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miscadmin.h

/*-------------------------------------------------------------------------
 *
 * miscadmin.h
 *      This file contains general postgres administration and initialization
 *      stuff that used to be spread out between the following files:
 *          globals.h                                 global variables
 *          pdir.h                                          directory path crud
 *          pinit.h                                         postgres initialization
 *          pmod.h                                          processing modes
 *      Over time, this has also become the preferred place for widely known
 *      resource-limitation stuff, such as work_mem and check_stack_depth().
 *
 * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * $PostgreSQL$
 *
 * NOTES
 *      some of the information in this file should be moved to other files.
 *
 *-------------------------------------------------------------------------
 */
#ifndef MISCADMIN_H
#define MISCADMIN_H

#include "pgtime.h"                       /* for pg_time_t */


#define PG_BACKEND_VERSIONSTR "postgres (PostgreSQL) " PG_VERSION "\n"


/*****************************************************************************
 *      System interrupt and critical section handling
 *
 * There are two types of interrupts that a running backend needs to accept
 * without messing up its state: QueryCancel (SIGINT) and ProcDie (SIGTERM).
 * In both cases, we need to be able to clean up the current transaction
 * gracefully, so we can't respond to the interrupt instantaneously ---
 * there's no guarantee that internal data structures would be self-consistent
 * if the code is interrupted at an arbitrary instant.      Instead, the signal
 * handlers set flags that are checked periodically during execution.
 *
 * The CHECK_FOR_INTERRUPTS() macro is called at strategically located spots
 * where it is normally safe to accept a cancel or die interrupt.  In some
 * cases, we invoke CHECK_FOR_INTERRUPTS() inside low-level subroutines that
 * might sometimes be called in contexts that do *not* want to allow a cancel
 * or die interrupt.  The HOLD_INTERRUPTS() and RESUME_INTERRUPTS() macros
 * allow code to ensure that no cancel or die interrupt will be accepted,
 * even if CHECK_FOR_INTERRUPTS() gets called in a subroutine.    The interrupt
 * will be held off until CHECK_FOR_INTERRUPTS() is done outside any
 * HOLD_INTERRUPTS() ... RESUME_INTERRUPTS() section.
 *
 * Special mechanisms are used to let an interrupt be accepted when we are
 * waiting for a lock or when we are waiting for command input (but, of
 * course, only if the interrupt holdoff counter is zero).  See the
 * related code for details.
 *
 * A related, but conceptually distinct, mechanism is the "critical section"
 * mechanism.  A critical section not only holds off cancel/die interrupts,
 * but causes any ereport(ERROR) or ereport(FATAL) to become ereport(PANIC)
 * --- that is, a system-wide reset is forced.  Needless to say, only really
 * *critical* code should be marked as a critical section!  Currently, this
 * mechanism is only used for XLOG-related code.
 *
 *****************************************************************************/

/* in globals.c */
/* these are marked volatile because they are set by signal handlers: */
extern PGDLLIMPORT volatile bool InterruptPending;
extern volatile bool QueryCancelPending;
extern volatile bool ProcDiePending;

/* these are marked volatile because they are examined by signal handlers: */
extern volatile bool ImmediateInterruptOK;
extern PGDLLIMPORT volatile uint32 InterruptHoldoffCount;
extern PGDLLIMPORT volatile uint32 CritSectionCount;

/* in tcop/postgres.c */
extern void ProcessInterrupts(void);

#ifndef WIN32

#define CHECK_FOR_INTERRUPTS() \
do { \
      if (InterruptPending) \
            ProcessInterrupts(); \
} while(0)
#else                                     /* WIN32 */

#define CHECK_FOR_INTERRUPTS() \
do { \
      if (UNBLOCKED_SIGNAL_QUEUE()) \
            pgwin32_dispatch_queued_signals(); \
      if (InterruptPending) \
            ProcessInterrupts(); \
} while(0)
#endif   /* WIN32 */


#define HOLD_INTERRUPTS()  (InterruptHoldoffCount++)

#define RESUME_INTERRUPTS() \
do { \
      Assert(InterruptHoldoffCount > 0); \
      InterruptHoldoffCount--; \
} while(0)

#define START_CRIT_SECTION()  (CritSectionCount++)

#define END_CRIT_SECTION() \
do { \
      Assert(CritSectionCount > 0); \
      CritSectionCount--; \
} while(0)


/*****************************************************************************
 *      globals.h --                                                                                         *
 *****************************************************************************/

/*
 * from utils/init/globals.c
 */
extern pid_t PostmasterPid;
extern bool IsPostmasterEnvironment;
extern PGDLLIMPORT bool IsUnderPostmaster;

extern bool ExitOnAnyError;

extern PGDLLIMPORT char *DataDir;

extern PGDLLIMPORT int NBuffers;
extern int  MaxBackends;
extern int  MaxConnections;

extern PGDLLIMPORT int MyProcPid;
extern PGDLLIMPORT pg_time_t MyStartTime;
extern PGDLLIMPORT struct Port *MyProcPort;
extern long MyCancelKey;

extern char OutputFileName[];
extern PGDLLIMPORT char my_exec_path[];
extern char pkglib_path[];

#ifdef EXEC_BACKEND
extern char postgres_exec_path[];
#endif

/*
 * done in storage/backendid.h for now.
 *
 * extern BackendId    MyBackendId;
 */
extern PGDLLIMPORT Oid MyDatabaseId;

extern PGDLLIMPORT Oid MyDatabaseTableSpace;

/*
 * Date/Time Configuration
 *
 * DateStyle defines the output formatting choice for date/time types:
 *    USE_POSTGRES_DATES specifies traditional Postgres format
 *    USE_ISO_DATES specifies ISO-compliant format
 *    USE_SQL_DATES specifies Oracle/Ingres-compliant format
 *    USE_GERMAN_DATES specifies German-style dd.mm/yyyy
 *
 * DateOrder defines the field order to be assumed when reading an
 * ambiguous date (anything not in YYYY-MM-DD format, with a four-digit
 * year field first, is taken to be ambiguous):
 *    DATEORDER_YMD specifies field order yy-mm-dd
 *    DATEORDER_DMY specifies field order dd-mm-yy ("European" convention)
 *    DATEORDER_MDY specifies field order mm-dd-yy ("US" convention)
 *
 * In the Postgres and SQL DateStyles, DateOrder also selects output field
 * order: day comes before month in DMY style, else month comes before day.
 *
 * The user-visible "DateStyle" run-time parameter subsumes both of these.
 */

/* valid DateStyle values */
#define USE_POSTGRES_DATES          0
#define USE_ISO_DATES               1
#define USE_SQL_DATES               2
#define USE_GERMAN_DATES            3
#define USE_XSD_DATES               4

/* valid DateOrder values */
#define DATEORDER_YMD               0
#define DATEORDER_DMY               1
#define DATEORDER_MDY               2

extern int  DateStyle;
extern int  DateOrder;
 
/*
 * IntervalStyles
 *   INTSTYLE_POSTGRES             Like Postgres < 8.4 when DateStyle = 'iso'
 *   INTSTYLE_POSTGRES_VERBOSE     Like Postgres < 8.4 when DateStyle != 'iso'
 *   INTSTYLE_SQL_STANDARD         SQL standard interval literals
 *   INTSTYLE_ISO_8601             ISO-8601-basic formatted intervals
 */
#define INTSTYLE_POSTGRES                 0
#define INTSTYLE_POSTGRES_VERBOSE   1
#define INTSTYLE_SQL_STANDARD       2
#define INTSTYLE_ISO_8601                 3

extern int  IntervalStyle;

/*
 * HasCTZSet is true if user has set timezone as a numeric offset from UTC.
 * If so, CTimeZone is the timezone offset in seconds (using the Unix-ish
 * sign convention, ie, positive offset is west of UTC, rather than the
 * SQL-ish convention that positive is east of UTC).
 */
extern bool HasCTZSet;
extern int  CTimeZone;

#define MAXTZLEN        10          /* max TZ name len, not counting tr. null */

extern bool enableFsync;
extern bool allowSystemTableMods;
extern PGDLLIMPORT int work_mem;
extern PGDLLIMPORT int maintenance_work_mem;

extern int  VacuumCostPageHit;
extern int  VacuumCostPageMiss;
extern int  VacuumCostPageDirty;
extern int  VacuumCostLimit;
extern int  VacuumCostDelay;

extern int  VacuumCostBalance;
extern bool VacuumCostActive;


/* in tcop/postgres.c */
extern void check_stack_depth(void);


/*****************************************************************************
 *      pdir.h --                                                                                            *
 *                POSTGRES directory path definitions.                                           *
 *****************************************************************************/

extern char *DatabasePath;

/* now in utils/init/miscinit.c */
extern void SetDatabasePath(const char *path);

extern char *GetUserNameFromId(Oid roleid);
extern Oid  GetUserId(void);
extern Oid  GetOuterUserId(void);
extern Oid  GetSessionUserId(void);
extern void GetUserIdAndContext(Oid *userid, bool *sec_def_context);
extern void SetUserIdAndContext(Oid userid, bool sec_def_context);
extern bool InSecurityDefinerContext(void);
extern void InitializeSessionUserId(const char *rolename);
extern void InitializeSessionUserIdStandalone(void);
extern void SetSessionAuthorization(Oid userid, bool is_superuser);
extern Oid  GetCurrentRoleId(void);
extern void SetCurrentRoleId(Oid roleid, bool is_superuser);

extern void SetDataDir(const char *dir);
extern void ChangeToDataDir(void);
extern char *make_absolute_path(const char *path);

/* in utils/misc/superuser.c */
extern bool superuser(void);  /* current user is superuser */
extern bool superuser_arg(Oid roleid);    /* given user is superuser */


/*****************************************************************************
 *      pmod.h --                                                                                            *
 *                POSTGRES processing mode definitions.                                          *
 *****************************************************************************/

/*
 * Description:
 *          There are three processing modes in POSTGRES.  They are
 * BootstrapProcessing or "bootstrap," InitProcessing or
 * "initialization," and NormalProcessing or "normal."
 *
 * The first two processing modes are used during special times. When the
 * system state indicates bootstrap processing, transactions are all given
 * transaction id "one" and are consequently guaranteed to commit. This mode
 * is used during the initial generation of template databases.
 *
 * Initialization mode: used while starting a backend, until all normal
 * initialization is complete.      Some code behaves differently when executed
 * in this mode to enable system bootstrapping.
 *
 * If a POSTGRES binary is in normal mode, then all code may be executed
 * normally.
 */

typedef enum ProcessingMode
{
      BootstrapProcessing,          /* bootstrap creation of template database */
      InitProcessing,                     /* initializing system */
      NormalProcessing              /* normal processing */
} ProcessingMode;

extern ProcessingMode Mode;

#define IsBootstrapProcessingMode() ((bool)(Mode == BootstrapProcessing))
#define IsInitProcessingMode() ((bool)(Mode == InitProcessing))
#define IsNormalProcessingMode() ((bool)(Mode == NormalProcessing))

#define SetProcessingMode(mode) \
      do { \
            AssertArg((mode) == BootstrapProcessing || \
                          (mode) == InitProcessing || \
                          (mode) == NormalProcessing); \
            Mode = (mode); \
      } while(0)

#define GetProcessingMode() Mode


/*****************************************************************************
 *      pinit.h --                                                                                           *
 *                POSTGRES initialization and cleanup definitions.                         *
 *****************************************************************************/

/* in utils/init/postinit.c */
extern bool InitPostgres(const char *in_dbname, Oid dboid, const char *username,
                   char **out_dbname);
extern void BaseInit(void);

/* in utils/init/miscinit.c */
extern bool IgnoreSystemIndexes;
extern PGDLLIMPORT bool process_shared_preload_libraries_in_progress;
extern char *shared_preload_libraries_string;
extern char *local_preload_libraries_string;

extern void SetReindexProcessing(Oid heapOid, Oid indexOid);
extern void ResetReindexProcessing(void);
extern bool ReindexIsProcessingHeap(Oid heapOid);
extern bool ReindexIsProcessingIndex(Oid indexOid);
extern void CreateDataDirLockFile(bool amPostmaster);
extern void CreateSocketLockFile(const char *socketfile, bool amPostmaster);
extern void TouchSocketLockFile(void);
extern void RecordSharedMemoryInLockFile(unsigned long id1,
                                           unsigned long id2);
extern void ValidatePgVersion(const char *path);
extern void process_shared_preload_libraries(void);
extern void process_local_preload_libraries(void);
extern void pg_bindtextdomain(const char *domain);

/* in access/transam/xlog.c */
extern bool BackupInProgress(void);
extern void CancelBackup(void);

#endif   /* MISCADMIN_H */

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