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) 1996-2008, PostgreSQL Global Development Group
  14  * Portions Copyright (c) 1994, Regents of the University of California
  15  *
  16  * $PostgreSQL$
  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 "pgtime.h"                             /* for pg_time_t */
  27
  28
  29 #define PG_BACKEND_VERSIONSTR "postgres (PostgreSQL) " PG_VERSION "\n"
  30
  31
  32 /*****************************************************************************
  33  *        System interrupt and critical section handling
  34  *
  35  * There are two types of interrupts that a running backend needs to accept
  36  * without messing up its state: QueryCancel (SIGINT) and ProcDie (SIGTERM).
  37  * In both cases, we need to be able to clean up the current transaction
  38  * gracefully, so we can't respond to the interrupt instantaneously ---
  39  * there's no guarantee that internal data structures would be self-consistent
  40  * if the code is interrupted at an arbitrary instant.  Instead, the signal
  41  * handlers set flags that are checked periodically during execution.
  42  *
  43  * The CHECK_FOR_INTERRUPTS() macro is called at strategically located spots
  44  * where it is normally safe to accept a cancel or die interrupt.  In some
  45  * cases, we invoke CHECK_FOR_INTERRUPTS() inside low-level subroutines that
  46  * might sometimes be called in contexts that do *not* want to allow a cancel
  47  * or die interrupt.  The HOLD_INTERRUPTS() and RESUME_INTERRUPTS() macros
  48  * allow code to ensure that no cancel or die interrupt will be accepted,
  49  * even if CHECK_FOR_INTERRUPTS() gets called in a subroutine.  The interrupt
  50  * will be held off until CHECK_FOR_INTERRUPTS() is done outside any
  51  * HOLD_INTERRUPTS() ... RESUME_INTERRUPTS() section.
  52  *
  53  * Special mechanisms are used to let an interrupt be accepted when we are
  54  * waiting for a lock or when we are waiting for command input (but, of
  55  * course, only if the interrupt holdoff counter is zero).      See the
  56  * related code for details.
  57  *
  58  * A related, but conceptually distinct, mechanism is the "critical section"
  59  * mechanism.  A critical section not only holds off cancel/die interrupts,
  60  * but causes any ereport(ERROR) or ereport(FATAL) to become ereport(PANIC)
  61  * --- that is, a system-wide reset is forced.  Needless to say, only really
  62  * *critical* code should be marked as a critical section!      Currently, this
  63  * mechanism is only used for XLOG-related code.
  64  *
  65  *****************************************************************************/
  66
  67 /* in globals.c */
  68 /* these are marked volatile because they are set by signal handlers: */
  69 extern PGDLLIMPORT volatile bool InterruptPending;
  70 extern volatile bool QueryCancelPending;
  71 extern volatile bool ProcDiePending;
  72
  73 /* these are marked volatile because they are examined by signal handlers: */
  74 extern volatile bool ImmediateInterruptOK;
  75 extern PGDLLIMPORT volatile uint32 InterruptHoldoffCount;
  76 extern PGDLLIMPORT volatile uint32 CritSectionCount;
  77
  78 /* in tcop/postgres.c */
  79 extern void ProcessInterrupts(void);
  80
  81 #ifndef WIN32
  82
  83 #define CHECK_FOR_INTERRUPTS() \
  84 do { \
  85         if (InterruptPending) \
  86                 ProcessInterrupts(); \
  87 } while(0)
  88 #else                                                   /* WIN32 */
  89
  90 #define CHECK_FOR_INTERRUPTS() \
  91 do { \
  92         if (UNBLOCKED_SIGNAL_QUEUE()) \
  93                 pgwin32_dispatch_queued_signals(); \
  94         if (InterruptPending) \
  95                 ProcessInterrupts(); \
  96 } while(0)
  97 #endif   /* WIN32 */
  98
  99
 100 #define HOLD_INTERRUPTS()  (InterruptHoldoffCount++)
 101
 102 #define RESUME_INTERRUPTS() \
 103 do { \
 104         Assert(InterruptHoldoffCount > 0); \
 105         InterruptHoldoffCount--; \
 106 } while(0)
 107
 108 #define START_CRIT_SECTION()  (CritSectionCount++)
 109
 110 #define END_CRIT_SECTION() \
 111 do { \
 112         Assert(CritSectionCount > 0); \
 113         CritSectionCount--; \
 114 } while(0)
 115
 116
 117 /*****************************************************************************
 118  *        globals.h --                                                                                                                   *
 119  *****************************************************************************/
 120
 121 /*
 122  * from utils/init/globals.c
 123  */
 124 extern pid_t PostmasterPid;
 125 extern bool IsPostmasterEnvironment;
 126 extern bool IsUnderPostmaster;
 127
 128 extern bool ExitOnAnyError;
 129
 130 extern PGDLLIMPORT char *DataDir;
 131
 132 extern PGDLLIMPORT int NBuffers;
 133 extern int      MaxBackends;
 134 extern int      MaxConnections;
 135
 136 extern PGDLLIMPORT int MyProcPid;
 137 extern PGDLLIMPORT pg_time_t MyStartTime;
 138 extern PGDLLIMPORT struct Port *MyProcPort;
 139 extern long MyCancelKey;
 140
 141 extern char OutputFileName[];
 142 extern PGDLLIMPORT char my_exec_path[];
 143 extern char pkglib_path[];
 144
 145 #ifdef EXEC_BACKEND
 146 extern char postgres_exec_path[];
 147 #endif
 148
 149 /*
 150  * done in storage/backendid.h for now.
 151  *
 152  * extern BackendId    MyBackendId;
 153  */
 154 extern PGDLLIMPORT Oid MyDatabaseId;
 155
 156 extern PGDLLIMPORT Oid MyDatabaseTableSpace;
 157
 158 /*
 159  * Date/Time Configuration
 160  *
 161  * DateStyle defines the output formatting choice for date/time types:
 162  *      USE_POSTGRES_DATES specifies traditional Postgres format
 163  *      USE_ISO_DATES specifies ISO-compliant format
 164  *      USE_SQL_DATES specifies Oracle/Ingres-compliant format
 165  *      USE_GERMAN_DATES specifies German-style dd.mm/yyyy
 166  *
 167  * DateOrder defines the field order to be assumed when reading an
 168  * ambiguous date (anything not in YYYY-MM-DD format, with a four-digit
 169  * year field first, is taken to be ambiguous):
 170  *      DATEORDER_YMD specifies field order yy-mm-dd
 171  *      DATEORDER_DMY specifies field order dd-mm-yy ("European" convention)
 172  *      DATEORDER_MDY specifies field order mm-dd-yy ("US" convention)
 173  *
 174  * In the Postgres and SQL DateStyles, DateOrder also selects output field
 175  * order: day comes before month in DMY style, else month comes before day.
 176  *
 177  * The user-visible "DateStyle" run-time parameter subsumes both of these.
 178  */
 179
 180 /* valid DateStyle values */
 181 #define USE_POSTGRES_DATES              0
 182 #define USE_ISO_DATES                   1
 183 #define USE_SQL_DATES                   2
 184 #define USE_GERMAN_DATES                3
 185 #define USE_XSD_DATES                   4
 186
 187 /* valid DateOrder values */
 188 #define DATEORDER_YMD                   0
 189 #define DATEORDER_DMY                   1
 190 #define DATEORDER_MDY                   2
 191
 192 extern int      DateStyle;
 193 extern int      DateOrder;
 194
 195 /*
 196  * IntervalStyles
 197  *   INTSTYLE_POSTGRES             Like Postgres < 8.4 when DateStyle = 'iso'
 198  *   INTSTYLE_POSTGRES_VERBOSE     Like Postgres < 8.4 when DateStyle != 'iso'
 199  *   INTSTYLE_SQL_STANDARD         SQL standard interval literals
 200  *   INTSTYLE_ISO_8601             ISO-8601-basic formatted intervals
 201  */
 202 #define INTSTYLE_POSTGRES                       0
 203 #define INTSTYLE_POSTGRES_VERBOSE       1
 204 #define INTSTYLE_SQL_STANDARD           2
 205 #define INTSTYLE_ISO_8601                       3
 206
 207 extern int      IntervalStyle;
 208
 209 /*
 210  * HasCTZSet is true if user has set timezone as a numeric offset from UTC.
 211  * If so, CTimeZone is the timezone offset in seconds (using the Unix-ish
 212  * sign convention, ie, positive offset is west of UTC, rather than the
 213  * SQL-ish convention that positive is east of UTC).
 214  */
 215 extern bool HasCTZSet;
 216 extern int      CTimeZone;
 217
 218 #define MAXTZLEN                10              /* max TZ name len, not counting tr. null */
 219
 220 extern bool enableFsync;
 221 extern bool allowSystemTableMods;
 222 extern PGDLLIMPORT int work_mem;
 223 extern PGDLLIMPORT int maintenance_work_mem;
 224
 225 extern int      VacuumCostPageHit;
 226 extern int      VacuumCostPageMiss;
 227 extern int      VacuumCostPageDirty;
 228 extern int      VacuumCostLimit;
 229 extern int      VacuumCostDelay;
 230
 231 extern int      VacuumCostBalance;
 232 extern bool VacuumCostActive;
 233
 234
 235 /* in tcop/postgres.c */
 236 extern void check_stack_depth(void);
 237
 238
 239 /*****************************************************************************
 240  *        pdir.h --                                                                                                                              *
 241  *                      POSTGRES directory path definitions.                                                     *
 242  *****************************************************************************/
 243
 244 extern char *DatabasePath;
 245
 246 /* now in utils/init/miscinit.c */
 247 extern void SetDatabasePath(const char *path);
 248
 249 extern char *GetUserNameFromId(Oid roleid);
 250 extern Oid      GetUserId(void);
 251 extern Oid      GetOuterUserId(void);
 252 extern Oid      GetSessionUserId(void);
 253 extern void GetUserIdAndContext(Oid *userid, bool *sec_def_context);
 254 extern void SetUserIdAndContext(Oid userid, bool sec_def_context);
 255 extern bool InSecurityDefinerContext(void);
 256 extern void InitializeSessionUserId(const char *rolename);
 257 extern void InitializeSessionUserIdStandalone(void);
 258 extern void SetSessionAuthorization(Oid userid, bool is_superuser);
 259 extern Oid      GetCurrentRoleId(void);
 260 extern void SetCurrentRoleId(Oid roleid, bool is_superuser);
 261
 262 extern void SetDataDir(const char *dir);
 263 extern void ChangeToDataDir(void);
 264 extern char *make_absolute_path(const char *path);
 265
 266 /* in utils/misc/superuser.c */
 267 extern bool superuser(void);    /* current user is superuser */
 268 extern bool superuser_arg(Oid roleid);  /* given user is superuser */
 269
 270
 271 /*****************************************************************************
 272  *        pmod.h --                                                                                                                              *
 273  *                      POSTGRES processing mode definitions.                                                    *
 274  *****************************************************************************/
 275
 276 /*
 277  * Description:
 278  *              There are three processing modes in POSTGRES.  They are
 279  * BootstrapProcessing or "bootstrap," InitProcessing or
 280  * "initialization," and NormalProcessing or "normal."
 281  *
 282  * The first two processing modes are used during special times. When the
 283  * system state indicates bootstrap processing, transactions are all given
 284  * transaction id "one" and are consequently guaranteed to commit. This mode
 285  * is used during the initial generation of template databases.
 286  *
 287  * Initialization mode: used while starting a backend, until all normal
 288  * initialization is complete.  Some code behaves differently when executed
 289  * in this mode to enable system bootstrapping.
 290  *
 291  * If a POSTGRES binary is in normal mode, then all code may be executed
 292  * normally.
 293  */
 294
 295 typedef enum ProcessingMode
 296 {
 297         BootstrapProcessing,            /* bootstrap creation of template database */
 298         InitProcessing,                         /* initializing system */
 299         NormalProcessing                        /* normal processing */
 300 } ProcessingMode;
 301
 302 extern ProcessingMode Mode;
 303
 304 #define IsBootstrapProcessingMode() ((bool)(Mode == BootstrapProcessing))
 305 #define IsInitProcessingMode() ((bool)(Mode == InitProcessing))
 306 #define IsNormalProcessingMode() ((bool)(Mode == NormalProcessing))
 307
 308 #define SetProcessingMode(mode) \
 309         do { \
 310                 AssertArg((mode) == BootstrapProcessing || \
 311                                   (mode) == InitProcessing || \
 312                                   (mode) == NormalProcessing); \
 313                 Mode = (mode); \
 314         } while(0)
 315
 316 #define GetProcessingMode() Mode
 317
 318
 319 /*****************************************************************************
 320  *        pinit.h --                                                                                                                     *
 321  *                      POSTGRES initialization and cleanup definitions.                                 *
 322  *****************************************************************************/
 323
 324 /* in utils/init/postinit.c */
 325 extern bool InitPostgres(const char *in_dbname, Oid dboid, const char *username,
 326                          char **out_dbname);
 327 extern void BaseInit(void);
 328
 329 /* in utils/init/miscinit.c */
 330 extern bool IgnoreSystemIndexes;
 331 extern char *shared_preload_libraries_string;
 332 extern char *local_preload_libraries_string;
 333
 334 extern void SetReindexProcessing(Oid heapOid, Oid indexOid);
 335 extern void ResetReindexProcessing(void);
 336 extern bool ReindexIsProcessingHeap(Oid heapOid);
 337 extern bool ReindexIsProcessingIndex(Oid indexOid);
 338 extern void CreateDataDirLockFile(bool amPostmaster);
 339 extern void CreateSocketLockFile(const char *socketfile, bool amPostmaster);
 340 extern void TouchSocketLockFile(void);
 341 extern void RecordSharedMemoryInLockFile(unsigned long id1,
 342                                                          unsigned long id2);
 343 extern void ValidatePgVersion(const char *path);
 344 extern void process_shared_preload_libraries(void);
 345 extern void process_local_preload_libraries(void);
 346 extern void set_text_domain(const char *domain);
 347
 348 /* in access/transam/xlog.c */
 349 extern bool BackupInProgress(void);
 350 extern void CancelBackup(void);
 351
 352 #endif   /* MISCADMIN_H */