src/include/miscadmin.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * miscadmin.h
   4  *        This file contains general postgres administration and initialization
   5  *        stuff that used to be spread out between the following files:
   6  *              globals.h                                               global variables
   7  *              pdir.h                                                  directory path crud
   8  *              pinit.h                                                 postgres initialization
   9  *              pmod.h                                                  processing modes
  10  *        Over time, this has also become the preferred place for widely known
  11  *        resource-limitation stuff, such as work_mem and check_stack_depth().
  12  *
  13  * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
  14  * Portions Copyright (c) 1994, Regents of the University of California
  15  *
  16  * src/include/miscadmin.h
  17  *
  18  * NOTES
  19  *        some of the information in this file should be moved to other files.
  20  *
  21  *-------------------------------------------------------------------------
  22  */
  23 #ifndef MISCADMIN_H
  24 #define MISCADMIN_H
  25
  26 #include <signal.h>
  27
  28 #include "datatype/timestamp.h" /* for TimestampTz */
  29 #include "pgtime.h"                             /* for pg_time_t */
  30
  31
  32 #define InvalidPid                              (-1)
  33
  34
  35 /*****************************************************************************
  36  *        System interrupt and critical section handling
  37  *
  38  * There are two types of interrupts that a running backend needs to accept
  39  * without messing up its state: QueryCancel (SIGINT) and ProcDie (SIGTERM).
  40  * In both cases, we need to be able to clean up the current transaction
  41  * gracefully, so we can't respond to the interrupt instantaneously ---
  42  * there's no guarantee that internal data structures would be self-consistent
  43  * if the code is interrupted at an arbitrary instant.  Instead, the signal
  44  * handlers set flags that are checked periodically during execution.
  45  *
  46  * The CHECK_FOR_INTERRUPTS() macro is called at strategically located spots
  47  * where it is normally safe to accept a cancel or die interrupt.  In some
  48  * cases, we invoke CHECK_FOR_INTERRUPTS() inside low-level subroutines that
  49  * might sometimes be called in contexts that do *not* want to allow a cancel
  50  * or die interrupt.  The HOLD_INTERRUPTS() and RESUME_INTERRUPTS() macros
  51  * allow code to ensure that no cancel or die interrupt will be accepted,
  52  * even if CHECK_FOR_INTERRUPTS() gets called in a subroutine.  The interrupt
  53  * will be held off until CHECK_FOR_INTERRUPTS() is done outside any
  54  * HOLD_INTERRUPTS() ... RESUME_INTERRUPTS() section.
  55  *
  56  * There is also a mechanism to prevent query cancel interrupts, while still
  57  * allowing die interrupts: HOLD_CANCEL_INTERRUPTS() and
  58  * RESUME_CANCEL_INTERRUPTS().
  59  *
  60  * Note that ProcessInterrupts() has also acquired a number of tasks that
  61  * do not necessarily cause a query-cancel-or-die response.  Hence, it's
  62  * possible that it will just clear InterruptPending and return.
  63  *
  64  * INTERRUPTS_PENDING_CONDITION() can be checked to see whether an
  65  * interrupt needs to be serviced, without trying to do so immediately.
  66  * Some callers are also interested in INTERRUPTS_CAN_BE_PROCESSED(),
  67  * which tells whether ProcessInterrupts is sure to clear the interrupt.
  68  *
  69  * Special mechanisms are used to let an interrupt be accepted when we are
  70  * waiting for a lock or when we are waiting for command input (but, of
  71  * course, only if the interrupt holdoff counter is zero).  See the
  72  * related code for details.
  73  *
  74  * A lost connection is handled similarly, although the loss of connection
  75  * does not raise a signal, but is detected when we fail to write to the
  76  * socket. If there was a signal for a broken connection, we could make use of
  77  * it by setting ClientConnectionLost in the signal handler.
  78  *
  79  * A related, but conceptually distinct, mechanism is the "critical section"
  80  * mechanism.  A critical section not only holds off cancel/die interrupts,
  81  * but causes any ereport(ERROR) or ereport(FATAL) to become ereport(PANIC)
  82  * --- that is, a system-wide reset is forced.  Needless to say, only really
  83  * *critical* code should be marked as a critical section!      Currently, this
  84  * mechanism is only used for XLOG-related code.
  85  *
  86  *****************************************************************************/
  87
  88 /* in globals.c */
  89 /* these are marked volatile because they are set by signal handlers: */
  90 extern PGDLLIMPORT volatile sig_atomic_t InterruptPending;
  91 extern PGDLLIMPORT volatile sig_atomic_t QueryCancelPending;
  92 extern PGDLLIMPORT volatile sig_atomic_t ProcDiePending;
  93 extern PGDLLIMPORT volatile sig_atomic_t IdleInTransactionSessionTimeoutPending;
  94 extern PGDLLIMPORT volatile sig_atomic_t TransactionTimeoutPending;
  95 extern PGDLLIMPORT volatile sig_atomic_t IdleSessionTimeoutPending;
  96 extern PGDLLIMPORT volatile sig_atomic_t ProcSignalBarrierPending;
  97 extern PGDLLIMPORT volatile sig_atomic_t LogMemoryContextPending;
  98 extern PGDLLIMPORT volatile sig_atomic_t IdleStatsUpdateTimeoutPending;
  99
 100 extern PGDLLIMPORT volatile sig_atomic_t CheckClientConnectionPending;
 101 extern PGDLLIMPORT volatile sig_atomic_t ClientConnectionLost;
 102
 103 /* these are marked volatile because they are examined by signal handlers: */
 104 extern PGDLLIMPORT volatile uint32 InterruptHoldoffCount;
 105 extern PGDLLIMPORT volatile uint32 QueryCancelHoldoffCount;
 106 extern PGDLLIMPORT volatile uint32 CritSectionCount;
 107
 108 /* in tcop/postgres.c */
 109 extern void ProcessInterrupts(void);
 110
 111 /* Test whether an interrupt is pending */
 112 #ifndef WIN32
 113 #define INTERRUPTS_PENDING_CONDITION() \
 114         (unlikely(InterruptPending))
 115 #else
 116 #define INTERRUPTS_PENDING_CONDITION() \
 117         (unlikely(UNBLOCKED_SIGNAL_QUEUE()) ? pgwin32_dispatch_queued_signals() : 0, \
 118          unlikely(InterruptPending))
 119 #endif
 120
 121 /* Service interrupt, if one is pending and it's safe to service it now */
 122 #define CHECK_FOR_INTERRUPTS() \
 123 do { \
 124         if (INTERRUPTS_PENDING_CONDITION()) \
 125                 ProcessInterrupts(); \
 126 } while(0)
 127
 128 /* Is ProcessInterrupts() guaranteed to clear InterruptPending? */
 129 #define INTERRUPTS_CAN_BE_PROCESSED() \
 130         (InterruptHoldoffCount == 0 && CritSectionCount == 0 && \
 131          QueryCancelHoldoffCount == 0)
 132
 133 #define HOLD_INTERRUPTS()  (InterruptHoldoffCount++)
 134
 135 #define RESUME_INTERRUPTS() \
 136 do { \
 137         Assert(InterruptHoldoffCount > 0); \
 138         InterruptHoldoffCount--; \
 139 } while(0)
 140
 141 #define HOLD_CANCEL_INTERRUPTS()  (QueryCancelHoldoffCount++)
 142
 143 #define RESUME_CANCEL_INTERRUPTS() \
 144 do { \
 145         Assert(QueryCancelHoldoffCount > 0); \
 146         QueryCancelHoldoffCount--; \
 147 } while(0)
 148
 149 #define START_CRIT_SECTION()  (CritSectionCount++)
 150
 151 #define END_CRIT_SECTION() \
 152 do { \
 153         Assert(CritSectionCount > 0); \
 154         CritSectionCount--; \
 155 } while(0)
 156
 157
 158 /*****************************************************************************
 159  *        globals.h --                                                                                                                   *
 160  *****************************************************************************/
 161
 162 /*
 163  * from utils/init/globals.c
 164  */
 165 extern PGDLLIMPORT pid_t PostmasterPid;
 166 extern PGDLLIMPORT bool IsPostmasterEnvironment;
 167 extern PGDLLIMPORT bool IsUnderPostmaster;
 168 extern PGDLLIMPORT bool IsBinaryUpgrade;
 169
 170 extern PGDLLIMPORT bool ExitOnAnyError;
 171
 172 extern PGDLLIMPORT char *DataDir;
 173 extern PGDLLIMPORT int data_directory_mode;
 174
 175 extern PGDLLIMPORT int NBuffers;
 176 extern PGDLLIMPORT int MaxBackends;
 177 extern PGDLLIMPORT int MaxConnections;
 178 extern PGDLLIMPORT int max_worker_processes;
 179 extern PGDLLIMPORT int max_parallel_workers;
 180
 181 extern PGDLLIMPORT int commit_timestamp_buffers;
 182 extern PGDLLIMPORT int multixact_member_buffers;
 183 extern PGDLLIMPORT int multixact_offset_buffers;
 184 extern PGDLLIMPORT int notify_buffers;
 185 extern PGDLLIMPORT int serializable_buffers;
 186 extern PGDLLIMPORT int subtransaction_buffers;
 187 extern PGDLLIMPORT int transaction_buffers;
 188
 189 extern PGDLLIMPORT int MyProcPid;
 190 extern PGDLLIMPORT pg_time_t MyStartTime;
 191 extern PGDLLIMPORT TimestampTz MyStartTimestamp;
 192 extern PGDLLIMPORT struct Port *MyProcPort;
 193 extern PGDLLIMPORT struct Latch *MyLatch;
 194 extern PGDLLIMPORT bool MyCancelKeyValid;
 195 extern PGDLLIMPORT int32 MyCancelKey;
 196 extern PGDLLIMPORT int MyPMChildSlot;
 197
 198 extern PGDLLIMPORT char OutputFileName[];
 199 extern PGDLLIMPORT char my_exec_path[];
 200 extern PGDLLIMPORT char pkglib_path[];
 201
 202 #ifdef EXEC_BACKEND
 203 extern PGDLLIMPORT char postgres_exec_path[];
 204 #endif
 205
 206 extern PGDLLIMPORT Oid MyDatabaseId;
 207
 208 extern PGDLLIMPORT Oid MyDatabaseTableSpace;
 209
 210 extern PGDLLIMPORT bool MyDatabaseHasLoginEventTriggers;
 211
 212 /*
 213  * Date/Time Configuration
 214  *
 215  * DateStyle defines the output formatting choice for date/time types:
 216  *      USE_POSTGRES_DATES specifies traditional Postgres format
 217  *      USE_ISO_DATES specifies ISO-compliant format
 218  *      USE_SQL_DATES specifies Oracle/Ingres-compliant format
 219  *      USE_GERMAN_DATES specifies German-style dd.mm/yyyy
 220  *
 221  * DateOrder defines the field order to be assumed when reading an
 222  * ambiguous date (anything not in YYYY-MM-DD format, with a four-digit
 223  * year field first, is taken to be ambiguous):
 224  *      DATEORDER_YMD specifies field order yy-mm-dd
 225  *      DATEORDER_DMY specifies field order dd-mm-yy ("European" convention)
 226  *      DATEORDER_MDY specifies field order mm-dd-yy ("US" convention)
 227  *
 228  * In the Postgres and SQL DateStyles, DateOrder also selects output field
 229  * order: day comes before month in DMY style, else month comes before day.
 230  *
 231  * The user-visible "DateStyle" run-time parameter subsumes both of these.
 232  */
 233
 234 /* valid DateStyle values */
 235 #define USE_POSTGRES_DATES              0
 236 #define USE_ISO_DATES                   1
 237 #define USE_SQL_DATES                   2
 238 #define USE_GERMAN_DATES                3
 239 #define USE_XSD_DATES                   4
 240
 241 /* valid DateOrder values */
 242 #define DATEORDER_YMD                   0
 243 #define DATEORDER_DMY                   1
 244 #define DATEORDER_MDY                   2
 245
 246 extern PGDLLIMPORT int DateStyle;
 247 extern PGDLLIMPORT int DateOrder;
 248
 249 /*
 250  * IntervalStyles
 251  *       INTSTYLE_POSTGRES                         Like Postgres < 8.4 when DateStyle = 'iso'
 252  *       INTSTYLE_POSTGRES_VERBOSE         Like Postgres < 8.4 when DateStyle != 'iso'
 253  *       INTSTYLE_SQL_STANDARD             SQL standard interval literals
 254  *       INTSTYLE_ISO_8601                         ISO-8601-basic formatted intervals
 255  */
 256 #define INTSTYLE_POSTGRES                       0
 257 #define INTSTYLE_POSTGRES_VERBOSE       1
 258 #define INTSTYLE_SQL_STANDARD           2
 259 #define INTSTYLE_ISO_8601                       3
 260
 261 extern PGDLLIMPORT int IntervalStyle;
 262
 263 #define MAXTZLEN                10              /* max TZ name len, not counting tr. null */
 264
 265 extern PGDLLIMPORT bool enableFsync;
 266 extern PGDLLIMPORT bool allowSystemTableMods;
 267 extern PGDLLIMPORT int work_mem;
 268 extern PGDLLIMPORT double hash_mem_multiplier;
 269 extern PGDLLIMPORT int maintenance_work_mem;
 270 extern PGDLLIMPORT int max_parallel_maintenance_workers;
 271
 272 /*
 273  * Upper and lower hard limits for the buffer access strategy ring size
 274  * specified by the VacuumBufferUsageLimit GUC and BUFFER_USAGE_LIMIT option
 275  * to VACUUM and ANALYZE.
 276  */
 277 #define MIN_BAS_VAC_RING_SIZE_KB 128
 278 #define MAX_BAS_VAC_RING_SIZE_KB (16 * 1024 * 1024)
 279
 280 extern PGDLLIMPORT int VacuumBufferUsageLimit;
 281 extern PGDLLIMPORT int VacuumCostPageHit;
 282 extern PGDLLIMPORT int VacuumCostPageMiss;
 283 extern PGDLLIMPORT int VacuumCostPageDirty;
 284 extern PGDLLIMPORT int VacuumCostLimit;
 285 extern PGDLLIMPORT double VacuumCostDelay;
 286
 287 extern PGDLLIMPORT int VacuumCostBalance;
 288 extern PGDLLIMPORT bool VacuumCostActive;
 289
 290
 291 /* in tcop/postgres.c */
 292
 293 typedef char *pg_stack_base_t;
 294
 295 extern pg_stack_base_t set_stack_base(void);
 296 extern void restore_stack_base(pg_stack_base_t base);
 297 extern void check_stack_depth(void);
 298 extern bool stack_is_too_deep(void);
 299
 300 /* in tcop/utility.c */
 301 extern void PreventCommandIfReadOnly(const char *cmdname);
 302 extern void PreventCommandIfParallelMode(const char *cmdname);
 303 extern void PreventCommandDuringRecovery(const char *cmdname);
 304
 305 /*****************************************************************************
 306  *        pdir.h --                                                                                                                              *
 307  *                      POSTGRES directory path definitions.                             *
 308  *****************************************************************************/
 309
 310 /* flags to be OR'd to form sec_context */
 311 #define SECURITY_LOCAL_USERID_CHANGE    0x0001
 312 #define SECURITY_RESTRICTED_OPERATION   0x0002
 313 #define SECURITY_NOFORCE_RLS                    0x0004
 314
 315 extern PGDLLIMPORT char *DatabasePath;
 316
 317 /* now in utils/init/miscinit.c */
 318 extern void InitPostmasterChild(void);
 319 extern void InitStandaloneProcess(const char *argv0);
 320 extern void InitProcessLocalLatch(void);
 321 extern void SwitchToSharedLatch(void);
 322 extern void SwitchBackToLocalLatch(void);
 323
 324 /*
 325  * MyBackendType indicates what kind of a backend this is.
 326  *
 327  * If you add entries, please also update the child_process_kinds array in
 328  * launch_backend.c.
 329  */
 330 typedef enum BackendType
 331 {
 332         B_INVALID = 0,
 333
 334         /* Backends and other backend-like processes */
 335         B_BACKEND,
 336         B_AUTOVAC_LAUNCHER,
 337         B_AUTOVAC_WORKER,
 338         B_BG_WORKER,
 339         B_WAL_SENDER,
 340         B_SLOTSYNC_WORKER,
 341
 342         B_STANDALONE_BACKEND,
 343
 344         /*
 345          * Auxiliary processes. These have PGPROC entries, but they are not
 346          * attached to any particular database. There can be only one of each of
 347          * these running at a time.
 348          *
 349          * If you modify these, make sure to update NUM_AUXILIARY_PROCS and the
 350          * glossary in the docs.
 351          */
 352         B_ARCHIVER,
 353         B_BG_WRITER,
 354         B_CHECKPOINTER,
 355         B_STARTUP,
 356         B_WAL_RECEIVER,
 357         B_WAL_SUMMARIZER,
 358         B_WAL_WRITER,
 359
 360         /*
 361          * Logger is not connected to shared memory and does not have a PGPROC
 362          * entry.
 363          */
 364         B_LOGGER,
 365 } BackendType;
 366
 367 #define BACKEND_NUM_TYPES (B_LOGGER + 1)
 368
 369 extern PGDLLIMPORT BackendType MyBackendType;
 370
 371 #define AmAutoVacuumLauncherProcess() (MyBackendType == B_AUTOVAC_LAUNCHER)
 372 #define AmAutoVacuumWorkerProcess()     (MyBackendType == B_AUTOVAC_WORKER)
 373 #define AmBackgroundWorkerProcess() (MyBackendType == B_BG_WORKER)
 374 #define AmWalSenderProcess()        (MyBackendType == B_WAL_SENDER)
 375 #define AmLogicalSlotSyncWorkerProcess() (MyBackendType == B_SLOTSYNC_WORKER)
 376 #define AmArchiverProcess()                     (MyBackendType == B_ARCHIVER)
 377 #define AmBackgroundWriterProcess() (MyBackendType == B_BG_WRITER)
 378 #define AmCheckpointerProcess()         (MyBackendType == B_CHECKPOINTER)
 379 #define AmStartupProcess()                      (MyBackendType == B_STARTUP)
 380 #define AmWalReceiverProcess()          (MyBackendType == B_WAL_RECEIVER)
 381 #define AmWalSummarizerProcess()        (MyBackendType == B_WAL_SUMMARIZER)
 382 #define AmWalWriterProcess()            (MyBackendType == B_WAL_WRITER)
 383
 384 extern const char *GetBackendTypeDesc(BackendType backendType);
 385
 386 extern void SetDatabasePath(const char *path);
 387 extern void checkDataDir(void);
 388 extern void SetDataDir(const char *dir);
 389 extern void ChangeToDataDir(void);
 390
 391 extern char *GetUserNameFromId(Oid roleid, bool noerr);
 392 extern Oid      GetUserId(void);
 393 extern Oid      GetOuterUserId(void);
 394 extern Oid      GetSessionUserId(void);
 395 extern Oid      GetAuthenticatedUserId(void);
 396 extern void GetUserIdAndSecContext(Oid *userid, int *sec_context);
 397 extern void SetUserIdAndSecContext(Oid userid, int sec_context);
 398 extern bool InLocalUserIdChange(void);
 399 extern bool InSecurityRestrictedOperation(void);
 400 extern bool InNoForceRLSOperation(void);
 401 extern void GetUserIdAndContext(Oid *userid, bool *sec_def_context);
 402 extern void SetUserIdAndContext(Oid userid, bool sec_def_context);
 403 extern void InitializeSessionUserId(const char *rolename, Oid roleid,
 404                                                                         bool bypass_login_check);
 405 extern void InitializeSessionUserIdStandalone(void);
 406 extern void SetSessionAuthorization(Oid userid, bool is_superuser);
 407 extern Oid      GetCurrentRoleId(void);
 408 extern void SetCurrentRoleId(Oid roleid, bool is_superuser);
 409 extern void InitializeSystemUser(const char *authn_id,
 410                                                                  const char *auth_method);
 411 extern const char *GetSystemUser(void);
 412
 413 /* in utils/misc/superuser.c */
 414 extern bool superuser(void);    /* current user is superuser */
 415 extern bool superuser_arg(Oid roleid);  /* given user is superuser */
 416
 417
 418 /*****************************************************************************
 419  *        pmod.h --                                                                                                                              *
 420  *                      POSTGRES processing mode definitions.                            *
 421  *****************************************************************************/
 422
 423 /*
 424  * Description:
 425  *              There are three processing modes in POSTGRES.  They are
 426  * BootstrapProcessing or "bootstrap," InitProcessing or
 427  * "initialization," and NormalProcessing or "normal."
 428  *
 429  * The first two processing modes are used during special times. When the
 430  * system state indicates bootstrap processing, transactions are all given
 431  * transaction id "one" and are consequently guaranteed to commit. This mode
 432  * is used during the initial generation of template databases.
 433  *
 434  * Initialization mode: used while starting a backend, until all normal
 435  * initialization is complete.  Some code behaves differently when executed
 436  * in this mode to enable system bootstrapping.
 437  *
 438  * If a POSTGRES backend process is in normal mode, then all code may be
 439  * executed normally.
 440  */
 441
 442 typedef enum ProcessingMode
 443 {
 444         BootstrapProcessing,            /* bootstrap creation of template database */
 445         InitProcessing,                         /* initializing system */
 446         NormalProcessing,                       /* normal processing */
 447 } ProcessingMode;
 448
 449 extern PGDLLIMPORT ProcessingMode Mode;
 450
 451 #define IsBootstrapProcessingMode() (Mode == BootstrapProcessing)
 452 #define IsInitProcessingMode()          (Mode == InitProcessing)
 453 #define IsNormalProcessingMode()        (Mode == NormalProcessing)
 454
 455 #define GetProcessingMode() Mode
 456
 457 #define SetProcessingMode(mode) \
 458         do { \
 459                 Assert((mode) == BootstrapProcessing || \
 460                                   (mode) == InitProcessing || \
 461                                   (mode) == NormalProcessing); \
 462                 Mode = (mode); \
 463         } while(0)
 464
 465
 466 /*****************************************************************************
 467  *        pinit.h --                                                                                                                     *
 468  *                      POSTGRES initialization and cleanup definitions.                 *
 469  *****************************************************************************/
 470
 471 /* in utils/init/postinit.c */
 472 /* flags for InitPostgres() */
 473 #define INIT_PG_LOAD_SESSION_LIBS               0x0001
 474 #define INIT_PG_OVERRIDE_ALLOW_CONNS    0x0002
 475 #define INIT_PG_OVERRIDE_ROLE_LOGIN             0x0004
 476 extern void pg_split_opts(char **argv, int *argcp, const char *optstr);
 477 extern void InitializeMaxBackends(void);
 478 extern void InitializeFastPathLocks(void);
 479 extern void InitPostgres(const char *in_dbname, Oid dboid,
 480                                                  const char *username, Oid useroid,
 481                                                  bits32 flags,
 482                                                  char *out_dbname);
 483 extern void BaseInit(void);
 484
 485 /* in utils/init/miscinit.c */
 486 extern PGDLLIMPORT bool IgnoreSystemIndexes;
 487 extern PGDLLIMPORT bool process_shared_preload_libraries_in_progress;
 488 extern PGDLLIMPORT bool process_shared_preload_libraries_done;
 489 extern PGDLLIMPORT bool process_shmem_requests_in_progress;
 490 extern PGDLLIMPORT char *session_preload_libraries_string;
 491 extern PGDLLIMPORT char *shared_preload_libraries_string;
 492 extern PGDLLIMPORT char *local_preload_libraries_string;
 493
 494 extern void CreateDataDirLockFile(bool amPostmaster);
 495 extern void CreateSocketLockFile(const char *socketfile, bool amPostmaster,
 496                                                                  const char *socketDir);
 497 extern void TouchSocketLockFiles(void);
 498 extern void AddToDataDirLockFile(int target_line, const char *str);
 499 extern bool RecheckDataDirLockFile(void);
 500 extern void ValidatePgVersion(const char *path);
 501 extern void process_shared_preload_libraries(void);
 502 extern void process_session_preload_libraries(void);
 503 extern void process_shmem_requests(void);
 504 extern void pg_bindtextdomain(const char *domain);
 505 extern bool has_rolreplication(Oid roleid);
 506
 507 typedef void (*shmem_request_hook_type) (void);
 508 extern PGDLLIMPORT shmem_request_hook_type shmem_request_hook;
 509
 510 extern Size EstimateClientConnectionInfoSpace(void);
 511 extern void SerializeClientConnectionInfo(Size maxsize, char *start_address);
 512 extern void RestoreClientConnectionInfo(char *conninfo);
 513
 514 /* in executor/nodeHash.c */
 515 extern size_t get_hash_memory_limit(void);
 516
 517 #endif                                                  /* MISCADMIN_H */