare mode
 * varprefix    SQL commands terminated with \gset or \aset have this set
 *                              to a non NULL value.  If nonempty, it's used to prefix the
 *                              variable name that receives the value.
 * aset                 do gset on all possible queries of a combined query (\;).
 * expr                 Parsed expression, if needed.
 * stats                Time spent in this command.
 * retries              Number of retries after a serialization or deadlock error in the
 *                              current command.
 * failures             Number of errors in the current command that were not retried.
 */
typedef struct Command
{
        PQExpBufferData lines;
        char       *first_line;
        int                     type;
        MetaCommand meta;
        int                     argc;
        char       *argv[MAX_ARGS];
        char       *prepname;
        char       *varprefix;
        PgBenchExpr *expr;
        SimpleStats stats;
        int64           retries;
        int64           failures;
} Command;

typedef struct ParsedScript
{
        const char *desc;                       /* script descriptor (eg, file name) */
        int                     weight;                 /* selection weight */
        Command   **commands;           /* NULL-terminated array of Commands */
        StatsData       stats;                  /* total time spent in script */
} ParsedScript;

static ParsedScript sql_script[MAX_SCRIPTS];    /* SQL script files */
static int      num_scripts;            /* number of scripts in sql_script[] */
static int64 total_weight = 0;

static bool verbose_errors = false; /* print verbose messages of all errors */

static bool exit_on_abort = false;      /* exit when any client is aborted */

/* Builtin test scripts */
typedef struct BuiltinScript
{
        const char *name;                       /* very short name for -b ... */
        const char *desc;                       /* short description */
        const char *script;                     /* actual pgbench script */
} BuiltinScript;

static const BuiltinScript builtin_script[] =
{
        {
                "tpcb-like",
                "<builtin: TPC-B (sort of)>",
                "\\set aid random(1, " CppAsString2(naccounts) " * :scale)\n"
                "\\set bid random(1, " CppAsString2(nbranches) " * :scale)\n"
                "\\set tid random(1, " CppAsString2(ntellers) " * :scale)\n"
                "\\set delta random(-5000, 5000)\n"
                "BEGIN;\n"
                "UPDATE pgbench_accounts SET abalance = abalance + :delta WHERE aid = :aid;\n"
                "SELECT abalance FROM pgbench_accounts WHERE aid = :aid;\n"
                "UPDATE pgbench_tellers SET tbalance = tbalance + :delta WHERE tid = :tid;\n"
                "UPDATE pgbench_branches SET bbalance = bbalance + :delta WHERE bid = :bid;\n"
                "INSERT INTO pgbench_history (tid, bid, aid, delta, mtime) VALUES (:tid, :bid, :aid, :delta, CURRENT_TIMESTAMP);\n"
                "END;\n"
        },
        {
                "simple-update",
                "<builtin: simple update>",
                "\\set aid random(1, " CppAsString2(naccounts) " * :scale)\n"
                "\\set bid random(1, " CppAsString2(nbranches) " * :scale)\n"
                "\\set tid random(1, " CppAsString2(ntellers) " * :scale)\n"
                "\\set delta random(-5000, 5000)\n"
                "BEGIN;\n"
                "UPDATE pgbench_accounts SET abalance = abalance + :delta WHERE aid = :aid;\n"
                "SELECT abalance FROM pgbench_accounts WHERE aid = :aid;\n"
                "INSERT INTO pgbench_history (tid, bid, aid, delta, mtime) VALUES (:tid, :bid, :aid, :delta, CURRENT_TIMESTAMP);\n"
                "END;\n"
        },
        {
                "select-only",
                "<builtin: select only>",
                "\\set aid random(1, " CppAsString2(naccounts) " * :scale)\n"
                "SELECT abalance FROM pgbench_accounts WHERE aid = :aid;\n"
        }
};


/* Function prototypes */
static void setNullValue(PgBenchValue *pv);
static void setBoolValue(PgBenchValue *pv, bool bval);
static void setIntValue(PgBenchValue *pv, int64 ival);
static void setDoubleValue(PgBenchValue *pv, double dval);
static bool evaluateExpr(CState *st, PgBenchExpr *expr,
                                                 PgBenchValue *retval);
static ConnectionStateEnum executeMetaCommand(CState *st, pg_time_usec_t *now);
static void doLog(TState *thread, CState *st,
                                  StatsData *agg, bool skipped, double latency, double lag);
static void processXactStats(TState *thread, CState *st, pg_time_usec_t *now,
                                                         bool skipped, StatsData *agg);
static void addScript(const ParsedScript *script);
static THREAD_FUNC_RETURN_TYPE THREAD_FUNC_CC threadRun(void *arg);
static void finishCon(CState *st);
static void setalarm(int seconds);
static socket_set *alloc_socket_set(int count);
static void free_socket_set(socket_set *sa);
static void clear_socket_set(socket_set *sa);
static void add_socket_to_set(socket_set *sa, int fd, int idx);
static int      wait_on_socket_set(socket_set *sa, int64 usecs);
static bool socket_has_input(socket_set *sa, int fd, int idx);

/* callback used to build rows for COPY during data loading */
typedef void (*initRowMethod) (PQExpBufferData *sql, int64 curr);

/* callback functions for our flex lexer */
static const PsqlScanCallbacks pgbench_callbacks = {
        NULL,                                           /* don't need get_variable functionality */
};

static inline pg_time_usec_t
pg_time_now(void)
{
        instr_time      now;

        INSTR_TIME_SET_CURRENT(now);

        return (pg_time_usec_t) INSTR_TIME_GET_MICROSEC(now);
}

static inline void
pg_time_now_lazy(pg_time_usec_t *now)
{
        if ((*now) == 0)
                (*now) = pg_time_now();
}

#define PG_TIME_GET_DOUBLE(t) (0.000001 * (t))

static void
usage(void)
{
        printf("%s is a benchmarking tool for PostgreSQL.\n\n"
                   "Usage:\n"
                   "  %s [OPTION]... [DBNAME]\n"
                   "\nInitialization options:\n"
                   "  -i, --initialize         invokes initialization mode\n"
                   "  -I, --init-steps=[" ALL_INIT_STEPS "]+ (default \"" DEFAULT_INIT_STEPS "\")\n"
                   "                           run selected initialization steps, in the specified order\n"
                   "                           d: drop any existing pgbench tables\n"
                   "                           t: create the tables used by the standard pgbench scenario\n"
                   "                           g: generate data, client-side\n"
                   "                           G: generate data, server-side\n"
                   "                           v: invoke VACUUM on the standard tables\n"
                   "                           p: create primary key indexes on the standard tables\n"
                   "                           f: create foreign keys between the standard tables\n"
                   "  -F, --fillfactor=NUM     set fill factor\n"
                   "  -n, --no-vacuum          do not run VACUUM during initialization\n"
                   "  -q, --quiet              quiet logging (one message each 5 seconds)\n"
                   "  -s, --scale=NUM          scaling factor\n"
                   "  --foreign-keys           create foreign key constraints between tables\n"
                   "  --index-tablespace=TABLESPACE\n"
                   "                           create indexes in the specified tablespace\n"
                   "  --partition-method=(range|hash)\n"
                   "                           partition pgbench_accounts with this method (default: range)\n"
                   "  --partitions=NUM         partition pgbench_accounts into NUM parts (default: 0)\n"
                   "  --tablespace=TABLESPACE  create tables in the specified tablespace\n"
                   "  --unlogged-tables        create tables as unlogged tables\n"
                   "\nOptions to select what to run:\n"
                   "  -b, --builtin=NAME[@W]   add builtin script NAME weighted at W (default: 1)\n"
                   "                           (use \"-b list\" to list available scripts)\n"
                   "  -f, --file=FILENAME[@W]  add script FILENAME weighted at W (default: 1)\n"
                   "  -N, --skip-some-updates  skip updates of pgbench_tellers and pgbench_branches\n"
                   "                           (same as \"-b simple-update\")\n"
                   "  -S, --select-only        perform SELECT-only transactions\n"
                   "                           (same as \"-b select-only\")\n"
                   "\nBenchmarking options:\n"
                   "  -c, --client=NUM         number of concurrent database clients (default: 1)\n"
                   "  -C, --connect            establish new connection for each transaction\n"
                   "  -D, --define=VARNAME=VALUE\n"
                   "                           define variable for use by custom script\n"
                   "  -j, --jobs=NUM           number of threads (default: 1)\n"
                   "  -l, --log                write transaction times to log file\n"
                   "  -L, --latency-limit=NUM  count transactions lasting more than NUM ms as late\n"
                   "  -M, --protocol=simple|extended|prepared\n"
                   "                           protocol for submitting queries (default: simple)\n"
                   "  -n, --no-vacuum          do not run VACUUM before tests\n"
                   "  -P, --progress=NUM       show thread progress report every NUM seconds\n"
                   "  -r, --report-per-command report latencies, failures, and retries per command\n"
                   "  -R, --rate=NUM           target rate in transactions per second\n"
                   "  -s, --scale=NUM          report this scale factor in output\n"
                   "  -t, --transactions=NUM   number of transactions each client runs (default: 10)\n"
                   "  -T, --time=NUM           duration of benchmark test in seconds\n"
                   "  -v, --vacuum-all         vacuum all four standard tables before tests\n"
                   "  --aggregate-interval=NUM aggregate data over NUM seconds\n"
                   "  --exit-on-abort          exit when any client is aborted\n"
                   "  --failures-detailed      report the failures grouped by basic types\n"
                   "  --log-prefix=PREFIX      prefix for transaction time log file\n"
                   "                           (default: \"pgbench_log\")\n"
                   "  --max-tries=NUM          max number of tries to run transaction (default: 1)\n"
                   "  --progress-timestamp     use Unix epoch timestamps for progress\n"
                   "  --random-seed=SEED       set random seed (\"time\", \"rand\", integer)\n"
                   "  --sampling-rate=NUM      fraction of transactions to log (e.g., 0.01 for 1%%)\n"
                   "  --show-script=NAME       show builtin script code, then exit\n"
                   "  --verbose-errors         print messages of all errors\n"
                   "\nCommon options:\n"
                   "  -d, --debug              print debugging output\n"
                   "  -h, --host=HOSTNAME      database server host or socket directory\n"
                   "  -p, --port=PORT          database server port number\n"
                   "  -U, --username=USERNAME  connect as specified database user\n"
                   "  -V, --version            output version information, then exit\n"
                   "  -?, --help               show this help, then exit\n"
                   "\n"
                   "Report bugs to <%s>.\n"
                   "%s home page: <%s>\n",
                   progname, progname, PACKAGE_BUGREPORT, PACKAGE_NAME, PACKAGE_URL);
}

/* return whether str matches "^\s*[-+]?[0-9]+$" */
static bool
is_an_int(const char *str)
{
        const char *ptr = str;

        /* skip leading spaces; cast is consistent with strtoint64 */
        while (*ptr && isspace((unsigned char) *ptr))
                ptr++;

        /* skip sign */
        if (*ptr == '+' || *ptr == '-')
                ptr++;

        /* at least one digit */
        if (*ptr && !isdigit((unsigned char) *ptr))
                return false;

        /* eat all digits */
        while (*ptr && isdigit((unsigned char) *ptr))
                ptr++;

        /* must have reached end of string */
        return *ptr == '\0';
}


/*
 * strtoint64 -- convert a string to 64-bit integer
 *
 * This function is a slightly modified version of pg_strtoint64() from
 * src/backend/utils/adt/numutils.c.
 *
 * The function returns whether the conversion worked, and if so
 * "*result" is set to the result.
 *
 * If not errorOK, an error message is also printed out on errors.
 */
bool
strtoint64(const char *str, bool errorOK, int64 *result)
{
        const char *ptr = str;
        int64           tmp = 0;
        bool            neg = false;

        /*
         * Do our own scan, rather than relying on sscanf which might be broken
         * for long long.
         *
         * As INT64_MIN can't be stored as a positive 64 bit integer, accumulate
         * value as a negative number.
         */

        /* skip leading spaces */
        while (*ptr && isspace((unsigned char) *ptr))
                ptr++;

        /* handle sign */
        if (*ptr == '-')
        {
                ptr++;
                neg = true;
        }
        else if (*ptr == '+')
                ptr++;

        /* require at least one digit */
        if (unlikely(!isdigit((unsigned char) *ptr)))
                goto invalid_syntax;

        /* process digits */
        while (*ptr && isdigit((unsigned char) *ptr))
        {
                int8            digit = (*ptr++ - '0');

                if (unlikely(pg_mul_s64_overflow(tmp, 10, &tmp)) ||
                        unlikely(pg_sub_s64_overflow(tmp, digit, &tmp)))
                        goto out_of_range;
        }

        /* allow trailing whitespace, but not other trailing chars */
        while (*ptr != '\0' && isspace((unsigned char) *ptr))
                ptr++;

        if (unlikely(*ptr != '\0'))
                goto invalid_syntax;

        if (!neg)
        {
                if (unlikely(tmp == PG_INT64_MIN))
                        goto out_of_range;
                tmp = -tmp;
        }

        *result = tmp;
        return true;

out_of_range:
        if (!errorOK)
                pg_log_error("value \"%s\" is out of range for type bigint", str);
        return false;

invalid_syntax:
        if (!errorOK)
                pg_log_error("invalid input syntax for type bigint: \"%s\"", str);
        return false;
}

/* convert string to double, detecting overflows/underflows */
bool
strtodouble(const char *str, bool errorOK, double *dv)
{
        char       *end;

        errno = 0;
        *dv = strtod(str, &end);

        if (unlikely(errno != 0))
        {
                if (!errorOK)
                        pg_log_error("value \"%s\" is out of range for type double", str);
                return false;
        }

        if (unlikely(end == str || *end != '\0'))
        {
                if (!errorOK)
                        pg_log_error("invalid input syntax for type double: \"%s\"", str);
                return false;
        }
        return true;
}

/*
 * Initialize a prng state struct.
 *
 * We derive the seed from base_random_sequence, which must be set up already.
 */
static void
initRandomState(pg_prng_state *state)
{
        pg_prng_seed(state, pg_prng_uint64(&base_random_sequence));
}


/*
 * random number generator: uniform distribution from min to max inclusive.
 *
 * Although the limits are expressed as int64, you can't generate the full
 * int64 range in one call, because the difference of the limits mustn't
 * overflow int64.  This is not checked.
 */
static int64
getrand(pg_prng_state *state, int64 min, int64 max)
{
        return min + (int64) pg_prng_uint64_range(state, 0, max - min);
}

/*
 * random number generator: exponential distribution from min to max inclusive.
 * the parameter is so that the density of probability for the last cut-off max
 * value is exp(-parameter).
 */
static int64
getExponentialRand(pg_prng_state *state, int64 min, int64 max,
                                   double parameter)
{
        double          cut,
                                uniform,
                                rand;

        /* abort if wrong parameter, but must really be checked beforehand */
        Assert(parameter > 0.0);
        cut = exp(-parameter);
        /* pg_prng_double value in [0, 1), uniform in (0, 1] */
        uniform = 1.0 - pg_prng_double(state);

        /*
         * inner expression in (cut, 1] (if parameter > 0), rand in [0, 1)
         */
        Assert((1.0 - cut) != 0.0);
        rand = -log(cut + (1.0 - cut) * uniform) / parameter;
        /* return int64 random number within between min and max */
        return min + (int64) ((max - min + 1) * rand);
}

/* random number generator: gaussian distribution from min to max inclusive */
static int64
getGaussianRand(pg_prng_state *state, int64 min, int64 max,
                                double parameter)
{
        double          stdev;
        double          rand;

        /* abort if parameter is too low, but must really be checked beforehand */
        Assert(parameter >= MIN_GAUSSIAN_PARAM);

        /*
         * Get normally-distributed random number in the range -parameter <= stdev
         * < parameter.
         *
         * This loop is executed until the number is in the expected range.
         *
         * As the minimum parameter is 2.0, the probability of looping is low:
         * sqrt(-2 ln(r)) <= 2 => r >= e^{-2} ~ 0.135, then when taking the
         * average sinus multiplier as 2/pi, we have a 8.6% looping probability in
         * the worst case. For a parameter value of 5.0, the looping probability
         * is about e^{-5} * 2 / pi ~ 0.43%.
         */
        do
        {
                stdev = pg_prng_double_normal(state);
        }
        while (stdev < -parameter || stdev >= parameter);

        /* stdev is in [-parameter, parameter), normalization to [0,1) */
        rand = (stdev + parameter) / (parameter * 2.0);

        /* return int64 random number within between min and max */
        return min + (int64) ((max - min + 1) * rand);
}

/*
 * random number generator: generate a value, such that the series of values
 * will approximate a Poisson distribution centered on the given value.
 *
 * Individual results are rounded to integers, though the center value need
 * not be one.
 */
static int64
getPoissonRand(pg_prng_state *state, double center)
{
        /*
         * Use inverse transform sampling to generate a value > 0, such that the
         * expected (i.e. average) value is the given argument.
         */
        double          uniform;

        /* pg_prng_double value in [0, 1), uniform in (0, 1] */
        uniform = 1.0 - pg_prng_double(state);

        return (int64) (-log(uniform) * center + 0.5);
}

/*
 * Computing zipfian using rejection method, based on
 * "Non-Uniform Random Variate Generation",
 * Luc Devroye, p. 550-551, Springer 1986.
 *
 * This works for s > 1.0, but may perform badly for s very close to 1.0.
 */
static int64
computeIterativeZipfian(pg_prng_state *state, int64 n, double s)
{
        double          b = pow(2.0, s - 1.0);
        double          x,
                                t,
                                u,
                                v;

        /* Ensure n is sane */
        if (n <= 1)
                return 1;

        while (true)
        {
                /* random variates */
                u = pg_prng_double(state);
                v = pg_prng_double(state);

                x = floor(pow(u, -1.0 / (s - 1.0)));

                t = pow(1.0 + 1.0 / x, s - 1.0);
                /* reject if too large or out of bound */
                if (v * x * (t - 1.0) / (b - 1.0) <= t / b && x <= n)
                        break;
        }
        return (int64) x;
}

/* random number generator: zipfian distribution from min to max inclusive */
static int64
getZipfianRand(pg_prng_state *state, int64 min, int64 max, double s)
{
        int64           n = max - min + 1;

        /* abort if parameter is invalid */
        Assert(MIN_ZIPFIAN_PARAM <= s && s <= MAX_ZIPFIAN_PARAM);

        return min - 1 + computeIterativeZipfian(state, n, s);
}

/*
 * FNV-1a hash function
 */
static int64
getHashFnv1a(int64 val, uint64 seed)
{
        int64           result;
        int                     i;

        result = FNV_OFFSET_BASIS ^ seed;
        for (i = 0; i < 8; ++i)
        {
                int32           octet = val & 0xff;

                val = val >> 8;
                result = result ^ octet;
                result = result * FNV_PRIME;
        }

        return result;
}

/*
 * Murmur2 hash function
 *
 * Based on original work of Austin Appleby
 * https://github.com/aappleby/smhasher/blob/master/src/MurmurHash2.cpp
 */
static int64
getHashMurmur2(int64 val, uint64 seed)
{
        uint64          result = seed ^ MM2_MUL_TIMES_8;        /* sizeof(int64) */
        uint64          k = (uint64) val;

        k *= MM2_MUL;
        k ^= k >> MM2_ROT;
        k *= MM2_MUL;

        result ^= k;
        result *= MM2_MUL;

        result ^= result >> MM2_ROT;
        result *= MM2_MUL;
        result ^= result >> MM2_ROT;

        return (int64) result;
}

/*
 * Pseudorandom permutation function
 *
 * For small sizes, this generates each of the (size!) possible permutations
 * of integers in the range [0, size) with roughly equal probability.  Once
 * the size is larger than 20, the number of possible permutations exceeds the
 * number of distinct states of the internal pseudorandom number generator,
 * and so not all possible permutations can be generated, but the permutations
 * chosen should continue to give the appearance of being random.
 *
 * THIS FUNCTION IS NOT CRYPTOGRAPHICALLY SECURE.
 * DO NOT USE FOR SUCH PURPOSE.
 */
static int64
permute(const int64 val, const int64 isize, const int64 seed)
{
        /* using a high-end PRNG is probably overkill */
        pg_prng_state state;
        uint64          size;
        uint64          v;
        int                     masklen;
        uint64          mask;
        int                     i;

        if (isize < 2)
                return 0;                               /* nothing to permute */

        /* Initialize prng state using the seed */
        pg_prng_seed(&state, (uint64) seed);

        /* Computations are performed on unsigned values */
        size = (uint64) isize;
        v = (uint64) val % size;

        /* Mask to work modulo largest power of 2 less than or equal to size */
        masklen = pg_leftmost_one_pos64(size);
        mask = (((uint64) 1) << masklen) - 1;

        /*
         * Permute the input value by applying several rounds of pseudorandom
         * bijective transformations.  The intention here is to distribute each
         * input uniformly randomly across the range, and separate adjacent inputs
         * approximately uniformly randomly from each other, leading to a fairly
         * random overall choice of permutation.
         *
         * To separate adjacent inputs, we multiply by a random number modulo
         * (mask + 1), which is a power of 2.  For this to be a bijection, the
         * multiplier must be odd.  Since this is known to lead to less randomness
         * in the lower bits, we also apply a rotation that shifts the topmost bit
         * into the least significant bit.  In the special cases where size <= 3,
         * mask = 1 and each of these operations is actually a no-op, so we also
         * XOR the value with a different random number to inject additional
         * randomness.  Since the size is generally not a power of 2, we apply
         * this bijection on overlapping upper and lower halves of the input.
         *
         * To distribute the inputs uniformly across the range, we then also apply
         * a random offset modulo the full range.
         *
         * Taken together, these operations resemble a modified linear
         * congruential generator, as is commonly used in pseudorandom number
         * generators.  The number of rounds is fairly arbitrary, but six has been
         * found empirically to give a fairly good tradeoff between performance
         * and uniform randomness.  For small sizes it selects each of the (size!)
         * possible permutations with roughly equal probability.  For larger
         * sizes, not all permutations can be generated, but the intended random
         * spread is still produced.
         */
        for (i = 0; i < 6; i++)
        {
                uint64          m,
                                        r,
                                        t;

                /* Random multiply (by an odd number), XOR and rotate of lower half */
                m = (pg_prng_uint64(&state) & mask) | 1;
                r = pg_prng_uint64(&state) & mask;
                if (v <= mask)
                {
                        v = ((v * m) ^ r) & mask;
                        v = ((v << 1) & mask) | (v >> (masklen - 1));
                }

                /* Random multiply (by an odd number), XOR and rotate of upper half */
                m = (pg_prng_uint64(&state) & mask) | 1;
                r = pg_prng_uint64(&state) & mask;
                t = size - 1 - v;
                if (t <= mask)
                {
                        t = ((t * m) ^ r) & mask;
                        t = ((t << 1) & mask) | (t >> (masklen - 1));
                        v = size - 1 - t;
                }

                /* Random offset */
                r = pg_prng_uint64_range(&state, 0, size - 1);
                v = (v + r) % size;
        }

        return (int64) v;
}

/*
 * Initialize the given SimpleStats struct to all zeroes
 */
static void
initSimpleStats(SimpleStats *ss)
{
        memset(ss, 0, sizeof(SimpleStats));
}

/*
 * Accumulate one value into a SimpleStats struct.
 */
static void
addToSimpleStats(SimpleStats *ss, double val)
{
        if (ss->count == 0 || val < ss->min)
                ss->min = val;
        if (ss->count == 0 || val > ss->max)
                ss->max = val;
        ss->count++;
        ss->sum += val;
        ss->sum2 += val * val;
}

/*
 * Merge two SimpleStats objects
 */
static void
mergeSimpleStats(SimpleStats *acc, SimpleStats *ss)
{
        if (acc->count == 0 || ss->min < acc->min)
                acc->min = ss->min;
        if (acc->count == 0 || ss->max > acc->max)
                acc->max = ss->max;
        acc->count += ss->count;
        acc->sum += ss->sum;
        acc->sum2 += ss->sum2;
}

/*
 * Initialize a StatsData struct to mostly zeroes, with its start time set to
 * the given value.
 */
static void
initStats(StatsData *sd, pg_time_usec_t start)
{
        sd->start_time = start;
        sd->cnt = 0;
        sd->skipped = 0;
        sd->retries = 0;
        sd->retried = 0;
        sd->serialization_failures = 0;
        sd->deadlock_failures = 0;
        initSimpleStats(&sd->latency);
        initSimpleStats(&sd->lag);
}

/*
 * Accumulate one additional item into the given stats object.
 */
static void
accumStats(StatsData *stats, bool skipped, double lat, double lag,
                   EStatus estatus, int64 tries)
{
        /* Record the skipped transaction */
        if (skipped)
        {
                /* no latency to record on skipped transactions */
                stats->skipped++;
                return;
        }

        /*
         * Record the number of retries regardless of whether the transaction was
         * successful or failed.
         */
        if (tries > 1)
        {
                stats->retries += (tries - 1);
                stats->retried++;
        }

        switch (estatus)
        {
                        /* Record the successful transaction */
                case ESTATUS_NO_ERROR:
                        stats->cnt++;

                        addToSimpleStats(&stats->latency, lat);

                        /* and possibly the same for schedule lag */
                        if (throttle_delay)
                                addToSimpleStats(&stats->lag, lag);
                        break;

                        /* Record the failed transaction */
                case ESTATUS_SERIALIZATION_ERROR:
                        stats->serialization_failures++;
                        break;
                case ESTATUS_DEADLOCK_ERROR:
                        stats->deadlock_failures++;
                        break;
                default:
                        /* internal error which should never occur */
                        pg_fatal("unexpected error status: %d", estatus);
        }
}

/* call PQexec() and exit() on failure */
static void
executeStatement(PGconn *con, const char *sql)
{
        PGresult   *res;

        res = PQexec(con, sql);
        if (PQresultStatus(res) != PGRES_COMMAND_OK)
        {
                pg_log_error("query failed: %s", PQerrorMessage(con));
                pg_log_error_detail("Query was: %s", sql);
                exit(1);
        }
        PQclear(res);
}

/* call PQexec() and complain, but without exiting, on failure */
static void
tryExecuteStatement(PGconn *con, const char *sql)
{
        PGresult   *res;

        res = PQexec(con, sql);
        if (PQresultStatus(res) != PGRES_COMMAND_OK)
        {
                pg_log_error("%s", PQerrorMessage(con));
                pg_log_error_detail("(ignoring this error and continuing anyway)");
        }
        PQclear(res);
}

/* set up a connection to the backend */
static PGconn *
doConnect(void)
{
        PGconn     *conn;
        bool            new_pass;
        static char *password = NULL;

        /*
         * Start the connection.  Loop until we have a password if requested by
         * backend.
         */
        do
        {
#define PARAMS_ARRAY_SIZE       7

                const char *keywords[PARAMS_ARRAY_SIZE];
                const char *values[PARAMS_ARRAY_SIZE];

                keywords[0] = "host";
                values[0] = pghost;
                keywords[1] = "port";
                values[1] = pgport;
                keywords[2] = "user";
                values[2] = username;
                keywords[3] = "password";
                values[3] = password;
                keywords[4] = "dbname";
                values[4] = dbName;
                keywords[5] = "fallback_application_name";
                values[5] = progname;
                keywords[6] = NULL;
                values[6] = NULL;

                new_pass = false;

                conn = PQconnectdbParams(keywords, values, true);

                if (!conn)
                {
                        pg_log_error("connection to database \"%s\" failed", dbName);
                        return NULL;
                }

                if (PQstatus(conn) == CONNECTION_BAD &&
                        PQconnectionNeedsPassword(conn) &&
                        !password)
                {
                        PQfinish(conn);
                        password = simple_prompt("Password: ", false);
                        new_pass = true;
                }
        } while (new_pass);

        /* check to see that the backend connection was successfully made */
        if (PQstatus(conn) == CONNECTION_BAD)
        {
                pg_log_error("%s", PQerrorMessage(conn));
                PQfinish(conn);
                return NULL;
        }

        return conn;
}

/* qsort comparator for Variable array */
static int
compareVariableNames(const void *v1, const void *v2)
{
        return strcmp(((const Variable *) v1)->name,
                                  ((const Variable *) v2)->name);
}

/* Locate a variable by name; returns NULL if unknown */
static Variable *
lookupVariable(Variables *variables, char *name)
{
        Variable        key;

        /* On some versions of Solaris, bsearch of zero items dumps core */
        if (variables->nvars <= 0)
                return NULL;

        /* Sort if we have to */
        if (!variables->vars_sorted)
        {
                qsort(variables->vars, variables->nvars, sizeof(Variable),
                          compareVariableNames);
                variables->vars_sorted = true;
        }

        /* Now we can search */
        key.name = name;
        return (Variable *) bsearch(&key,
                                                                variables->vars,
                                                                variables->nvars,
                                                                sizeof(Variable),
                                                                compareVariableNames);
}

/* Get the value of a variable, in string form; returns NULL if unknown */
static char *
getVariable(Variables *variables, char *name)
{
        Variable   *var;
        char            stringform[64];

        var = lookupVariable(variables, name);
        if (var == NULL)
                return NULL;                    /* not found */

        if (var->svalue)
                return var->svalue;             /* we have it in string form */

        /* We need to produce a string equivalent of the value */
        Assert(var->value.type != PGBT_NO_VALUE);
        if (var->value.type == PGBT_NULL)
                snprintf(stringform, sizeof(stringform), "NULL");
        else if (var->value.type == PGBT_BOOLEAN)
                snprintf(stringform, sizeof(stringform),
                                 "%s", var->value.u.bval ? "true" : "false");
        else if (var->value.type == PGBT_INT)
                snprintf(stringform, sizeof(stringform),
                                 INT64_FORMAT, var->value.u.ival);
        else if (var->value.type == PGBT_DOUBLE)
                snprintf(stringform, sizeof(stringform),
                                 "%.*g", DBL_DIG, var->value.u.dval);
        else                                            /* internal error, unexpected type */
                Assert(0);
        var->svalue = pg_strdup(stringform);
        return var->svalue;
}

/* Try to convert variable to a value; return false on failure */
static bool
makeVariableValue(Variable *var)
{
        size_t          slen;

        if (var->value.type != PGBT_NO_VALUE)
                return true;                    /* no work */

        slen = strlen(var->svalue);

        if (slen == 0)
                /* what should it do on ""? */
                return false;

        if (pg_strcasecmp(var->svalue, "null") == 0)
        {
                setNullValue(&var->value);
        }

        /*
         * accept prefixes such as y, ye, n, no... but not for "o". 0/1 are
         * recognized later as an int, which is converted to bool if needed.
         */
        else if (pg_strncasecmp(var->svalue, "true", slen) == 0 ||
                         pg_strncasecmp(var->svalue, "yes", slen) == 0 ||
                         pg_strcasecmp(var->svalue, "on") == 0)
        {
                setBoolValue(&var->value, true);
        }
        else if (pg_strncasecmp(var->svalue, "false", slen) == 0 ||
                         pg_strncasecmp(var->svalue, "no", slen) == 0 ||
                         pg_strcasecmp(var->svalue, "off") == 0 ||
                         pg_strcasecmp(var->svalue, "of") == 0)
        {
                setBoolValue(&var->value, false);
        }
        else if (is_an_int(var->svalue))
        {
                /* if it looks like an int, it must be an int without overflow */
                int64           iv;

                if (!strtoint64(var->svalue, false, &iv))
                        return false;

                setIntValue(&var->value, iv);
        }
        else                                            /* type should be double */
        {
                double          dv;

                if (!strtodouble(var->svalue, true, &dv))
                {
                        pg_log_error("malformed variable \"%s\" value: \"%s\"",
                                                 var->name, var->svalue);
                        return false;
                }
                setDoubleValue(&var->value, dv);
        }
        return true;
}

/*
 * Check whether a variable's name is allowed.
 *
 * We allow any non-ASCII character, as well as ASCII letters, digits, and
 * underscore.
 *
 * Keep this in sync with the definitions of variable name characters in
 * "src/fe_utils/psqlscan.l", "src/bin/psql/psqlscanslash.l" and
 * "src/bin/pgbench/exprscan.l".  Also see parseVariable(), below.
 *
 * Note: this static function is copied from "src/bin/psql/variables.c"
 * but changed to disallow variable names starting with a digit.
 */
static bool
valid_variable_name(const char *name)
{
        const unsigned char *ptr = (const unsigned char *) name;

        /* Mustn't be zero-length */
        if (*ptr == '\0')
                return false;

        /* must not start with [0-9] */
        if (IS_HIGHBIT_SET(*ptr) ||
                strchr("ABCDEFGHIJKLMNOPQRSTUVWXYZ" "abcdefghijklmnopqrstuvwxyz"
                           "_", *ptr) != NULL)
                ptr++;
        else
                return false;

        /* remaining characters can include [0-9] */
        while (*ptr)
        {
                if (IS_HIGHBIT_SET(*ptr) ||
                        strchr("ABCDEFGHIJKLMNOPQRSTUVWXYZ" "abcdefghijklmnopqrstuvwxyz"
                                   "_0123456789", *ptr) != NULL)
                        ptr++;
                else
                        return false;
        }

        return true;
}

/*
 * Make sure there is enough space for 'needed' more variable in the variables
 * array.
 */
static void
enlargeVariables(Variables *variables, int needed)
{
        /* total number of variables required now */
        needed += variables->nvars;

        if (variables->max_vars < needed)
        {
                variables->max_vars = needed + VARIABLES_ALLOC_MARGIN;
                variables->vars = (Variable *)
                        pg_realloc(variables->vars, variables->max_vars * sizeof(Variable));
        }
}

/*
 * Lookup a variable by name, creating it if need be.
 * Caller is expected to assign a value to the variable.
 * Returns NULL on failure (bad name).
 */
static Variable *
lookupCreateVariable(Variables *variables, const char *context, char *name)
{
        Variable   *var;

        var = lookupVariable(variables, name);
        if (var == NULL)
        {
                /*
                 * Check for the name only when declaring a new variable to avoid
                 * overhead.
                 */
                if (!valid_variable_name(name))
                {
                        pg_log_error("%s: invalid variable name: \"%s\"", context, name);
                        return NULL;
                }

                /* Create variable at the end of the array */
                enlargeVariables(variables, 1);

                var = &(variables->vars[variables->nvars]);

                var->name = pg_strdup(name);
                var->svalue = NULL;
                /* caller is expected to initialize remaining fields */

                variables->nvars++;
                /* we don't re-sort the array till we have to */
                variables->vars_sorted = false;
        }

        return var;
}

/* Assign a string value to a variable, creating it if need be */
/* Returns false on failure (bad name) */
static bool
putVariable(Variables *variables, const char *context, char *name,
                        const char *value)
{
        Variable   *var;
        char       *val;

        var = lookupCreateVariable(variables, context, name);
        if (!var)
                return false;

        /* dup then free, in case value is pointing at this variable */
        val = pg_strdup(value);

        free(var->svalue);
        var->svalue = val;
        var->value.type = PGBT_NO_VALUE;

        return true;
}

/* Assign a value to a variable, creating it if need be */
/* Returns false on failure (bad name) */
static bool
putVariableValue(Variables *variables, const char *context, char *name,
                                 const PgBenchValue *value)
{
        Variable   *var;

        var = lookupCreateVariable(variables, context, name);
        if (!var)
                return false;

        free(var->svalue);
        var->svalue = NULL;
        var->value = *value;

        return true;
}

/* Assign an integer value to a variable, creating it if need be */
/* Returns false on failure (bad name) */
static bool
putVariableInt(Variables *variables, const char *context, char *name,
                           int64 value)
{
        PgBenchValue val;

        setIntValue(&val, value);
        return putVariableValue(variables, context, name, &val);
}

/*
 * Parse a possible variable reference (:varname).
 *
 * "sql" points at a colon.  If what follows it looks like a valid
 * variable name, return a malloc'd string containing the variable name,
 * and set *eaten to the number of characters consumed (including the colon).
 * Otherwise, return NULL.
 */
static char *
parseVariable(const char *sql, int *eaten)
{
        int                     i = 1;                  /* starting at 1 skips the colon */
        char       *name;

        /* keep this logic in sync with valid_variable_name() */
        if (IS_HIGHBIT_SET(sql[i]) ||
                strchr("ABCDEFGHIJKLMNOPQRSTUVWXYZ" "abcdefghijklmnopqrstuvwxyz"
                           "_", sql[i]) != NULL)
                i++;
        else
                return NULL;

        while (IS_HIGHBIT_SET(sql[i]) ||
                   strchr("ABCDEFGHIJKLMNOPQRSTUVWXYZ" "abcdefghijklmnopqrstuvwxyz"
                                  "_0123456789", sql[i]) != NULL)
                i++;

        name = pg_malloc(i);
        memcpy(name, &sql[1], i - 1);
        name[i - 1] = '\0';

        *eaten = i;
        return name;
}

static char *
replaceVariable(char **sql, char *param, int len, char *value)
{
        int                     valueln = strlen(value);

        if (valueln > len)
        {
                size_t          offset = param - *sql;

                *sql = pg_realloc(*sql, strlen(*sql) - len + valueln + 1);
                param = *sql + offset;
        }

        if (valueln != len)
                memmove(param + valueln, param + len, strlen(param + len) + 1);
        memcpy(param, value, valueln);

        return param + valueln;
}

static char *
assignVariables(Variables *variables, char *sql)
{
        char       *p,
                           *name,
                           *val;

        p = sql;
        while ((p = strchr(p, ':')) != NULL)
        {
                int                     eaten;

                name = parseVariable(p, &eaten);
                if (name == NULL)
                {
                        while (*p == ':')
                        {
                                p++;
                        }
                        continue;
                }

                val = getVariable(variables, name);
                free(name);
                if (val == NULL)
                {
                        p++;
                        continue;
                }

                p = replaceVariable(&sql, p, eaten, val);
        }

        return sql;
}

static void
getQueryParams(Variables *variables, const Command *command,
                           const char **params)
{
        int                     i;

        for (i = 0; i < command->argc - 1; i++)
                params[i] = getVariable(variables, command->argv[i + 1]);
}

static char *
valueTypeName(PgBenchValue *pval)
{
        if (pval->type == PGBT_NO_VALUE)
                return "none";
        else if (pval->type == PGBT_NULL)
                return "null";
        else if (pval->type == PGBT_INT)
                return "int";
        else if (pval->type == PGBT_DOUBLE)
                return "double";
        else if (pval->type == PGBT_BOOLEAN)
                return "boolean";
        else
        {
                /* internal error, should never get there */
                Assert(false);
                return NULL;
        }
}

/* get a value as a boolean, or tell if there is a problem */
static bool
coerceToBool(PgBenchValue *pval, bool *bval)
{
        if (pval->type == PGBT_BOOLEAN)
        {
                *bval = pval->u.bval;
                return true;
        }
        else                                            /* NULL, INT or DOUBLE */
        {
                pg_log_error("cannot coerce %s to boolean", valueTypeName(pval));
                *bval = false;                  /* suppress uninitialized-variable warnings */
                return false;
        }
}

/*
 * Return true or false from an expression for conditional purposes.
 * Non zero numerical values are true, zero and NULL are false.
 */
static bool
valueTruth(PgBenchValue *pval)
{
        switch (pval->type)
        {
                case PGBT_NULL:
                        return false;
                case PGBT_BOOLEAN:
                        return pval->u.bval;
                case PGBT_INT:
                        return pval->u.ival != 0;
                case PGBT_DOUBLE:
                        return pval->u.dval != 0.0;
                default:
                        /* internal error, unexpected type */
                        Assert(0);
                        return false;
        }
}

/* get a value as an int, tell if there is a problem */
static bool
coerceToInt(PgBenchValue *pval, int64 *ival)
{
        if (pval->type == PGBT_INT)
        {
                *ival = pval->u.ival;
                return true;
        }
        else if (pval->type == PGBT_DOUBLE)
        {
                double          dval = rint(pval->u.dval);

                if (isnan(dval) || !FLOAT8_FITS_IN_INT64(dval))
                {
                        pg_log_error("double to int overflow for %f", dval);
                        return false;
                }
                *ival = (int64) dval;
                return true;
        }
        else                                            /* BOOLEAN or NULL */
        {
                pg_log_error("cannot coerce %s to int", valueTypeName(pval));
                return false;
        }
}

/* get a value as a double, or tell if there is a problem */
static bool
coerceToDouble(PgBenchValue *pval, double *dval)
{
        if (pval->type == PGBT_DOUBLE)
        {
                *dval = pval->u.dval;
                return true;
        }
        else if (pval->type == PGBT_INT)
        {
                *dval = (double) pval->u.ival;
                return true;
        }
        else                                            /* BOOLEAN or NULL */
        {
                pg_log_error("cannot coerce %s to double", valueTypeName(pval));
                return false;
        }
}

/* assign a null value */
static void
setNullValue(PgBenchValue *pv)
{
        pv->type = PGBT_NULL;
        pv->u.ival = 0;
}

/* assign a boolean value */
static void
setBoolValue(PgBenchValue *pv, bool bval)
{
        pv->type = PGBT_BOOLEAN;
        pv->u.bval = bval;
}

/* assign an integer value */
static void
setIntValue(PgBenchValue *pv, int64 ival)
{
        pv->type = PGBT_INT;
        pv->u.ival = ival;
}

/* assign a double value */
static void
setDoubleValue(PgBenchValue *pv, double dval)
{
        pv->type = PGBT_DOUBLE;
        pv->u.dval = dval;
}

static bool
isLazyFunc(PgBenchFunction func)
{
        return func == PGBENCH_AND || func == PGBENCH_OR || func == PGBENCH_CASE;
}

/* lazy evaluation of some functions */
static bool
evalLazyFunc(CState *st,
                         PgBenchFunction func, PgBenchExprLink *args, PgBenchValue *retval)
{
        PgBenchValue a1,
                                a2;
        bool            ba1,
                                ba2;

        Assert(isLazyFunc(func) && args != NULL && args->next != NULL);

        /* args points to first condition */
        if (!evaluateExpr(st, args->expr, &a1))
                return false;

        /* second condition for AND/OR and corresponding branch for CASE */
        args = args->next;

        switch (func)
        {
                case PGBENCH_AND:
                        if (a1.type == PGBT_NULL)
                        {
                                setNullValue(retval);
                                return true;
                        }

                        if (!coerceToBool(&a1, &ba1))
                                return false;

                        if (!ba1)
                        {
                                setBoolValue(retval, false);
                                return true;
                        }

                        if (!evaluateExpr(st, args->expr, &a2))
                                return false;

                        if (a2.type == PGBT_NULL)
                        {
                                setNullValue(retval);
                                return true;
                        }
                        else if (!coerceToBool(&a2, &ba2))
                                return false;
                        else
                        {
                                setBoolValue(retval, ba2);
                                return true;
                        }

                        return true;

                case PGBENCH_OR:

                        if (a1.type == PGBT_NULL)
                        {
                                setNullValue(retval);
                                return true;
                        }

                        if (!coerceToBool(&a1, &ba1))
                                return false;

                        if (ba1)
                        {
                                setBoolValue(retval, true);
                                return true;
                        }

                        if (!evaluateExpr(st, args->expr, &a2))
                                return false;

                        if (a2.type == PGBT_NULL)
                        {
                                setNullValue(retval);
                                return true;
                        }
                        else if (!coerceToBool(&a2, &ba2))
                                return false;
                        else
                        {
                                setBoolValue(retval, ba2);
                                return true;
                        }

                case PGBENCH_CASE:
                        /* when true, execute branch */
                        if (valueTruth(&a1))
                                return evaluateExpr(st, args->expr, retval);

                        /* now args contains next condition or final else expression */
                        args = args->next;

                        /* final else case? */
                        if (args->next == NULL)
                                return evaluateExpr(st, args->expr, retval);

                        /* no, another when, proceed */
                        return evalLazyFunc(st, PGBENCH_CASE, args, retval);

                default:
                        /* internal error, cannot get here */
                        Assert(0);
                        break;
        }
        return false;
}

/* maximum number of function arguments */
#define MAX_FARGS 16

/*
 * Recursive evaluation of standard functions,
 * which do not require lazy evaluation.
 */
static bool
evalStandardFunc(CState *st,
                                 PgBenchFunction func, PgBenchExprLink *args,
                                 PgBenchValue *retval)
{
        /* evaluate all function arguments */
        int                     nargs = 0;
        PgBenchExprLink *l = args;
        bool            has_null = false;

        /*
         * This value is double braced to workaround GCC bug 53119, which seems to
         * exist at least on gcc (Debian 4.7.2-5) 4.7.2, 32-bit.
         */
        PgBenchValue vargs[MAX_FARGS] = {{0}};

        for (nargs = 0; nargs < MAX_FARGS && l != NULL; nargs++, l = l->next)
        {
                if (!evaluateExpr(st, l->expr, &vargs[nargs]))
                        return false;
                has_null |= vargs[nargs].type == PGBT_NULL;
        }

        if (l != NULL)
        {
                pg_log_error("too many function arguments, maximum is %d", MAX_FARGS);
                return false;
        }

        /* NULL arguments */
        if (has_null && func != PGBENCH_IS && func != PGBENCH_DEBUG)
        {
                setNullValue(retval);
                return true;
        }

        /* then evaluate function */
        switch (func)
        {
                        /* overloaded operators */
                case PGBENCH_ADD:
                case PGBENCH_SUB:
                case PGBENCH_MUL:
                case PGBENCH_DIV:
                case PGBENCH_MOD:
                case PGBENCH_EQ:
                case PGBENCH_NE:
                case PGBENCH_LE:
                case PGBENCH_LT:
                        {
                                PgBenchValue *lval = &vargs[0],
                                                   *rval = &vargs[1];

                                Assert(nargs == 2);

                                /* overloaded type management, double if some double */
                                if ((lval->type == PGBT_DOUBLE ||
                                         rval->type == PGBT_DOUBLE) && func != PGBENCH_MOD)
                                {
                                        double          ld,
                                                                rd;

                                        if (!coerceToDouble(lval, &ld) ||
                                                !coerceToDouble(rval, &rd))
                                                return false;

                                        switch (func)
                                        {
                                                case PGBENCH_ADD:
                                                        setDoubleValue(retval, ld + rd);
                                                        return true;

                                                case PGBENCH_SUB:
                                                        setDoubleValue(retval, ld - rd);
                                                        return true;

                                                case PGBENCH_MUL:
                                                        setDoubleValue(retval, ld * rd);
                                                        return true;

                                                case PGBENCH_DIV:
                                                        setDoubleValue(retval, ld / rd);
                                                        return true;

                                                case PGBENCH_EQ:
                                                        setBoolValue(retval, ld == rd);
                                                        return true;

                                                case PGBENCH_NE:
                                                        setBoolValue(retval, ld != rd);
                                                        return true;

                                                case PGBENCH_LE:
                                                        setBoolValue(retval, ld <= rd);
                                                        return true;

                                                case PGBENCH_LT:
                                                        setBoolValue(retval, ld < rd);
                                                        return true;

                                                default:
                                                        /* cannot get here */
                                                        Assert(0);
                                        }
                                }
                                else                    /* we have integer operands, or % */
                                {
                                        int64           li,
                                                                ri,
                                                                res;

                                        if (!coerceToInt(lval, &li) ||
                                                !coerceToInt(rval, &ri))
                                                return false;

                                        switch (func)
                                        {
                                                case PGBENCH_ADD:
                                                        if (pg_add_s64_overflow(li, ri, &res))
                                                        {
                                                                pg_log_error("bigint add out of range");
                                                                return false;
                                                        }
                                                        setIntValue(retval, res);
                                                        return true;

                                                case PGBENCH_SUB:
                                                        if (pg_sub_s64_overflow(li, ri, &res))
                                                        {
                                                                pg_log_error("bigint sub out of range");
                                                                return false;
                                                        }
                                                        setIntValue(retval, res);
                                                        return true;

                                                case PGBENCH_MUL:
                                                        if (pg_mul_s64_overflow(li, ri, &res))
                                                        {
                                                                pg_log_error("bigint mul out of range");
                                                                return false;
                                                        }
                                                        setIntValue(retval, res);
                                                        return true;

                                                case PGBENCH_EQ:
                                                        setBoolValue(retval, li == ri);
                                                        return true;

                                                case PGBENCH_NE:
                                                        setBoolValue(retval, li != ri);
                                                        return true;

                                                case PGBENCH_LE:
                                                        setBoolValue(retval, li <= ri);
                                                        return true;

                                                case PGBENCH_LT:
                                                        setBoolValue(retval, li < ri);
                                                        return true;

                                                case PGBENCH_DIV:
                                                case PGBENCH_MOD:
                                                        if (ri == 0)
                                                        {
                                                                pg_log_error("division by zero");
                                                                return false;
                                                        }
                                                        /* special handling of -1 divisor */
                                                        if (ri == -1)
                                                        {
                                                                if (func == PGBENCH_DIV)
                                                                {
                                                                        /* overflow check (needed for INT64_MIN) */
                                                                        if (li == PG_INT64_MIN)
                                                                        {
                                                                                pg_log_error("bigint div out of range");
                                                                                return false;
                                                                        }
                                                                        else
                                                                                setIntValue(retval, -li);
                                                                }
                                                                else
                                                                        setIntValue(retval, 0);
                                                                return true;
                                                        }
                                                        /* else divisor is not -1 */
                                                        if (func == PGBENCH_DIV)
                                                                setIntValue(retval, li / ri);
                                                        else    /* func == PGBENCH_MOD */
                                                                setIntValue(retval, li % ri);

                                                        return true;

                                                default:
                                                        /* cannot get here */
                                                        Assert(0);
                                        }
                                }

                                Assert(0);
                                return false;   /* NOTREACHED */
                        }

                        /* integer bitwise operators */
                case PGBENCH_BITAND:
                case PGBENCH_BITOR:
                case PGBENCH_BITXOR:
                case PGBENCH_LSHIFT:
                case PGBENCH_RSHIFT:
                        {
                                int64           li,
                                                        ri;

                                if (!coerceToInt(&vargs[0], &li) || !coerceToInt(&vargs[1], &ri))
                                        return false;

                                if (func == PGBENCH_BITAND)
                                        setIntValue(retval, li & ri);
                                else if (func == PGBENCH_BITOR)
                                        setIntValue(retval, li | ri);
                                else if (func == PGBENCH_BITXOR)
                                        setIntValue(retval, li ^ ri);
                                else if (func == PGBENCH_LSHIFT)
                                        setIntValue(retval, li << ri);
                                else if (func == PGBENCH_RSHIFT)
                                        setIntValue(retval, li >> ri);
                                else                    /* cannot get here */
                                        Assert(0);

                                return true;
                        }

                        /* logical operators */
                case PGBENCH_NOT:
                        {
                                bool            b;

                                if (!coerceToBool(&vargs[0], &b))
                                        return false;

                                setBoolValue(retval, !b);
                                return true;
                        }

                        /* no arguments */
                case PGBENCH_PI:
                        setDoubleValue(retval, M_PI);
                        return true;

                        /* 1 overloaded argument */
                case PGBENCH_ABS:
                        {
                                PgBenchValue *varg = &vargs[0];

                                Assert(nargs == 1);

                                if (varg->type == PGBT_INT)
                                {
                                        int64           i = varg->u.ival;

                                        setIntValue(retval, i < 0 ? -i : i);
                                }
                                else
                                {
                                        double          d = varg->u.dval;

                                        Assert(varg->type == PGBT_DOUBLE);
                                        setDoubleValue(retval, d < 0.0 ? -d : d);
                                }

                                return true;
                        }

                case PGBENCH_DEBUG:
                        {
                                PgBenchValue *varg = &vargs[0];

                                Assert(nargs == 1);

                                fprintf(stderr, "debug(script=%d,command=%d): ",
                                                st->use_file, st->command + 1);

                                if (varg->type == PGBT_NULL)
                                        fprintf(stderr, "null\n");
                                else if (varg->type == PGBT_BOOLEAN)
                                        fprintf(stderr, "boolean %s\n", varg->u.bval ? "true" : "false");
                                else if (varg->type == PGBT_INT)
                                        fprintf(stderr, "int " INT64_FORMAT "\n", varg->u.ival);
                                else if (varg->type == PGBT_DOUBLE)
                                        fprintf(stderr, "double %.*g\n", DBL_DIG, varg->u.dval);
                                else                    /* internal error, unexpected type */
                                        Assert(0);

                                *retval = *varg;

                                return true;
                        }

                        /* 1 double argument */
                case PGBENCH_DOUBLE:
                case PGBENCH_SQRT:
                case PGBENCH_LN:
                case PGBENCH_EXP:
                        {
                                double          dval;

                                Assert(nargs == 1);

                                if (!coerceToDouble(&vargs[0], &dval))
                                        return false;

                                if (func == PGBENCH_SQRT)
                                        dval = sqrt(dval);
                                else if (func == PGBENCH_LN)
                                        dval = log(dval);
                                else if (func == PGBENCH_EXP)
                                        dval = exp(dval);
                                /* else is cast: do nothing */

                                setDoubleValue(retval, dval);
                                return true;
                        }

                        /* 1 int argument */
                case PGBENCH_INT:
                        {
                                int64           ival;

                                Assert(nargs == 1);

                                if (!coerceToInt(&vargs[0], &ival))
                                        return false;

                                setIntValue(retval, ival);
                                return true;
                        }

                        /* variable number of arguments */
                case PGBENCH_LEAST:
                case PGBENCH_GREATEST:
                        {
                                bool            havedouble;
                                int                     i;

                                Assert(nargs >= 1);

                                /* need double result if any input is double */
                                havedouble = false;
                                for (i = 0; i < nargs; i++)
                                {
                                        if (vargs[i].type == PGBT_DOUBLE)
                                        {
                                                havedouble = true;
                                                break;
                                        }
                                }
                                if (havedouble)
                                {
                                        double          extremum;

                                        if (!coerceToDouble(&vargs[0], &extremum))
                                                return false;
                                        for (i = 1; i < nargs; i++)
                                        {
                                                double          dval;

                                                if (!coerceToDouble(&vargs[i], &dval))
                                                        return false;
                                                if (func == PGBENCH_LEAST)
                                                        extremum = Min(extremum, dval);
                                                else
                                                        extremum = Max(extremum, dval);
                                        }
                                        setDoubleValue(retval, extremum);
                                }
                                else
                                {
                                        int64           extremum;

                                        if (!coerceToInt(&vargs[0], &extremum))
                                                return false;
                                        for (i = 1; i < nargs; i++)
                                        {
                                                int64           ival;

                                                if (!coerceToInt(&vargs[i], &ival))
                                                        return false;
                                                if (func == PGBENCH_LEAST)
                                                        extremum = Min(extremum, ival);
                                                else
                                                        extremum = Max(extremum, ival);
                                        }
                                        setIntValue(retval, extremum);
                                }
                                return true;
                        }

                        /* random functions */
                case PGBENCH_RANDOM:
                case PGBENCH_RANDOM_EXPONENTIAL:
                case PGBENCH_RANDOM_GAUSSIAN:
                case PGBENCH_RANDOM_ZIPFIAN:
                        {
                                int64           imin,
                                                        imax,
                                                        delta;

                                Assert(nargs >= 2);

                                if (!coerceToInt(&vargs[0], &imin) ||
                                        !coerceToInt(&vargs[1], &imax))
                                        return false;

                                /* check random range */
                                if (unlikely(imin > imax))
                                {
                                        pg_log_error("empty range given to random");
                                        return false;
                                }
                                else if (unlikely(pg_sub_s64_overflow(imax, imin, &delta) ||
                                                                  pg_add_s64_overflow(delta, 1, &delta)))
                                {
                                        /* prevent int overflows in random functions */
                                        pg_log_error("random range is too large");
                                        return false;
                                }

                                if (func == PGBENCH_RANDOM)
                                {
                                        Assert(nargs == 2);
                                        setIntValue(retval, getrand(&st->cs_func_rs, imin, imax));
                                }
                                else                    /* gaussian & exponential */
                                {
                                        double          param;

                                        Assert(nargs == 3);

                                        if (!coerceToDouble(&vargs[2], &param))
                                                return false;

                                        if (func == PGBENCH_RANDOM_GAUSSIAN)
                                        {
                                                if (param < MIN_GAUSSIAN_PARAM)
                                                {
                                                        pg_log_error("gaussian parameter must be at least %f (not %f)",
                                                                                 MIN_GAUSSIAN_PARAM, param);
                                                        return false;
                                                }

                                                setIntValue(retval,
                                                                        getGaussianRand(&st->cs_func_rs,
                                                                                                        imin, imax, param));
                                        }
                                        else if (func == PGBENCH_RANDOM_ZIPFIAN)
                                        {
                                                if (param < MIN_ZIPFIAN_PARAM || param > MAX_ZIPFIAN_PARAM)
                                                {
                                                        pg_log_error("zipfian parameter must be in range [%.3f, %.0f] (not %f)",
                                                                                 MIN_ZIPFIAN_PARAM, MAX_ZIPFIAN_PARAM, param);
                                                        return false;
                                                }

                                                setIntValue(retval,
                                                                        getZipfianRand(&st->cs_func_rs, imin, imax, param));
                                        }
                                        else            /* exponential */
                                        {
                                                if (param <= 0.0)
                                                {
                                                        pg_log_error("exponential parameter must be greater than zero (not %f)",
                                                                                 param);
                                                        return false;
                                                }

                                                setIntValue(retval,
                                                                        getExponentialRand(&st->cs_func_rs,
                                                                                                           imin, imax, param));
                                        }
                                }

                                return true;
                        }

                case PGBENCH_POW:
                        {
                                PgBenchValue *lval = &vargs[0];
                                PgBenchValue *rval = &vargs[1];
                                double          ld,
                                                        rd;

                                Assert(nargs == 2);

                                if (!coerceToDouble(lval, &ld) ||
                                        !coerceToDouble(rval, &rd))
                                        return false;

                                setDoubleValue(retval, pow(ld, rd));

                                return true;
                        }

                case PGBENCH_IS:
                        {
                                Assert(nargs == 2);

                                /*
                                 * note: this simple implementation is more permissive than
                                 * SQL
                                 */
                                setBoolValue(retval,
                                                         vargs[0].type == vargs[1].type &&
                                                         vargs[0].u.bval == vargs[1].u.bval);
                                return true;
                        }

                        /* hashing */
                case PGBENCH_HASH_FNV1A:
                case PGBENCH_HASH_MURMUR2:
                        {
                                int64           val,
                                                        seed;

                                Assert(nargs == 2);

                                if (!coerceToInt(&vargs[0], &val) ||
                                        !coerceToInt(&vargs[1], &seed))
                                        return false;

                                if (func == PGBENCH_HASH_MURMUR2)
                                        setIntValue(retval, getHashMurmur2(val, seed));
                                else if (func == PGBENCH_HASH_FNV1A)
                                        setIntValue(retval, getHashFnv1a(val, seed));
                                else
                                        /* cannot get here */
                                        Assert(0);

                                return true;
                        }

                case PGBENCH_PERMUTE:
                        {
                                int64           val,
                                                        size,
                                                        seed;

                                Assert(nargs == 3);

                                if (!coerceToInt(&vargs[0], &val) ||
                                        !coerceToInt(&vargs[1], &size) ||
                                        !coerceToInt(&vargs[2], &seed))
                                        return false;

                                if (size <= 0)
                                {
                                        pg_log_error("permute size parameter must be greater than zero");
                                        return false;
                                }

                                setIntValue(retval, permute(val, size, seed));
                                return true;
                        }

                default:
                        /* cannot get here */
                        Assert(0);
                        /* dead code to avoid a compiler warning */
                        return false;
        }
}

/* evaluate some function */
static bool
evalFunc(CState *st,
                 PgBenchFunction func, PgBenchExprLink *args, PgBenchValue *retval)
{
        if (isLazyFunc(func))
                return evalLazyFunc(st, func, args, retval);
        else
                return evalStandardFunc(st, func, args, retval);
}

/*
 * Recursive evaluation of an expression in a pgbench script
 * using the current state of variables.
 * Returns whether the evaluation was ok,
 * the value itself is returned through the retval pointer.
 */
static bool
evaluateExpr(CState *st, PgBenchExpr *expr, PgBenchValue *retval)
{
        switch (expr->etype)
        {
                case ENODE_CONSTANT:
                        {
                                *retval = expr->u.constant;
                                return true;
                        }

                case ENODE_VARIABLE:
                        {
                                Variable   *var;

                                if ((var = lookupVariable(&st->variables, expr->u.variable.varname)) == NULL)
                                {
                                        pg_log_error("undefined variable \"%s\"", expr->u.variable.varname);
                                        return false;
                                }

                                if (!makeVariableValue(var))
                                        return false;

                                *retval = var->value;
                                return true;
                        }

                case ENODE_FUNCTION:
                        return evalFunc(st,
                                                        expr->u.function.function,
                                                        expr->u.function.args,
                                                        retval);

                default:
                        /* internal error which should never occur */
                        pg_fatal("unexpected enode type in evaluation: %d", expr->etype);
        }
}

/*
 * Convert command name to meta-command enum identifier
 */
static MetaCommand
getMetaCommand(const char *cmd)
{
        MetaCommand mc;

        if (cmd == NULL)
                mc = META_NONE;
        else if (pg_strcasecmp(cmd, "set") == 0)
                mc = META_SET;
        else if (pg_strcasecmp(cmd, "setshell") == 0)
                mc = META_SETSHELL;
        else if (pg_strcasecmp(cmd, "shell") == 0)
                mc = META_SHELL;
        else if (pg_strcasecmp(cmd, "sleep") == 0)
                mc = META_SLEEP;
        else if (pg_strcasecmp(cmd, "if") == 0)
                mc = META_IF;
        else if (pg_strcasecmp(cmd, "elif") == 0)
                mc = META_ELIF;
        else if (pg_strcasecmp(cmd, "else") == 0)
                mc = META_ELSE;
        else if (pg_strcasecmp(cmd, "endif") == 0)
                mc = META_ENDIF;
        else if (pg_strcasecmp(cmd, "gset") == 0)
                mc = META_GSET;
        else if (pg_strcasecmp(cmd, "aset") == 0)
                mc = META_ASET;
        else if (pg_strcasecmp(cmd, "startpipeline") == 0)
                mc = META_STARTPIPELINE;
        else if (pg_strcasecmp(cmd, "endpipeline") == 0)
                mc = META_ENDPIPELINE;
        else
                mc = META_NONE;
        return mc;
}

/*
 * Run a shell command. The result is assigned to the variable if not NULL.
 * Return true if succeeded, or false on error.
 */
static bool
runShellCommand(Variables *variables, char *variable, char **argv, int argc)
{
        char            command[SHELL_COMMAND_SIZE];
        int                     i,
                                len = 0;
        FILE       *fp;
        char            res[64];
        char       *endptr;
        int                     retval;

        /*----------
         * Join arguments with whitespace separators. Arguments starting with
         * exactly one colon are treated as variables:
         *      name - append a string "name"
         *      :var - append a variable named 'var'
         *      ::name - append a string ":name"
         *----------
         */
        for (i = 0; i < argc; i++)
        {
                char       *arg;
                int                     arglen;

                if (argv[i][0] != ':')
                {
                        arg = argv[i];          /* a string literal */
                }
                else if (argv[i][1] == ':')
                {
                        arg = argv[i] + 1;      /* a string literal starting with colons */
                }
                else if ((arg = getVariable(variables, argv[i] + 1)) == NULL)
                {
                        pg_log_error("%s: undefined variable \"%s\"", argv[0], argv[i]);
                        return false;
                }

                arglen = strlen(arg);
                if (len + arglen + (i > 0 ? 1 : 0) >= SHELL_COMMAND_SIZE - 1)
                {
                        pg_log_error("%s: shell command is too long", argv[0]);
                        return false;
                }

                if (i > 0)
                        command[len++] = ' ';
                memcpy(command + len, arg, arglen);
                len += arglen;
        }

        command[len] = '\0';

        fflush(NULL);                           /* needed before either system() or popen() */

        /* Fast path for non-assignment case */
        if (variable == NULL)
        {
                if (system(command))
                {
                        if (!timer_exceeded)
                                pg_log_error("%s: could not launch shell command", argv[0]);
                        return false;
                }
                return true;
        }

        /* Execute the command with pipe and read the standard output. */
        if ((fp = popen(command, "r")) == NULL)
        {
                pg_log_error("%s: could not launch shell command", argv[0]);
                return false;
        }
        if (fgets(res, sizeof(res), fp) == NULL)
        {
                if (!timer_exceeded)
                        pg_log_error("%s: could not read result of shell command", argv[0]);
                (void) pclose(fp);
                return false;
        }
        if (pclose(fp) < 0)
        {
                pg_log_error("%s: could not run shell command: %m", argv[0]);
                return false;
        }

        /* Check whether the result is an integer and assign it to the variable */
        retval = (int) strtol(res, &endptr, 10);
        while (*endptr != '\0' && isspace((unsigned char) *endptr))
                endptr++;
        if (*res == '\0' || *endptr != '\0')
        {
                pg_log_error("%s: shell command must return an integer (not \"%s\")", argv[0], res);
                return false;
        }
        if (!putVariableInt(variables, "setshell", variable, retval))
                return false;

        pg_log_debug("%s: shell parameter name: \"%s\", value: \"%s\"", argv[0], argv[1], res);

        return true;
}

/*
 * Report the abortion of the client when processing SQL commands.
 */
static void
commandFailed(CState *st, const char *cmd, const char *message)
{
        pg_log_error("client %d aborted in command %d (%s) of script %d; %s",
                                 st->id, st->command, cmd, st->use_file, message);
}

/*
 * Report the error in the command while the script is executing.
 */
static void
commandError(CState *st, const char *message)
{
        Assert(sql_script[st->use_file].commands[st->command]->type == SQL_COMMAND);
        pg_log_info("client %d got an error in command %d (SQL) of script %d; %s",
                                st->id, st->command, st->use_file, message);
}

/* return a script number with a weighted choice. */
static int
chooseScript(TState *thread)
{
        int                     i = 0;
        int64           w;

        if (num_scripts == 1)
                return 0;

        w = getrand(&thread->ts_choose_rs, 0, total_weight - 1);
        do
        {
                w -= sql_script[i++].weight;
        } while (w >= 0);

        return i - 1;
}

/*
 * Allocate space for CState->prepared: we need one boolean for each command
 * of each script.
 */
static void
allocCStatePrepared(CState *st)
{
        Assert(st->prepared == NULL);

        st->prepared = pg_malloc(sizeof(bool *) * num_scripts);
        for (int i = 0; i < num_scripts; i++)
        {
                ParsedScript *script = &sql_script[i];
                int                     numcmds;

                for (numcmds = 0; script->commands[numcmds] != NULL; numcmds++)
                        ;
                st->prepared[i] = pg_malloc0(sizeof(bool) * numcmds);
        }
}

/*
 * Prepare the SQL command from st->use_file at command_num.
 */
static void
prepareCommand(CState *st, int command_num)
{
        Command    *command = sql_script[st->use_file].commands[command_num];

        /* No prepare for non-SQL commands */
        if (command->type != SQL_COMMAND)
                return;

        if (!st->prepared)
                allocCStatePrepared(st);

        if (!st->prepared[st->use_file][command_num])
        {
                PGresult   *res;

                pg_log_debug("client %d preparing %s", st->id, command->prepname);
                res = PQprepare(st->con, command->prepname,
                                                command->argv[0], command->argc - 1, NULL);
                if (PQresultStatus(res) != PGRES_COMMAND_OK)
                        pg_log_error("%s", PQerrorMessage(st->con));
                PQclear(res);
                st->prepared[st->use_file][command_num] = true;
        }
}

/*
 * Prepare all the commands in the script that come after the \startpipeline
 * that's at position st->command, and the first \endpipeline we find.
 *
 * This sets the ->prepared flag for each relevant command as well as the
 * \startpipeline itself, but doesn't move the st->command counter.
 */
static void
prepareCommandsInPipeline(CState *st)
{
        int                     j;
        Command   **commands = sql_script[st->use_file].commands;

        Assert(commands[st->command]->type == META_COMMAND &&
                   commands[st->command]->meta == META_STARTPIPELINE);

        if (!st->prepared)
                allocCStatePrepared(st);

        /*
         * We set the 'prepared' flag on the \startpipeline itself to flag that we
         * don't need to do this next time without calling prepareCommand(), even
         * though we don't actually prepare this command.
         */
        if (st->prepared[st->use_file][st->command])
                return;

        for (j = st->command + 1; commands[j] != NULL; j++)
        {
                if (commands[j]->type == META_COMMAND &&
                        commands[j]->meta == META_ENDPIPELINE)
                        break;

                prepareCommand(st, j);
        }

        st->prepared[st->use_file][st->command] = true;
}

/* Send a SQL command, using the chosen querymode */
static bool
sendCommand(CState *st, Command *command)
{
        int                     r;

        if (querymode == QUERY_SIMPLE)
        {
                char       *sql;

                sql = pg_strdup(command->argv[0]);
                sql = assignVariables(&st->variables, sql);

                pg_log_debug("client %d sending %s", st->id, sql);
                r = PQsendQuery(st->con, sql);
                free(sql);
        }
        else if (querymode == QUERY_EXTENDED)
        {
                const char *sql = command->argv[0];
                const char *params[MAX_ARGS];

                getQueryParams(&st->variables, command, params);

                pg_log_debug("client %d sending %s", st->id, sql);
                r = PQsendQueryParams(st->con, sql, command->argc - 1,
                                                          NULL, params, NULL, NULL, 0);
        }
        else if (querymode == QUERY_PREPARED)
        {
                const char *params[MAX_ARGS];

                prepareCommand(st, st->command);
                getQueryParams(&st->variables, command, params);

                pg_log_debug("client %d sending %s", st->id, command->prepname);
                r = PQsendQueryPrepared(st->con, command->prepname, command->argc - 1,
                                                                params, NULL, NULL, 0);
        }
        else                                            /* unknown sql mode */
                r = 0;

        if (r == 0)
        {
                pg_log_debug("client %d could not send %s", st->id, command->argv[0]);
                return false;
        }
        else
                return true;
}

/*
 * Get the error status from the error code.
 */
static EStatus
getSQLErrorStatus(const char *sqlState)
{
        if (sqlState != NULL)
        {
                if (strcmp(sqlState, ERRCODE_T_R_SERIALIZATION_FAILURE) == 0)
                        return ESTATUS_SERIALIZATION_ERROR;
                else if (strcmp(sqlState, ERRCODE_T_R_DEADLOCK_DETECTED) == 0)
                        return ESTATUS_DEADLOCK_ERROR;
        }

        return ESTATUS_OTHER_SQL_ERROR;
}

/*
 * Returns true if this type of error can be retried.
 */
static bool
canRetryError(EStatus estatus)
{
        return (estatus == ESTATUS_SERIALIZATION_ERROR ||
                        estatus == ESTATUS_DEADLOCK_ERROR);
}

/*
 * Process query response from the backend.
 *
 * If varprefix is not NULL, it's the variable name prefix where to store
 * the results of the *last* command (META_GSET) or *all* commands
 * (META_ASET).
 *
 * Returns true if everything is A-OK, false if any error occurs.
 */
static bool
readCommandResponse(CState *st, MetaCommand meta, char *varprefix)
{
        PGresult   *res;
        PGresult   *next_res;
        int                     qrynum = 0;

        /*
         * varprefix should be set only with \gset or \aset, and \endpipeline and
         * SQL commands do not need it.
         */
        Assert((meta == META_NONE && varprefix == NULL) ||
                   ((meta == META_ENDPIPELINE) && varprefix == NULL) ||
                   ((meta == META_GSET || meta == META_ASET) && varprefix != NULL));

        res = PQgetResult(st->con);

        while (res != NULL)
        {
                bool            is_last;

                /* peek at the next result to know whether the current is last */
                next_res = PQgetResult(st->con);
                is_last = (next_res == NULL);

                switch (PQresultStatus(res))
                {
                        case PGRES_COMMAND_OK:  /* non-SELECT commands */
                        case PGRES_EMPTY_QUERY: /* may be used for testing no-op overhead */
                                if (is_last && meta == META_GSET)
                                {
                                        pg_log_error("client %d script %d command %d query %d: expected one row, got %d",
                                                                 st->id, st->use_file, st->command, qrynum, 0);
                                        st->estatus = ESTATUS_META_COMMAND_ERROR;
                                        goto error;
                                }
                                break;

                        case PGRES_TUPLES_OK:
                                if ((is_last && meta == META_GSET) || meta == META_ASET)
                                {
                                        int                     ntuples = PQntuples(res);

                                        if (meta == META_GSET && ntuples != 1)
                                        {
                                                /* under \gset, report the error */
                                                pg_log_error("client %d script %d command %d query %d: expected one row, got %d",
                                                                         st->id, st->use_file, st->command, qrynum, PQntuples(res));
                                                st->estatus = ESTATUS_META_COMMAND_ERROR;
                                                goto error;
                                        }
                                        else if (meta == META_ASET && ntuples <= 0)
                                        {
                                                /* coldly skip empty result under \aset */
                                                break;
                                        }

                                        /* store results into variables */
                                        for (int fld = 0; fld < PQnfields(res); fld++)
                                        {
                                                char       *varname = PQfname(res, fld);

                                                /* allocate varname only if necessary, freed below */
                                                if (*varprefix != '\0')
                                                        varname = psprintf("%s%s", varprefix, varname);

                                                /* store last row result as a string */
                                                if (!putVariable(&st->variables, meta == META_ASET ? "aset" : "gset", varname,
                                                                                 PQgetvalue(res, ntuples - 1, fld)))
                                                {
                                                        /* internal error */
                                                        pg_log_error("client %d script %d command %d query %d: error storing into variable %s",
                                                                                 st->id, st->use_file, st->command, qrynum, varname);
                                                        st->estatus = ESTATUS_META_COMMAND_ERROR;
                                                        goto error;
                                                }

                                                if (*varprefix != '\0')
                                                        pg_free(varname);
                                        }
                                }
                                /* otherwise the result is simply thrown away by PQclear below */
                                break;

                        case PGRES_PIPELINE_SYNC:
                                pg_log_debug("client %d pipeline ending", st->id);
                                if (PQexitPipelineMode(st->con) != 1)
                                        pg_log_error("client %d failed to exit pipeline mode: %s", st->id,
                                                                 PQerrorMessage(st->con));
                                break;

                        case PGRES_NONFATAL_ERROR:
                        case PGRES_FATAL_ERROR:
                                st->estatus = getSQLErrorStatus(PQresultErrorField(res,
                                                                                                                                   PG_DIAG_SQLSTATE));
                                if (canRetryError(st->estatus))
                                {
                                        if (verbose_errors)
                                                commandError(st, PQerrorMessage(st->con));
                                        goto error;
                                }
                                /* fall through */

                        default:
                                /* anything else is unexpected */
                                pg_log_error("client %d script %d aborted in command %d query %d: %s",
                                                         st->id, st->use_file, st->command, qrynum,
                                                         PQerrorMessage(st->con));
                                goto error;
                }

                PQclear(res);
                qrynum++;
                res = next_res;
        }

        if (qrynum == 0)
        {
                pg_log_error("client %d command %d: no results", st->id, st->command);
                return false;
        }

        return true;

error:
        PQclear(res);
        PQclear(next_res);
        do
        {
                res = PQgetResult(st->con);
                PQclear(res);
        } while (res);

        return false;
}

/*
 * Parse the argument to a \sleep command, and return the requested amount
 * of delay, in microseconds.  Returns true on success, false on error.
 */
static bool
evaluateSleep(Variables *variables, int argc, char **argv, int *usecs)
{
        char       *var;
        int                     usec;

        if (*argv[1] == ':')
        {
                if ((var = getVariable(variables, argv[1] + 1)) == NULL)
                {
                        pg_log_error("%s: undefined variable \"%s\"", argv[0], argv[1] + 1);
                        return false;
                }

                usec = atoi(var);

                /* Raise an error if the value of a variable is not a number */
                if (usec == 0 && !isdigit((unsigned char) *var))
                {
                        pg_log_error("%s: invalid sleep time \"%s\" for variable \"%s\"",
                                                 argv[0], var, argv[1] + 1);
                        return false;
                }
        }
        else
                usec = atoi(argv[1]);

        if (argc > 2)
        {
                if (pg_strcasecmp(argv[2], "ms") == 0)
                        usec *= 1000;
                else if (pg_strcasecmp(argv[2], "s") == 0)
                        usec *= 1000000;
        }
        else
                usec *= 1000000;

        *usecs = usec;
        return true;
}


/*
 * Returns true if the error can be retried.
 */
static bool
doRetry(CState *st, pg_time_usec_t *now)
{
        Assert(st->estatus != ESTATUS_NO_ERROR);

        /* We can only retry serialization or deadlock errors. */
        if (!canRetryError(st->estatus))
                return false;

        /*
         * We must have at least one option to limit the retrying of transactions
         * that got an error.
         */
        Assert(max_tries || latency_limit || duration > 0);

        /*
         * We cannot retry the error if we have reached the maximum number of
         * tries.
         */
        if (max_tries && st->tries >= max_tries)
                return false;

        /*
         * We cannot retry the error if we spent too much time on this
         * transaction.
         */
        if (latency_limit)
        {
                pg_time_now_lazy(now);
                if (*now - st->txn_scheduled > latency_limit)
                        return false;
        }

        /*
         * We cannot retry the error if the benchmark duration is over.
         */
        if (timer_exceeded)
                return false;

        /* OK */
        return true;
}

/*
 * Read results and discard it until a sync point.
 */
static int
discardUntilSync(CState *st)
{
        /* send a sync */
        if (!PQpipelineSync(st->con))
        {
                pg_log_error("client %d aborted: failed to send a pipeline sync",
                                         st->id);
                return 0;
        }

        /* receive PGRES_PIPELINE_SYNC and null following it */
        for (;;)
        {
                PGresult   *res = PQgetResult(st->con);

                if (PQresultStatus(res) == PGRES_PIPELINE_SYNC)
                {
                        PQclear(res);
                        res = PQgetResult(st->con);
                        Assert(res == NULL);
                        break;
                }
                PQclear(res);
        }

        /* exit pipeline */
        if (PQexitPipelineMode(st->con) != 1)
        {
                pg_log_error("client %d aborted: failed to exit pipeline mode for rolling back the failed transaction",
                                         st->id);
                return 0;
        }
        return 1;
}

/*
 * Get the transaction status at the end of a command especially for
 * checking if we are in a (failed) transaction block.
 */
static TStatus
getTransactionStatus(PGconn *con)
{
        PGTransactionStatusType tx_status;

        tx_status = PQtransactionStatus(con);
        switch (tx_status)
        {
                case PQTRANS_IDLE:
                        return TSTATUS_IDLE;
                case PQTRANS_INTRANS:
                case PQTRANS_INERROR:
                        return TSTATUS_IN_BLOCK;
                case PQTRANS_UNKNOWN:
                        /* PQTRANS_UNKNOWN is expected given a broken connection */
                        if (PQstatus(con) == CONNECTION_BAD)
                                return TSTATUS_CONN_ERROR;
                        /* fall through */
                case PQTRANS_ACTIVE:
                default:

                        /*
                         * We cannot find out whether we are in a transaction block or
                         * not. Internal error which should never occur.
                         */
                        pg_log_error("unexpected transaction status %d", tx_status);
                        return TSTATUS_OTHER_ERROR;
        }

        /* not reached */
        Assert(false);
        return TSTATUS_OTHER_ERROR;
}

/*
 * Print verbose messages of an error
 */
static void
printVerboseErrorMessages(CState *st, pg_time_usec_t *now, bool is_retry)
{
        static PQExpBuffer buf = NULL;

        if (buf == NULL)
                buf = createPQExpBuffer();
        else
                resetPQExpBuffer(buf);

        printfPQExpBuffer(buf, "client %d ", st->id);
        appendPQExpBufferStr(buf, (is_retry ?
                                                           "repeats the transaction after the error" :
                                                           "ends the failed transaction"));
        appendPQExpBuffer(buf, " (try %u", st->tries);

        /* Print max_tries if it is not unlimited. */
        if (max_tries)
                appendPQExpBuffer(buf, "/%u", max_tries);

        /*
         * If the latency limit is used, print a percentage of the current
         * transaction latency from the latency limit.
         */
        if (latency_limit)
        {
                pg_time_now_lazy(now);
                appendPQExpBuffer(buf, ", %.3f%% of the maximum time of tries was used",
                                                  (100.0 * (*now - st->txn_scheduled) / latency_limit));
        }
        appendPQExpBufferStr(buf, ")\n");

        pg_log_info("%s", buf->data);
}

/*
 * Advance the state machine of a connection.
 */
static void
advanceConnectionState(TState *thread, CState *st, StatsData *agg)
{

        /*
         * gettimeofday() isn't free, so we get the current timestamp lazily the
         * first time it's needed, and reuse the same value throughout this
         * function after that.  This also ensures that e.g. the calculated
         * latency reported in the log file and in the totals are the same. Zero
         * means "not set yet".  Reset "now" when we execute shell commands or
         * expressions, which might take a non-negligible amount of time, though.
         */
        pg_time_usec_t now = 0;

        /*
         * Loop in the state machine, until we have to wait for a result from the
         * server or have to sleep for throttling or \sleep.
         *
         * Note: In the switch-statement below, 'break' will loop back here,
         * meaning "continue in the state machine".  Return is used to return to
         * the caller, giving the thread the opportunity to advance another
         * client.
         */
        for (;;)
        {
                Command    *command;

                switch (st->state)
                {
                                /* Select transaction (script) to run.  */
                        case CSTATE_CHOOSE_SCRIPT:
                                st->use_file = chooseScript(thread);
                                Assert(conditional_stack_empty(st->cstack));

                                /* reset transaction variables to default values */
                                st->estatus = ESTATUS_NO_ERROR;
                                st->tries = 1;

                                pg_log_debug("client %d executing script \"%s\"",
                                                         st->id, sql_script[st->use_file].desc);

                                /*
                                 * If time is over, we're done; otherwise, get ready to start
                                 * a new transaction, or to get throttled if that's requested.
                                 */
                                st->state = timer_exceeded ? CSTATE_FINISHED :
                                        throttle_delay > 0 ? CSTATE_PREPARE_THROTTLE : CSTATE_START_TX;
                                break;

                                /* Start new transaction (script) */
                        case CSTATE_START_TX:
                                pg_time_now_lazy(&now);

                                /* establish connection if needed, i.e. under --connect */
                                if (st->con == NULL)
                                {
                                        pg_time_usec_t start = now;

                                        if ((st->con = doConnect()) == NULL)
                                        {
                                                /*
                                                 * as the bench is already running, we do not abort
                                                 * the process
                                                 */
                                                pg_log_error("client %d aborted while establishing connection", st->id);
                                                st->state = CSTATE_ABORTED;
                                                break;
                                        }

                                        /* reset now after connection */
                                        now = pg_time_now();

                                        thread->conn_duration += now - start;

                                        /* Reset session-local state */
                                        pg_free(st->prepared);
                                        st->prepared = NULL;
                                }

                                /*
                                 * It is the first try to run this transaction. Remember the
                                 * random state: maybe it will get an error and we will need
                                 * to run it again.
                                 */
                                st->random_state = st->cs_func_rs;

                                /* record transaction start time */
                                st->txn_begin = now;

                                /*
                                 * When not throttling, this is also the transaction's
                                 * scheduled start time.
                                 */
                                if (!throttle_delay)
                                        st->txn_scheduled = now;

                                /* Begin with the first command */
                                st->state = CSTATE_START_COMMAND;
                                st->command = 0;
                                break;

                                /*
                                 * Handle throttling once per transaction by sleeping.
                                 */
                        case CSTATE_PREPARE_THROTTLE:

                                /*
                                 * Generate a delay such that the series of delays will
                                 * approximate a Poisson distribution centered on the
                                 * throttle_delay time.
                                 *
                                 * If transactions are too slow or a given wait is shorter
                                 * than a transaction, the next transaction will start right
                                 * away.
                                 */
                                Assert(throttle_delay > 0);

                                thread->throttle_trigger +=
                                        getPoissonRand(&thread->ts_throttle_rs, throttle_delay);
                                st->txn_scheduled = thread->throttle_trigger;

                                /*
                                 * If --latency-limit is used, and this slot is already late
                                 * so that the transaction will miss the latency limit even if
                                 * it completed immediately, skip this time slot and loop to
                                 * reschedule.
                                 */
                                if (latency_limit)
                                {
                                        pg_time_now_lazy(&now);

                                        if (thread->throttle_trigger < now - latency_limit)
                                        {
                                                processXactStats(thread, st, &now, true, agg);

                                                /*
                                                 * Finish client if -T or -t was exceeded.
                                                 *
                                                 * Stop counting skipped transactions under -T as soon
                                                 * as the timer is exceeded. Because otherwise it can
                                                 * take a very long time to count all of them
                                                 * especially when quite a lot of them happen with
                                                 * unrealistically high rate setting in -R, which
                                                 * would prevent pgbench from ending immediately.
                                                 * Because of this behavior, note that there is no
                                                 * guarantee that all skipped transactions are counted
                                                 * under -T though there is under -t. This is OK in
                                                 * practice because it's very unlikely to happen with
                                                 * realistic setting.
                                                 */
                                                if (timer_exceeded || (nxacts > 0 && st->cnt >= nxacts))
                                                        st->state = CSTATE_FINISHED;

                                                /* Go back to top of loop with CSTATE_PREPARE_THROTTLE */
                                                break;
                                        }
                                }

                                /*
                                 * stop client if next transaction is beyond pgbench end of
                                 * execution; otherwise, throttle it.
                                 */
                                st->state = end_time > 0 && st->txn_scheduled > end_time ?
                                        CSTATE_FINISHED : CSTATE_THROTTLE;
                                break;

                                /*
                                 * Wait until it's time to start next transaction.
                                 */
                        case CSTATE_THROTTLE:
                                pg_time_now_lazy(&now);

                                if (now < st->txn_scheduled)
                                        return;         /* still sleeping, nothing to do here */

                                /* done sleeping, but don't start transaction if we're done */
                                st->state = timer_exceeded ? CSTATE_FINISHED : CSTATE_START_TX;
                                break;

                                /*
                                 * Send a command to server (or execute a meta-command)
                                 */
                        case CSTATE_START_COMMAND:
                                command = sql_script[st->use_file].commands[st->command];

                                /*
                                 * Transition to script end processing if done, but close up
                                 * shop if a pipeline is open at this point.
                                 */
                                if (command == NULL)
                                {
                                        if (PQpipelineStatus(st->con) == PQ_PIPELINE_OFF)
                                                st->state = CSTATE_END_TX;
                                        else
                                        {
                                                pg_log_error("client %d aborted: end of script reached with pipeline open",
                                                                         st->id);
                                                st->state = CSTATE_ABORTED;
                                        }

                                        break;
                                }

                                /* record begin time of next command, and initiate it */
                                if (report_per_command)
                                {
                                        pg_time_now_lazy(&now);
                                        st->stmt_begin = now;
                                }

                                /* Execute the command */
                                if (command->type == SQL_COMMAND)
                                {
                                        /* disallow \aset and \gset in pipeline mode */
                                        if (PQpipelineStatus(st->con) != PQ_PIPELINE_OFF)
                                        {
                                                if (command->meta == META_GSET)
                                                {
                                                        commandFailed(st, "gset", "\\gset is not allowed in pipeline mode");
                                                        st->state = CSTATE_ABORTED;
                                                        break;
                                                }
                                                else if (command->meta == META_ASET)
                                                {
                                                        commandFailed(st, "aset", "\\aset is not allowed in pipeline mode");
                                                        st->state = CSTATE_ABORTED;
                                                        break;
                                                }
                                        }

                                        if (!sendCommand(st, command))
                                        {
                                                commandFailed(st, "SQL", "SQL command send failed");
                                                st->state = CSTATE_ABORTED;
                                        }
                                        else
                                        {
                                                /* Wait for results, unless in pipeline mode */
                                                if (PQpipelineStatus(st->con) == PQ_PIPELINE_OFF)
                                                        st->state = CSTATE_WAIT_RESULT;
                                                else
                                                        st->state = CSTATE_END_COMMAND;
                                        }
                                }
                                else if (command->type == META_COMMAND)
                                {
                                        /*-----
                                         * Possible state changes when executing meta commands:
                                         * - on errors CSTATE_ABORTED
                                         * - on sleep CSTATE_SLEEP
                                         * - else CSTATE_END_COMMAND
                                         */
                                        st->state = executeMetaCommand(st, &now);
                                        if (st->state == CSTATE_ABORTED)
                                                st->estatus = ESTATUS_META_COMMAND_ERROR;
                                }

                                /*
                                 * We're now waiting for an SQL command to complete, or
                                 * finished processing a metacommand, or need to sleep, or
                                 * something bad happened.
                                 */
                                Assert(st->state == CSTATE_WAIT_RESULT ||
                                           st->state == CSTATE_END_COMMAND ||
                                           st->state == CSTATE_SLEEP ||
                                           st->state == CSTATE_ABORTED);
                                break;

                                /*
                                 * non executed conditional branch
                                 */
                        case CSTATE_SKIP_COMMAND:
                                Assert(!conditional_active(st->cstack));
                                /* quickly skip commands until something to do... */
                                while (true)
                                {
                                        command = sql_script[st->use_file].commands[st->command];

                                        /* cannot reach end of script in that state */
                                        Assert(command != NULL);

                                        /*
                                         * if this is conditional related, update conditional
                                         * state
                                         */
                                        if (command->type == META_COMMAND &&
                                                (command->meta == META_IF ||
                                                 command->meta == META_ELIF ||
                                                 command->meta == META_ELSE ||
                                                 command->meta == META_ENDIF))
                                        {
                                                switch (conditional_stack_peek(st->cstack))
                                                {
                                                        case IFSTATE_FALSE:
                                                                if (command->meta == META_IF ||
                                                                        command->meta == META_ELIF)
                                                                {
                                                                        /* we must evaluate the condition */
                                                                        st->state = CSTATE_START_COMMAND;
                                                                }
                                                                else if (command->meta == META_ELSE)
                                                                {
                                                                        /* we must execute next command */
                                                                        conditional_stack_poke(st->cstack,
                                                                                                                   IFSTATE_ELSE_TRUE);
                                                                        st->state = CSTATE_START_COMMAND;
                                                                        st->command++;
                                                                }
                                                                else if (command->meta == META_ENDIF)
                                                                {
                                                                        Assert(!conditional_stack_empty(st->cstack));
                                                                        conditional_stack_pop(st->cstack);
                                                                        if (conditional_active(st->cstack))
                                                                                st->state = CSTATE_START_COMMAND;

                                                                        /*
                                                                         * else state remains in
                                                                         * CSTATE_SKIP_COMMAND
                                                                         */
                                                                        st->command++;
                                                                }
                                                                break;

                                                        case IFSTATE_IGNORED:
                                                        case IFSTATE_ELSE_FALSE:
                                                                if (command->meta == META_IF)
                                                                        conditional_stack_push(st->cstack,
                                                                                                                   IFSTATE_IGNORED);
                                                                else if (command->meta == META_ENDIF)
                                                                {
                                                                        Assert(!conditional_stack_empty(st->cstack));
                                                                        conditional_stack_pop(st->cstack);
                                                                        if (conditional_active(st->cstack))
                                                                                st->state = CSTATE_START_COMMAND;
                                                                }
                                                                /* could detect "else" & "elif" after "else" */
                                                                st->command++;
                                                                break;

                                                        case IFSTATE_NONE:
                                                        case IFSTATE_TRUE:
                                                        case IFSTATE_ELSE_TRUE:
                                                        default:

                                                                /*
                                                                 * inconsistent if inactive, unreachable dead
                                                                 * code
                                                                 */
                                                                Assert(false);
                                                }
                                        }
                                        else
                                        {
                                                /* skip and consider next */
                                                st->command++;
                                        }

                                        if (st->state != CSTATE_SKIP_COMMAND)
                                                /* out of quick skip command loop */
                                                break;
                                }
                                break;

                                /*
                                 * Wait for the current SQL command to complete
                                 */
                        case CSTATE_WAIT_RESULT:
                                pg_log_debug("client %d receiving", st->id);

                                /*
                                 * Only check for new network data if we processed all data
                                 * fetched prior. Otherwise we end up doing a syscall for each
                                 * individual pipelined query, which has a measurable
                                 * performance impact.
                                 */
                                if (PQisBusy(st->con) && !PQconsumeInput(st->con))
                                {
                                        /* there's something wrong */
                                        commandFailed(st, "SQL", "perhaps the backend died while processing");
                                        st->state = CSTATE_ABORTED;
                                        break;
                                }
                                if (PQisBusy(st->con))
                                        return;         /* don't have the whole result yet */

                                /* store or discard the query results */
                                if (readCommandResponse(st,
                                                                                sql_script[st->use_file].commands[st->command]->meta,
                                                                                sql_script[st->use_file].commands[st->command]->varprefix))
                                {
                                        /*
                                         * outside of pipeline mode: stop reading results.
                                         * pipeline mode: continue reading results until an
                                         * end-of-pipeline response.
                                         */
                                        if (PQpipelineStatus(st->con) != PQ_PIPELINE_ON)
                                                st->state = CSTATE_END_COMMAND;
                                }
                                else if (canRetryError(st->estatus))
                                        st->state = CSTATE_ERROR;
                                else
                                        st->state = CSTATE_ABORTED;
                                break;

                                /*
                                 * Wait until sleep is done. This state is entered after a
                                 * \sleep metacommand. The behavior is similar to
                                 * CSTATE_THROTTLE, but proceeds to CSTATE_START_COMMAND
                                 * instead of CSTATE_START_TX.
                                 */
                        case CSTATE_SLEEP:
                                pg_time_now_lazy(&now);
                                if (now < st->sleep_until)
                                        return;         /* still sleeping, nothing to do here */
                                /* Else done sleeping. */
                                st->state = CSTATE_END_COMMAND;
                                break;

                                /*
                                 * End of command: record stats and proceed to next command.
                                 */
                        case CSTATE_END_COMMAND:

                                /*
                                 * command completed: accumulate per-command execution times
                                 * in thread-local data structure, if per-command latencies
                                 * are requested.
                                 */
                                if (report_per_command)
                                {
                                        pg_time_now_lazy(&now);

                                        command = sql_script[st->use_file].commands[st->command];
                                        /* XXX could use a mutex here, but we choose not to */
                                        addToSimpleStats(&command->stats,
                                                                         PG_TIME_GET_DOUBLE(now - st->stmt_begin));
                                }

                                /* Go ahead with next command, to be executed or skipped */
                                st->command++;
                                st->state = conditional_active(st->cstack) ?
                                        CSTATE_START_COMMAND : CSTATE_SKIP_COMMAND;
                                break;

                                /*
                                 * Clean up after an error.
                                 */
                        case CSTATE_ERROR:
                                {
                                        TStatus         tstatus;

                                        Assert(st->estatus != ESTATUS_NO_ERROR);

                                        /* Clear the conditional stack */
                                        conditional_stack_reset(st->cstack);

                                        /* Read and discard until a sync point in pipeline mode */
                                        if (PQpipelineStatus(st->con) != PQ_PIPELINE_OFF)
                                        {
                                                if (!discardUntilSync(st))
                                                {
                                                        st->state = CSTATE_ABORTED;
                                                        break;
                                                }
                                        }

                                        /*
                                         * Check if we have a (failed) transaction block or not,
                                         * and roll it back if any.
                                         */
                                        tstatus = getTransactionStatus(st->con);
                                        if (tstatus == TSTATUS_IN_BLOCK)
                                        {
                                                /* Try to rollback a (failed) transaction block. */
                                                if (!PQsendQuery(st->con, "ROLLBACK"))
                                                {
                                                        pg_log_error("client %d aborted: failed to send sql command for rolling back the failed transaction",
                                                                                 st->id);
                                                        st->state = CSTATE_ABORTED;
                                                }
                                                else
                                                        st->state = CSTATE_WAIT_ROLLBACK_RESULT;
                                        }
                                        else if (tstatus == TSTATUS_IDLE)
                                        {
                                                /*
                                                 * If time is over, we're done; otherwise, check if we
                                                 * can retry the error.
                                                 */
                                                st->state = timer_exceeded ? CSTATE_FINISHED :
                                                        doRetry(st, &now) ? CSTATE_RETRY : CSTATE_FAILURE;
                                        }
                                        else
                                        {
                                                if (tstatus == TSTATUS_CONN_ERROR)
                                                        pg_log_error("perhaps the backend died while processing");

                                                pg_log_error("client %d aborted while receiving the transaction status", st->id);
                                                st->state = CSTATE_ABORTED;
                                        }
                                        break;
                                }

                                /*
                                 * Wait for the rollback command to complete
                                 */
                        case CSTATE_WAIT_ROLLBACK_RESULT:
                                {
                                        PGresult   *res;

                                        pg_log_debug("client %d receiving", st->id);
                                        if (!PQconsumeInput(st->con))
                                        {
                                                pg_log_error("client %d aborted while rolling back the transaction after an error; perhaps the backend died while processing",
                                                                         st->id);
                                                st->state = CSTATE_ABORTED;
                                                break;
                                        }
                                        if (PQisBusy(st->con))
                                                return; /* don't have the whole result yet */

                                        /*
                                         * Read and discard the query result;
                                         */
                                        res = PQgetResult(st->con);
                                        switch (PQresultStatus(res))
                                        {
                                                case PGRES_COMMAND_OK:
                                                        /* OK */
                                                        PQclear(res);
                                                        /* null must be returned */
                                                        res = PQgetResult(st->con);
                                                        Assert(res == NULL);

                                                        /*
                                                         * If time is over, we're done; otherwise, check
                                                         * if we can retry the error.
                                                         */
                                                        st->state = timer_exceeded ? CSTATE_FINISHED :
                                                                doRetry(st, &now) ? CSTATE_RETRY : CSTATE_FAILURE;
                                                        break;
                                                default:
                                                        pg_log_error("client %d aborted while rolling back the transaction after an error; %s",
                                                                                 st->id, PQerrorMessage(st->con));
                                                        PQclear(res);
                                                        st->state = CSTATE_ABORTED;
                                                        break;
                                        }
                                        break;
                                }

                                /*
                                 * Retry the transaction after an error.
                                 */
                        case CSTATE_RETRY:
                                command = sql_script[st->use_file].commands[st->command];

                                /*
                                 * Inform that the transaction will be retried after the
                                 * error.
                                 */
                                if (verbose_errors)
                                        printVerboseErrorMessages(st, &now, true);

                                /* Count tries and retries */
                                st->tries++;
                                command->retries++;

                                /*
                                 * Reset the random state as they were at the beginning of the
                                 * transaction.
                                 */
                                st->cs_func_rs = st->random_state;

                                /* Process the first transaction command. */
                                st->command = 0;
                                st->estatus = ESTATUS_NO_ERROR;
                                st->state = CSTATE_START_COMMAND;
                                break;

                                /*
                                 * Record a failed transaction.
                                 */
                        case CSTATE_FAILURE:
                                command = sql_script[st->use_file].commands[st->command];

                                /* Accumulate the failure. */
                                command->failures++;

                                /*
                                 * Inform that the failed transaction will not be retried.
                                 */
                                if (verbose_errors)
                                        printVerboseErrorMessages(st, &now, false);

                                /* End the failed transaction. */
                                st->state = CSTATE_END_TX;
                                break;

                                /*
                                 * End of transaction (end of script, really).
                                 */
                        case CSTATE_END_TX:
                                {
                                        TStatus         tstatus;

                                        /* transaction finished: calculate latency and do log */
                                        processXactStats(thread, st, &now, false, agg);

                                        /*
                                         * missing \endif... cannot happen if CheckConditional was
                                         * okay
                                         */
                                        Assert(conditional_stack_empty(st->cstack));

                                        /*
                                         * We must complete all the transaction blocks that were
                                         * started in this script.
                                         */
                                        tstatus = getTransactionStatus(st->con);
                                        if (tstatus == TSTATUS_IN_BLOCK)
                                        {
                                                pg_log_error("client %d aborted: end of script reached without completing the last transaction",
                                                                         st->id);
                                                st->state = CSTATE_ABORTED;
                                                break;
                                        }
                                        else if (tstatus != TSTATUS_IDLE)
                                        {
                                                if (tstatus == TSTATUS_CONN_ERROR)
                                                        pg_log_error("perhaps the backend died while processing");

                                                pg_log_error("client %d aborted while receiving the transaction status", st->id);
                                                st->state = CSTATE_ABORTED;
                                                break;
                                        }

                                        if (is_connect)
                                        {
                                                pg_time_usec_t start = now;

                                                pg_time_now_lazy(&start);
                                                finishCon(st);
                                                now = pg_time_now();
                                                thread->conn_duration += now - start;
                                        }

                                        if ((st->cnt >= nxacts && duration <= 0) || timer_exceeded)
                                        {
                                                /* script completed */
                                                st->state = CSTATE_FINISHED;
                                                break;
                                        }

                                        /* next transaction (script) */
                                        st->state = CSTATE_CHOOSE_SCRIPT;

                                        /*
                                         * Ensure that we always return on this point, so as to
                                         * avoid an infinite loop if the script only contains meta
                                         * commands.
                                         */
                                        return;
                                }

                                /*
                                 * Final states.  Close the connection if it's still open.
                                 */
                        case CSTATE_ABORTED:
                        case CSTATE_FINISHED:

                                /*
                                 * Don't measure the disconnection delays here even if in
                                 * CSTATE_FINISHED and -C/--connect option is specified.
                                 * Because in this case all the connections that this thread
                                 * established are closed at the end of transactions and the
                                 * disconnection delays should have already been measured at
                                 * that moment.
                                 *
                                 * In CSTATE_ABORTED state, the measurement is no longer
                                 * necessary because we cannot report complete results anyways
                                 * in this case.
                                 */
                                finishCon(st);
                                return;
                }
        }
}

/*
 * Subroutine for advanceConnectionState -- initiate or execute the current
 * meta command, and return the next state to set.
 *
 * *now is updated to the current time, unless the command is expected to
 * take no time to execute.
 */
static ConnectionStateEnum
executeMetaCommand(CState *st, pg_time_usec_t *now)
{
        Command    *command = sql_script[st->use_file].commands[st->command];
        int                     argc;
        char      **argv;

        Assert(command != NULL && command->type == META_COMMAND);

        argc = command->argc;
        argv = command->argv;

        if (unlikely(__pg_log_level <= PG_LOG_DEBUG))
        {
                PQExpBufferData buf;

                initPQExpBuffer(&buf);

                printfPQExpBuffer(&buf, "client %d executing \\%s", st->id, argv[0]);
                for (int i = 1; i < argc; i++)
                        appendPQExpBuffer(&buf, " %s", argv[i]);

                pg_log_debug("%s", buf.data);

                termPQExpBuffer(&buf);
        }

        if (command->meta == META_SLEEP)
        {
                int                     usec;

                /*
                 * A \sleep doesn't execute anything, we just get the delay from the
                 * argument, and enter the CSTATE_SLEEP state.  (The per-command
                 * latency will be recorded in CSTATE_SLEEP state, not here, after the
                 * delay has elapsed.)
                 */
                if (!evaluateSleep(&st->variables, argc, argv, &usec))
                {
                        commandFailed(st, "sleep", "execution of meta-command failed");
                        return CSTATE_ABORTED;
                }

                pg_time_now_lazy(now);
                st->sleep_until = (*now) + usec;
                return CSTATE_SLEEP;
        }
        else if (command->meta == META_SET)
        {
                PgBenchExpr *expr = command->expr;
                PgBenchValue result;

                if (!evaluateExpr(st, expr, &result))
                {
                        commandFailed(st, argv[0], "evaluation of meta-command failed");
                        return CSTATE_ABORTED;
                }

                if (!putVariableValue(&st->variables, argv[0], argv[1], &result))
                {
                        commandFailed(st, "set", "assignment of meta-command failed");
                        return CSTATE_ABORTED;
                }
        }
        else if (command->meta == META_IF)
        {
                /* backslash commands with an expression to evaluate */
                PgBenchExpr *expr = command->expr;
                PgBenchValue result;
                bool            cond;

                if (!evaluateExpr(st, expr, &result))
                {
                        commandFailed(st, argv[0], "evaluation of meta-command failed");
                        return CSTATE_ABORTED;
                }

                cond = valueTruth(&result);
                conditional_stack_push(st->cstack, cond ? IFSTATE_TRUE : IFSTATE_FALSE);
        }
        else if (command->meta == META_ELIF)
        {
                /* backslash commands with an expression to evaluate */
                PgBenchExpr *expr = command->expr;
                PgBenchValue result;
                bool            cond;

                if (conditional_stack_peek(st->cstack) == IFSTATE_TRUE)
                {
                        /* elif after executed block, skip eval and wait for endif. */
                        conditional_stack_poke(st->cstack, IFSTATE_IGNORED);
                        return CSTATE_END_COMMAND;
                }

                if (!evaluateExpr(st, expr, &result))
                {
                        commandFailed(st, argv[0], "evaluation of meta-command failed");
                        return CSTATE_ABORTED;
                }

                cond = valueTruth(&result);
                Assert(conditional_stack_peek(st->cstack) == IFSTATE_FALSE);
                conditional_stack_poke(st->cstack, cond ? IFSTATE_TRUE : IFSTATE_FALSE);
        }
        else if (command->meta == META_ELSE)
        {
                switch (conditional_stack_peek(st->cstack))
                {
                        case IFSTATE_TRUE:
                                conditional_stack_poke(st->cstack, IFSTATE_ELSE_FALSE);
                                break;
                        case IFSTATE_FALSE: /* inconsistent if active */
                        case IFSTATE_IGNORED:   /* inconsistent if active */
                        case IFSTATE_NONE:      /* else without if */
                        case IFSTATE_ELSE_TRUE: /* else after else */
                        case IFSTATE_ELSE_FALSE:        /* else after else */
                        default:
                                /* dead code if conditional check is ok */
                                Assert(false);
                }
        }
        else if (command->meta == META_ENDIF)
        {
                Assert(!conditional_stack_empty(st->cstack));
                conditional_stack_pop(st->cstack);
        }
        else if (command->meta == META_SETSHELL)
        {
                if (!runShellCommand(&st->variables, argv[1], argv + 2, argc - 2))
                {
                        commandFailed(st, "setshell", "execution of meta-command failed");
                        return CSTATE_ABORTED;
                }
        }
        else if (command->meta == META_SHELL)
        {
                if (!runShellCommand(&st->variables, NULL, argv + 1, argc - 1))
                {
                        commandFailed(st, "shell", "execution of meta-command failed");
                        return CSTATE_ABORTED;
                }
        }
        else if (command->meta == META_STARTPIPELINE)
        {
                /*
                 * In pipeline mode, we use a workflow based on libpq pipeline
                 * functions.
                 */
                if (querymode == QUERY_SIMPLE)
                {
                        commandFailed(st, "startpipeline", "cannot use pipeline mode with the simple query protocol");
                        return CSTATE_ABORTED;
                }

                /*
                 * If we're in prepared-query mode, we need to prepare all the
                 * commands that are inside the pipeline before we actually start the
                 * pipeline itself.  This solves the problem that running BEGIN
                 * ISOLATION LEVEL SERIALIZABLE in a pipeline would fail due to a
                 * snapshot having been acquired by the prepare within the pipeline.
                 */
                if (querymode == QUERY_PREPARED)
                        prepareCommandsInPipeline(st);

                if (PQpipelineStatus(st->con) != PQ_PIPELINE_OFF)
                {
                        commandFailed(st, "startpipeline", "already in pipeline mode");
                        return CSTATE_ABORTED;
                }
                if (PQenterPipelineMode(st->con) == 0)
                {
                        commandFailed(st, "startpipeline", "failed to enter pipeline mode");
                        return CSTATE_ABORTED;
                }
        }
        else if (command->meta == META_ENDPIPELINE)
        {
                if (PQpipelineStatus(st->con) != PQ_PIPELINE_ON)
                {
                        commandFailed(st, "endpipeline", "not in pipeline mode");
                        return CSTATE_ABORTED;
                }
                if (!PQpipelineSync(st->con))
                {
                        commandFailed(st, "endpipeline", "failed to send a pipeline sync");
                        return CSTATE_ABORTED;
                }
                /* Now wait for the PGRES_PIPELINE_SYNC and exit pipeline mode there */
                /* collect pending results before getting out of pipeline mode */
                return CSTATE_WAIT_RESULT;
        }

        /*
         * executing the expression or shell command might have taken a
         * non-negligible amount of time, so reset 'now'
         */
        *now = 0;

        return CSTATE_END_COMMAND;
}

/*
 * Return the number of failed transactions.
 */
static int64
getFailures(const StatsData *stats)
{
        return (stats->serialization_failures +
                        stats->deadlock_failures);
}

/*
 * Return a string constant representing the result of a transaction
 * that is not successfully processed.
 */
static const char *
getResultString(bool skipped, EStatus estatus)
{
        if (skipped)
                return "skipped";
        else if (failures_detailed)
        {
                switch (estatus)
                {
                        case ESTATUS_SERIALIZATION_ERROR:
                                return "serialization";
                        case ESTATUS_DEADLOCK_ERROR:
                                return "deadlock";
                        default:
                                /* internal error which should never occur */
                                pg_fatal("unexpected error status: %d", estatus);
                }
        }
        else
                return "failed";
}

/*
 * Print log entry after completing one transaction.
 *
 * We print Unix-epoch timestamps in the log, so that entries can be
 * correlated against other logs.
 *
 * XXX We could obtain the time from the caller and just shift it here, to
 * avoid the cost of an extra call to pg_time_now().
 */
static void
doLog(TState *thread, CState *st,
          StatsData *agg, bool skipped, double latency, double lag)
{
        FILE       *logfile = thread->logfile;
        pg_time_usec_t now = pg_time_now() + epoch_shift;

        Assert(use_log);

        /*
         * Skip the log entry if sampling is enabled and this row doesn't belong
         * to the random sample.
         */
        if (sample_rate != 0.0 &&
                pg_prng_double(&thread->ts_sample_rs) > sample_rate)
                return;

        /* should we aggregate the results or not? */
        if (agg_interval > 0)
        {
                pg_time_usec_t next;

                /*
                 * Loop until we reach the interval of the current moment, and print
                 * any empty intervals in between (this may happen with very low tps,
                 * e.g. --rate=0.1).
                 */

                while ((next = agg->start_time + agg_interval * INT64CONST(1000000)) <= now)
                {
                        double          lag_sum = 0.0;
                        double          lag_sum2 = 0.0;
                        double          lag_min = 0.0;
                        double          lag_max = 0.0;
                        int64           skipped = 0;
                        int64           serialization_failures = 0;
                        int64           deadlock_failures = 0;
                        int64           retried = 0;
                        int64           retries = 0;

                        /* print aggregated report to logfile */
                        fprintf(logfile, INT64_FORMAT " " INT64_FORMAT " %.0f %.0f %.0f %.0f",
                                        agg->start_time / 1000000,      /* seconds since Unix epoch */
                                        agg->cnt,
                                        agg->latency.sum,
                                        agg->latency.sum2,
                                        agg->latency.min,
                                        agg->latency.max);

                        if (throttle_delay)
                        {
                                lag_sum = agg->lag.sum;
                                lag_sum2 = agg->lag.sum2;
                                lag_min = agg->lag.min;
                                lag_max = agg->lag.max;
                        }
                        fprintf(logfile, " %.0f %.0f %.0f %.0f",
                                        lag_sum,
                                        lag_sum2,
                                        lag_min,
                                        lag_max);

                        if (latency_limit)
                                skipped = agg->skipped;
                        fprintf(logfile, " " INT64_FORMAT, skipped);

                        if (max_tries != 1)
                        {
                                retried = agg->retried;
                                retries = agg->retries;
                        }
                        fprintf(logfile, " " INT64_FORMAT " " INT64_FORMAT, retried, retries);

                        if (failures_detailed)
                        {
                                serialization_failures = agg->serialization_failures;
                                deadlock_failures = agg->deadlock_failures;
                        }
                        fprintf(logfile, " " INT64_FORMAT " " INT64_FORMAT,
                                        serialization_failures,
                                        deadlock_failures);

                        fputc('\n', logfile);

                        /* reset data and move to next interval */
                        initStats(agg, next);
                }

                /* accumulate the current transaction */
                accumStats(agg, skipped, latency, lag, st->estatus, st->tries);
        }
        else
        {
                /* no, print raw transactions */
                if (!skipped && st->estatus == ESTATUS_NO_ERROR)
                        fprintf(logfile, "%d " INT64_FORMAT " %.0f %d " INT64_FORMAT " "
                                        INT64_FORMAT,
                                        st->id, st->cnt, latency, st->use_file,
                                        now / 1000000, now % 1000000);
                else
                        fprintf(logfile, "%d " INT64_FORMAT " %s %d " INT64_FORMAT " "
                                        INT64_FORMAT,
                                        st->id, st->cnt, getResultString(skipped, st->estatus),
                                        st->use_file, now / 1000000, now % 1000000);

                if (throttle_delay)
                        fprintf(logfile, " %.0f", lag);
                if (max_tries != 1)
                        fprintf(logfile, " %u", st->tries - 1);
                fputc('\n', logfile);
        }
}

/*
 * Accumulate and report statistics at end of a transaction.
 *
 * (This is also called when a transaction is late and thus skipped.
 * Note that even skipped and failed transactions are counted in the CState
 * "cnt" field.)
 */
static void
processXactStats(TState *thread, CState *st, pg_time_usec_t *now,
                                 bool skipped, StatsData *agg)
{
        double          latency = 0.0,
                                lag = 0.0;
        bool            detailed = progress || throttle_delay || latency_limit ||
                use_log || per_script_stats;

        if (detailed && !skipped && st->estatus == ESTATUS_NO_ERROR)
        {
                pg_time_now_lazy(now);

                /* compute latency & lag */
                latency = (*now) - st->txn_scheduled;
                lag = st->txn_begin - st->txn_scheduled;
        }

        /* keep detailed thread stats */
        accumStats(&thread->stats, skipped, latency, lag, st->estatus, st->tries);

        /* count transactions over the latency limit, if needed */
        if (latency_limit && latency > latency_limit)
                thread->latency_late++;

        /* client stat is just counting */
        st->cnt++;

        if (use_log)
                doLog(thread, st, agg, skipped, latency, lag);

        /* XXX could use a mutex here, but we choose not to */
        if (per_script_stats)
                accumStats(&sql_script[st->use_file].stats, skipped, latency, lag,
                                   st->estatus, st->tries);
}


/* discard connections */
static void
disconnect_all(CState *state, int length)
{
        int                     i;

        for (i = 0; i < length; i++)
                finishCon(&state[i]);
}

/*
 * Remove old pgbench tables, if any exist
 */
static void
initDropTables(PGconn *con)
{
        fprintf(stderr, "dropping old tables...\n");

        /*
         * We drop all the tables in one command, so that whether there are
         * foreign key dependencies or not doesn't matter.
         */
        executeStatement(con, "drop table if exists "
                                         "pgbench_accounts, "
                                         "pgbench_branches, "
                                         "pgbench_history, "
                                         "pgbench_tellers");
}

/*
 * Create "pgbench_accounts" partitions if needed.
 *
 * This is the larger table of pgbench default tpc-b like schema
 * with a known size, so we choose to partition it.
 */
static void
createPartitions(PGconn *con)
{
        PQExpBufferData query;

        /* we must have to create some partitions */
        Assert(partitions > 0);

        fprintf(stderr, "creating %d partitions...\n", partitions);

        initPQExpBuffer(&query);

        for (int p = 1; p <= partitions; p++)
        {
                if (partition_method == PART_RANGE)
                {
                        int64           part_size = (naccounts * (int64) scale + partitions - 1) / partitions;

                        printfPQExpBuffer(&query,
                                                          "create%s table pgbench_accounts_%d\n"
                                                          "  partition of pgbench_accounts\n"
                                                          "  for values from (",
                                                          unlogged_tables ? " unlogged" : "", p);

                        /*
                         * For RANGE, we use open-ended partitions at the beginning and
                         * end to allow any valid value for the primary key.  Although the
                         * actual minimum and maximum values can be derived from the
                         * scale, it is more generic and the performance is better.
                         */
                        if (p == 1)
                                appendPQExpBufferStr(&query, "minvalue");
                        else
                                appendPQExpBuffer(&query, INT64_FORMAT, (p - 1) * part_size + 1);

                        appendPQExpBufferStr(&query, ") to (");

                        if (p < partitions)
                                appendPQExpBuffer(&query, INT64_FORMAT, p * part_size + 1);
                        else
                                appendPQExpBufferStr(&query, "maxvalue");

                        appendPQExpBufferChar(&query, ')');
                }
                else if (partition_method == PART_HASH)
                        printfPQExpBuffer(&query,
                                                          "create%s table pgbench_accounts_%d\n"
                                                          "  partition of pgbench_accounts\n"
                                                          "  for values with (modulus %d, remainder %d)",
                                                          unlogged_tables ? " unlogged" : "", p,
                                                          partitions, p - 1);
                else                                    /* cannot get there */
                        Assert(0);

                /*
                 * Per ddlinfo in initCreateTables, fillfactor is needed on table
                 * pgbench_accounts.
                 */
                appendPQExpBuffer(&query, " with (fillfactor=%d)", fillfactor);

                executeStatement(con, query.data);
        }

        termPQExpBuffer(&query);
}

/*
 * Create pgbench's standard tables
 */
static void
initCreateTables(PGconn *con)
{
        /*
         * Note: TPC-B requires at least 100 bytes per row, and the "filler"
         * fields in these table declarations were intended to comply with that.
         * The pgbench_accounts table complies with that because the "filler"
         * column is set to blank-padded empty string. But for all other tables
         * the columns default to NULL and so don't actually take any space.  We
         * could fix that by giving them non-null default values.  However, that
         * would completely break comparability of pgbench results with prior
         * versions. Since pgbench has never pretended to be fully TPC-B compliant
         * anyway, we stick with the historical behavior.
         */
        struct ddlinfo
        {
                const char *table;              /* table name */
                const char *smcols;             /* column decls if accountIDs are 32 bits */
                const char *bigcols;    /* column decls if accountIDs are 64 bits */
                int                     declare_fillfactor;
        };
        static const struct ddlinfo DDLs[] = {
                {
                        "pgbench_history",
                        "tid int,bid int,aid    int,delta int,mtime timestamp,filler char(22)",
                        "tid int,bid int,aid bigint,delta int,mtime timestamp,filler char(22)",
                        0
                },
                {
                        "pgbench_tellers",
                        "tid int not null,bid int,tbalance int,filler char(84)",
                        "tid int not null,bid int,tbalance int,filler char(84)",
                        1
                },
                {
                        "pgbench_accounts",
                        "aid    int not null,bid int,abalance int,filler char(84)",
                        "aid bigint not null,bid int,abalance int,filler char(84)",
                        1
                },
                {
                        "pgbench_branches",
                        "bid int not null,bbalance int,filler char(88)",
                        "bid int not null,bbalance int,filler char(88)",
                        1
                }
        };
        int                     i;
        PQExpBufferData query;

        fprintf(stderr, "creating tables...\n");

        initPQExpBuffer(&query);

        for (i = 0; i < lengthof(DDLs); i++)
        {
                const struct ddlinfo *ddl = &DDLs[i];

                /* Construct new create table statement. */
                printfPQExpBuffer(&query, "create%s table %s(%s)",
                                                  unlogged_tables ? " unlogged" : "",
                                                  ddl->table,
                                                  (scale >= SCALE_32BIT_THRESHOLD) ? ddl->bigcols : ddl->smcols);

                /* Partition pgbench_accounts table */
                if (partition_method != PART_NONE && strcmp(ddl->table, "pgbench_accounts") == 0)
                        appendPQExpBuffer(&query,
                                                          " partition by %s (aid)", PARTITION_METHOD[partition_method]);
                else if (ddl->declare_fillfactor)
                {
                        /* fillfactor is only expected on actual tables */
                        appendPQExpBuffer(&query, " with (fillfactor=%d)", fillfactor);
                }

                if (tablespace != NULL)
                {
                        char       *escape_tablespace;

                        escape_tablespace = PQescapeIdentifier(con, tablespace, strlen(tablespace));
                        appendPQExpBuffer(&query, " tablespace %s", escape_tablespace);
                        PQfreemem(escape_tablespace);
                }

                executeStatement(con, query.data);
        }

        termPQExpBuffer(&query);

        if (partition_method != PART_NONE)
                createPartitions(con);
}

/*
 * Truncate away any old data, in one command in case there are foreign keys
 */
static void
initTruncateTables(PGconn *con)
{
        executeStatement(con, "truncate table "
                                         "pgbench_accounts, "
                                         "pgbench_branches, "
                                         "pgbench_history, "
                                         "pgbench_tellers");
}

static void
initBranch(PQExpBufferData *sql, int64 curr)
{
        /* "filler" column uses NULL */
        printfPQExpBuffer(sql,
                                          INT64_FORMAT "\t0\t\\N\n",
                                          curr + 1);
}

static void
initTeller(PQExpBufferData *sql, int64 curr)
{
        /* "filler" column uses NULL */
        printfPQExpBuffer(sql,
                                          INT64_FORMAT "\t" INT64_FORMAT "\t0\t\\N\n",
                                          curr + 1, curr / ntellers + 1);
}

static void
initAccount(PQExpBufferData *sql, int64 curr)
{
        /* "filler" column defaults to blank padded empty string */
        printfPQExpBuffer(sql,
                                          INT64_FORMAT "\t" INT64_FORMAT "\t0\t\n",
                                          curr + 1, curr / naccounts + 1);
}

static void
initPopulateTable(PGconn *con, const char *table, int64 base,
                                  initRowMethod init_row)
{
        int                     n;
        int64           k;
        int                     chars = 0;
        PGresult   *res;
        PQExpBufferData sql;
        char            copy_statement[256];
        const char *copy_statement_fmt = "copy %s from stdin";
        int64           total = base * scale;

        /* used to track elapsed time and estimate of the remaining time */
        pg_time_usec_t start;
        int                     log_interval = 1;

        /* Stay on the same line if reporting to a terminal */
        char            eol = isatty(fileno(stderr)) ? '\r' : '\n';

        initPQExpBuffer(&sql);

        /*
         * Use COPY with FREEZE on v14 and later for all the tables except
         * pgbench_accounts when it is partitioned.
         */
        if (PQserverVersion(con) >= 140000)
        {
                if (strcmp(table, "pgbench_accounts") != 0 ||
                        partitions == 0)
                        copy_statement_fmt = "copy %s from stdin with (freeze on)";
        }

        n = pg_snprintf(copy_statement, sizeof(copy_statement), copy_statement_fmt, table);
        if (n >= sizeof(copy_statement))
                pg_fatal("invalid buffer size: must be at least %d characters long", n);
        else if (n == -1)
                pg_fatal("invalid format string");

        res = PQexec(con, copy_statement);

        if (PQresultStatus(res) != PGRES_COPY_IN)
                pg_fatal("unexpected copy in result: %s", PQerrorMessage(con));
        PQclear(res);

        start = pg_time_now();

        for (k = 0; k < total; k++)
        {
                int64           j = k + 1;

                init_row(&sql, k);
                if (PQputline(con, sql.data))
                        pg_fatal("PQputline failed");

                if (CancelRequested)
                        break;

                /*
                 * If we want to stick with the original logging, print a message each
                 * 100k inserted rows.
                 */
                if ((!use_quiet) && (j % 100000 == 0))
                {
                        double          elapsed_sec = PG_TIME_GET_DOUBLE(pg_time_now() - start);
                        double          remaining_sec = ((double) total - j) * elapsed_sec / j;

                        chars = fprintf(stderr, INT64_FORMAT " of " INT64_FORMAT " tuples (%d%%) of %s done (elapsed %.2f s, remaining %.2f s)%c",
                                                        j, total,
                                                        (int) ((j * 100) / total),
                                                        table, elapsed_sec, remaining_sec, eol);
                }
                /* let's not call the timing for each row, but only each 100 rows */
                else if (use_quiet && (j % 100 == 0))
                {
                        double          elapsed_sec = PG_TIME_GET_DOUBLE(pg_time_now() - start);
                        double          remaining_sec = ((double) total - j) * elapsed_sec / j;

                        /* have we reached the next interval (or end)? */
                        if ((j == total) || (elapsed_sec >= log_interval * LOG_STEP_SECONDS))
                        {
                                chars = fprintf(stderr, INT64_FORMAT " of " INT64_FORMAT " tuples (%d%%) of %s done (elapsed %.2f s, remaining %.2f s)%c",
                                                                j, total,
                                                                (int) ((j * 100) / total),
                                                                table, elapsed_sec, remaining_sec, eol);

                                /* skip to the next interval */
                                log_interval = (int) ceil(elapsed_sec / LOG_STEP_SECONDS);
                        }
                }
        }

        if (chars != 0 && eol != '\n')
                fprintf(stderr, "%*c\r", chars - 1, ' ');       /* Clear the current line */

        if (PQputline(con, "\\.\n"))
                pg_fatal("very last PQputline failed");
        if (PQendcopy(con))
                pg_fatal("PQendcopy failed");

        termPQExpBuffer(&sql);
}

/*
 * Fill the standard tables with some data generated and sent from the client.
 *
 * The filler column is NULL in pgbench_branches and pgbench_tellers, and is
 * a blank-padded string in pgbench_accounts.
 */
static void
initGenerateDataClientSide(PGconn *con)
{
        fprintf(stderr, "generating data (client-side)...\n");

        /*
         * we do all of this in one transaction to enable the backend's
         * data-loading optimizations
         */
        executeStatement(con, "begin");

        /* truncate away any old data */
        initTruncateTables(con);

        /*
         * fill branches, tellers, accounts in that order in case foreign keys
         * already exist
         */
        initPopulateTable(con, "pgbench_branches", nbranches, initBranch);
        initPopulateTable(con, "pgbench_tellers", ntellers, initTeller);
        initPopulateTable(con, "pgbench_accounts", naccounts, initAccount);

        executeStatement(con, "commit");
}

/*
 * Fill the standard tables with some data generated on the server
 *
 * As already the case with the client-side data generation, the filler
 * column defaults to NULL in pgbench_branches and pgbench_tellers,
 * and is a blank-padded string in pgbench_accounts.
 */
static void
initGenerateDataServerSide(PGconn *con)
{
        PQExpBufferData sql;

        fprintf(stderr, "generating data (server-side)...\n");

        /*
         * we do all of this in one transaction to enable the backend's
         * data-loading optimizations
         */
        executeStatement(con, "begin");

        /* truncate away any old data */
        initTruncateTables(con);

        initPQExpBuffer(&sql);

        printfPQExpBuffer(&sql,
                                          "insert into pgbench_branches(bid,bbalance) "
                                          "select bid, 0 "
                                          "from generate_series(1, %d) as bid", nbranches * scale);
        executeStatement(con, sql.data);

        printfPQExpBuffer(&sql,
                                          "insert into pgbench_tellers(tid,bid,tbalance) "
                                          "select tid, (tid - 1) / %d + 1, 0 "
                                          "from generate_series(1, %d) as tid", ntellers, ntellers * scale);
        executeStatement(con, sql.data);

        printfPQExpBuffer(&sql,
                                          "insert into pgbench_accounts(aid,bid,abalance,filler) "
                                          "select aid, (aid - 1) / %d + 1, 0, '' "
                                          "from generate_series(1, " INT64_FORMAT ") as aid",
                                          naccounts, (int64) naccounts * scale);
        executeStatement(con, sql.data);

        termPQExpBuffer(&sql);

        executeStatement(con, "commit");
}

/*
 * Invoke vacuum on the standard tables
 */
static void
initVacuum(PGconn *con)
{
        fprintf(stderr, "vacuuming...\n");
        executeStatement(con, "vacuum analyze pgbench_branches");
        executeStatement(con, "vacuum analyze pgbench_tellers");
        executeStatement(con, "vacuum analyze pgbench_accounts");
        executeStatement(con, "vacuum analyze pgbench_history");
}

/*
 * Create primary keys on the standard tables
 */
static void
initCreatePKeys(PGconn *con)
{
        static const char *const DDLINDEXes[] = {
                "alter table pgbench_branches add primary key (bid)",
                "alter table pgbench_tellers add primary key (tid)",
                "alter table pgbench_accounts add primary key (aid)"
        };
        int                     i;
        PQExpBufferData query;

        fprintf(stderr, "creating primary keys...\n");
        initPQExpBuffer(&query);

        for (i = 0; i < lengthof(DDLINDEXes); i++)
        {
                resetPQExpBuffer(&query);
                appendPQExpBufferStr(&query, DDLINDEXes[i]);

                if (index_tablespace != NULL)
                {
                        char       *escape_tablespace;

                        escape_tablespace = PQescapeIdentifier(con, index_tablespace,
                                                                                                   strlen(index_tablespace));
                        appendPQExpBuffer(&query, " using index tablespace %s", escape_tablespace);
                        PQfreemem(escape_tablespace);
                }

                executeStatement(con, query.data);
        }

        termPQExpBuffer(&query);
}

/*
 * Create foreign key constraints between the standard tables
 */
static void
initCreateFKeys(PGconn *con)
{
        static const char *const DDLKEYs[] = {
                "alter table pgbench_tellers add constraint pgbench_tellers_bid_fkey foreign key (bid) references pgbench_branches",
                "alter table pgbench_accounts add constraint pgbench_accounts_bid_fkey foreign key (bid) references pgbench_branches",
                "alter table pgbench_history add constraint pgbench_history_bid_fkey foreign key (bid) references pgbench_branches",
                "alter table pgbench_history add constraint pgbench_history_tid_fkey foreign key (tid) references pgbench_tellers",
                "alter table pgbench_history add constraint pgbench_history_aid_fkey foreign key (aid) references pgbench_accounts"
        };
        int                     i;

        fprintf(stderr, "creating foreign keys...\n");
        for (i = 0; i < lengthof(DDLKEYs); i++)
        {
                executeStatement(con, DDLKEYs[i]);
        }
}

/*
 * Validate an initialization-steps string
 *
 * (We could just leave it to runInitSteps() to fail if there are wrong
 * characters, but since initialization can take awhile, it seems friendlier
 * to check during option parsing.)
 */
static void
checkInitSteps(const char *initialize_steps)
{
        if (initialize_steps[0] == '\0')
                pg_fatal("no initialization steps specified");

        for (const char *step = initialize_steps; *step != '\0'; step++)
        {
                if (strchr(ALL_INIT_STEPS " ", *step) == NULL)
                {
                        pg_log_error("unrecognized initialization step \"%c\"", *step);
                        pg_log_error_detail("Allowed step characters are: \"" ALL_INIT_STEPS "\".");
                        exit(1);
                }
        }
}

/*
 * Invoke each initialization step in the given string
 */
static void
runInitSteps(const char *initialize_steps)
{
        PQExpBufferData stats;
        PGconn     *con;
        const char *step;
        double          run_time = 0.0;
        bool            first = true;

        initPQExpBuffer(&stats);

        if ((con = doConnect()) == NULL)
                pg_fatal("could not create connection for initialization");

        setup_cancel_handler(NULL);
        SetCancelConn(con);

        for (step = initialize_steps; *step != '\0'; step++)
        {
                char       *op = NULL;
                pg_time_usec_t start = pg_time_now();

                switch (*step)
                {
                        case 'd':
                                op = "drop tables";
                                initDropTables(con);
                                break;
                        case 't':
                                op = "create tables";
                                initCreateTables(con);
                                break;
                        case 'g':
                                op = "client-side generate";
                                initGenerateDataClientSide(con);
                                break;
                        case 'G':
                                op = "server-side generate";
                                initGenerateDataServerSide(con);
                                break;
                        case 'v':
                                op = "vacuum";
                                initVacuum(con);
                                break;
                        case 'p':
                                op = "primary keys";
                                initCreatePKeys(con);
                                break;
                        case 'f':
                                op = "foreign keys";
                                initCreateFKeys(con);
                                break;
                        case ' ':
                                break;                  /* ignore */
                        default:
                                pg_log_error("unrecognized initialization step \"%c\"", *step);
                                PQfinish(con);
                                exit(1);
                }

                if (op != NULL)
                {
                        double          elapsed_sec = PG_TIME_GET_DOUBLE(pg_time_now() - start);

                        if (!first)
                                appendPQExpBufferStr(&stats, ", ");
                        else
                                first = false;

                        appendPQExpBuffer(&stats, "%s %.2f s", op, elapsed_sec);

                        run_time += elapsed_sec;
                }
        }

        fprintf(stderr, "done in %.2f s (%s).\n", run_time, stats.data);
        ResetCancelConn();
        PQfinish(con);
        termPQExpBuffer(&stats);
}

/*
 * Extract pgbench table information into global variables scale,
 * partition_method and partitions.
 */
static void
GetTableInfo(PGconn *con, bool scale_given)
{
        PGresult   *res;

        /*
         * get the scaling factor that should be same as count(*) from
         * pgbench_branches if this is not a custom query
         */
        res = PQexec(con, "select count(*) from pgbench_branches");
        if (PQresultStatus(res) != PGRES_TUPLES_OK)
        {
                char       *sqlState = PQresultErrorField(res, PG_DIAG_SQLSTATE);

                pg_log_error("could not count number of branches: %s", PQerrorMessage(con));

                if (sqlState && strcmp(sqlState, ERRCODE_UNDEFINED_TABLE) == 0)
                        pg_log_error_hint("Perhaps you need to do initialization (\"pgbench -i\") in database \"%s\".",
                                                          PQdb(con));

                exit(1);
        }
        scale = atoi(PQgetvalue(res, 0, 0));
        if (scale < 0)
                pg_fatal("invalid count(*) from pgbench_branches: \"%s\"",
                                 PQgetvalue(res, 0, 0));
        PQclear(res);

        /* warn if we override user-given -s switch */
        if (scale_given)
                pg_log_warning("scale option ignored, using count from pgbench_branches table (%d)",
                                           scale);

        /*
         * Get the partition information for the first "pgbench_accounts" table
         * found in search_path.
         *
         * The result is empty if no "pgbench_accounts" is found.
         *
         * Otherwise, it always returns one row even if the table is not
         * partitioned (in which case the partition strategy is NULL).
         *
         * The number of partitions can be 0 even for partitioned tables, if no
         * partition is attached.
         *
         * We assume no partitioning on any failure, so as to avoid failing on an
         * old version without "pg_partitioned_table".
         */
        res = PQexec(con,
                                 "select o.n, p.partstrat, pg_catalog.count(i.inhparent) "
                                 "from pg_catalog.pg_class as c "
                                 "join pg_catalog.pg_namespace as n on (n.oid = c.relnamespace) "
                                 "cross join lateral (select pg_catalog.array_position(pg_catalog.current_schemas(true), n.nspname)) as o(n) "
                                 "left join pg_catalog.pg_partitioned_table as p on (p.partrelid = c.oid) "
                                 "left join pg_catalog.pg_inherits as i on (c.oid = i.inhparent) "
                                 "where c.relname = 'pgbench_accounts' and o.n is not null "
                                 "group by 1, 2 "
                                 "order by 1 asc "
                                 "limit 1");

        if (PQresultStatus(res) != PGRES_TUPLES_OK)
        {
                /* probably an older version, coldly assume no partitioning */
                partition_method = PART_NONE;
                partitions = 0;
        }
        else if (PQntuples(res) == 0)
        {
                /*
                 * This case is unlikely as pgbench already found "pgbench_branches"
                 * above to compute the scale.
                 */
                pg_log_error("no pgbench_accounts table found in search_path");
                pg_log_error_hint("Perhaps you need to do initialization (\"pgbench -i\") in database \"%s\".", PQdb(con));
                exit(1);
        }
        else                                            /* PQntuples(res) == 1 */
        {
                /* normal case, extract partition information */
                if (PQgetisnull(res, 0, 1))
                        partition_method = PART_NONE;
                else
                {
                        char       *ps = PQgetvalue(res, 0, 1);

                        /* column must be there */
                        Assert(ps != NULL);

                        if (strcmp(ps, "r") == 0)
                                partition_method = PART_RANGE;
                        else if (strcmp(ps, "h") == 0)
                                partition_method = PART_HASH;
                        else
                        {
                                /* possibly a newer version with new partition method */
                                pg_fatal("unexpected partition method: \"%s\"", ps);
                        }
                }

                partitions = atoi(PQgetvalue(res, 0, 2));
        }

        PQclear(res);
}

/*
 * Replace :param with $n throughout the command's SQL text, which
 * is a modifiable string in cmd->lines.
 */
static bool
parseQuery(Command *cmd)
{
        char       *sql,
                           *p;

        cmd->argc = 1;

        p = sql = pg_strdup(cmd->lines.data);
        while ((p = strchr(p, ':')) != NULL)
        {
                char            var[13];
                char       *name;
                int                     eaten;

                name = parseVariable(p, &eaten);
                if (name == NULL)
                {
                        while (*p == ':')
                        {
                                p++;
                        }
                        continue;
                }

                /*
                 * cmd->argv[0] is the SQL statement itself, so the max number of
                 * arguments is one less than MAX_ARGS
                 */
                if (cmd->argc >= MAX_ARGS)
                {
                        pg_log_error("statement has too many arguments (maximum is %d): %s",
                                                 MAX_ARGS - 1, cmd->lines.data);
                        pg_free(name);
                        return false;
                }

                sprintf(var, "$%d", cmd->argc);
                p = replaceVariable(&sql, p, eaten, var);

                cmd->argv[cmd->argc] = name;
                cmd->argc++;
        }

        Assert(cmd->argv[0] == NULL);
        cmd->argv[0] = sql;
        return true;
}

/*
 * syntax error while parsing a script (in practice, while parsing a
 * backslash command, because we don't detect syntax errors in SQL)
 *
 * source: source of script (filename or builtin-script ID)
 * lineno: line number within script (count from 1)
 * line: whole line of backslash command, if available
 * command: backslash command name, if available
 * msg: the actual error message
 * more: optional extra message
 * column: zero-based column number, or -1 if unknown
 */
void
syntax_error(const char *source, int lineno,
                         const char *line, const char *command,
                         const char *msg, const char *more, int column)
{
        PQExpBufferData buf;

        initPQExpBuffer(&buf);

        printfPQExpBuffer(&buf, "%s:%d: %s", source, lineno, msg);
        if (more != NULL)
                appendPQExpBuffer(&buf, " (%s)", more);
        if (column >= 0 && line == NULL)
                appendPQExpBuffer(&buf, " at column %d", column + 1);
        if (command != NULL)
                appendPQExpBuffer(&buf, " in command \"%s\"", command);

        pg_log_error("%s", buf.data);

        termPQExpBuffer(&buf);

        if (line != NULL)
        {
                fprintf(stderr, "%s\n", line);
                if (column >= 0)
                        fprintf(stderr, "%*c error found here\n", column + 1, '^');
        }

        exit(1);
}

/*
 * Return a pointer to the start of the SQL command, after skipping over
 * whitespace and "--" comments.
 * If the end of the string is reached, return NULL.
 */
static char *
skip_sql_comments(char *sql_command)
{
        char       *p = sql_command;

        /* Skip any leading whitespace, as well as "--" style comments */
        for (;;)
        {
                if (isspace((unsigned char) *p))
                        p++;
                else if (strncmp(p, "--", 2) == 0)
                {
                        p = strchr(p, '\n');
                        if (p == NULL)
                                return NULL;
                        p++;
                }
                else
                        break;
        }

        /* NULL if there's nothing but whitespace and comments */
        if (*p == '\0')
                return NULL;

        return p;
}

/*
 * Parse a SQL command; return a Command struct, or NULL if it's a comment
 *
 * On entry, psqlscan.l has collected the command into "buf", so we don't
 * really need to do much here except check for comments and set up a Command
 * struct.
 */
static Command *
create_sql_command(PQExpBuffer buf, const char *source)
{
        Command    *my_command;
        char       *p = skip_sql_comments(buf->data);

        if (p == NULL)
                return NULL;

        /* Allocate and initialize Command structure */
        my_command = (Command *) pg_malloc(sizeof(Command));
        initPQExpBuffer(&my_command->lines);
        appendPQExpBufferStr(&my_command->lines, p);
        my_command->first_line = NULL;  /* this is set later */
        my_command->type = SQL_COMMAND;
        my_command->meta = META_NONE;
        my_command->argc = 0;
        my_command->retries = 0;
        my_command->failures = 0;
        memset(my_command->argv, 0, sizeof(my_command->argv));
        my_command->varprefix = NULL;   /* allocated later, if needed */
        my_command->expr = NULL;
        initSimpleStats(&my_command->stats);
        my_command->prepname = NULL;    /* set later, if needed */

        return my_command;
}

/* Free a Command structure and associated data */
static void
free_command(Command *command)
{
        termPQExpBuffer(&command->lines);
        pg_free(command->first_line);
        for (int i = 0; i < command->argc; i++)
                pg_free(command->argv[i]);
        pg_free(command->varprefix);

        /*
         * It should also free expr recursively, but this is currently not needed
         * as only gset commands (which do not have an expression) are freed.
         */
        pg_free(command);
}

/*
 * Once an SQL command is fully parsed, possibly by accumulating several
 * parts, complete other fields of the Command structure.
 */
static void
postprocess_sql_command(Command *my_command)
{
        char            buffer[128];
        static int      prepnum = 0;

        Assert(my_command->type == SQL_COMMAND);

        /* Save the first line for error display. */
        strlcpy(buffer, my_command->lines.data, sizeof(buffer));
        buffer[strcspn(buffer, "\n\r")] = '\0';
        my_command->first_line = pg_strdup(buffer);

        /* Parse query and generate prepared statement name, if necessary */
        switch (querymode)
        {
                case QUERY_SIMPLE:
                        my_command->argv[0] = my_command->lines.data;
                        my_command->argc++;
                        break;
                case QUERY_PREPARED:
                        my_command->prepname = psprintf("P_%d", prepnum++);
                        /* fall through */
                case QUERY_EXTENDED:
                        if (!parseQuery(my_command))
                                exit(1);
                        break;
                default:
                        exit(1);
        }
}

/*
 * Parse a backslash command; return a Command struct, or NULL if comment
 *
 * At call, we have scanned only the initial backslash.
 */
static Command *
process_backslash_command(PsqlScanState sstate, const char *source)
{
        Command    *my_command;
        PQExpBufferData word_buf;
        int                     word_offset;
        int                     offsets[MAX_ARGS];      /* offsets of argument words */
        int                     start_offset;
        int                     lineno;
        int                     j;

        initPQExpBuffer(&word_buf);

        /* Remember location of the backslash */
        start_offset = expr_scanner_offset(sstate) - 1;
        lineno = expr_scanner_get_lineno(sstate, start_offset);

        /* Collect first word of command */
        if (!expr_lex_one_word(sstate, &word_buf, &word_offset))
        {
                termPQExpBuffer(&word_buf);
                return NULL;
        }

        /* Allocate and initialize Command structure */
        my_command = (Command *) pg_malloc0(sizeof(Command));
        my_command->type = META_COMMAND;
        my_command->argc = 0;
        initSimpleStats(&my_command->stats);

        /* Save first word (command name) */
        j = 0;
        offsets[j] = word_offset;
        my_command->argv[j++] = pg_strdup(word_buf.data);
        my_command->argc++;

        /* ... and convert it to enum form */
        my_command->meta = getMetaCommand(my_command->argv[0]);

        if (my_command->meta == META_SET ||
                my_command->meta == META_IF ||
                my_command->meta == META_ELIF)
        {
                yyscan_t        yyscanner;

                /* For \set, collect var name */
                if (my_command->meta == META_SET)
                {
                        if (!expr_lex_one_word(sstate, &word_buf, &word_offset))
                                syntax_error(source, lineno, my_command->first_line, my_command->argv[0],
                                                         "missing argument", NULL, -1);

                        offsets[j] = word_offset;
                        my_command->argv[j++] = pg_strdup(word_buf.data);
                        my_command->argc++;
                }

                /* then for all parse the expression */
                yyscanner = expr_scanner_init(sstate, source, lineno, start_offset,
                                                                          my_command->argv[0]);

                if (expr_yyparse(yyscanner) != 0)
                {
                        /* dead code: exit done from syntax_error called by yyerror */
                        exit(1);
                }

                my_command->expr = expr_parse_result;

                /* Save line, trimming any trailing newline */
                my_command->first_line =
                        expr_scanner_get_substring(sstate,
                                                                           start_offset,
                                                                           expr_scanner_offset(sstate),
                                                                           true);

                expr_scanner_finish(yyscanner);

                termPQExpBuffer(&word_buf);

                return my_command;
        }

        /* For all other commands, collect remaining words. */
        while (expr_lex_one_word(sstate, &word_buf, &word_offset))
        {
                /*
                 * my_command->argv[0] is the command itself, so the max number of
                 * arguments is one less than MAX_ARGS
                 */
                if (j >= MAX_ARGS)
                        syntax_error(source, lineno, my_command->first_line, my_command->argv[0],
                                                 "too many arguments", NULL, -1);

                offsets[j] = word_offset;
                my_command->argv[j++] = pg_strdup(word_buf.data);
                my_command->argc++;
        }

        /* Save line, trimming any trailing newline */
        my_command->first_line =
                expr_scanner_get_substring(sstate,
                                                                   start_offset,
                                                                   expr_scanner_offset(sstate),
                                                                   true);

        if (my_command->meta == META_SLEEP)
        {
                if (my_command->argc < 2)
                        syntax_error(source, lineno, my_command->first_line, my_command->argv[0],
                                                 "missing argument", NULL, -1);

                if (my_command->argc > 3)
                        syntax_error(source, lineno, my_command->first_line, my_command->argv[0],
                                                 "too many arguments", NULL,
                                                 offsets[3] - start_offset);

                /*
                 * Split argument into number and unit to allow "sleep 1ms" etc. We
                 * don't have to terminate the number argument with null because it
                 * will be parsed with atoi, which ignores trailing non-digit
                 * characters.
                 */
                if (my_command->argv[1][0] != ':')
                {
                        char       *c = my_command->argv[1];
                        bool            have_digit = false;

                        /* Skip sign */
                        if (*c == '+' || *c == '-')
                                c++;

                        /* Require at least one digit */
                        if (*c && isdigit((unsigned char) *c))
                                have_digit = true;

                        /* Eat all digits */
                        while (*c && isdigit((unsigned char) *c))
                                c++;

                        if (*c)
                        {
                                if (my_command->argc == 2 && have_digit)
                                {
                                        my_command->argv[2] = c;
                                        offsets[2] = offsets[1] + (c - my_command->argv[1]);
                                        my_command->argc = 3;
                                }
                                else
                                {
                                        /*
                                         * Raise an error if argument starts with non-digit
                                         * character (after sign).
                                         */
                                        syntax_error(source, lineno, my_command->first_line, my_command->argv[0],
                                                                 "invalid sleep time, must be an integer",
                                                                 my_command->argv[1], offsets[1] - start_offset);
                                }
                        }
                }

                if (my_command->argc == 3)
                {
                        if (pg_strcasecmp(my_command->argv[2], "us") != 0 &&
                                pg_strcasecmp(my_command->argv[2], "ms") != 0 &&
                                pg_strcasecmp(my_command->argv[2], "s") != 0)
                                syntax_error(source, lineno, my_command->first_line, my_command->argv[0],
                                                         "unrecognized time unit, must be us, ms or s",
                                                         my_command->argv[2], offsets[2] - start_offset);
                }
        }
        else if (my_command->meta == META_SETSHELL)
        {
                if (my_command->argc < 3)
                        syntax_error(source, lineno, my_command->first_line, my_command->argv[0],
                                                 "missing argument", NULL, -1);
        }
        else if (my_command->meta == META_SHELL)
        {
                if (my_command->argc < 2)
                        syntax_error(source, lineno, my_command->first_line, my_command->argv[0],
                                                 "missing command", NULL, -1);
        }
        else if (my_command->meta == META_ELSE || my_command->meta == META_ENDIF ||
                         my_command->meta == META_STARTPIPELINE ||
                         my_command->meta == META_ENDPIPELINE)
        {
                if (my_command->argc != 1)
                        syntax_error(source, lineno, my_command->first_line, my_command->argv[0],
                                                 "unexpected argument", NULL, -1);
        }
        else if (my_command->meta == META_GSET || my_command->meta == META_ASET)
        {
                if (my_command->argc > 2)
                        syntax_error(source, lineno, my_command->first_line, my_command->argv[0],
                                                 "too many arguments", NULL, -1);
        }
        else
        {
                /* my_command->meta == META_NONE */
                syntax_error(source, lineno, my_command->first_line, my_command->argv[0],
                                         "invalid command", NULL, -1);
        }

        termPQExpBuffer(&word_buf);

        return my_command;
}

static void
ConditionError(const char *desc, int cmdn, const char *msg)
{
        pg_fatal("condition error in script \"%s\" command %d: %s",
                         desc, cmdn, msg);
}

/*
 * Partial evaluation of conditionals before recording and running the script.
 */
static void
CheckConditional(const ParsedScript *ps)
{
        /* statically check conditional structure */
        ConditionalStack cs = conditional_stack_create();
        int                     i;

        for (i = 0; ps->commands[i] != NULL; i++)
        {
                Command    *cmd = ps->commands[i];

                if (cmd->type == META_COMMAND)
                {
                        switch (cmd->meta)
                        {
                                case META_IF:
                                        conditional_stack_push(cs, IFSTATE_FALSE);
                                        break;
                                case META_ELIF:
                                        if (conditional_stack_empty(cs))
                                                ConditionError(ps->desc, i + 1, "\\elif without matching \\if");
                                        if (conditional_stack_peek(cs) == IFSTATE_ELSE_FALSE)
                                                ConditionError(ps->desc, i + 1, "\\elif after \\else");
                                        break;
                                case META_ELSE:
                                        if (conditional_stack_empty(cs))
                                                ConditionError(ps->desc, i + 1, "\\else without matching \\if");
                                        if (conditional_stack_peek(cs) == IFSTATE_ELSE_FALSE)
                                                ConditionError(ps->desc, i + 1, "\\else after \\else");
                                        conditional_stack_poke(cs, IFSTATE_ELSE_FALSE);
                                        break;
                                case META_ENDIF:
                                        if (!conditional_stack_pop(cs))
                                                ConditionError(ps->desc, i + 1, "\\endif without matching \\if");
                                        break;
                                default:
                                        /* ignore anything else... */
                                        break;
                        }
                }
        }
        if (!conditional_stack_empty(cs))
                ConditionError(ps->desc, i + 1, "\\if without matching \\endif");
        conditional_stack_destroy(cs);
}

/*
 * Parse a script (either the contents of a file, or a built-in script)
 * and add it to the list of scripts.
 */
static void
ParseScript(const char *script, const char *desc, int weight)
{
        ParsedScript ps;
        PsqlScanState sstate;
        PQExpBufferData line_buf;
        int                     alloc_num;
        int                     index;
        int                     lineno;
        int                     start_offset;

#define COMMANDS_ALLOC_NUM 128
        alloc_num = COMMANDS_ALLOC_NUM;

        /* Initialize all fields of ps */
        ps.desc = desc;
        ps.weight = weight;
        ps.commands = (Command **) pg_malloc(sizeof(Command *) * alloc_num);
        initStats(&ps.stats, 0);

        /* Prepare to parse script */
        sstate = psql_scan_create(&pgbench_callbacks);

        /*
         * Ideally, we'd scan scripts using the encoding and stdstrings settings
         * we get from a DB connection.  However, without major rearrangement of
         * pgbench's argument parsing, we can't have a DB connection at the time
         * we parse scripts.  Using SQL_ASCII (encoding 0) should work well enough
         * with any backend-safe encoding, though conceivably we could be fooled
         * if a script file uses a client-only encoding.  We also assume that
         * stdstrings should be true, which is a bit riskier.
         */
        psql_scan_setup(sstate, script, strlen(script), 0, true);
        start_offset = expr_scanner_offset(sstate) - 1;

        initPQExpBuffer(&line_buf);

        index = 0;

        for (;;)
        {
                PsqlScanResult sr;
                promptStatus_t prompt;
                Command    *command = NULL;

                resetPQExpBuffer(&line_buf);
                lineno = expr_scanner_get_lineno(sstate, start_offset);

                sr = psql_scan(sstate, &line_buf, &prompt);

                /* If we collected a new SQL command, process that */
                command = create_sql_command(&line_buf, desc);

                /* store new command */
                if (command)
                        ps.commands[index++] = command;

                /* If we reached a backslash, process that */
                if (sr == PSCAN_BACKSLASH)
                {
                        command = process_backslash_command(sstate, desc);

                        if (command)
                        {
                                /*
                                 * If this is gset or aset, merge into the preceding command.
                                 * (We don't use a command slot in this case).
                                 */
                                if (command->meta == META_GSET || command->meta == META_ASET)
                                {
                                        Command    *cmd;

                                        if (index == 0)
                                                syntax_error(desc, lineno, NULL, NULL,
                                                                         "\\gset must follow an SQL command",
                                                                         NULL, -1);

                                        cmd = ps.commands[index - 1];

                                        if (cmd->type != SQL_COMMAND ||
                                                cmd->varprefix != NULL)
                                                syntax_error(desc, lineno, NULL, NULL,
                                                                         "\\gset must follow an SQL command",
                                                                         cmd->first_line, -1);

                                        /* get variable prefix */
                                        if (command->argc <= 1 || command->argv[1][0] == '\0')
                                                cmd->varprefix = pg_strdup("");
                                        else
                                                cmd->varprefix = pg_strdup(command->argv[1]);

                                        /* update the sql command meta */
                                        cmd->meta = command->meta;

                                        /* cleanup unused command */
                                        free_command(command);

                                        continue;
                                }

                                /* Attach any other backslash command as a new command */
                                ps.commands[index++] = command;
                        }
                }

                /*
                 * Since we used a command slot, allocate more if needed.  Note we
                 * always allocate one more in order to accommodate the NULL
                 * terminator below.
                 */
                if (index >= alloc_num)
                {
                        alloc_num += COMMANDS_ALLOC_NUM;
                        ps.commands = (Command **)
                                pg_realloc(ps.commands, sizeof(Command *) * alloc_num);
                }

                /* Done if we reached EOF */
                if (sr == PSCAN_INCOMPLETE || sr == PSCAN_EOL)
                        break;
        }

        ps.commands[index] = NULL;

        addScript(&ps);

        termPQExpBuffer(&line_buf);
        psql_scan_finish(sstate);
        psql_scan_destroy(sstate);
}

/*
 * Read the entire contents of file fd, and return it in a malloc'd buffer.
 *
 * The buffer will typically be larger than necessary, but we don't care
 * in this program, because we'll free it as soon as we've parsed the script.
 */
static char *
read_file_contents(FILE *fd)
{
        char       *buf;
        size_t          buflen = BUFSIZ;
        size_t          used = 0;

        buf = (char *) pg_malloc(buflen);

        for (;;)
        {
                size_t          nread;

                nread = fread(buf + used, 1, BUFSIZ, fd);
                used += nread;
                /* If fread() read less than requested, must be EOF or error */
                if (nread < BUFSIZ)
                        break;
                /* Enlarge buf so we can read some more */
                buflen += BUFSIZ;
                buf = (char *) pg_realloc(buf, buflen);
        }
        /* There is surely room for a terminator */
        buf[used] = '\0';

        return buf;
}

/*
 * Given a file name, read it and add its script to the list.
 * "-" means to read stdin.
 * NB: filename must be storage that won't disappear.
 */
static void
process_file(const char *filename, int weight)
{
        FILE       *fd;
        char       *buf;

        /* Slurp the file contents into "buf" */
        if (strcmp(filename, "-") == 0)
                fd = stdin;
        else if ((fd = fopen(filename, "r")) == NULL)
                pg_fatal("could not open file \"%s\": %m", filename);

        buf = read_file_contents(fd);

        if (ferror(fd))
                pg_fatal("could not read file \"%s\": %m", filename);

        if (fd != stdin)
                fclose(fd);

        ParseScript(buf, filename, weight);

        free(buf);
}

/* Parse the given builtin script and add it to the list. */
static void
process_builtin(const BuiltinScript *bi, int weight)
{
        ParseScript(bi->script, bi->desc, weight);
}

/* show available builtin scripts */
static void
listAvailableScripts(void)
{
        int                     i;

        fprintf(stderr, "Available builtin scripts:\n");
        for (i = 0; i < lengthof(builtin_script); i++)
                fprintf(stderr, "  %13s: %s\n", builtin_script[i].name, builtin_script[i].desc);
        fprintf(stderr, "\n");
}

/* return builtin script "name" if unambiguous, fails if not found */
static const BuiltinScript *
findBuiltin(const char *name)
{
        int                     i,
                                found = 0,
                                len = strlen(name);
        const BuiltinScript *result = NULL;

        for (i = 0; i < lengthof(builtin_script); i++)
        {
                if (strncmp(builtin_script[i].name, name, len) == 0)
                {
                        result = &builtin_script[i];
                        found++;
                }
        }

        /* ok, unambiguous result */
        if (found == 1)
                return result;

        /* error cases */
        if (found == 0)
                pg_log_error("no builtin script found for name \"%s\"", name);
        else                                            /* found > 1 */
                pg_log_error("ambiguous builtin name: %d builtin scripts found for prefix \"%s\"", found, name);

        listAvailableScripts();
        exit(1);
}

/*
 * Determine the weight specification from a script option (-b, -f), if any,
 * and return it as an integer (1 is returned if there's no weight).  The
 * script name is returned in *script as a malloc'd string.
 */
static int
parseScriptWeight(const char *option, char **script)
{
        char       *sep;
        int                     weight;

        if ((sep = strrchr(option, WSEP)))
        {
                int                     namelen = sep - option;
                long            wtmp;
                char       *badp;

                /* generate the script name */
                *script = pg_malloc(namelen + 1);
                strncpy(*script, option, namelen);
                (*script)[namelen] = '\0';

                /* process digits of the weight spec */
                errno = 0;
                wtmp = strtol(sep + 1, &badp, 10);
                if (errno != 0 || badp == sep + 1 || *badp != '\0')
                        pg_fatal("invalid weight specification: %s", sep);
                if (wtmp > INT_MAX || wtmp < 0)
                        pg_fatal("weight specification out of range (0 .. %d): %lld",
                                         INT_MAX, (long long) wtmp);
                weight = wtmp;
        }
        else
        {
                *script = pg_strdup(option);
                weight = 1;
        }

        return weight;
}

/* append a script to the list of scripts to process */
static void
addScript(const ParsedScript *script)
{
        if (script->commands == NULL || script->commands[0] == NULL)
                pg_fatal("empty command list for script \"%s\"", script->desc);

        if (num_scripts >= MAX_SCRIPTS)
                pg_fatal("at most %d SQL scripts are allowed", MAX_SCRIPTS);

        CheckConditional(script);

        sql_script[num_scripts] = *script;
        num_scripts++;
}

/*
 * Print progress report.
 *
 * On entry, *last and *last_report contain the statistics and time of last
 * progress report.  On exit, they are updated with the new stats.
 */
static void
printProgressReport(TState *threads, int64 test_start, pg_time_usec_t now,
                                        StatsData *last, int64 *last_report)
{
        /* generate and show report */
        pg_time_usec_t run = now - *last_report;
        int64           cnt,
                                failures,
                                retried;
        double          tps,
                                total_run,
                                latency,
                                sqlat,
                                lag,
                                stdev;
        char            tbuf[315];
        StatsData       cur;

        /*
         * Add up the statistics of all threads.
         *
         * XXX: No locking.  There is no guarantee that we get an atomic snapshot
         * of the transaction count and latencies, so these figures can well be
         * off by a small amount.  The progress report's purpose is to give a
         * quick overview of how the test is going, so that shouldn't matter too
         * much.  (If a read from a 64-bit integer is not atomic, you might get a
         * "torn" read and completely bogus latencies though!)
         */
        initStats(&cur, 0);
        for (int i = 0; i < nthreads; i++)
        {
                mergeSimpleStats(&cur.latency, &threads[i].stats.latency);
                mergeSimpleStats(&cur.lag, &threads[i].stats.lag);
                cur.cnt += threads[i].stats.cnt;
                cur.skipped += threads[i].stats.skipped;
                cur.retries += threads[i].stats.retries;
                cur.retried += threads[i].stats.retried;
                cur.serialization_failures +=
                        threads[i].stats.serialization_failures;
                cur.deadlock_failures += threads[i].stats.deadlock_failures;
        }

        /* we count only actually executed transactions */
        cnt = cur.cnt - last->cnt;
        total_run = (now - test_start) / 1000000.0;
        tps = 1000000.0 * cnt / run;
        if (cnt > 0)
        {
                latency = 0.001 * (cur.latency.sum - last->latency.sum) / cnt;
                sqlat = 1.0 * (cur.latency.sum2 - last->latency.sum2) / cnt;
                stdev = 0.001 * sqrt(sqlat - 1000000.0 * latency * latency);
                lag = 0.001 * (cur.lag.sum - last->lag.sum) / cnt;
        }
        else
        {
                latency = sqlat = stdev = lag = 0;
        }
        failures = getFailures(&cur) - getFailures(last);
        retried = cur.retried - last->retried;

        if (progress_timestamp)
        {
                snprintf(tbuf, sizeof(tbuf), "%.3f s",
                                 PG_TIME_GET_DOUBLE(now + epoch_shift));
        }
        else
        {
                /* round seconds are expected, but the thread may be late */
                snprintf(tbuf, sizeof(tbuf), "%.1f s", total_run);
        }

        fprintf(stderr,
                        "progress: %s, %.1f tps, lat %.3f ms stddev %.3f, " INT64_FORMAT " failed",
                        tbuf, tps, latency, stdev, failures);

        if (throttle_delay)
        {
                fprintf(stderr, ", lag %.3f ms", lag);
                if (latency_limit)
                        fprintf(stderr, ", " INT64_FORMAT " skipped",
                                        cur.skipped - last->skipped);
        }

        /* it can be non-zero only if max_tries is not equal to one */
        if (max_tries != 1)
                fprintf(stderr,
                                ", " INT64_FORMAT " retried, " INT64_FORMAT " retries",
                                retried, cur.retries - last->retries);
        fprintf(stderr, "\n");

        *last = cur;
        *last_report = now;
}

static void
printSimpleStats(const char *prefix, SimpleStats *ss)
{
        if (ss->count > 0)
        {
                double          latency = ss->sum / ss->count;
                double          stddev = sqrt(ss->sum2 / ss->count - latency * latency);

                printf("%s average = %.3f ms\n", prefix, 0.001 * latency);
                printf("%s stddev = %.3f ms\n", prefix, 0.001 * stddev);
        }
}

/* print version banner */
static void
printVersion(PGconn *con)
{
        int                     server_ver = PQserverVersion(con);
        int                     client_ver = PG_VERSION_NUM;

        if (server_ver != client_ver)
        {
                const char *server_version;
                char            sverbuf[32];

                /* Try to get full text form, might include "devel" etc */
                server_version = PQparameterStatus(con, "server_version");
                /* Otherwise fall back on server_ver */
                if (!server_version)
                {
                        formatPGVersionNumber(server_ver, true,
                                                                  sverbuf, sizeof(sverbuf));
                        server_version = sverbuf;
                }

                printf(_("%s (%s, server %s)\n"),
                           "pgbench", PG_VERSION, server_version);
        }
        /* For version match, only print pgbench version */
        else
                printf("%s (%s)\n", "pgbench", PG_VERSION);
        fflush(stdout);
}

/* print out results */
static void
printResults(StatsData *total,
                         pg_time_usec_t total_duration, /* benchmarking time */
                         pg_time_usec_t conn_total_duration,    /* is_connect */
                         pg_time_usec_t conn_elapsed_duration,  /* !is_connect */
                         int64 latency_late)
{
        /* tps is about actually executed transactions during benchmarking */
        int64           failures = getFailures(total);
        int64           total_cnt = total->cnt + total->skipped + failures;
        double          bench_duration = PG_TIME_GET_DOUBLE(total_duration);
        double          tps = total->cnt / bench_duration;

        /* Report test parameters. */
        printf("transaction type: %s\n",
                   num_scripts == 1 ? sql_script[0].desc : "multiple scripts");
        printf("scaling factor: %d\n", scale);
        /* only print partitioning information if some partitioning was detected */
        if (partition_method != PART_NONE)
                printf("partition method: %s\npartitions: %d\n",
                           PARTITION_METHOD[partition_method], partitions);
        printf("query mode: %s\n", QUERYMODE[querymode]);
        printf("number of clients: %d\n", nclients);
        printf("number of threads: %d\n", nthreads);

        if (max_tries)
                printf("maximum number of tries: %u\n", max_tries);

        if (duration <= 0)
        {
                printf("number of transactions per client: %d\n", nxacts);
                printf("number of transactions actually processed: " INT64_FORMAT "/%d\n",
                           total->cnt, nxacts * nclients);
        }
        else
        {
                printf("duration: %d s\n", duration);
                printf("number of transactions actually processed: " INT64_FORMAT "\n",
                           total->cnt);
        }

        printf("number of failed transactions: " INT64_FORMAT " (%.3f%%)\n",
                   failures, 100.0 * failures / total_cnt);

        if (failures_detailed)
        {
                printf("number of serialization failures: " INT64_FORMAT " (%.3f%%)\n",
                           total->serialization_failures,
                           100.0 * total->serialization_failures / total_cnt);
                printf("number of deadlock failures: " INT64_FORMAT " (%.3f%%)\n",
                           total->deadlock_failures,
                           100.0 * total->deadlock_failures / total_cnt);
        }

        /* it can be non-zero only if max_tries is not equal to one */
        if (max_tries != 1)
        {
                printf("number of transactions retried: " INT64_FORMAT " (%.3f%%)\n",
                           total->retried, 100.0 * total->retried / total_cnt);
                printf("total number of retries: " INT64_FORMAT "\n", total->retries);
        }

        /* Remaining stats are nonsensical if we failed to execute any xacts */
        if (total->cnt + total->skipped <= 0)
                return;

        if (throttle_delay && latency_limit)
                printf("number of transactions skipped: " INT64_FORMAT " (%.3f%%)\n",
                           total->skipped, 100.0 * total->skipped / total_cnt);

        if (latency_limit)
                printf("number of transactions above the %.1f ms latency limit: " INT64_FORMAT "/" INT64_FORMAT " (%.3f%%)\n",
                           latency_limit / 1000.0, latency_late, total->cnt,
                           (total->cnt > 0) ? 100.0 * latency_late / total->cnt : 0.0);

        if (throttle_delay || progress || latency_limit)
                printSimpleStats("latency", &total->latency);
        else
        {
                /* no measurement, show average latency computed from run time */
                printf("latency average = %.3f ms%s\n",
                           0.001 * total_duration * nclients / total_cnt,
                           failures > 0 ? " (including failures)" : "");
        }

        if (throttle_delay)
        {
                /*
                 * Report average transaction lag under rate limit throttling.  This
                 * is the delay between scheduled and actual start times for the
                 * transaction.  The measured lag may be caused by thread/client load,
                 * the database load, or the Poisson throttling process.
                 */
                printf("rate limit schedule lag: avg %.3f (max %.3f) ms\n",
                           0.001 * total->lag.sum / total->cnt, 0.001 * total->lag.max);
        }

        /*
         * Under -C/--connect, each transaction incurs a significant connection
         * cost, it would not make much sense to ignore it in tps, and it would
         * not be tps anyway.
         *
         * Otherwise connections are made just once at the beginning of the run
         * and should not impact performance but for very short run, so they are
         * (right)fully ignored in tps.
         */
        if (is_connect)
        {
                printf("average connection time = %.3f ms\n", 0.001 * conn_total_duration / (total->cnt + failures));
                printf("tps = %f (including reconnection times)\n", tps);
        }
        else
        {
                printf("initial connection time = %.3f ms\n", 0.001 * conn_elapsed_duration);
                printf("tps = %f (without initial connection time)\n", tps);
        }

        /* Report per-script/command statistics */
        if (per_script_stats || report_per_command)
        {
                int                     i;

                for (i = 0; i < num_scripts; i++)
                {
                        if (per_script_stats)
                        {
                                StatsData  *sstats = &sql_script[i].stats;
                                int64           script_failures = getFailures(sstats);
                                int64           script_total_cnt =
                                        sstats->cnt + sstats->skipped + script_failures;

                                printf("SQL script %d: %s\n"
                                           " - weight: %d (targets %.1f%% of total)\n"
                                           " - " INT64_FORMAT " transactions (%.1f%% of total, tps = %f)\n",
                                           i + 1, sql_script[i].desc,
                                           sql_script[i].weight,
                                           100.0 * sql_script[i].weight / total_weight,
                                           sstats->cnt,
                                           100.0 * sstats->cnt / total->cnt,
                                           sstats->cnt / bench_duration);

                                printf(" - number of failed transactions: " INT64_FORMAT " (%.3f%%)\n",
                                           script_failures,
                                           100.0 * script_failures / script_total_cnt);

                                if (failures_detailed)
                                {
                                        printf(" - number of serialization failures: " INT64_FORMAT " (%.3f%%)\n",
                                                   sstats->serialization_failures,
                                                   (100.0 * sstats->serialization_failures /
                                                        script_total_cnt));
                                        printf(" - number of deadlock failures: " INT64_FORMAT " (%.3f%%)\n",
                                                   sstats->deadlock_failures,
                                                   (100.0 * sstats->deadlock_failures /
                                                        script_total_cnt));
                                }

                                /* it can be non-zero only if max_tries is not equal to one */
                                if (max_tries != 1)
                                {
                                        printf(" - number of transactions retried: " INT64_FORMAT " (%.3f%%)\n",
                                                   sstats->retried,
                                                   100.0 * sstats->retried / script_total_cnt);
                                        printf(" - total number of retries: " INT64_FORMAT "\n",
                                                   sstats->retries);
                                }

                                if (throttle_delay && latency_limit && script_total_cnt > 0)
                                        printf(" - number of transactions skipped: " INT64_FORMAT " (%.3f%%)\n",
                                                   sstats->skipped,
                                                   100.0 * sstats->skipped / script_total_cnt);

                                printSimpleStats(" - latency", &sstats->latency);
                        }

                        /*
                         * Report per-command statistics: latencies, retries after errors,
                         * failures (errors without retrying).
                         */
                        if (report_per_command)
                        {
                                Command   **commands;

                                printf("%sstatement latencies in milliseconds%s:\n",
                                           per_script_stats ? " - " : "",
                                           (max_tries == 1 ?
                                                " and failures" :
                                                ", failures and retries"));

                                for (commands = sql_script[i].commands;
                                         *commands != NULL;
                                         commands++)
                                {
                                        SimpleStats *cstats = &(*commands)->stats;

                                        if (max_tries == 1)
                                                printf("   %11.3f  %10" INT64_MODIFIER "d  %s\n",
                                                           (cstats->count > 0) ?
                                                           1000.0 * cstats->sum / cstats->count : 0.0,
                                                           (*commands)->failures,
                                                           (*commands)->first_line);
                                        else
                                                printf("   %11.3f  %10" INT64_MODIFIER "d  %10" INT64_MODIFIER "d  %s\n",
                                                           (cstats->count > 0) ?
                                                           1000.0 * cstats->sum / cstats->count : 0.0,
                                                           (*commands)->failures,
                                                           (*commands)->retries,
                                                           (*commands)->first_line);
                                }
                        }
                }
        }
}

/*
 * Set up a random seed according to seed parameter (NULL means default),
 * and initialize base_random_sequence for use in initializing other sequences.
 */
static bool
set_random_seed(const char *seed)
{
        uint64          iseed;

        if (seed == NULL || strcmp(seed, "time") == 0)
        {
                /* rely on current time */
                iseed = pg_time_now();
        }
        else if (strcmp(seed, "rand") == 0)
        {
                /* use some "strong" random source */
                if (!pg_strong_random(&iseed, sizeof(iseed)))
                {
                        pg_log_error("could not generate random seed");
                        return false;
                }
        }
        else
        {
                /* parse unsigned-int seed value */
                unsigned long ulseed;
                char            garbage;

                /* Don't try to use UINT64_FORMAT here; it might not work for sscanf */
                if (sscanf(seed, "%lu%c", &ulseed, &garbage) != 1)
                {
                        pg_log_error("unrecognized random seed option \"%s\"", seed);
                        pg_log_error_detail("Expecting an unsigned integer, \"time\" or \"rand\".");
                        return false;
                }
                iseed = (uint64) ulseed;
        }

        if (seed != NULL)
                pg_log_info("setting random seed to %llu", (unsigned long long) iseed);

        random_seed = iseed;

        /* Initialize base_random_sequence using seed */
        pg_prng_seed(&base_random_sequence, (uint64) iseed);

        return true;
}

int
main(int argc, char **argv)
{
        static struct option long_options[] = {
                /* systematic long/short named options */
                {"builtin", required_argument, NULL, 'b'},
                {"client", required_argument, NULL, 'c'},
                {"connect", no_argument, NULL, 'C'},
                {"debug", no_argument, NULL, 'd'},
                {"define", required_argument, NULL, 'D'},
                {"file", required_argument, NULL, 'f'},
                {"fillfactor", required_argument, NULL, 'F'},
                {"host", required_argument, NULL, 'h'},
                {"initialize", no_argument, NULL, 'i'},
                {"init-steps", required_argument, NULL, 'I'},
                {"jobs", required_argument, NULL, 'j'},
                {"log", no_argument, NULL, 'l'},
                {"latency-limit", required_argument, NULL, 'L'},
                {"no-vacuum", no_argument, NULL, 'n'},
                {"port", required_argument, NULL, 'p'},
                {"progress", required_argument, NULL, 'P'},
                {"protocol", required_argument, NULL, 'M'},
                {"quiet", no_argument, NULL, 'q'},
                {"report-per-command", no_argument, NULL, 'r'},
                {"rate", required_argument, NULL, 'R'},
                {"scale", required_argument, NULL, 's'},
                {"select-only", no_argument, NULL, 'S'},
                {"skip-some-updates", no_argument, NULL, 'N'},
                {"time", required_argument, NULL, 'T'},
                {"transactions", required_argument, NULL, 't'},
                {"username", required_argument, NULL, 'U'},
                {"vacuum-all", no_argument, NULL, 'v'},
                /* long-named only options */
                {"unlogged-tables", no_argument, NULL, 1},
                {"tablespace", required_argument, NULL, 2},
                {"index-tablespace", required_argument, NULL, 3},
                {"sampling-rate", required_argument, NULL, 4},
                {"aggregate-interval", required_argument, NULL, 5},
                {"progress-timestamp", no_argument, NULL, 6},
                {"log-prefix", required_argument, NULL, 7},
                {"foreign-keys", no_argument, NULL, 8},
                {"random-seed", required_argument, NULL, 9},
                {"show-script", required_argument, NULL, 10},
                {"partitions", required_argument, NULL, 11},
                {"partition-method", required_argument, NULL, 12},
                {"failures-detailed", no_argument, NULL, 13},
                {"max-tries", required_argument, NULL, 14},
                {"verbose-errors", no_argument, NULL, 15},
                {"exit-on-abort", no_argument, NULL, 16},
                {NULL, 0, NULL, 0}
        };

        int                     c;
        bool            is_init_mode = false;   /* initialize mode? */
        char       *initialize_steps = NULL;
        bool            foreign_keys = false;
        bool            is_no_vacuum = false;
        bool            do_vacuum_accounts = false; /* vacuum accounts table? */
        int                     optindex;
        bool            scale_given = false;

        bool            benchmarking_option_set = false;
        bool            initialization_option_set = false;
        bool            internal_script_used = false;

        CState     *state;                      /* status of clients */
        TState     *threads;            /* array of thread */

        pg_time_usec_t
                                start_time,             /* start up time */
                                bench_start = 0,        /* first recorded benchmarking time */
                                conn_total_duration;    /* cumulated connection time in
                                                                                 * threads */
        int64           latency_late = 0;
        StatsData       stats;
        int                     weight;

        int                     i;
        int                     nclients_dealt;

#ifdef HAVE_GETRLIMIT
        struct rlimit rlim;
#endif

        PGconn     *con;
        char       *env;

        int                     exit_code = 0;
        struct timeval tv;

        /*
         * Record difference between Unix time and instr_time time.  We'll use
         * this for logging and aggregation.
         */
        gettimeofday(&tv, NULL);
        epoch_shift = tv.tv_sec * INT64CONST(1000000) + tv.tv_usec - pg_time_now();

        pg_logging_init(argv[0]);
        progname = get_progname(argv[0]);

        if (argc > 1)
        {
                if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
                {
                        usage();
                        exit(0);
                }
                if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
                {
                        puts("pgbench (PostgreSQL) " PG_VERSION);
                        exit(0);
                }
        }

        state = (CState *) pg_malloc0(sizeof(CState));

        /* set random seed early, because it may be used while parsing scripts. */
        if (!set_random_seed(getenv("PGBENCH_RANDOM_SEED")))
                pg_fatal("error while setting random seed from PGBENCH_RANDOM_SEED environment variable");

        while ((c = getopt_long(argc, argv, "b:c:CdD:f:F:h:iI:j:lL:M:nNp:P:qrR:s:St:T:U:v", long_options, &optindex)) != -1)
        {
                char       *script;

                switch (c)
                {
                        case 'b':
                                if (strcmp(optarg, "list") == 0)
                                {
                                        listAvailableScripts();
                                        exit(0);
                                }
                                weight = parseScriptWeight(optarg, &script);
                                process_builtin(findBuiltin(script), weight);
                                benchmarking_option_set = true;
                                internal_script_used = true;
                                break;
                        case 'c':
                                benchmarking_option_set = true;
                                if (!option_parse_int(optarg, "-c/--clients", 1, INT_MAX,
                                                                          &nclients))
                                {
                                        exit(1);
                                }
#ifdef HAVE_GETRLIMIT
                                if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
                                        pg_fatal("getrlimit failed: %m");
                                if (rlim.rlim_cur < nclients + 3)
                                {
                                        pg_log_error("need at least %d open files, but system limit is %ld",
                                                                 nclients + 3, (long) rlim.rlim_cur);
                                        pg_log_error_hint("Reduce number of clients, or use limit/ulimit to increase the system limit.");
                                        exit(1);
                                }
#endif                                                  /* HAVE_GETRLIMIT */
                                break;
                        case 'C':
                                benchmarking_option_set = true;
                                is_connect = true;
                                break;
                        case 'd':
                                pg_logging_increase_verbosity();
                                break;
                        case 'D':
                                {
                                        char       *p;

                                        benchmarking_option_set = true;

                                        if ((p = strchr(optarg, '=')) == NULL || p == optarg || *(p + 1) == '\0')
                                                pg_fatal("invalid variable definition: \"%s\"", optarg);

                                        *p++ = '\0';
                                        if (!putVariable(&state[0].variables, "option", optarg, p))
                                                exit(1);
                                }
                                break;
                        case 'f':
                                weight = parseScriptWeight(optarg, &script);
                                process_file(script, weight);
                                benchmarking_option_set = true;
                                break;
                        case 'F':
                                initialization_option_set = true;
                                if (!option_parse_int(optarg, "-F/--fillfactor", 10, 100,
                                                                          &fillfactor))
                                        exit(1);
                                break;
                        case 'h':
                                pghost = pg_strdup(optarg);
                                break;
                        case 'i':
                                is_init_mode = true;
                                break;
                        case 'I':
                                pg_free(initialize_steps);
                                initialize_steps = pg_strdup(optarg);
                                checkInitSteps(initialize_steps);
                                initialization_option_set = true;
                                break;
                        case 'j':                       /* jobs */
                                benchmarking_option_set = true;
                                if (!option_parse_int(optarg, "-j/--jobs", 1, INT_MAX,
                                                                          &nthreads))
                                {
                                        exit(1);
                                }
                                break;
                        case 'l':
                                benchmarking_option_set = true;
                                use_log = true;
                                break;
                        case 'L':
                                {
                                        double          limit_ms = atof(optarg);

                                        if (limit_ms <= 0.0)
                                                pg_fatal("invalid latency limit: \"%s\"", optarg);
                                        benchmarking_option_set = true;
                                        latency_limit = (int64) (limit_ms * 1000);
                                }
                                break;
                        case 'M':
                                benchmarking_option_set = true;
                                for (querymode = 0; querymode < NUM_QUERYMODE; querymode++)
                                        if (strcmp(optarg, QUERYMODE[querymode]) == 0)
                                                break;
                                if (querymode >= NUM_QUERYMODE)
                                        pg_fatal("invalid query mode (-M): \"%s\"", optarg);
                                break;
                        case 'n':
                                is_no_vacuum = true;
                                break;
                        case 'N':
                                process_builtin(findBuiltin("simple-update"), 1);
                                benchmarking_option_set = true;
                                internal_script_used = true;
                                break;
                        case 'p':
                                pgport = pg_strdup(optarg);
                                break;
                        case 'P':
                                benchmarking_option_set = true;
                                if (!option_parse_int(optarg, "-P/--progress", 1, INT_MAX,
                                                                          &progress))
                                        exit(1);
                                break;
                        case 'q':
                                initialization_option_set = true;
                                use_quiet = true;
                                break;
                        case 'r':
                                benchmarking_option_set = true;
                                report_per_command = true;
                                break;
                        case 'R':
                                {
                                        /* get a double from the beginning of option value */
                                        double          throttle_value = atof(optarg);

                                        benchmarking_option_set = true;

                                        if (throttle_value <= 0.0)
                                                pg_fatal("invalid rate limit: \"%s\"", optarg);
                                        /* Invert rate limit into per-transaction delay in usec */
                                        throttle_delay = 1000000.0 / throttle_value;
                                }
                                break;
                        case 's':
                                scale_given = true;
                                if (!option_parse_int(optarg, "-s/--scale", 1, INT_MAX,
                                                                          &scale))
                                        exit(1);
                                break;
                        case 'S':
                                process_builtin(findBuiltin("select-only"), 1);
                                benchmarking_option_set = true;
                                internal_script_used = true;
                                break;
                        case 't':
                                benchmarking_option_set = true;
                                if (!option_parse_int(optarg, "-t/--transactions", 1, INT_MAX,
                                                                          &nxacts))
                                        exit(1);
                                break;
                        case 'T':
                                benchmarking_option_set = true;
                                if (!option_parse_int(optarg, "-T/--time", 1, INT_MAX,
                                                                          &duration))
                                        exit(1);
                                break;
                        case 'U':
                                username = pg_strdup(optarg);
                                break;
                        case 'v':
                                benchmarking_option_set = true;
                                do_vacuum_accounts = true;
                                break;
                        case 1:                         /* unlogged-tables */
                                initialization_option_set = true;
                                unlogged_tables = true;
                                break;
                        case 2:                         /* tablespace */
                                initialization_option_set = true;
                                tablespace = pg_strdup(optarg);
                                break;
                        case 3:                         /* index-tablespace */
                                initialization_option_set = true;
                                index_tablespace = pg_strdup(optarg);
                                break;
                        case 4:                         /* sampling-rate */
                                benchmarking_option_set = true;
                                sample_rate = atof(optarg);
                                if (sample_rate <= 0.0 || sample_rate > 1.0)
                                        pg_fatal("invalid sampling rate: \"%s\"", optarg);
                                break;
                        case 5:                         /* aggregate-interval */
                                benchmarking_option_set = true;
                                if (!option_parse_int(optarg, "--aggregate-interval", 1, INT_MAX,
                                                                          &agg_interval))
                                        exit(1);
                                break;
                        case 6:                         /* progress-timestamp */
                                progress_timestamp = true;
                                benchmarking_option_set = true;
                                break;
                        case 7:                         /* log-prefix */
                                benchmarking_option_set = true;
                                logfile_prefix = pg_strdup(optarg);
                                break;
                        case 8:                         /* foreign-keys */
                                initialization_option_set = true;
                                foreign_keys = true;
                                break;
                        case 9:                         /* random-seed */
                                benchmarking_option_set = true;
                                if (!set_random_seed(optarg))
                                        pg_fatal("error while setting random seed from --random-seed option");
                                break;
                        case 10:                        /* list */
                                {
                                        const BuiltinScript *s = findBuiltin(optarg);

                                        fprintf(stderr, "-- %s: %s\n%s\n", s->name, s->desc, s->script);
                                        exit(0);
                                }
                                break;
                        case 11:                        /* partitions */
                                initialization_option_set = true;
                                if (!option_parse_int(optarg, "--partitions", 0, INT_MAX,
                                                                          &partitions))
                                        exit(1);
                                break;
                        case 12:                        /* partition-method */
                                initialization_option_set = true;
                                if (pg_strcasecmp(optarg, "range") == 0)
                                        partition_method = PART_RANGE;
                                else if (pg_strcasecmp(optarg, "hash") == 0)
                                        partition_method = PART_HASH;
                                else
                                        pg_fatal("invalid partition method, expecting \"range\" or \"hash\", got: \"%s\"",
                                                         optarg);
                                break;
                        case 13:                        /* failures-detailed */
                                benchmarking_option_set = true;
                                failures_detailed = true;
                                break;
                        case 14:                        /* max-tries */
                                {
                                        int32           max_tries_arg = atoi(optarg);

                                        if (max_tries_arg < 0)
                                                pg_fatal("invalid number of maximum tries: \"%s\"", optarg);

                                        benchmarking_option_set = true;
                                        max_tries = (uint32) max_tries_arg;
                                }
                                break;
                        case 15:                        /* verbose-errors */
                                benchmarking_option_set = true;
                                verbose_errors = true;
                                break;
                        case 16:                        /* exit-on-abort */
                                benchmarking_option_set = true;
                                exit_on_abort = true;
                                break;
                        default:
                                /* getopt_long already emitted a complaint */
                                pg_log_error_hint("Try \"%s --help\" for more information.", progname);
                                exit(1);
                }
        }

        /* set default script if none */
        if (num_scripts == 0 && !is_init_mode)
        {
                process_builtin(findBuiltin("tpcb-like"), 1);
                benchmarking_option_set = true;
                internal_script_used = true;
        }

        /* complete SQL command initialization and compute total weight */
        for (i = 0; i < num_scripts; i++)
        {
                Command   **commands = sql_script[i].commands;

                for (int j = 0; commands[j] != NULL; j++)
                        if (commands[j]->type == SQL_COMMAND)
                                postprocess_sql_command(commands[j]);

                /* cannot overflow: weight is 32b, total_weight 64b */
                total_weight += sql_script[i].weight;
        }

        if (total_weight == 0 && !is_init_mode)
                pg_fatal("total script weight must not be zero");

        /* show per script stats if several scripts are used */
        if (num_scripts > 1)
                per_script_stats = true;

        /*
         * Don't need more threads than there are clients.  (This is not merely an
         * optimization; throttle_delay is calculated incorrectly below if some
         * threads have no clients assigned to them.)
         */
        if (nthreads > nclients)
                nthreads = nclients;

        /*
         * Convert throttle_delay to a per-thread delay time.  Note that this
         * might be a fractional number of usec, but that's OK, since it's just
         * the center of a Poisson distribution of delays.
         */
        throttle_delay *= nthreads;

        if (argc > optind)
                dbName = argv[optind++];
        else
        {
                if ((env = getenv("PGDATABASE")) != NULL && *env != '\0')
                        dbName = env;
                else if ((env = getenv("PGUSER")) != NULL && *env != '\0')
                        dbName = env;
                else
                        dbName = get_user_name_or_exit(progname);
        }

        if (optind < argc)
        {
                pg_log_error("too many command-line arguments (first is \"%s\")",
                                         argv[optind]);
                pg_log_error_hint("Try \"%s --help\" for more information.", progname);
                exit(1);
        }

        if (is_init_mode)
        {
                if (benchmarking_option_set)
                        pg_fatal("some of the specified options cannot be used in initialization (-i) mode");

                if (partitions == 0 && partition_method != PART_NONE)
                        pg_fatal("--partition-method requires greater than zero --partitions");

                /* set default method */
                if (partitions > 0 && partition_method == PART_NONE)
                        partition_method = PART_RANGE;

                if (initialize_steps == NULL)
                        initialize_steps = pg_strdup(DEFAULT_INIT_STEPS);

                if (is_no_vacuum)
                {
                        /* Remove any vacuum step in initialize_steps */
                        char       *p;

                        while ((p = strchr(initialize_steps, 'v')) != NULL)
                                *p = ' ';
                }

                if (foreign_keys)
                {
                        /* Add 'f' to end of initialize_steps, if not already there */
                        if (strchr(initialize_steps, 'f') == NULL)
                        {
                                initialize_steps = (char *)
                                        pg_realloc(initialize_steps,
                                                           strlen(initialize_steps) + 2);
                                strcat(initialize_steps, "f");
                        }
                }

                runInitSteps(initialize_steps);
                exit(0);
        }
        else
        {
                if (initialization_option_set)
                        pg_fatal("some of the specified options cannot be used in benchmarking mode");
        }

        if (nxacts > 0 && duration > 0)
                pg_fatal("specify either a number of transactions (-t) or a duration (-T), not both");

        /* Use DEFAULT_NXACTS if neither nxacts nor duration is specified. */
        if (nxacts <= 0 && duration <= 0)
                nxacts = DEFAULT_NXACTS;

        /* --sampling-rate may be used only with -l */
        if (sample_rate > 0.0 && !use_log)
                pg_fatal("log sampling (--sampling-rate) is allowed only when logging transactions (-l)");

        /* --sampling-rate may not be used with --aggregate-interval */
        if (sample_rate > 0.0 && agg_interval > 0)
                pg_fatal("log sampling (--sampling-rate) and aggregation (--aggregate-interval) cannot be used at the same time");

        if (agg_interval > 0 && !use_log)
                pg_fatal("log aggregation is allowed only when actually logging transactions");

        if (!use_log && logfile_prefix)
                pg_fatal("log file prefix (--log-prefix) is allowed only when logging transactions (-l)");

        if (duration > 0 && agg_interval > duration)
                pg_fatal("number of seconds for aggregation (%d) must not be higher than test duration (%d)", agg_interval, duration);

        if (duration > 0 && agg_interval > 0 && duration % agg_interval != 0)
                pg_fatal("duration (%d) must be a multiple of aggregation interval (%d)", duration, agg_interval);

        if (progress_timestamp && progress == 0)
                pg_fatal("--progress-timestamp is allowed only under --progress");

        if (!max_tries)
        {
                if (!latency_limit && duration <= 0)
                        pg_fatal("an unlimited number of transaction tries can only be used with --latency-limit or a duration (-T)");
        }

        /*
         * save main process id in the global variable because process id will be
         * changed after fork.
         */
        main_pid = (int) getpid();

        if (nclients > 1)
        {
                state = (CState *) pg_realloc(state, sizeof(CState) * nclients);
                memset(state + 1, 0, sizeof(CState) * (nclients - 1));

                /* copy any -D switch values to all clients */
                for (i = 1; i < nclients; i++)
                {
                        int                     j;

                        state[i].id = i;
                        for (j = 0; j < state[0].variables.nvars; j++)
                        {
                                Variable   *var = &state[0].variables.vars[j];

                                if (var->value.type != PGBT_NO_VALUE)
                                {
                                        if (!putVariableValue(&state[i].variables, "startup",
                                                                                  var->name, &var->value))
                                                exit(1);
                                }
                                else
                                {
                                        if (!putVariable(&state[i].variables, "startup",
                                                                         var->name, var->svalue))
                                                exit(1);
                                }
                        }
                }
        }

        /* other CState initializations */
        for (i = 0; i < nclients; i++)
        {
                state[i].cstack = conditional_stack_create();
                initRandomState(&state[i].cs_func_rs);
        }

        /* opening connection... */
        con = doConnect();
        if (con == NULL)
                pg_fatal("could not create connection for setup");

        /* report pgbench and server versions */
        printVersion(con);

        pg_log_debug("pghost: %s pgport: %s nclients: %d %s: %d dbName: %s",
                                 PQhost(con), PQport(con), nclients,
                                 duration <= 0 ? "nxacts" : "duration",
                                 duration <= 0 ? nxacts : duration, PQdb(con));

        if (internal_script_used)
                GetTableInfo(con, scale_given);

        /*
         * :scale variables normally get -s or database scale, but don't override
         * an explicit -D switch
         */
        if (lookupVariable(&state[0].variables, "scale") == NULL)
        {
                for (i = 0; i < nclients; i++)
                {
                        if (!putVariableInt(&state[i].variables, "startup", "scale", scale))
                                exit(1);
                }
        }

        /*
         * Define a :client_id variable that is unique per connection. But don't
         * override an explicit -D switch.
         */
        if (lookupVariable(&state[0].variables, "client_id") == NULL)
        {
                for (i = 0; i < nclients; i++)
                        if (!putVariableInt(&state[i].variables, "startup", "client_id", i))
                                exit(1);
        }

        /* set default seed for hash functions */
        if (lookupVariable(&state[0].variables, "default_seed") == NULL)
        {
                uint64          seed = pg_prng_uint64(&base_random_sequence);

                for (i = 0; i < nclients; i++)
                        if (!putVariableInt(&state[i].variables, "startup", "default_seed",
                                                                (int64) seed))
                                exit(1);
        }

        /* set random seed unless overwritten */
        if (lookupVariable(&state[0].variables, "random_seed") == NULL)
        {
                for (i = 0; i < nclients; i++)
                        if (!putVariableInt(&state[i].variables, "startup", "random_seed",
                                                                random_seed))
                                exit(1);
        }

        if (!is_no_vacuum)
        {
                fprintf(stderr, "starting vacuum...");
                tryExecuteStatement(con, "vacuum pgbench_branches");
                tryExecuteStatement(con, "vacuum pgbench_tellers");
                tryExecuteStatement(con, "truncate pgbench_history");
                fprintf(stderr, "end.\n");

                if (do_vacuum_accounts)
                {
                        fprintf(stderr, "starting vacuum pgbench_accounts...");
                        tryExecuteStatement(con, "vacuum analyze pgbench_accounts");
                        fprintf(stderr, "end.\n");
                }
        }
        PQfinish(con);

        /* set up thread data structures */
        threads = (TState *) pg_malloc(sizeof(TState) * nthreads);
        nclients_dealt = 0;

        for (i = 0; i < nthreads; i++)
        {
                TState     *thread = &threads[i];

                thread->tid = i;
                thread->state = &state[nclients_dealt];
                thread->nstate =
                        (nclients - nclients_dealt + nthreads - i - 1) / (nthreads - i);
                initRandomState(&thread->ts_choose_rs);
                initRandomState(&thread->ts_throttle_rs);
                initRandomState(&thread->ts_sample_rs);
                thread->logfile = NULL; /* filled in later */
                thread->latency_late = 0;
                initStats(&thread->stats, 0);

                nclients_dealt += thread->nstate;
        }

        /* all clients must be assigned to a thread */
        Assert(nclients_dealt == nclients);

        /* get start up time for the whole computation */
        start_time = pg_time_now();

        /* set alarm if duration is specified. */
        if (duration > 0)
                setalarm(duration);

        errno = THREAD_BARRIER_INIT(&barrier, nthreads);
        if (errno != 0)
                pg_fatal("could not initialize barrier: %m");

        /* start all threads but thread 0 which is executed directly later */
        for (i = 1; i < nthreads; i++)
        {
                TState     *thread = &threads[i];

                thread->create_time = pg_time_now();
                errno = THREAD_CREATE(&thread->thread, threadRun, thread);

                if (errno != 0)
                        pg_fatal("could not create thread: %m");
        }

        /* compute when to stop */
        threads[0].create_time = pg_time_now();
        if (duration > 0)
                end_time = threads[0].create_time + (int64) 1000000 * duration;

        /* run thread 0 directly */
        (void) threadRun(&threads[0]);

        /* wait for other threads and accumulate results */
        initStats(&stats, 0);
        conn_total_duration = 0;

        for (i = 0; i < nthreads; i++)
        {
                TState     *thread = &threads[i];

                if (i > 0)
                        THREAD_JOIN(thread->thread);

                for (int j = 0; j < thread->nstate; j++)
                        if (thread->state[j].state != CSTATE_FINISHED)
                                exit_code = 2;

                /* aggregate thread level stats */
                mergeSimpleStats(&stats.latency, &thread->stats.latency);
                mergeSimpleStats(&stats.lag, &thread->stats.lag);
                stats.cnt += thread->stats.cnt;
                stats.skipped += thread->stats.skipped;
                stats.retries += thread->stats.retries;
                stats.retried += thread->stats.retried;
                stats.serialization_failures += thread->stats.serialization_failures;
                stats.deadlock_failures += thread->stats.deadlock_failures;
                latency_late += thread->latency_late;
                conn_total_duration += thread->conn_duration;

                /* first recorded benchmarking start time */
                if (bench_start == 0 || thread->bench_start < bench_start)
                        bench_start = thread->bench_start;
        }

        /*
         * All connections should be already closed in threadRun(), so this
         * disconnect_all() will be a no-op, but clean up the connections just to
         * be sure. We don't need to measure the disconnection delays here.
         */
        disconnect_all(state, nclients);

        /*
         * Beware that performance of short benchmarks with many threads and
         * possibly long transactions can be deceptive because threads do not
         * start and finish at the exact same time. The total duration computed
         * here encompasses all transactions so that tps shown is somehow slightly
         * underestimated.
         */
        printResults(&stats, pg_time_now() - bench_start, conn_total_duration,
                                 bench_start - start_time, latency_late);

        THREAD_BARRIER_DESTROY(&barrier);

        if (exit_code != 0)
                pg_log_error("Run was aborted; the above results are incomplete.");

        return exit_code;
}

static THREAD_FUNC_RETURN_TYPE THREAD_FUNC_CC
threadRun(void *arg)
{
        TState     *thread = (TState *) arg;
        CState     *state = thread->state;
        pg_time_usec_t start;
        int                     nstate = thread->nstate;
        int                     remains = nstate;       /* number of remaining clients */
        socket_set *sockets = alloc_socket_set(nstate);
        int64           thread_start,
                                last_report,
                                next_report;
        StatsData       last,
                                aggs;

        /* open log file if requested */
        if (use_log)
        {
                char            logpath[MAXPGPATH];
                char       *prefix = logfile_prefix ? logfile_prefix : "pgbench_log";

                if (thread->tid == 0)
                        snprintf(logpath, sizeof(logpath), "%s.%d", prefix, main_pid);
                else
                        snprintf(logpath, sizeof(logpath), "%s.%d.%d", prefix, main_pid, thread->tid);

                thread->logfile = fopen(logpath, "w");

                if (thread->logfile == NULL)
                        pg_fatal("could not open logfile \"%s\": %m", logpath);
        }

        /* explicitly initialize the state machines */
        for (int i = 0; i < nstate; i++)
                state[i].state = CSTATE_CHOOSE_SCRIPT;

        /* READY */
        THREAD_BARRIER_WAIT(&barrier);

        thread_start = pg_time_now();
        thread->started_time = thread_start;
        thread->conn_duration = 0;
        last_report = thread_start;
        next_report = last_report + (int64) 1000000 * progress;

        /* STEADY */
        if (!is_connect)
        {
                /* make connections to the database before starting */
                for (int i = 0; i < nstate; i++)
                {
                        if ((state[i].con = doConnect()) == NULL)
                        {
                                /* coldly abort on initial connection failure */
                                pg_fatal("could not create connection for client %d",
                                                 state[i].id);
                        }
                }
        }

        /* GO */
        THREAD_BARRIER_WAIT(&barrier);

        start = pg_time_now();
        thread->bench_start = start;
        thread->throttle_trigger = start;

        /*
         * The log format currently has Unix epoch timestamps with whole numbers
         * of seconds.  Round the first aggregate's start time down to the nearest
         * Unix epoch second (the very first aggregate might really have started a
         * fraction of a second later, but later aggregates are measured from the
         * whole number time that is actually logged).
         */
        initStats(&aggs, (start + epoch_shift) / 1000000 * 1000000);
        last = aggs;

        /* loop till all clients have terminated */
        while (remains > 0)
        {
                int                     nsocks;         /* number of sockets to be waited for */
                pg_time_usec_t min_usec;
                pg_time_usec_t now = 0; /* set this only if needed */

                /*
                 * identify which client sockets should be checked for input, and
                 * compute the nearest time (if any) at which we need to wake up.
                 */
                clear_socket_set(sockets);
                nsocks = 0;
                min_usec = PG_INT64_MAX;
                for (int i = 0; i < nstate; i++)
                {
                        CState     *st = &state[i];

                        if (st->state == CSTATE_SLEEP || st->state == CSTATE_THROTTLE)
                        {
                                /* a nap from the script, or under throttling */
                                pg_time_usec_t this_usec;

                                /* get current time if needed */
                                pg_time_now_lazy(&now);

                                /* min_usec should be the minimum delay across all clients */
                                this_usec = (st->state == CSTATE_SLEEP ?
                                                         st->sleep_until : st->txn_scheduled) - now;
                                if (min_usec > this_usec)
                                        min_usec = this_usec;
                        }
                        else if (st->state == CSTATE_WAIT_RESULT ||
                                         st->state == CSTATE_WAIT_ROLLBACK_RESULT)
                        {
                                /*
                                 * waiting for result from server - nothing to do unless the
                                 * socket is readable
                                 */
                                int                     sock = PQsocket(st->con);

                                if (sock < 0)
                                {
                                        pg_log_error("invalid socket: %s", PQerrorMessage(st->con));
                                        goto done;
                                }

                                add_socket_to_set(sockets, sock, nsocks++);
                        }
                        else if (st->state != CSTATE_ABORTED &&
                                         st->state != CSTATE_FINISHED)
                        {
                                /*
                                 * This client thread is ready to do something, so we don't
                                 * want to wait.  No need to examine additional clients.
                                 */
                                min_usec = 0;
                                break;
                        }
                }

                /* also wake up to print the next progress report on time */
                if (progress && min_usec > 0 && thread->tid == 0)
                {
                        pg_time_now_lazy(&now);

                        if (now >= next_report)
                                min_usec = 0;
                        else if ((next_report - now) < min_usec)
                                min_usec = next_report - now;
                }

                /*
                 * If no clients are ready to execute actions, sleep until we receive
                 * data on some client socket or the timeout (if any) elapses.
                 */
                if (min_usec > 0)
                {
                        int                     rc = 0;

                        if (min_usec != PG_INT64_MAX)
                        {
                                if (nsocks > 0)
                                {
                                        rc = wait_on_socket_set(sockets, min_usec);
                                }
                                else                    /* nothing active, simple sleep */
                                {
                                        pg_usleep(min_usec);
                                }
                        }
                        else                            /* no explicit delay, wait without timeout */
                        {
                                rc = wait_on_socket_set(sockets, 0);
                        }

                        if (rc < 0)
                        {
                                if (errno == EINTR)
                                {
                                        /* On EINTR, go back to top of loop */
                                        continue;
                                }
                                /* must be something wrong */
                                pg_log_error("%s() failed: %m", SOCKET_WAIT_METHOD);
                                goto done;
                        }
                }
                else
                {
                        /* min_usec <= 0, i.e. something needs to be executed now */

                        /* If we didn't wait, don't try to read any data */
                        clear_socket_set(sockets);
                }

                /* ok, advance the state machine of each connection */
                nsocks = 0;
                for (int i = 0; i < nstate; i++)
                {
                        CState     *st = &state[i];

                        if (st->state == CSTATE_WAIT_RESULT ||
                                st->state == CSTATE_WAIT_ROLLBACK_RESULT)
                        {
                                /* don't call advanceConnectionState unless data is available */
                                int                     sock = PQsocket(st->con);

                                if (sock < 0)
                                {
                                        pg_log_error("invalid socket: %s", PQerrorMessage(st->con));
                                        goto done;
                                }

                                if (!socket_has_input(sockets, sock, nsocks++))
                                        continue;
                        }
                        else if (st->state == CSTATE_FINISHED ||
                                         st->state == CSTATE_ABORTED)
                        {
                                /* this client is done, no need to consider it anymore */
                                continue;
                        }

                        advanceConnectionState(thread, st, &aggs);

                        /*
                         * If --exit-on-abort is used, the program is going to exit when
                         * any client is aborted.
                         */
                        if (exit_on_abort && st->state == CSTATE_ABORTED)
                                goto done;

                        /*
                         * If advanceConnectionState changed client to finished state,
                         * that's one fewer client that remains.
                         */
                        else if (st->state == CSTATE_FINISHED ||
                                         st->state == CSTATE_ABORTED)
                                remains--;
                }

                /* progress report is made by thread 0 for all threads */
                if (progress && thread->tid == 0)
                {
                        pg_time_usec_t now2 = pg_time_now();

                        if (now2 >= next_report)
                        {
                                /*
                                 * Horrible hack: this relies on the thread pointer we are
                                 * passed to be equivalent to threads[0], that is the first
                                 * entry of the threads array.  That is why this MUST be done
                                 * by thread 0 and not any other.
                                 */
                                printProgressReport(thread, thread_start, now2,
                                                                        &last, &last_report);

                                /*
                                 * Ensure that the next report is in the future, in case
                                 * pgbench/postgres got stuck somewhere.
                                 */
                                do
                                {
                                        next_report += (int64) 1000000 * progress;
                                } while (now2 >= next_report);
                        }
                }
        }

done:
        if (exit_on_abort)
        {
                /*
                 * Abort if any client is not finished, meaning some error occurred.
                 */
                for (int i = 0; i < nstate; i++)
                {
                        if (state[i].state != CSTATE_FINISHED)
                        {
                                pg_log_error("Run was aborted due to an error in thread %d",
                                                         thread->tid);
                                exit(2);
                        }
                }
        }

        disconnect_all(state, nstate);

        if (thread->logfile)
        {
                if (agg_interval > 0)
                {
                        /* log aggregated but not yet reported transactions */
                        doLog(thread, state, &aggs, false, 0, 0);
                }
                fclose(thread->logfile);
                thread->logfile = NULL;
        }
        free_socket_set(sockets);
        THREAD_FUNC_RETURN;
}

static void
finishCon(CState *st)
{
        if (st->con != NULL)
        {
                PQfinish(st->con);
                st->con = NULL;
        }
}

/*
 * Support for duration option: set timer_exceeded after so many seconds.
 */

#ifndef WIN32

static void
handle_sig_alarm(SIGNAL_ARGS)
{
        timer_exceeded = true;
}

static void
setalarm(int seconds)
{
        pqsignal(SIGALRM, handle_sig_alarm);
        alarm(seconds);
}

#else                                                   /* WIN32 */

static VOID CALLBACK
win32_timer_callback(PVOID lpParameter, BOOLEAN TimerOrWaitFired)
{
        timer_exceeded = true;
}

static void
setalarm(int seconds)
{
        HANDLE          queue;
        HANDLE          timer;

        /* This function will be called at most once, so we can cheat a bit. */
        queue = CreateTimerQueue();
        if (seconds > ((DWORD) -1) / 1000 ||
                !CreateTimerQueueTimer(&timer, queue,
                                                           win32_timer_callback, NULL, seconds * 1000, 0,
                                                           WT_EXECUTEINTIMERTHREAD | WT_EXECUTEONLYONCE))
                pg_fatal("failed to set timer");
}

#endif                                                  /* WIN32 */


/*
 * These functions provide an abstraction layer that hides the syscall
 * we use to wait for input on a set of sockets.
 *
 * Currently there are two implementations, based on ppoll(2) and select(2).
 * ppoll() is preferred where available due to its typically higher ceiling
 * on the number of usable sockets.  We do not use the more-widely-available
 * poll(2) because it only offers millisecond timeout resolution, which could
 * be problematic with high --rate settings.
 *
 * Function APIs:
 *
 * alloc_socket_set: allocate an empty socket set with room for up to
 *              "count" sockets.
 *
 * free_socket_set: deallocate a socket set.
 *
 * clear_socket_set: reset a socket set to empty.
 *
 * add_socket_to_set: add socket with indicated FD to slot "idx" in the
 *              socket set.  Slots must be filled in order, starting with 0.
 *
 * wait_on_socket_set: wait for input on any socket in set, or for timeout
 *              to expire.  timeout is measured in microseconds; 0 means wait forever.
 *              Returns result code of underlying syscall (>=0 if OK, else see errno).
 *
 * socket_has_input: after waiting, call this to see if given socket has
 *              input.  fd and idx parameters should match some previous call to
 *              add_socket_to_set.
 *
 * Note that wait_on_socket_set destructively modifies the state of the
 * socket set.  After checking for input, caller must apply clear_socket_set
 * and add_socket_to_set again before waiting again.
 */

#ifdef POLL_USING_PPOLL

static socket_set *
alloc_socket_set(int count)
{
        socket_set *sa;

        sa = (socket_set *) pg_malloc0(offsetof(socket_set, pollfds) +
                                                                   sizeof(struct pollfd) * count);
        sa->maxfds = count;
        sa->curfds = 0;
        return sa;
}

static void
free_socket_set(socket_set *sa)
{
        pg_free(sa);
}

static void
clear_socket_set(socket_set *sa)
{
        sa->curfds = 0;
}

static void
add_socket_to_set(socket_set *sa, int fd, int idx)
{
        Assert(idx < sa->maxfds && idx == sa->curfds);
        sa->pollfds[idx].fd = fd;
        sa->pollfds[idx].events = POLLIN;
        sa->pollfds[idx].revents = 0;
        sa->curfds++;
}

static int
wait_on_socket_set(socket_set *sa, int64 usecs)
{
        if (usecs > 0)
        {
                struct timespec timeout;

                timeout.tv_sec = usecs / 1000000;
                timeout.tv_nsec = (usecs % 1000000) * 1000;
                return ppoll(sa->pollfds, sa->curfds, &timeout, NULL);
        }
        else
        {
                return ppoll(sa->pollfds, sa->curfds, NULL, NULL);
        }
}

static bool
socket_has_input(socket_set *sa, int fd, int idx)
{
        /*
         * In some cases, threadRun will apply clear_socket_set and then try to
         * apply socket_has_input anyway with arguments that it used before that,
         * or might've used before that except that it exited its setup loop
         * early.  Hence, if the socket set is empty, silently return false
         * regardless of the parameters.  If it's not empty, we can Assert that
         * the parameters match a previous call.
         */
        if (sa->curfds == 0)
                return false;

        Assert(idx < sa->curfds && sa->pollfds[idx].fd == fd);
        return (sa->pollfds[idx].revents & POLLIN) != 0;
}

#endif                                                  /* POLL_USING_PPOLL */

#ifdef POLL_USING_SELECT

static socket_set *
alloc_socket_set(int count)
{
        return (socket_set *) pg_malloc0(sizeof(socket_set));
}

static void
free_socket_set(socket_set *sa)
{
        pg_free(sa);
}

static void
clear_socket_set(socket_set *sa)
{
        FD_ZERO(&sa->fds);
        sa->maxfd = -1;
}

static void
add_socket_to_set(socket_set *sa, int fd, int idx)
{
        /* See connect_slot() for background on this code. */
#ifdef WIN32
        if (sa->fds.fd_count + 1 >= FD_SETSIZE)
        {
                pg_log_error("too many concurrent database clients for this platform: %d",
                                         sa->fds.fd_count + 1);
                exit(1);
        }
#else
        if (fd < 0 || fd >= FD_SETSIZE)
        {
                pg_log_error("socket file descriptor out of range for select(): %d",
                                         fd);
                pg_log_error_hint("Try fewer concurrent database clients.");
                exit(1);
        }
#endif
        FD_SET(fd, &sa->fds);
        if (fd > sa->maxfd)
                sa->maxfd = fd;
}

static int
wait_on_socket_set(socket_set *sa, int64 usecs)
{
        if (usecs > 0)
        {
                struct timeval timeout;

                timeout.tv_sec = usecs / 1000000;
                timeout.tv_usec = usecs % 1000000;
                return select(sa->maxfd + 1, &sa->fds, NULL, NULL, &timeout);
        }
        else
        {
                return select(sa->maxfd + 1, &sa->fds, NULL, NULL, NULL);
        }
}

static bool
socket_has_input(socket_set *sa, int fd, int idx)
{
        return (FD_ISSET(fd, &sa->fds) != 0);
}

#endif                                                  /* POLL_USING_SELECT */