1 /*-------------------------------------------------------------------------
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().
13 * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
14 * Portions Copyright (c) 1994, Regents of the University of California
16 * src/include/miscadmin.h
19 * some of the information in this file should be moved to other files.
21 *-------------------------------------------------------------------------
28 #include "datatype/timestamp.h" /* for TimestampTz */
29 #include "pgtime.h" /* for pg_time_t */
32 #define InvalidPid (-1)
35 /*****************************************************************************
36 * System interrupt and critical section handling
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.
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.
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().
60 * Special mechanisms are used to let an interrupt be accepted when we are
61 * waiting for a lock or when we are waiting for command input (but, of
62 * course, only if the interrupt holdoff counter is zero). See the
63 * related code for details.
65 * A lost connection is handled similarly, although the loss of connection
66 * does not raise a signal, but is detected when we fail to write to the
67 * socket. If there was a signal for a broken connection, we could make use of
68 * it by setting ClientConnectionLost in the signal handler.
70 * A related, but conceptually distinct, mechanism is the "critical section"
71 * mechanism. A critical section not only holds off cancel/die interrupts,
72 * but causes any ereport(ERROR) or ereport(FATAL) to become ereport(PANIC)
73 * --- that is, a system-wide reset is forced. Needless to say, only really
74 * *critical* code should be marked as a critical section! Currently, this
75 * mechanism is only used for XLOG-related code.
77 *****************************************************************************/
80 /* these are marked volatile because they are set by signal handlers: */
81 extern PGDLLIMPORT volatile sig_atomic_t InterruptPending;
82 extern PGDLLIMPORT volatile sig_atomic_t QueryCancelPending;
83 extern PGDLLIMPORT volatile sig_atomic_t ProcDiePending;
84 extern PGDLLIMPORT volatile sig_atomic_t IdleInTransactionSessionTimeoutPending;
85 extern PGDLLIMPORT volatile sig_atomic_t ConfigReloadPending;
87 extern PGDLLIMPORT volatile sig_atomic_t ClientConnectionLost;
89 /* these are marked volatile because they are examined by signal handlers: */
90 extern PGDLLIMPORT volatile uint32 InterruptHoldoffCount;
91 extern PGDLLIMPORT volatile uint32 QueryCancelHoldoffCount;
92 extern PGDLLIMPORT volatile uint32 CritSectionCount;
94 /* in tcop/postgres.c */
95 extern void ProcessInterrupts(void);
99 #define CHECK_FOR_INTERRUPTS() \
101 if (InterruptPending) \
102 ProcessInterrupts(); \
106 #define CHECK_FOR_INTERRUPTS() \
108 if (UNBLOCKED_SIGNAL_QUEUE()) \
109 pgwin32_dispatch_queued_signals(); \
110 if (InterruptPending) \
111 ProcessInterrupts(); \
116 #define HOLD_INTERRUPTS() (InterruptHoldoffCount++)
118 #define RESUME_INTERRUPTS() \
120 Assert(InterruptHoldoffCount > 0); \
121 InterruptHoldoffCount--; \
124 #define HOLD_CANCEL_INTERRUPTS() (QueryCancelHoldoffCount++)
126 #define RESUME_CANCEL_INTERRUPTS() \
128 Assert(QueryCancelHoldoffCount > 0); \
129 QueryCancelHoldoffCount--; \
132 #define START_CRIT_SECTION() (CritSectionCount++)
134 #define END_CRIT_SECTION() \
136 Assert(CritSectionCount > 0); \
137 CritSectionCount--; \
141 /*****************************************************************************
143 *****************************************************************************/
146 * from utils/init/globals.c
148 extern PGDLLIMPORT pid_t PostmasterPid;
149 extern PGDLLIMPORT bool IsPostmasterEnvironment;
150 extern PGDLLIMPORT bool IsUnderPostmaster;
151 extern PGDLLIMPORT bool IsBackgroundWorker;
152 extern PGDLLIMPORT bool IsBinaryUpgrade;
154 extern PGDLLIMPORT bool ExitOnAnyError;
156 extern PGDLLIMPORT char *DataDir;
157 extern PGDLLIMPORT int data_directory_mode;
159 extern PGDLLIMPORT int NBuffers;
160 extern PGDLLIMPORT int MaxBackends;
161 extern PGDLLIMPORT int MaxConnections;
162 extern PGDLLIMPORT int max_worker_processes;
163 extern PGDLLIMPORT int max_parallel_workers;
165 extern PGDLLIMPORT int MyProcPid;
166 extern PGDLLIMPORT pg_time_t MyStartTime;
167 extern PGDLLIMPORT TimestampTz MyStartTimestamp;
168 extern PGDLLIMPORT struct Port *MyProcPort;
169 extern PGDLLIMPORT struct Latch *MyLatch;
170 extern int32 MyCancelKey;
171 extern int MyPMChildSlot;
173 extern char OutputFileName[];
174 extern PGDLLIMPORT char my_exec_path[];
175 extern char pkglib_path[];
178 extern char postgres_exec_path[];
182 * done in storage/backendid.h for now.
184 * extern BackendId MyBackendId;
186 extern PGDLLIMPORT Oid MyDatabaseId;
188 extern PGDLLIMPORT Oid MyDatabaseTableSpace;
191 * Date/Time Configuration
193 * DateStyle defines the output formatting choice for date/time types:
194 * USE_POSTGRES_DATES specifies traditional Postgres format
195 * USE_ISO_DATES specifies ISO-compliant format
196 * USE_SQL_DATES specifies Oracle/Ingres-compliant format
197 * USE_GERMAN_DATES specifies German-style dd.mm/yyyy
199 * DateOrder defines the field order to be assumed when reading an
200 * ambiguous date (anything not in YYYY-MM-DD format, with a four-digit
201 * year field first, is taken to be ambiguous):
202 * DATEORDER_YMD specifies field order yy-mm-dd
203 * DATEORDER_DMY specifies field order dd-mm-yy ("European" convention)
204 * DATEORDER_MDY specifies field order mm-dd-yy ("US" convention)
206 * In the Postgres and SQL DateStyles, DateOrder also selects output field
207 * order: day comes before month in DMY style, else month comes before day.
209 * The user-visible "DateStyle" run-time parameter subsumes both of these.
212 /* valid DateStyle values */
213 #define USE_POSTGRES_DATES 0
214 #define USE_ISO_DATES 1
215 #define USE_SQL_DATES 2
216 #define USE_GERMAN_DATES 3
217 #define USE_XSD_DATES 4
219 /* valid DateOrder values */
220 #define DATEORDER_YMD 0
221 #define DATEORDER_DMY 1
222 #define DATEORDER_MDY 2
224 extern PGDLLIMPORT int DateStyle;
225 extern PGDLLIMPORT int DateOrder;
229 * INTSTYLE_POSTGRES Like Postgres < 8.4 when DateStyle = 'iso'
230 * INTSTYLE_POSTGRES_VERBOSE Like Postgres < 8.4 when DateStyle != 'iso'
231 * INTSTYLE_SQL_STANDARD SQL standard interval literals
232 * INTSTYLE_ISO_8601 ISO-8601-basic formatted intervals
234 #define INTSTYLE_POSTGRES 0
235 #define INTSTYLE_POSTGRES_VERBOSE 1
236 #define INTSTYLE_SQL_STANDARD 2
237 #define INTSTYLE_ISO_8601 3
239 extern PGDLLIMPORT int IntervalStyle;
241 #define MAXTZLEN 10 /* max TZ name len, not counting tr. null */
243 extern bool enableFsync;
244 extern PGDLLIMPORT bool allowSystemTableMods;
245 extern PGDLLIMPORT int work_mem;
246 extern PGDLLIMPORT int maintenance_work_mem;
247 extern PGDLLIMPORT int max_parallel_maintenance_workers;
249 extern int VacuumCostPageHit;
250 extern int VacuumCostPageMiss;
251 extern int VacuumCostPageDirty;
252 extern int VacuumCostLimit;
253 extern double VacuumCostDelay;
255 extern int VacuumPageHit;
256 extern int VacuumPageMiss;
257 extern int VacuumPageDirty;
259 extern int VacuumCostBalance;
260 extern bool VacuumCostActive;
262 extern double vacuum_cleanup_index_scale_factor;
265 /* in tcop/postgres.c */
267 #if defined(__ia64__) || defined(__ia64)
270 char *stack_base_ptr;
271 char *register_stack_base_ptr;
274 typedef char *pg_stack_base_t;
277 extern pg_stack_base_t set_stack_base(void);
278 extern void restore_stack_base(pg_stack_base_t base);
279 extern void check_stack_depth(void);
280 extern bool stack_is_too_deep(void);
282 extern void PostgresSigHupHandler(SIGNAL_ARGS);
284 /* in tcop/utility.c */
285 extern void PreventCommandIfReadOnly(const char *cmdname);
286 extern void PreventCommandIfParallelMode(const char *cmdname);
287 extern void PreventCommandDuringRecovery(const char *cmdname);
289 /* in utils/misc/guc.c */
290 extern int trace_recovery_messages;
291 extern int trace_recovery(int trace_level);
293 /*****************************************************************************
295 * POSTGRES directory path definitions. *
296 *****************************************************************************/
298 /* flags to be OR'd to form sec_context */
299 #define SECURITY_LOCAL_USERID_CHANGE 0x0001
300 #define SECURITY_RESTRICTED_OPERATION 0x0002
301 #define SECURITY_NOFORCE_RLS 0x0004
303 extern char *DatabasePath;
305 /* now in utils/init/miscinit.c */
306 extern void InitPostmasterChild(void);
307 extern void InitStandaloneProcess(const char *argv0);
309 extern void SetDatabasePath(const char *path);
311 extern char *GetUserNameFromId(Oid roleid, bool noerr);
312 extern Oid GetUserId(void);
313 extern Oid GetOuterUserId(void);
314 extern Oid GetSessionUserId(void);
315 extern Oid GetAuthenticatedUserId(void);
316 extern void GetUserIdAndSecContext(Oid *userid, int *sec_context);
317 extern void SetUserIdAndSecContext(Oid userid, int sec_context);
318 extern bool InLocalUserIdChange(void);
319 extern bool InSecurityRestrictedOperation(void);
320 extern bool InNoForceRLSOperation(void);
321 extern void GetUserIdAndContext(Oid *userid, bool *sec_def_context);
322 extern void SetUserIdAndContext(Oid userid, bool sec_def_context);
323 extern void InitializeSessionUserId(const char *rolename, Oid useroid);
324 extern void InitializeSessionUserIdStandalone(void);
325 extern void SetSessionAuthorization(Oid userid, bool is_superuser);
326 extern Oid GetCurrentRoleId(void);
327 extern void SetCurrentRoleId(Oid roleid, bool is_superuser);
329 extern void checkDataDir(void);
330 extern void SetDataDir(const char *dir);
331 extern void ChangeToDataDir(void);
333 extern void SwitchToSharedLatch(void);
334 extern void SwitchBackToLocalLatch(void);
336 /* in utils/misc/superuser.c */
337 extern bool superuser(void); /* current user is superuser */
338 extern bool superuser_arg(Oid roleid); /* given user is superuser */
341 /*****************************************************************************
343 * POSTGRES processing mode definitions. *
344 *****************************************************************************/
348 * There are three processing modes in POSTGRES. They are
349 * BootstrapProcessing or "bootstrap," InitProcessing or
350 * "initialization," and NormalProcessing or "normal."
352 * The first two processing modes are used during special times. When the
353 * system state indicates bootstrap processing, transactions are all given
354 * transaction id "one" and are consequently guaranteed to commit. This mode
355 * is used during the initial generation of template databases.
357 * Initialization mode: used while starting a backend, until all normal
358 * initialization is complete. Some code behaves differently when executed
359 * in this mode to enable system bootstrapping.
361 * If a POSTGRES backend process is in normal mode, then all code may be
365 typedef enum ProcessingMode
367 BootstrapProcessing, /* bootstrap creation of template database */
368 InitProcessing, /* initializing system */
369 NormalProcessing /* normal processing */
372 extern ProcessingMode Mode;
374 #define IsBootstrapProcessingMode() (Mode == BootstrapProcessing)
375 #define IsInitProcessingMode() (Mode == InitProcessing)
376 #define IsNormalProcessingMode() (Mode == NormalProcessing)
378 #define GetProcessingMode() Mode
380 #define SetProcessingMode(mode) \
382 AssertArg((mode) == BootstrapProcessing || \
383 (mode) == InitProcessing || \
384 (mode) == NormalProcessing); \
390 * Auxiliary-process type identifiers. These used to be in bootstrap.h
391 * but it seems saner to have them here, with the ProcessingMode stuff.
392 * The MyAuxProcType global is defined and set in bootstrap.c.
397 NotAnAuxProcess = -1,
406 NUM_AUXPROCTYPES /* Must be last! */
409 extern AuxProcType MyAuxProcType;
411 #define AmBootstrapProcess() (MyAuxProcType == BootstrapProcess)
412 #define AmStartupProcess() (MyAuxProcType == StartupProcess)
413 #define AmBackgroundWriterProcess() (MyAuxProcType == BgWriterProcess)
414 #define AmCheckpointerProcess() (MyAuxProcType == CheckpointerProcess)
415 #define AmWalWriterProcess() (MyAuxProcType == WalWriterProcess)
416 #define AmWalReceiverProcess() (MyAuxProcType == WalReceiverProcess)
419 /*****************************************************************************
421 * POSTGRES initialization and cleanup definitions. *
422 *****************************************************************************/
424 /* in utils/init/postinit.c */
425 extern void pg_split_opts(char **argv, int *argcp, const char *optstr);
426 extern void InitializeMaxBackends(void);
427 extern void InitPostgres(const char *in_dbname, Oid dboid, const char *username,
428 Oid useroid, char *out_dbname, bool override_allow_connections);
429 extern void BaseInit(void);
431 /* in utils/init/miscinit.c */
432 extern bool IgnoreSystemIndexes;
433 extern PGDLLIMPORT bool process_shared_preload_libraries_in_progress;
434 extern char *session_preload_libraries_string;
435 extern char *shared_preload_libraries_string;
436 extern char *local_preload_libraries_string;
438 extern void CreateDataDirLockFile(bool amPostmaster);
439 extern void CreateSocketLockFile(const char *socketfile, bool amPostmaster,
440 const char *socketDir);
441 extern void TouchSocketLockFiles(void);
442 extern void AddToDataDirLockFile(int target_line, const char *str);
443 extern bool RecheckDataDirLockFile(void);
444 extern void ValidatePgVersion(const char *path);
445 extern void process_shared_preload_libraries(void);
446 extern void process_session_preload_libraries(void);
447 extern void pg_bindtextdomain(const char *domain);
448 extern bool has_rolreplication(Oid roleid);
450 /* in access/transam/xlog.c */
451 extern bool BackupInProgress(void);
452 extern void CancelBackup(void);
454 #endif /* MISCADMIN_H */