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  * HasCTZSet is true if user has set timezone as a numeric offset from UTC.
 197  * If so, CTimeZone is the timezone offset in seconds (using the Unix-ish
 198  * sign convention, ie, positive offset is west of UTC, rather than the
 199  * SQL-ish convention that positive is east of UTC).
 200  */
 201 extern bool HasCTZSet;
 202 extern int      CTimeZone;
 203
 204 #define MAXTZLEN                10              /* max TZ name len, not counting tr. null */
 205
 206 extern bool enableFsync;
 207 extern bool allowSystemTableMods;
 208 extern PGDLLIMPORT int work_mem;
 209 extern PGDLLIMPORT int maintenance_work_mem;
 210
 211 extern int      VacuumCostPageHit;
 212 extern int      VacuumCostPageMiss;
 213 extern int      VacuumCostPageDirty;
 214 extern int      VacuumCostLimit;
 215 extern int      VacuumCostDelay;
 216
 217 extern int      VacuumCostBalance;
 218 extern bool VacuumCostActive;
 219
 220
 221 /* in tcop/postgres.c */
 222 extern void check_stack_depth(void);
 223
 224
 225 /*****************************************************************************
 226  *        pdir.h --                                                                                                                              *
 227  *                      POSTGRES directory path definitions.                                                     *
 228  *****************************************************************************/
 229
 230 extern char *DatabasePath;
 231
 232 /* now in utils/init/miscinit.c */
 233 extern void SetDatabasePath(const char *path);
 234
 235 extern char *GetUserNameFromId(Oid roleid);
 236 extern Oid      GetUserId(void);
 237 extern Oid      GetOuterUserId(void);
 238 extern Oid      GetSessionUserId(void);
 239 extern void GetUserIdAndContext(Oid *userid, bool *sec_def_context);
 240 extern void SetUserIdAndContext(Oid userid, bool sec_def_context);
 241 extern bool InSecurityDefinerContext(void);
 242 extern void InitializeSessionUserId(const char *rolename);
 243 extern void InitializeSessionUserIdStandalone(void);
 244 extern void SetSessionAuthorization(Oid userid, bool is_superuser);
 245 extern Oid      GetCurrentRoleId(void);
 246 extern void SetCurrentRoleId(Oid roleid, bool is_superuser);
 247
 248 extern void SetDataDir(const char *dir);
 249 extern void ChangeToDataDir(void);
 250 extern char *make_absolute_path(const char *path);
 251
 252 /* in utils/misc/superuser.c */
 253 extern bool superuser(void);    /* current user is superuser */
 254 extern bool superuser_arg(Oid roleid);  /* given user is superuser */
 255
 256
 257 /*****************************************************************************
 258  *        pmod.h --                                                                                                                              *
 259  *                      POSTGRES processing mode definitions.                                                    *
 260  *****************************************************************************/
 261
 262 /*
 263  * Description:
 264  *              There are three processing modes in POSTGRES.  They are
 265  * BootstrapProcessing or "bootstrap," InitProcessing or
 266  * "initialization," and NormalProcessing or "normal."
 267  *
 268  * The first two processing modes are used during special times. When the
 269  * system state indicates bootstrap processing, transactions are all given
 270  * transaction id "one" and are consequently guaranteed to commit. This mode
 271  * is used during the initial generation of template databases.
 272  *
 273  * Initialization mode: used while starting a backend, until all normal
 274  * initialization is complete.  Some code behaves differently when executed
 275  * in this mode to enable system bootstrapping.
 276  *
 277  * If a POSTGRES binary is in normal mode, then all code may be executed
 278  * normally.
 279  */
 280
 281 typedef enum ProcessingMode
 282 {
 283         BootstrapProcessing,            /* bootstrap creation of template database */
 284         InitProcessing,                         /* initializing system */
 285         NormalProcessing                        /* normal processing */
 286 } ProcessingMode;
 287
 288 extern ProcessingMode Mode;
 289
 290 #define IsBootstrapProcessingMode() ((bool)(Mode == BootstrapProcessing))
 291 #define IsInitProcessingMode() ((bool)(Mode == InitProcessing))
 292 #define IsNormalProcessingMode() ((bool)(Mode == NormalProcessing))
 293
 294 #define SetProcessingMode(mode) \
 295         do { \
 296                 AssertArg((mode) == BootstrapProcessing || \
 297                                   (mode) == InitProcessing || \
 298                                   (mode) == NormalProcessing); \
 299                 Mode = (mode); \
 300         } while(0)
 301
 302 #define GetProcessingMode() Mode
 303
 304
 305 /*****************************************************************************
 306  *        pinit.h --                                                                                                                     *
 307  *                      POSTGRES initialization and cleanup definitions.                                 *
 308  *****************************************************************************/
 309
 310 /* in utils/init/postinit.c */
 311 extern bool InitPostgres(const char *in_dbname, Oid dboid, const char *username,
 312                          char **out_dbname);
 313 extern void BaseInit(void);
 314
 315 /* in utils/init/miscinit.c */
 316 extern bool IgnoreSystemIndexes;
 317 extern char *shared_preload_libraries_string;
 318 extern char *local_preload_libraries_string;
 319
 320 extern void SetReindexProcessing(Oid heapOid, Oid indexOid);
 321 extern void ResetReindexProcessing(void);
 322 extern bool ReindexIsProcessingHeap(Oid heapOid);
 323 extern bool ReindexIsProcessingIndex(Oid indexOid);
 324 extern void CreateDataDirLockFile(bool amPostmaster);
 325 extern void CreateSocketLockFile(const char *socketfile, bool amPostmaster);
 326 extern void TouchSocketLockFile(void);
 327 extern void RecordSharedMemoryInLockFile(unsigned long id1,
 328                                                          unsigned long id2);
 329 extern void ValidatePgVersion(const char *path);
 330 extern void process_shared_preload_libraries(void);
 331 extern void process_local_preload_libraries(void);
 332
 333 /* in access/transam/xlog.c */
 334 extern bool BackupInProgress(void);
 335 extern void CancelBackup(void);
 336
 337 #endif   /* MISCADMIN_H */