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PostgreSQL/src/include/miscadmin.h
Tom Lane 1a321f26d8 Code review for EXEC_BACKEND changes. Reduce the number of #ifdefs by 
about a third, make it work on non-Windows platforms again.  (But perhaps
I broke the WIN32 code, since I have no way to test that.)  Fold all the
paths that fork postmaster child processes to go through the single
routine SubPostmasterMain, which takes care of resurrecting the state that
would normally be inherited from the postmaster (including GUC variables).
Clean up some places where there's no particularly good reason for the
EXEC and non-EXEC cases to work differently.  Take care of one or two
FIXMEs that remained in the code.
2004-05-28 05:13:32 +00:00

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/*-------------------------------------------------------------------------
*
* 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) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/miscadmin.h,v 1.161 2004/05/28 05:13:24 tgl Exp $
*
* NOTES
* some of the information in this file should be moved to
* other files.
*
*-------------------------------------------------------------------------
*/
#ifndef MISCADMIN_H
#define MISCADMIN_H
/*****************************************************************************
* 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 DLLIMPORT 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 volatile uint32 InterruptHoldoffCount;
extern volatile uint32 CritSectionCount;
/* in tcop/postgres.c */
extern void ProcessInterrupts(void);
#ifndef WIN32
#define CHECK_FOR_INTERRUPTS() \
do { \
if (InterruptPending) \
ProcessInterrupts(); \
} while(0)
#else
#define CHECK_FOR_INTERRUPTS() \
do { \
if (WaitForSingleObject(pgwin32_signal_event,0) == WAIT_OBJECT_0) \
pgwin32_dispatch_queued_signals(); \
if (InterruptPending) \
ProcessInterrupts(); \
} while(0)
#endif
#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 postmaster/postmaster.c
*/
extern bool ClientAuthInProgress;
extern int PostmasterMain(int argc, char *argv[]);
extern void ClosePostmasterPorts(bool pgstat_too);
#ifdef EXEC_BACKEND
extern pid_t postmaster_forkexec(int argc, char *argv[]);
extern int SubPostmasterMain(int argc, char *argv[]);
#endif
#define PG_VERSIONSTR "postgres (PostgreSQL) " PG_VERSION "\n"
/*
* from utils/init/globals.c
*/
extern pid_t PostmasterPid;
extern bool IsPostmasterEnvironment;
extern bool IsUnderPostmaster;
extern bool ExitOnAnyError;
extern char *DataDir;
extern DLLIMPORT int MyProcPid;
extern struct Port *MyProcPort;
extern long MyCancelKey;
extern char OutputFileName[];
extern 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 DLLIMPORT Oid MyDatabaseId;
/*
* 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
/* valid DateOrder values */
#define DATEORDER_YMD 0
#define DATEORDER_DMY 1
#define DATEORDER_MDY 2
extern int DateStyle;
extern int DateOrder;
/*
* 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 DLLIMPORT int work_mem;
extern DLLIMPORT int maintenance_work_mem;
extern int VacuumCostPageHit;
extern int VacuumCostPageMiss;
extern int VacuumCostPageDirty;
extern int VacuumCostLimit;
extern int VacuumCostNaptime;
extern int VacuumCostBalance;
extern bool VacuumCostActive;
/*
* A few postmaster startup options are exported here so the
* configuration file processor can access them.
*/
extern bool EnableSSL;
extern bool SilentMode;
extern int MaxBackends;
extern int ReservedBackends;
extern DLLIMPORT int NBuffers;
extern int PostPortNumber;
extern int Unix_socket_permissions;
extern char *Unix_socket_group;
extern char *UnixSocketDir;
extern char *ListenAddresses;
/* in tcop/postgres.c */
extern void check_stack_depth(void);
/*****************************************************************************
* pdir.h -- *
* POSTGRES directory path definitions. *
*****************************************************************************/
extern char *DatabasePath;
/* in utils/misc/database.c */
extern void GetRawDatabaseInfo(const char *name, Oid *db_id, char *path);
/* now in utils/init/miscinit.c */
extern void SetDatabasePath(const char *path);
extern char *GetUserNameFromId(AclId userid);
extern AclId GetUserId(void);
extern void SetUserId(AclId userid);
extern AclId GetSessionUserId(void);
extern void SetSessionUserId(AclId userid);
extern void InitializeSessionUserId(const char *username);
extern void InitializeSessionUserIdStandalone(void);
extern void SetSessionAuthorization(AclId userid, bool is_superuser);
extern void SetDataDir(const char *dir);
/* in utils/misc/superuser.c */
extern bool superuser(void); /* current user is superuser */
extern bool superuser_arg(AclId userid); /* 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 void InitPostgres(const char *dbname, const char *username);
extern void BaseInit(void);
/* in utils/init/miscinit.c */
extern void IgnoreSystemIndexes(bool mode);
extern bool IsIgnoringSystemIndexes(void);
extern void SetReindexProcessing(Oid heapOid, Oid indexOid);
extern bool ReindexIsProcessingHeap(Oid heapOid);
extern bool ReindexIsProcessingIndex(Oid indexOid);
extern void CreateDataDirLockFile(const char *datadir, 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_preload_libraries(char *preload_libraries_string);
#endif /* MISCADMIN_H */
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