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) 1996-2020, 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 ProcSignalBarrierPending; 95 96 extern PGDLLIMPORT volatile sig_atomic_t ClientConnectionLost; 97 98 /* these are marked volatile because they are examined by signal handlers: */ 99 extern PGDLLIMPORT volatile uint32 InterruptHoldoffCount; 100 extern PGDLLIMPORT volatile uint32 QueryCancelHoldoffCount; 101 extern PGDLLIMPORT volatile uint32 CritSectionCount; 102 103 /* in tcop/postgres.c */ 104 extern void ProcessInterrupts(void); 105 106 /* Test whether an interrupt is pending */ 107 #ifndef WIN32 108 #define INTERRUPTS_PENDING_CONDITION() \ 109 (unlikely(InterruptPending)) 110 #else 111 #define INTERRUPTS_PENDING_CONDITION() \ 112 (unlikely(UNBLOCKED_SIGNAL_QUEUE()) ? pgwin32_dispatch_queued_signals() : 0, \ 113 unlikely(InterruptPending)) 114 #endif 115 116 /* Service interrupt, if one is pending and it's safe to service it now */ 117 #define CHECK_FOR_INTERRUPTS() \ 118 do { \ 119 if (INTERRUPTS_PENDING_CONDITION()) \ 120 ProcessInterrupts(); \ 121 } while(0) 122 123 /* Is ProcessInterrupts() guaranteed to clear InterruptPending? */ 124 #define INTERRUPTS_CAN_BE_PROCESSED() \ 125 (InterruptHoldoffCount == 0 && CritSectionCount == 0 && \ 126 QueryCancelHoldoffCount == 0) 127 128 #define HOLD_INTERRUPTS() (InterruptHoldoffCount++) 129 130 #define RESUME_INTERRUPTS() \ 131 do { \ 132 Assert(InterruptHoldoffCount > 0); \ 133 InterruptHoldoffCount--; \ 134 } while(0) 135 136 #define HOLD_CANCEL_INTERRUPTS() (QueryCancelHoldoffCount++) 137 138 #define RESUME_CANCEL_INTERRUPTS() \ 139 do { \ 140 Assert(QueryCancelHoldoffCount > 0); \ 141 QueryCancelHoldoffCount--; \ 142 } while(0) 143 144 #define START_CRIT_SECTION() (CritSectionCount++) 145 146 #define END_CRIT_SECTION() \ 147 do { \ 148 Assert(CritSectionCount > 0); \ 149 CritSectionCount--; \ 150 } while(0) 151 152 153 /***************************************************************************** 154 * globals.h -- * 155 *****************************************************************************/ 156 157 /* 158 * from utils/init/globals.c 159 */ 160 extern PGDLLIMPORT pid_t PostmasterPid; 161 extern PGDLLIMPORT bool IsPostmasterEnvironment; 162 extern PGDLLIMPORT bool IsUnderPostmaster; 163 extern PGDLLIMPORT bool IsBackgroundWorker; 164 extern PGDLLIMPORT bool IsBinaryUpgrade; 165 166 extern PGDLLIMPORT bool ExitOnAnyError; 167 168 extern PGDLLIMPORT char *DataDir; 169 extern PGDLLIMPORT int data_directory_mode; 170 171 extern PGDLLIMPORT int NBuffers; 172 extern PGDLLIMPORT int MaxBackends; 173 extern PGDLLIMPORT int MaxConnections; 174 extern PGDLLIMPORT int max_worker_processes; 175 extern PGDLLIMPORT int max_parallel_workers; 176 177 extern PGDLLIMPORT int MyProcPid; 178 extern PGDLLIMPORT pg_time_t MyStartTime; 179 extern PGDLLIMPORT TimestampTz MyStartTimestamp; 180 extern PGDLLIMPORT struct Port *MyProcPort; 181 extern PGDLLIMPORT struct Latch *MyLatch; 182 extern int32 MyCancelKey; 183 extern int MyPMChildSlot; 184 185 extern char OutputFileName[]; 186 extern PGDLLIMPORT char my_exec_path[]; 187 extern char pkglib_path[]; 188 189 #ifdef EXEC_BACKEND 190 extern char postgres_exec_path[]; 191 #endif 192 193 /* 194 * done in storage/backendid.h for now. 195 * 196 * extern BackendId MyBackendId; 197 */ 198 extern PGDLLIMPORT Oid MyDatabaseId; 199 200 extern PGDLLIMPORT Oid MyDatabaseTableSpace; 201 202 /* 203 * Date/Time Configuration 204 * 205 * DateStyle defines the output formatting choice for date/time types: 206 * USE_POSTGRES_DATES specifies traditional Postgres format 207 * USE_ISO_DATES specifies ISO-compliant format 208 * USE_SQL_DATES specifies Oracle/Ingres-compliant format 209 * USE_GERMAN_DATES specifies German-style dd.mm/yyyy 210 * 211 * DateOrder defines the field order to be assumed when reading an 212 * ambiguous date (anything not in YYYY-MM-DD format, with a four-digit 213 * year field first, is taken to be ambiguous): 214 * DATEORDER_YMD specifies field order yy-mm-dd 215 * DATEORDER_DMY specifies field order dd-mm-yy ("European" convention) 216 * DATEORDER_MDY specifies field order mm-dd-yy ("US" convention) 217 * 218 * In the Postgres and SQL DateStyles, DateOrder also selects output field 219 * order: day comes before month in DMY style, else month comes before day. 220 * 221 * The user-visible "DateStyle" run-time parameter subsumes both of these. 222 */ 223 224 /* valid DateStyle values */ 225 #define USE_POSTGRES_DATES 0 226 #define USE_ISO_DATES 1 227 #define USE_SQL_DATES 2 228 #define USE_GERMAN_DATES 3 229 #define USE_XSD_DATES 4 230 231 /* valid DateOrder values */ 232 #define DATEORDER_YMD 0 233 #define DATEORDER_DMY 1 234 #define DATEORDER_MDY 2 235 236 extern PGDLLIMPORT int DateStyle; 237 extern PGDLLIMPORT int DateOrder; 238 239 /* 240 * IntervalStyles 241 * INTSTYLE_POSTGRES Like Postgres < 8.4 when DateStyle = 'iso' 242 * INTSTYLE_POSTGRES_VERBOSE Like Postgres < 8.4 when DateStyle != 'iso' 243 * INTSTYLE_SQL_STANDARD SQL standard interval literals 244 * INTSTYLE_ISO_8601 ISO-8601-basic formatted intervals 245 */ 246 #define INTSTYLE_POSTGRES 0 247 #define INTSTYLE_POSTGRES_VERBOSE 1 248 #define INTSTYLE_SQL_STANDARD 2 249 #define INTSTYLE_ISO_8601 3 250 251 extern PGDLLIMPORT int IntervalStyle; 252 253 #define MAXTZLEN 10 /* max TZ name len, not counting tr. null */ 254 255 extern bool enableFsync; 256 extern PGDLLIMPORT bool allowSystemTableMods; 257 extern PGDLLIMPORT int work_mem; 258 extern PGDLLIMPORT double hash_mem_multiplier; 259 extern PGDLLIMPORT int maintenance_work_mem; 260 extern PGDLLIMPORT int max_parallel_maintenance_workers; 261 262 extern int VacuumCostPageHit; 263 extern int VacuumCostPageMiss; 264 extern int VacuumCostPageDirty; 265 extern int VacuumCostLimit; 266 extern double VacuumCostDelay; 267 268 extern int64 VacuumPageHit; 269 extern int64 VacuumPageMiss; 270 extern int64 VacuumPageDirty; 271 272 extern int VacuumCostBalance; 273 extern bool VacuumCostActive; 274 275 extern double vacuum_cleanup_index_scale_factor; 276 277 278 /* in tcop/postgres.c */ 279 280 #if defined(__ia64__) || defined(__ia64) 281 typedef struct 282 { 283 char *stack_base_ptr; 284 char *register_stack_base_ptr; 285 } pg_stack_base_t; 286 #else 287 typedef char *pg_stack_base_t; 288 #endif 289 290 extern pg_stack_base_t set_stack_base(void); 291 extern void restore_stack_base(pg_stack_base_t base); 292 extern void check_stack_depth(void); 293 extern bool stack_is_too_deep(void); 294 295 /* in tcop/utility.c */ 296 extern void PreventCommandIfReadOnly(const char *cmdname); 297 extern void PreventCommandIfParallelMode(const char *cmdname); 298 extern void PreventCommandDuringRecovery(const char *cmdname); 299 300 /* in utils/misc/guc.c */ 301 extern int trace_recovery_messages; 302 extern int trace_recovery(int trace_level); 303 304 /***************************************************************************** 305 * pdir.h -- * 306 * POSTGRES directory path definitions. * 307 *****************************************************************************/ 308 309 /* flags to be OR'd to form sec_context */ 310 #define SECURITY_LOCAL_USERID_CHANGE 0x0001 311 #define SECURITY_RESTRICTED_OPERATION 0x0002 312 #define SECURITY_NOFORCE_RLS 0x0004 313 314 extern char *DatabasePath; 315 316 /* now in utils/init/miscinit.c */ 317 extern void InitPostmasterChild(void); 318 extern void InitStandaloneProcess(const char *argv0); 319 extern void SwitchToSharedLatch(void); 320 extern void SwitchBackToLocalLatch(void); 321 322 typedef enum BackendType 323 { 324 B_INVALID = 0, 325 B_AUTOVAC_LAUNCHER, 326 B_AUTOVAC_WORKER, 327 B_BACKEND, 328 B_BG_WORKER, 329 B_BG_WRITER, 330 B_CHECKPOINTER, 331 B_STARTUP, 332 B_WAL_RECEIVER, 333 B_WAL_SENDER, 334 B_WAL_WRITER, 335 B_ARCHIVER, 336 B_STATS_COLLECTOR, 337 B_LOGGER, 338 } BackendType; 339 340 extern BackendType MyBackendType; 341 342 extern const char *GetBackendTypeDesc(BackendType backendType); 343 344 extern void SetDatabasePath(const char *path); 345 extern void checkDataDir(void); 346 extern void SetDataDir(const char *dir); 347 extern void ChangeToDataDir(void); 348 349 extern char *GetUserNameFromId(Oid roleid, bool noerr); 350 extern Oid GetUserId(void); 351 extern Oid GetOuterUserId(void); 352 extern Oid GetSessionUserId(void); 353 extern Oid GetAuthenticatedUserId(void); 354 extern void GetUserIdAndSecContext(Oid *userid, int *sec_context); 355 extern void SetUserIdAndSecContext(Oid userid, int sec_context); 356 extern bool InLocalUserIdChange(void); 357 extern bool InSecurityRestrictedOperation(void); 358 extern bool InNoForceRLSOperation(void); 359 extern void GetUserIdAndContext(Oid *userid, bool *sec_def_context); 360 extern void SetUserIdAndContext(Oid userid, bool sec_def_context); 361 extern void InitializeSessionUserId(const char *rolename, Oid useroid); 362 extern void InitializeSessionUserIdStandalone(void); 363 extern void SetSessionAuthorization(Oid userid, bool is_superuser); 364 extern Oid GetCurrentRoleId(void); 365 extern void SetCurrentRoleId(Oid roleid, bool is_superuser); 366 367 /* in utils/misc/superuser.c */ 368 extern bool superuser(void); /* current user is superuser */ 369 extern bool superuser_arg(Oid roleid); /* given user is superuser */ 370 371 372 /***************************************************************************** 373 * pmod.h -- * 374 * POSTGRES processing mode definitions. * 375 *****************************************************************************/ 376 377 /* 378 * Description: 379 * There are three processing modes in POSTGRES. They are 380 * BootstrapProcessing or "bootstrap," InitProcessing or 381 * "initialization," and NormalProcessing or "normal." 382 * 383 * The first two processing modes are used during special times. When the 384 * system state indicates bootstrap processing, transactions are all given 385 * transaction id "one" and are consequently guaranteed to commit. This mode 386 * is used during the initial generation of template databases. 387 * 388 * Initialization mode: used while starting a backend, until all normal 389 * initialization is complete. Some code behaves differently when executed 390 * in this mode to enable system bootstrapping. 391 * 392 * If a POSTGRES backend process is in normal mode, then all code may be 393 * executed normally. 394 */ 395 396 typedef enum ProcessingMode 397 { 398 BootstrapProcessing, /* bootstrap creation of template database */ 399 InitProcessing, /* initializing system */ 400 NormalProcessing /* normal processing */ 401 } ProcessingMode; 402 403 extern ProcessingMode Mode; 404 405 #define IsBootstrapProcessingMode() (Mode == BootstrapProcessing) 406 #define IsInitProcessingMode() (Mode == InitProcessing) 407 #define IsNormalProcessingMode() (Mode == NormalProcessing) 408 409 #define GetProcessingMode() Mode 410 411 #define SetProcessingMode(mode) \ 412 do { \ 413 AssertArg((mode) == BootstrapProcessing || \ 414 (mode) == InitProcessing || \ 415 (mode) == NormalProcessing); \ 416 Mode = (mode); \ 417 } while(0) 418 419 420 /* 421 * Auxiliary-process type identifiers. These used to be in bootstrap.h 422 * but it seems saner to have them here, with the ProcessingMode stuff. 423 * The MyAuxProcType global is defined and set in bootstrap.c. 424 */ 425 426 typedef enum 427 { 428 NotAnAuxProcess = -1, 429 CheckerProcess = 0, 430 BootstrapProcess, 431 StartupProcess, 432 BgWriterProcess, 433 CheckpointerProcess, 434 WalWriterProcess, 435 WalReceiverProcess, 436 437 NUM_AUXPROCTYPES /* Must be last! */ 438 } AuxProcType; 439 440 extern AuxProcType MyAuxProcType; 441 442 #define AmBootstrapProcess() (MyAuxProcType == BootstrapProcess) 443 #define AmStartupProcess() (MyAuxProcType == StartupProcess) 444 #define AmBackgroundWriterProcess() (MyAuxProcType == BgWriterProcess) 445 #define AmCheckpointerProcess() (MyAuxProcType == CheckpointerProcess) 446 #define AmWalWriterProcess() (MyAuxProcType == WalWriterProcess) 447 #define AmWalReceiverProcess() (MyAuxProcType == WalReceiverProcess) 448 449 450 /***************************************************************************** 451 * pinit.h -- * 452 * POSTGRES initialization and cleanup definitions. * 453 *****************************************************************************/ 454 455 /* in utils/init/postinit.c */ 456 extern void pg_split_opts(char **argv, int *argcp, const char *optstr); 457 extern void InitializeMaxBackends(void); 458 extern void InitPostgres(const char *in_dbname, Oid dboid, const char *username, 459 Oid useroid, char *out_dbname, bool override_allow_connections); 460 extern void BaseInit(void); 461 462 /* in utils/init/miscinit.c */ 463 extern bool IgnoreSystemIndexes; 464 extern PGDLLIMPORT bool process_shared_preload_libraries_in_progress; 465 extern char *session_preload_libraries_string; 466 extern char *shared_preload_libraries_string; 467 extern char *local_preload_libraries_string; 468 469 extern void CreateDataDirLockFile(bool amPostmaster); 470 extern void CreateSocketLockFile(const char *socketfile, bool amPostmaster, 471 const char *socketDir); 472 extern void TouchSocketLockFiles(void); 473 extern void AddToDataDirLockFile(int target_line, const char *str); 474 extern bool RecheckDataDirLockFile(void); 475 extern void ValidatePgVersion(const char *path); 476 extern void process_shared_preload_libraries(void); 477 extern void process_session_preload_libraries(void); 478 extern void pg_bindtextdomain(const char *domain); 479 extern bool has_rolreplication(Oid roleid); 480 481 /* in access/transam/xlog.c */ 482 extern bool BackupInProgress(void); 483 extern void CancelBackup(void); 484 485 /* in executor/nodeHash.c */ 486 extern size_t get_hash_memory_limit(void); 487 extern int get_hash_mem(void); 488 489 #endif /* MISCADMIN_H */ 490