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) 1996-2019, 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 ConfigReloadPending; 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 int maintenance_work_mem; 259 extern PGDLLIMPORT int max_parallel_maintenance_workers; 260 261 extern int VacuumCostPageHit; 262 extern int VacuumCostPageMiss; 263 extern int VacuumCostPageDirty; 264 extern int VacuumCostLimit; 265 extern double VacuumCostDelay; 266 267 extern int VacuumPageHit; 268 extern int VacuumPageMiss; 269 extern int VacuumPageDirty; 270 271 extern int VacuumCostBalance; 272 extern bool VacuumCostActive; 273 274 extern double vacuum_cleanup_index_scale_factor; 275 276 277 /* in tcop/postgres.c */ 278 279 #if defined(__ia64__) || defined(__ia64) 280 typedef struct 281 { 282 char *stack_base_ptr; 283 char *register_stack_base_ptr; 284 } pg_stack_base_t; 285 #else 286 typedef char *pg_stack_base_t; 287 #endif 288 289 extern pg_stack_base_t set_stack_base(void); 290 extern void restore_stack_base(pg_stack_base_t base); 291 extern void check_stack_depth(void); 292 extern bool stack_is_too_deep(void); 293 294 extern void PostgresSigHupHandler(SIGNAL_ARGS); 295 296 /* in tcop/utility.c */ 297 extern void PreventCommandIfReadOnly(const char *cmdname); 298 extern void PreventCommandIfParallelMode(const char *cmdname); 299 extern void PreventCommandDuringRecovery(const char *cmdname); 300 301 /* in utils/misc/guc.c */ 302 extern int trace_recovery_messages; 303 extern int trace_recovery(int trace_level); 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 char *DatabasePath; 316 317 /* now in utils/init/miscinit.c */ 318 extern void InitPostmasterChild(void); 319 extern void InitStandaloneProcess(const char *argv0); 320 321 extern void SetDatabasePath(const char *path); 322 323 extern char *GetUserNameFromId(Oid roleid, bool noerr); 324 extern Oid GetUserId(void); 325 extern Oid GetOuterUserId(void); 326 extern Oid GetSessionUserId(void); 327 extern Oid GetAuthenticatedUserId(void); 328 extern void GetUserIdAndSecContext(Oid *userid, int *sec_context); 329 extern void SetUserIdAndSecContext(Oid userid, int sec_context); 330 extern bool InLocalUserIdChange(void); 331 extern bool InSecurityRestrictedOperation(void); 332 extern bool InNoForceRLSOperation(void); 333 extern void GetUserIdAndContext(Oid *userid, bool *sec_def_context); 334 extern void SetUserIdAndContext(Oid userid, bool sec_def_context); 335 extern void InitializeSessionUserId(const char *rolename, Oid useroid); 336 extern void InitializeSessionUserIdStandalone(void); 337 extern void SetSessionAuthorization(Oid userid, bool is_superuser); 338 extern Oid GetCurrentRoleId(void); 339 extern void SetCurrentRoleId(Oid roleid, bool is_superuser); 340 341 extern void checkDataDir(void); 342 extern void SetDataDir(const char *dir); 343 extern void ChangeToDataDir(void); 344 345 extern void SwitchToSharedLatch(void); 346 extern void SwitchBackToLocalLatch(void); 347 348 /* in utils/misc/superuser.c */ 349 extern bool superuser(void); /* current user is superuser */ 350 extern bool superuser_arg(Oid roleid); /* given user is superuser */ 351 352 353 /***************************************************************************** 354 * pmod.h -- * 355 * POSTGRES processing mode definitions. * 356 *****************************************************************************/ 357 358 /* 359 * Description: 360 * There are three processing modes in POSTGRES. They are 361 * BootstrapProcessing or "bootstrap," InitProcessing or 362 * "initialization," and NormalProcessing or "normal." 363 * 364 * The first two processing modes are used during special times. When the 365 * system state indicates bootstrap processing, transactions are all given 366 * transaction id "one" and are consequently guaranteed to commit. This mode 367 * is used during the initial generation of template databases. 368 * 369 * Initialization mode: used while starting a backend, until all normal 370 * initialization is complete. Some code behaves differently when executed 371 * in this mode to enable system bootstrapping. 372 * 373 * If a POSTGRES backend process is in normal mode, then all code may be 374 * executed normally. 375 */ 376 377 typedef enum ProcessingMode 378 { 379 BootstrapProcessing, /* bootstrap creation of template database */ 380 InitProcessing, /* initializing system */ 381 NormalProcessing /* normal processing */ 382 } ProcessingMode; 383 384 extern ProcessingMode Mode; 385 386 #define IsBootstrapProcessingMode() (Mode == BootstrapProcessing) 387 #define IsInitProcessingMode() (Mode == InitProcessing) 388 #define IsNormalProcessingMode() (Mode == NormalProcessing) 389 390 #define GetProcessingMode() Mode 391 392 #define SetProcessingMode(mode) \ 393 do { \ 394 AssertArg((mode) == BootstrapProcessing || \ 395 (mode) == InitProcessing || \ 396 (mode) == NormalProcessing); \ 397 Mode = (mode); \ 398 } while(0) 399 400 401 /* 402 * Auxiliary-process type identifiers. These used to be in bootstrap.h 403 * but it seems saner to have them here, with the ProcessingMode stuff. 404 * The MyAuxProcType global is defined and set in bootstrap.c. 405 */ 406 407 typedef enum 408 { 409 NotAnAuxProcess = -1, 410 CheckerProcess = 0, 411 BootstrapProcess, 412 StartupProcess, 413 BgWriterProcess, 414 CheckpointerProcess, 415 WalWriterProcess, 416 WalReceiverProcess, 417 418 NUM_AUXPROCTYPES /* Must be last! */ 419 } AuxProcType; 420 421 extern AuxProcType MyAuxProcType; 422 423 #define AmBootstrapProcess() (MyAuxProcType == BootstrapProcess) 424 #define AmStartupProcess() (MyAuxProcType == StartupProcess) 425 #define AmBackgroundWriterProcess() (MyAuxProcType == BgWriterProcess) 426 #define AmCheckpointerProcess() (MyAuxProcType == CheckpointerProcess) 427 #define AmWalWriterProcess() (MyAuxProcType == WalWriterProcess) 428 #define AmWalReceiverProcess() (MyAuxProcType == WalReceiverProcess) 429 430 431 /***************************************************************************** 432 * pinit.h -- * 433 * POSTGRES initialization and cleanup definitions. * 434 *****************************************************************************/ 435 436 /* in utils/init/postinit.c */ 437 extern void pg_split_opts(char **argv, int *argcp, const char *optstr); 438 extern void InitializeMaxBackends(void); 439 extern void InitPostgres(const char *in_dbname, Oid dboid, const char *username, 440 Oid useroid, char *out_dbname, bool override_allow_connections); 441 extern void BaseInit(void); 442 443 /* in utils/init/miscinit.c */ 444 extern bool IgnoreSystemIndexes; 445 extern PGDLLIMPORT bool process_shared_preload_libraries_in_progress; 446 extern char *session_preload_libraries_string; 447 extern char *shared_preload_libraries_string; 448 extern char *local_preload_libraries_string; 449 450 extern void CreateDataDirLockFile(bool amPostmaster); 451 extern void CreateSocketLockFile(const char *socketfile, bool amPostmaster, 452 const char *socketDir); 453 extern void TouchSocketLockFiles(void); 454 extern void AddToDataDirLockFile(int target_line, const char *str); 455 extern bool RecheckDataDirLockFile(void); 456 extern void ValidatePgVersion(const char *path); 457 extern void process_shared_preload_libraries(void); 458 extern void process_session_preload_libraries(void); 459 extern void pg_bindtextdomain(const char *domain); 460 extern bool has_rolreplication(Oid roleid); 461 462 /* in access/transam/xlog.c */ 463 extern bool BackupInProgress(void); 464 extern void CancelBackup(void); 465 466 #endif /* MISCADMIN_H */ 467