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) 1996-2023, 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 IdleSessionTimeoutPending;
  95 extern PGDLLIMPORT volatile sig_atomic_t ProcSignalBarrierPending;
  96 extern PGDLLIMPORT volatile sig_atomic_t LogMemoryContextPending;
  97 extern PGDLLIMPORT volatile sig_atomic_t IdleStatsUpdateTimeoutPending;
  98
  99 extern PGDLLIMPORT volatile sig_atomic_t CheckClientConnectionPending;
 100 extern PGDLLIMPORT volatile sig_atomic_t ClientConnectionLost;
 101
 102 /* these are marked volatile because they are examined by signal handlers: */
 103 extern PGDLLIMPORT volatile uint32 InterruptHoldoffCount;
 104 extern PGDLLIMPORT volatile uint32 QueryCancelHoldoffCount;
 105 extern PGDLLIMPORT volatile uint32 CritSectionCount;
 106
 107 /* in tcop/postgres.c */
 108 extern void ProcessInterrupts(void);
 109
 110 /* Test whether an interrupt is pending */
 111 #ifndef WIN32
 112 #define INTERRUPTS_PENDING_CONDITION() \
 113         (unlikely(InterruptPending))
 114 #else
 115 #define INTERRUPTS_PENDING_CONDITION() \
 116         (unlikely(UNBLOCKED_SIGNAL_QUEUE()) ? pgwin32_dispatch_queued_signals() : 0, \
 117          unlikely(InterruptPending))
 118 #endif
 119
 120 /* Service interrupt, if one is pending and it's safe to service it now */
 121 #define CHECK_FOR_INTERRUPTS() \
 122 do { \
 123         if (INTERRUPTS_PENDING_CONDITION()) \
 124                 ProcessInterrupts(); \
 125 } while(0)
 126
 127 /* Is ProcessInterrupts() guaranteed to clear InterruptPending? */
 128 #define INTERRUPTS_CAN_BE_PROCESSED() \
 129         (InterruptHoldoffCount == 0 && CritSectionCount == 0 && \
 130          QueryCancelHoldoffCount == 0)
 131
 132 #define HOLD_INTERRUPTS()  (InterruptHoldoffCount++)
 133
 134 #define RESUME_INTERRUPTS() \
 135 do { \
 136         Assert(InterruptHoldoffCount > 0); \
 137         InterruptHoldoffCount--; \
 138 } while(0)
 139
 140 #define HOLD_CANCEL_INTERRUPTS()  (QueryCancelHoldoffCount++)
 141
 142 #define RESUME_CANCEL_INTERRUPTS() \
 143 do { \
 144         Assert(QueryCancelHoldoffCount > 0); \
 145         QueryCancelHoldoffCount--; \
 146 } while(0)
 147
 148 #define START_CRIT_SECTION()  (CritSectionCount++)
 149
 150 #define END_CRIT_SECTION() \
 151 do { \
 152         Assert(CritSectionCount > 0); \
 153         CritSectionCount--; \
 154 } while(0)
 155
 156
 157 /*****************************************************************************
 158  *        globals.h --                                                                                                                   *
 159  *****************************************************************************/
 160
 161 /*
 162  * from utils/init/globals.c
 163  */
 164 extern PGDLLIMPORT pid_t PostmasterPid;
 165 extern PGDLLIMPORT bool IsPostmasterEnvironment;
 166 extern PGDLLIMPORT bool IsUnderPostmaster;
 167 extern PGDLLIMPORT bool IsBackgroundWorker;
 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 MyProcPid;
 182 extern PGDLLIMPORT pg_time_t MyStartTime;
 183 extern PGDLLIMPORT TimestampTz MyStartTimestamp;
 184 extern PGDLLIMPORT struct Port *MyProcPort;
 185 extern PGDLLIMPORT struct Latch *MyLatch;
 186 extern PGDLLIMPORT int32 MyCancelKey;
 187 extern PGDLLIMPORT int MyPMChildSlot;
 188
 189 extern PGDLLIMPORT char OutputFileName[];
 190 extern PGDLLIMPORT char my_exec_path[];
 191 extern PGDLLIMPORT char pkglib_path[];
 192
 193 #ifdef EXEC_BACKEND
 194 extern PGDLLIMPORT char postgres_exec_path[];
 195 #endif
 196
 197 /*
 198  * done in storage/backendid.h for now.
 199  *
 200  * extern BackendId    MyBackendId;
 201  */
 202 extern PGDLLIMPORT Oid MyDatabaseId;
 203
 204 extern PGDLLIMPORT Oid MyDatabaseTableSpace;
 205
 206 /*
 207  * Date/Time Configuration
 208  *
 209  * DateStyle defines the output formatting choice for date/time types:
 210  *      USE_POSTGRES_DATES specifies traditional Postgres format
 211  *      USE_ISO_DATES specifies ISO-compliant format
 212  *      USE_SQL_DATES specifies Oracle/Ingres-compliant format
 213  *      USE_GERMAN_DATES specifies German-style dd.mm/yyyy
 214  *
 215  * DateOrder defines the field order to be assumed when reading an
 216  * ambiguous date (anything not in YYYY-MM-DD format, with a four-digit
 217  * year field first, is taken to be ambiguous):
 218  *      DATEORDER_YMD specifies field order yy-mm-dd
 219  *      DATEORDER_DMY specifies field order dd-mm-yy ("European" convention)
 220  *      DATEORDER_MDY specifies field order mm-dd-yy ("US" convention)
 221  *
 222  * In the Postgres and SQL DateStyles, DateOrder also selects output field
 223  * order: day comes before month in DMY style, else month comes before day.
 224  *
 225  * The user-visible "DateStyle" run-time parameter subsumes both of these.
 226  */
 227
 228 /* valid DateStyle values */
 229 #define USE_POSTGRES_DATES              0
 230 #define USE_ISO_DATES                   1
 231 #define USE_SQL_DATES                   2
 232 #define USE_GERMAN_DATES                3
 233 #define USE_XSD_DATES                   4
 234
 235 /* valid DateOrder values */
 236 #define DATEORDER_YMD                   0
 237 #define DATEORDER_DMY                   1
 238 #define DATEORDER_MDY                   2
 239
 240 extern PGDLLIMPORT int DateStyle;
 241 extern PGDLLIMPORT int DateOrder;
 242
 243 /*
 244  * IntervalStyles
 245  *       INTSTYLE_POSTGRES                         Like Postgres < 8.4 when DateStyle = 'iso'
 246  *       INTSTYLE_POSTGRES_VERBOSE         Like Postgres < 8.4 when DateStyle != 'iso'
 247  *       INTSTYLE_SQL_STANDARD             SQL standard interval literals
 248  *       INTSTYLE_ISO_8601                         ISO-8601-basic formatted intervals
 249  */
 250 #define INTSTYLE_POSTGRES                       0
 251 #define INTSTYLE_POSTGRES_VERBOSE       1
 252 #define INTSTYLE_SQL_STANDARD           2
 253 #define INTSTYLE_ISO_8601                       3
 254
 255 extern PGDLLIMPORT int IntervalStyle;
 256
 257 #define MAXTZLEN                10              /* max TZ name len, not counting tr. null */
 258
 259 extern PGDLLIMPORT bool enableFsync;
 260 extern PGDLLIMPORT bool allowSystemTableMods;
 261 extern PGDLLIMPORT int work_mem;
 262 extern PGDLLIMPORT double hash_mem_multiplier;
 263 extern PGDLLIMPORT int maintenance_work_mem;
 264 extern PGDLLIMPORT int max_parallel_maintenance_workers;
 265
 266 /*
 267  * Upper and lower hard limits for the buffer access strategy ring size
 268  * specified by the VacuumBufferUsageLimit GUC and BUFFER_USAGE_LIMIT option
 269  * to VACUUM and ANALYZE.
 270  */
 271 #define MIN_BAS_VAC_RING_SIZE_KB 128
 272 #define MAX_BAS_VAC_RING_SIZE_KB (16 * 1024 * 1024)
 273
 274 extern PGDLLIMPORT int VacuumBufferUsageLimit;
 275 extern PGDLLIMPORT int VacuumCostPageHit;
 276 extern PGDLLIMPORT int VacuumCostPageMiss;
 277 extern PGDLLIMPORT int VacuumCostPageDirty;
 278 extern PGDLLIMPORT int VacuumCostLimit;
 279 extern PGDLLIMPORT double VacuumCostDelay;
 280
 281 extern PGDLLIMPORT int64 VacuumPageHit;
 282 extern PGDLLIMPORT int64 VacuumPageMiss;
 283 extern PGDLLIMPORT int64 VacuumPageDirty;
 284
 285 extern PGDLLIMPORT int VacuumCostBalance;
 286 extern PGDLLIMPORT bool VacuumCostActive;
 287
 288
 289 /* in tcop/postgres.c */
 290
 291 typedef char *pg_stack_base_t;
 292
 293 extern pg_stack_base_t set_stack_base(void);
 294 extern void restore_stack_base(pg_stack_base_t base);
 295 extern void check_stack_depth(void);
 296 extern bool stack_is_too_deep(void);
 297
 298 /* in tcop/utility.c */
 299 extern void PreventCommandIfReadOnly(const char *cmdname);
 300 extern void PreventCommandIfParallelMode(const char *cmdname);
 301 extern void PreventCommandDuringRecovery(const char *cmdname);
 302
 303 /* in utils/misc/guc_tables.c */
 304 extern PGDLLIMPORT int trace_recovery_messages;
 305 extern int      trace_recovery(int trace_level);
 306
 307 /*****************************************************************************
 308  *        pdir.h --                                                                                                                              *
 309  *                      POSTGRES directory path definitions.                             *
 310  *****************************************************************************/
 311
 312 /* flags to be OR'd to form sec_context */
 313 #define SECURITY_LOCAL_USERID_CHANGE    0x0001
 314 #define SECURITY_RESTRICTED_OPERATION   0x0002
 315 #define SECURITY_NOFORCE_RLS                    0x0004
 316
 317 extern PGDLLIMPORT char *DatabasePath;
 318
 319 /* now in utils/init/miscinit.c */
 320 extern void InitPostmasterChild(void);
 321 extern void InitStandaloneProcess(const char *argv0);
 322 extern void InitProcessLocalLatch(void);
 323 extern void SwitchToSharedLatch(void);
 324 extern void SwitchBackToLocalLatch(void);
 325
 326 typedef enum BackendType
 327 {
 328         B_INVALID = 0,
 329         B_ARCHIVER,
 330         B_AUTOVAC_LAUNCHER,
 331         B_AUTOVAC_WORKER,
 332         B_BACKEND,
 333         B_BG_WORKER,
 334         B_BG_WRITER,
 335         B_CHECKPOINTER,
 336         B_LOGGER,
 337         B_STANDALONE_BACKEND,
 338         B_STARTUP,
 339         B_WAL_RECEIVER,
 340         B_WAL_SENDER,
 341         B_WAL_WRITER,
 342 } BackendType;
 343
 344 #define BACKEND_NUM_TYPES (B_WAL_WRITER + 1)
 345
 346 extern PGDLLIMPORT BackendType MyBackendType;
 347
 348 extern const char *GetBackendTypeDesc(BackendType backendType);
 349
 350 extern void SetDatabasePath(const char *path);
 351 extern void checkDataDir(void);
 352 extern void SetDataDir(const char *dir);
 353 extern void ChangeToDataDir(void);
 354
 355 extern char *GetUserNameFromId(Oid roleid, bool noerr);
 356 extern Oid      GetUserId(void);
 357 extern Oid      GetOuterUserId(void);
 358 extern Oid      GetSessionUserId(void);
 359 extern Oid      GetAuthenticatedUserId(void);
 360 extern void GetUserIdAndSecContext(Oid *userid, int *sec_context);
 361 extern void SetUserIdAndSecContext(Oid userid, int sec_context);
 362 extern bool InLocalUserIdChange(void);
 363 extern bool InSecurityRestrictedOperation(void);
 364 extern bool InNoForceRLSOperation(void);
 365 extern void GetUserIdAndContext(Oid *userid, bool *sec_def_context);
 366 extern void SetUserIdAndContext(Oid userid, bool sec_def_context);
 367 extern void InitializeSessionUserId(const char *rolename, Oid roleid);
 368 extern void InitializeSessionUserIdStandalone(void);
 369 extern void SetSessionAuthorization(Oid userid, bool is_superuser);
 370 extern Oid      GetCurrentRoleId(void);
 371 extern void SetCurrentRoleId(Oid roleid, bool is_superuser);
 372 extern void InitializeSystemUser(const char *authn_id,
 373                                                                  const char *auth_method);
 374 extern const char *GetSystemUser(void);
 375
 376 /* in utils/misc/superuser.c */
 377 extern bool superuser(void);    /* current user is superuser */
 378 extern bool superuser_arg(Oid roleid);  /* given user is superuser */
 379
 380
 381 /*****************************************************************************
 382  *        pmod.h --                                                                                                                              *
 383  *                      POSTGRES processing mode definitions.                            *
 384  *****************************************************************************/
 385
 386 /*
 387  * Description:
 388  *              There are three processing modes in POSTGRES.  They are
 389  * BootstrapProcessing or "bootstrap," InitProcessing or
 390  * "initialization," and NormalProcessing or "normal."
 391  *
 392  * The first two processing modes are used during special times. When the
 393  * system state indicates bootstrap processing, transactions are all given
 394  * transaction id "one" and are consequently guaranteed to commit. This mode
 395  * is used during the initial generation of template databases.
 396  *
 397  * Initialization mode: used while starting a backend, until all normal
 398  * initialization is complete.  Some code behaves differently when executed
 399  * in this mode to enable system bootstrapping.
 400  *
 401  * If a POSTGRES backend process is in normal mode, then all code may be
 402  * executed normally.
 403  */
 404
 405 typedef enum ProcessingMode
 406 {
 407         BootstrapProcessing,            /* bootstrap creation of template database */
 408         InitProcessing,                         /* initializing system */
 409         NormalProcessing                        /* normal processing */
 410 } ProcessingMode;
 411
 412 extern PGDLLIMPORT ProcessingMode Mode;
 413
 414 #define IsBootstrapProcessingMode() (Mode == BootstrapProcessing)
 415 #define IsInitProcessingMode()          (Mode == InitProcessing)
 416 #define IsNormalProcessingMode()        (Mode == NormalProcessing)
 417
 418 #define GetProcessingMode() Mode
 419
 420 #define SetProcessingMode(mode) \
 421         do { \
 422                 Assert((mode) == BootstrapProcessing || \
 423                                   (mode) == InitProcessing || \
 424                                   (mode) == NormalProcessing); \
 425                 Mode = (mode); \
 426         } while(0)
 427
 428
 429 /*
 430  * Auxiliary-process type identifiers.  These used to be in bootstrap.h
 431  * but it seems saner to have them here, with the ProcessingMode stuff.
 432  * The MyAuxProcType global is defined and set in auxprocess.c.
 433  *
 434  * Make sure to list in the glossary any items you add here.
 435  */
 436
 437 typedef enum
 438 {
 439         NotAnAuxProcess = -1,
 440         StartupProcess = 0,
 441         BgWriterProcess,
 442         ArchiverProcess,
 443         CheckpointerProcess,
 444         WalWriterProcess,
 445         WalReceiverProcess,
 446
 447         NUM_AUXPROCTYPES                        /* Must be last! */
 448 } AuxProcType;
 449
 450 extern PGDLLIMPORT AuxProcType MyAuxProcType;
 451
 452 #define AmStartupProcess()                      (MyAuxProcType == StartupProcess)
 453 #define AmBackgroundWriterProcess() (MyAuxProcType == BgWriterProcess)
 454 #define AmArchiverProcess()                     (MyAuxProcType == ArchiverProcess)
 455 #define AmCheckpointerProcess()         (MyAuxProcType == CheckpointerProcess)
 456 #define AmWalWriterProcess()            (MyAuxProcType == WalWriterProcess)
 457 #define AmWalReceiverProcess()          (MyAuxProcType == WalReceiverProcess)
 458
 459
 460 /*****************************************************************************
 461  *        pinit.h --                                                                                                                     *
 462  *                      POSTGRES initialization and cleanup definitions.                 *
 463  *****************************************************************************/
 464
 465 /* in utils/init/postinit.c */
 466 extern void pg_split_opts(char **argv, int *argcp, const char *optstr);
 467 extern void InitializeMaxBackends(void);
 468 extern void InitPostgres(const char *in_dbname, Oid dboid,
 469                                                  const char *username, Oid useroid,
 470                                                  bool load_session_libraries,
 471                                                  bool override_allow_connections,
 472                                                  char *out_dbname);
 473 extern void BaseInit(void);
 474
 475 /* in utils/init/miscinit.c */
 476 extern PGDLLIMPORT bool IgnoreSystemIndexes;
 477 extern PGDLLIMPORT bool process_shared_preload_libraries_in_progress;
 478 extern PGDLLIMPORT bool process_shared_preload_libraries_done;
 479 extern PGDLLIMPORT bool process_shmem_requests_in_progress;
 480 extern PGDLLIMPORT char *session_preload_libraries_string;
 481 extern PGDLLIMPORT char *shared_preload_libraries_string;
 482 extern PGDLLIMPORT char *local_preload_libraries_string;
 483
 484 extern void CreateDataDirLockFile(bool amPostmaster);
 485 extern void CreateSocketLockFile(const char *socketfile, bool amPostmaster,
 486                                                                  const char *socketDir);
 487 extern void TouchSocketLockFiles(void);
 488 extern void AddToDataDirLockFile(int target_line, const char *str);
 489 extern bool RecheckDataDirLockFile(void);
 490 extern void ValidatePgVersion(const char *path);
 491 extern void process_shared_preload_libraries(void);
 492 extern void process_session_preload_libraries(void);
 493 extern void process_shmem_requests(void);
 494 extern void pg_bindtextdomain(const char *domain);
 495 extern bool has_rolreplication(Oid roleid);
 496
 497 typedef void (*shmem_request_hook_type) (void);
 498 extern PGDLLIMPORT shmem_request_hook_type shmem_request_hook;
 499
 500 extern Size EstimateClientConnectionInfoSpace(void);
 501 extern void SerializeClientConnectionInfo(Size maxsize, char *start_address);
 502 extern void RestoreClientConnectionInfo(char *conninfo);
 503
 504 /* in executor/nodeHash.c */
 505 extern size_t get_hash_memory_limit(void);
 506
 507 #endif                                                  /* MISCADMIN_H */