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) 1996-2015, 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 *-------------------------------------------------------------------------
26 #include "pgtime.h" /* for pg_time_t */
29 #define PG_BACKEND_VERSIONSTR "postgres (PostgreSQL) " PG_VERSION "\n"
31 #define InvalidPid (-1)
34 /*****************************************************************************
35 * System interrupt and critical section handling
37 * There are two types of interrupts that a running backend needs to accept
38 * without messing up its state: QueryCancel (SIGINT) and ProcDie (SIGTERM).
39 * In both cases, we need to be able to clean up the current transaction
40 * gracefully, so we can't respond to the interrupt instantaneously ---
41 * there's no guarantee that internal data structures would be self-consistent
42 * if the code is interrupted at an arbitrary instant. Instead, the signal
43 * handlers set flags that are checked periodically during execution.
45 * The CHECK_FOR_INTERRUPTS() macro is called at strategically located spots
46 * where it is normally safe to accept a cancel or die interrupt. In some
47 * cases, we invoke CHECK_FOR_INTERRUPTS() inside low-level subroutines that
48 * might sometimes be called in contexts that do *not* want to allow a cancel
49 * or die interrupt. The HOLD_INTERRUPTS() and RESUME_INTERRUPTS() macros
50 * allow code to ensure that no cancel or die interrupt will be accepted,
51 * even if CHECK_FOR_INTERRUPTS() gets called in a subroutine. The interrupt
52 * will be held off until CHECK_FOR_INTERRUPTS() is done outside any
53 * HOLD_INTERRUPTS() ... RESUME_INTERRUPTS() section.
55 * There is also a mechanism to prevent query cancel interrupts, while still
56 * allowing die interrupts: HOLD_CANCEL_INTERRUPTS() and
57 * RESUME_CANCEL_INTERRUPTS().
59 * Special mechanisms are used to let an interrupt be accepted when we are
60 * waiting for a lock or when we are waiting for command input (but, of
61 * course, only if the interrupt holdoff counter is zero). See the
62 * related code for details.
64 * A lost connection is handled similarly, although the loss of connection
65 * does not raise a signal, but is detected when we fail to write to the
66 * socket. If there was a signal for a broken connection, we could make use of
67 * it by setting ClientConnectionLost in the signal handler.
69 * A related, but conceptually distinct, mechanism is the "critical section"
70 * mechanism. A critical section not only holds off cancel/die interrupts,
71 * but causes any ereport(ERROR) or ereport(FATAL) to become ereport(PANIC)
72 * --- that is, a system-wide reset is forced. Needless to say, only really
73 * *critical* code should be marked as a critical section! Currently, this
74 * mechanism is only used for XLOG-related code.
76 *****************************************************************************/
79 /* these are marked volatile because they are set by signal handlers: */
80 extern PGDLLIMPORT volatile bool InterruptPending;
81 extern PGDLLIMPORT volatile bool QueryCancelPending;
82 extern PGDLLIMPORT volatile bool ProcDiePending;
84 extern volatile bool ClientConnectionLost;
86 /* these are marked volatile because they are examined by signal handlers: */
87 extern PGDLLIMPORT volatile uint32 InterruptHoldoffCount;
88 extern PGDLLIMPORT volatile uint32 QueryCancelHoldoffCount;
89 extern PGDLLIMPORT volatile uint32 CritSectionCount;
91 /* in tcop/postgres.c */
92 extern void ProcessInterrupts(void);
96 #define CHECK_FOR_INTERRUPTS() \
98 if (InterruptPending) \
99 ProcessInterrupts(); \
103 #define CHECK_FOR_INTERRUPTS() \
105 if (UNBLOCKED_SIGNAL_QUEUE()) \
106 pgwin32_dispatch_queued_signals(); \
107 if (InterruptPending) \
108 ProcessInterrupts(); \
113 #define HOLD_INTERRUPTS() (InterruptHoldoffCount++)
115 #define RESUME_INTERRUPTS() \
117 Assert(InterruptHoldoffCount > 0); \
118 InterruptHoldoffCount--; \
121 #define HOLD_CANCEL_INTERRUPTS() (QueryCancelHoldoffCount++)
123 #define RESUME_CANCEL_INTERRUPTS() \
125 Assert(QueryCancelHoldoffCount > 0); \
126 QueryCancelHoldoffCount--; \
129 #define START_CRIT_SECTION() (CritSectionCount++)
131 #define END_CRIT_SECTION() \
133 Assert(CritSectionCount > 0); \
134 CritSectionCount--; \
138 /*****************************************************************************
140 *****************************************************************************/
143 * from utils/init/globals.c
145 extern pid_t PostmasterPid;
146 extern bool IsPostmasterEnvironment;
147 extern PGDLLIMPORT bool IsUnderPostmaster;
148 extern bool IsBackgroundWorker;
149 extern PGDLLIMPORT bool IsBinaryUpgrade;
151 extern bool ExitOnAnyError;
153 extern PGDLLIMPORT char *DataDir;
155 extern PGDLLIMPORT int NBuffers;
156 extern int MaxBackends;
157 extern int MaxConnections;
158 extern int max_worker_processes;
160 extern PGDLLIMPORT int MyProcPid;
161 extern PGDLLIMPORT pg_time_t MyStartTime;
162 extern PGDLLIMPORT struct Port *MyProcPort;
163 extern PGDLLIMPORT struct Latch *MyLatch;
164 extern long MyCancelKey;
165 extern int MyPMChildSlot;
167 extern char OutputFileName[];
168 extern PGDLLIMPORT char my_exec_path[];
169 extern char pkglib_path[];
172 extern char postgres_exec_path[];
176 * done in storage/backendid.h for now.
178 * extern BackendId MyBackendId;
180 extern PGDLLIMPORT Oid MyDatabaseId;
182 extern PGDLLIMPORT Oid MyDatabaseTableSpace;
185 * Date/Time Configuration
187 * DateStyle defines the output formatting choice for date/time types:
188 * USE_POSTGRES_DATES specifies traditional Postgres format
189 * USE_ISO_DATES specifies ISO-compliant format
190 * USE_SQL_DATES specifies Oracle/Ingres-compliant format
191 * USE_GERMAN_DATES specifies German-style dd.mm/yyyy
193 * DateOrder defines the field order to be assumed when reading an
194 * ambiguous date (anything not in YYYY-MM-DD format, with a four-digit
195 * year field first, is taken to be ambiguous):
196 * DATEORDER_YMD specifies field order yy-mm-dd
197 * DATEORDER_DMY specifies field order dd-mm-yy ("European" convention)
198 * DATEORDER_MDY specifies field order mm-dd-yy ("US" convention)
200 * In the Postgres and SQL DateStyles, DateOrder also selects output field
201 * order: day comes before month in DMY style, else month comes before day.
203 * The user-visible "DateStyle" run-time parameter subsumes both of these.
206 /* valid DateStyle values */
207 #define USE_POSTGRES_DATES 0
208 #define USE_ISO_DATES 1
209 #define USE_SQL_DATES 2
210 #define USE_GERMAN_DATES 3
211 #define USE_XSD_DATES 4
213 /* valid DateOrder values */
214 #define DATEORDER_YMD 0
215 #define DATEORDER_DMY 1
216 #define DATEORDER_MDY 2
218 extern PGDLLIMPORT int DateStyle;
219 extern PGDLLIMPORT int DateOrder;
223 * INTSTYLE_POSTGRES Like Postgres < 8.4 when DateStyle = 'iso'
224 * INTSTYLE_POSTGRES_VERBOSE Like Postgres < 8.4 when DateStyle != 'iso'
225 * INTSTYLE_SQL_STANDARD SQL standard interval literals
226 * INTSTYLE_ISO_8601 ISO-8601-basic formatted intervals
228 #define INTSTYLE_POSTGRES 0
229 #define INTSTYLE_POSTGRES_VERBOSE 1
230 #define INTSTYLE_SQL_STANDARD 2
231 #define INTSTYLE_ISO_8601 3
233 extern PGDLLIMPORT int IntervalStyle;
235 #define MAXTZLEN 10 /* max TZ name len, not counting tr. null */
237 extern bool enableFsync;
238 extern bool allowSystemTableMods;
239 extern PGDLLIMPORT int work_mem;
240 extern PGDLLIMPORT int maintenance_work_mem;
242 extern int VacuumCostPageHit;
243 extern int VacuumCostPageMiss;
244 extern int VacuumCostPageDirty;
245 extern int VacuumCostLimit;
246 extern int VacuumCostDelay;
248 extern int VacuumPageHit;
249 extern int VacuumPageMiss;
250 extern int VacuumPageDirty;
252 extern int VacuumCostBalance;
253 extern bool VacuumCostActive;
256 /* in tcop/postgres.c */
258 #if defined(__ia64__) || defined(__ia64)
261 char *stack_base_ptr;
262 char *register_stack_base_ptr;
265 typedef char *pg_stack_base_t;
268 extern pg_stack_base_t set_stack_base(void);
269 extern void restore_stack_base(pg_stack_base_t base);
270 extern void check_stack_depth(void);
272 /* in tcop/utility.c */
273 extern void PreventCommandIfReadOnly(const char *cmdname);
274 extern void PreventCommandDuringRecovery(const char *cmdname);
276 /* in utils/misc/guc.c */
277 extern int trace_recovery_messages;
278 extern int trace_recovery(int trace_level);
280 /*****************************************************************************
282 * POSTGRES directory path definitions. *
283 *****************************************************************************/
285 /* flags to be OR'd to form sec_context */
286 #define SECURITY_LOCAL_USERID_CHANGE 0x0001
287 #define SECURITY_RESTRICTED_OPERATION 0x0002
288 #define SECURITY_ROW_LEVEL_DISABLED 0x0004
290 extern char *DatabasePath;
292 /* now in utils/init/miscinit.c */
293 extern void InitPostmasterChild(void);
294 extern void InitStandaloneProcess(const char *argv0);
296 extern void SetDatabasePath(const char *path);
298 extern char *GetUserNameFromId(Oid roleid);
299 extern Oid GetUserId(void);
300 extern Oid GetOuterUserId(void);
301 extern Oid GetSessionUserId(void);
302 extern Oid GetAuthenticatedUserId(void);
303 extern void GetUserIdAndSecContext(Oid *userid, int *sec_context);
304 extern void SetUserIdAndSecContext(Oid userid, int sec_context);
305 extern bool InLocalUserIdChange(void);
306 extern bool InSecurityRestrictedOperation(void);
307 extern void GetUserIdAndContext(Oid *userid, bool *sec_def_context);
308 extern void SetUserIdAndContext(Oid userid, bool sec_def_context);
309 extern void InitializeSessionUserId(const char *rolename, Oid useroid);
310 extern void InitializeSessionUserIdStandalone(void);
311 extern void SetSessionAuthorization(Oid userid, bool is_superuser);
312 extern Oid GetCurrentRoleId(void);
313 extern void SetCurrentRoleId(Oid roleid, bool is_superuser);
315 extern void SetDataDir(const char *dir);
316 extern void ChangeToDataDir(void);
318 extern void SwitchToSharedLatch(void);
319 extern void SwitchBackToLocalLatch(void);
321 /* in utils/misc/superuser.c */
322 extern bool superuser(void); /* current user is superuser */
323 extern bool superuser_arg(Oid roleid); /* given user is superuser */
326 /*****************************************************************************
328 * POSTGRES processing mode definitions. *
329 *****************************************************************************/
333 * There are three processing modes in POSTGRES. They are
334 * BootstrapProcessing or "bootstrap," InitProcessing or
335 * "initialization," and NormalProcessing or "normal."
337 * The first two processing modes are used during special times. When the
338 * system state indicates bootstrap processing, transactions are all given
339 * transaction id "one" and are consequently guaranteed to commit. This mode
340 * is used during the initial generation of template databases.
342 * Initialization mode: used while starting a backend, until all normal
343 * initialization is complete. Some code behaves differently when executed
344 * in this mode to enable system bootstrapping.
346 * If a POSTGRES backend process is in normal mode, then all code may be
350 typedef enum ProcessingMode
352 BootstrapProcessing, /* bootstrap creation of template database */
353 InitProcessing, /* initializing system */
354 NormalProcessing /* normal processing */
357 extern ProcessingMode Mode;
359 #define IsBootstrapProcessingMode() (Mode == BootstrapProcessing)
360 #define IsInitProcessingMode() (Mode == InitProcessing)
361 #define IsNormalProcessingMode() (Mode == NormalProcessing)
363 #define GetProcessingMode() Mode
365 #define SetProcessingMode(mode) \
367 AssertArg((mode) == BootstrapProcessing || \
368 (mode) == InitProcessing || \
369 (mode) == NormalProcessing); \
375 * Auxiliary-process type identifiers. These used to be in bootstrap.h
376 * but it seems saner to have them here, with the ProcessingMode stuff.
377 * The MyAuxProcType global is defined and set in bootstrap.c.
382 NotAnAuxProcess = -1,
391 NUM_AUXPROCTYPES /* Must be last! */
394 extern AuxProcType MyAuxProcType;
396 #define AmBootstrapProcess() (MyAuxProcType == BootstrapProcess)
397 #define AmStartupProcess() (MyAuxProcType == StartupProcess)
398 #define AmBackgroundWriterProcess() (MyAuxProcType == BgWriterProcess)
399 #define AmCheckpointerProcess() (MyAuxProcType == CheckpointerProcess)
400 #define AmWalWriterProcess() (MyAuxProcType == WalWriterProcess)
401 #define AmWalReceiverProcess() (MyAuxProcType == WalReceiverProcess)
404 /*****************************************************************************
406 * POSTGRES initialization and cleanup definitions. *
407 *****************************************************************************/
409 /* in utils/init/postinit.c */
410 extern void pg_split_opts(char **argv, int *argcp, char *optstr);
411 extern void InitializeMaxBackends(void);
412 extern void InitPostgres(const char *in_dbname, Oid dboid, const char *username,
413 Oid useroid, char *out_dbname);
414 extern void BaseInit(void);
416 /* in utils/init/miscinit.c */
417 extern bool IgnoreSystemIndexes;
418 extern PGDLLIMPORT bool process_shared_preload_libraries_in_progress;
419 extern char *session_preload_libraries_string;
420 extern char *shared_preload_libraries_string;
421 extern char *local_preload_libraries_string;
424 * As of 9.1, the contents of the data-directory lock file are:
427 * 1 postmaster PID (or negative of a standalone backend's PID)
428 * 2 data directory path
429 * 3 postmaster start timestamp (time_t representation)
431 * 5 first Unix socket directory path (empty if none)
432 * 6 first listen_address (IP address or "*"; empty if no TCP port)
433 * 7 shared memory key (not present on Windows)
435 * Lines 6 and up are added via AddToDataDirLockFile() after initial file
438 * The socket lock file, if used, has the same contents as lines 1-5.
440 #define LOCK_FILE_LINE_PID 1
441 #define LOCK_FILE_LINE_DATA_DIR 2
442 #define LOCK_FILE_LINE_START_TIME 3
443 #define LOCK_FILE_LINE_PORT 4
444 #define LOCK_FILE_LINE_SOCKET_DIR 5
445 #define LOCK_FILE_LINE_LISTEN_ADDR 6
446 #define LOCK_FILE_LINE_SHMEM_KEY 7
448 extern void CreateDataDirLockFile(bool amPostmaster);
449 extern void CreateSocketLockFile(const char *socketfile, bool amPostmaster,
450 const char *socketDir);
451 extern void TouchSocketLockFiles(void);
452 extern void AddToDataDirLockFile(int target_line, const char *str);
453 extern void ValidatePgVersion(const char *path);
454 extern void process_shared_preload_libraries(void);
455 extern void process_session_preload_libraries(void);
456 extern void pg_bindtextdomain(const char *domain);
457 extern bool has_rolreplication(Oid roleid);
459 /* in access/transam/xlog.c */
460 extern bool BackupInProgress(void);
461 extern void CancelBackup(void);
463 #endif /* MISCADMIN_H */