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postgresql/src/include/miscadmin.h

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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) 1996-2024, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/miscadmin.h
*
* NOTES
* some of the information in this file should be moved to other files.
*
*-------------------------------------------------------------------------
*/
#ifndef MISCADMIN_H
#define MISCADMIN_H
#include <signal.h>
#include "datatype/timestamp.h" /* for TimestampTz */
#include "pgtime.h" /* for pg_time_t */
#define InvalidPid (-1)
/*****************************************************************************
* 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.
*
* There is also a mechanism to prevent query cancel interrupts, while still
* allowing die interrupts: HOLD_CANCEL_INTERRUPTS() and
* RESUME_CANCEL_INTERRUPTS().
*
* Note that ProcessInterrupts() has also acquired a number of tasks that
* do not necessarily cause a query-cancel-or-die response. Hence, it's
* possible that it will just clear InterruptPending and return.
*
* INTERRUPTS_PENDING_CONDITION() can be checked to see whether an
* interrupt needs to be serviced, without trying to do so immediately.
* Some callers are also interested in INTERRUPTS_CAN_BE_PROCESSED(),
* which tells whether ProcessInterrupts is sure to clear the interrupt.
*
* 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 lost connection is handled similarly, although the loss of connection
* does not raise a signal, but is detected when we fail to write to the
* socket. If there was a signal for a broken connection, we could make use of
* it by setting ClientConnectionLost in the signal handler.
*
* 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 sig_atomic_t InterruptPending;
extern PGDLLIMPORT volatile sig_atomic_t QueryCancelPending;
extern PGDLLIMPORT volatile sig_atomic_t ProcDiePending;
extern PGDLLIMPORT volatile sig_atomic_t IdleInTransactionSessionTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t TransactionTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t IdleSessionTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t ProcSignalBarrierPending;
extern PGDLLIMPORT volatile sig_atomic_t LogMemoryContextPending;
extern PGDLLIMPORT volatile sig_atomic_t IdleStatsUpdateTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t CheckClientConnectionPending;
extern PGDLLIMPORT volatile sig_atomic_t ClientConnectionLost;
/* these are marked volatile because they are examined by signal handlers: */
extern PGDLLIMPORT volatile uint32 InterruptHoldoffCount;
extern PGDLLIMPORT volatile uint32 QueryCancelHoldoffCount;
extern PGDLLIMPORT volatile uint32 CritSectionCount;
/* in tcop/postgres.c */
extern void ProcessInterrupts(void);
/* Test whether an interrupt is pending */
#ifndef WIN32
#define INTERRUPTS_PENDING_CONDITION() \
(unlikely(InterruptPending))
#else
#define INTERRUPTS_PENDING_CONDITION() \
(unlikely(UNBLOCKED_SIGNAL_QUEUE()) ? pgwin32_dispatch_queued_signals() : 0, \
unlikely(InterruptPending))
#endif
/* Service interrupt, if one is pending and it's safe to service it now */
#define CHECK_FOR_INTERRUPTS() \
do { \
if (INTERRUPTS_PENDING_CONDITION()) \
ProcessInterrupts(); \
} while(0)
/* Is ProcessInterrupts() guaranteed to clear InterruptPending? */
#define INTERRUPTS_CAN_BE_PROCESSED() \
(InterruptHoldoffCount == 0 && CritSectionCount == 0 && \
QueryCancelHoldoffCount == 0)
#define HOLD_INTERRUPTS() (InterruptHoldoffCount++)
#define RESUME_INTERRUPTS() \
do { \
Assert(InterruptHoldoffCount > 0); \
InterruptHoldoffCount--; \
} while(0)
#define HOLD_CANCEL_INTERRUPTS() (QueryCancelHoldoffCount++)
#define RESUME_CANCEL_INTERRUPTS() \
do { \
Assert(QueryCancelHoldoffCount > 0); \
QueryCancelHoldoffCount--; \
} 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 PGDLLIMPORT pid_t PostmasterPid;
extern PGDLLIMPORT bool IsPostmasterEnvironment;
extern PGDLLIMPORT bool IsUnderPostmaster;
extern PGDLLIMPORT bool IsBinaryUpgrade;
extern PGDLLIMPORT bool ExitOnAnyError;
extern PGDLLIMPORT char *DataDir;
extern PGDLLIMPORT int data_directory_mode;
extern PGDLLIMPORT int NBuffers;
extern PGDLLIMPORT int MaxBackends;
extern PGDLLIMPORT int MaxConnections;
extern PGDLLIMPORT int max_worker_processes;
extern PGDLLIMPORT int max_parallel_workers;
extern PGDLLIMPORT int commit_timestamp_buffers;
extern PGDLLIMPORT int multixact_member_buffers;
extern PGDLLIMPORT int multixact_offset_buffers;
extern PGDLLIMPORT int notify_buffers;
extern PGDLLIMPORT int serializable_buffers;
extern PGDLLIMPORT int subtransaction_buffers;
extern PGDLLIMPORT int transaction_buffers;
extern PGDLLIMPORT int MyProcPid;
extern PGDLLIMPORT pg_time_t MyStartTime;
extern PGDLLIMPORT TimestampTz MyStartTimestamp;
extern PGDLLIMPORT struct Port *MyProcPort;
extern PGDLLIMPORT struct Latch *MyLatch;
extern PGDLLIMPORT int32 MyCancelKey;
extern PGDLLIMPORT int MyPMChildSlot;
extern PGDLLIMPORT char OutputFileName[];
extern PGDLLIMPORT char my_exec_path[];
extern PGDLLIMPORT char pkglib_path[];
#ifdef EXEC_BACKEND
extern PGDLLIMPORT char postgres_exec_path[];
#endif
extern PGDLLIMPORT Oid MyDatabaseId;
extern PGDLLIMPORT Oid MyDatabaseTableSpace;
extern PGDLLIMPORT bool MyDatabaseHasLoginEventTriggers;
/*
* 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 PGDLLIMPORT int DateStyle;
extern PGDLLIMPORT 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 PGDLLIMPORT int IntervalStyle;
#define MAXTZLEN 10 /* max TZ name len, not counting tr. null */
extern PGDLLIMPORT bool enableFsync;
extern PGDLLIMPORT bool allowSystemTableMods;
extern PGDLLIMPORT int work_mem;
extern PGDLLIMPORT double hash_mem_multiplier;
extern PGDLLIMPORT int maintenance_work_mem;
extern PGDLLIMPORT int max_parallel_maintenance_workers;
/*
* Upper and lower hard limits for the buffer access strategy ring size
* specified by the VacuumBufferUsageLimit GUC and BUFFER_USAGE_LIMIT option
* to VACUUM and ANALYZE.
*/
#define MIN_BAS_VAC_RING_SIZE_KB 128
#define MAX_BAS_VAC_RING_SIZE_KB (16 * 1024 * 1024)
extern PGDLLIMPORT int VacuumBufferUsageLimit;
extern PGDLLIMPORT int VacuumCostPageHit;
extern PGDLLIMPORT int VacuumCostPageMiss;
extern PGDLLIMPORT int VacuumCostPageDirty;
extern PGDLLIMPORT int VacuumCostLimit;
extern PGDLLIMPORT double VacuumCostDelay;
extern PGDLLIMPORT int64 VacuumPageHit;
extern PGDLLIMPORT int64 VacuumPageMiss;
extern PGDLLIMPORT int64 VacuumPageDirty;
extern PGDLLIMPORT int VacuumCostBalance;
extern PGDLLIMPORT bool VacuumCostActive;
/* in tcop/postgres.c */
typedef char *pg_stack_base_t;
extern pg_stack_base_t set_stack_base(void);
extern void restore_stack_base(pg_stack_base_t base);
extern void check_stack_depth(void);
extern bool stack_is_too_deep(void);
/* in tcop/utility.c */
extern void PreventCommandIfReadOnly(const char *cmdname);
extern void PreventCommandIfParallelMode(const char *cmdname);
extern void PreventCommandDuringRecovery(const char *cmdname);
/*****************************************************************************
* pdir.h -- *
* POSTGRES directory path definitions. *
*****************************************************************************/
/* flags to be OR'd to form sec_context */
#define SECURITY_LOCAL_USERID_CHANGE 0x0001
#define SECURITY_RESTRICTED_OPERATION 0x0002
#define SECURITY_NOFORCE_RLS 0x0004
extern PGDLLIMPORT char *DatabasePath;
/* now in utils/init/miscinit.c */
extern void InitPostmasterChild(void);
extern void InitStandaloneProcess(const char *argv0);
extern void InitProcessLocalLatch(void);
extern void SwitchToSharedLatch(void);
extern void SwitchBackToLocalLatch(void);
/*
* MyBackendType indicates what kind of a backend this is.
*
* If you add entries, please also update the child_process_kinds array in
* launch_backend.c.
*/
typedef enum BackendType
{
B_INVALID = 0,
/* Backends and other backend-like processes */
B_BACKEND,
B_AUTOVAC_LAUNCHER,
B_AUTOVAC_WORKER,
B_BG_WORKER,
B_WAL_SENDER,
B_SLOTSYNC_WORKER,
B_STANDALONE_BACKEND,
/*
* Auxiliary processes. These have PGPROC entries, but they are not
* attached to any particular database. There can be only one of each of
* these running at a time.
*
* If you modify these, make sure to update NUM_AUXILIARY_PROCS and the
* glossary in the docs.
*/
B_ARCHIVER,
B_BG_WRITER,
B_CHECKPOINTER,
B_STARTUP,
B_WAL_RECEIVER,
B_WAL_SUMMARIZER,
B_WAL_WRITER,
/*
* Logger is not connected to shared memory and does not have a PGPROC
* entry.
*/
B_LOGGER,
} BackendType;
#define BACKEND_NUM_TYPES (B_LOGGER + 1)
extern PGDLLIMPORT BackendType MyBackendType;
#define AmAutoVacuumLauncherProcess() (MyBackendType == B_AUTOVAC_LAUNCHER)
#define AmAutoVacuumWorkerProcess() (MyBackendType == B_AUTOVAC_WORKER)
#define AmBackgroundWorkerProcess() (MyBackendType == B_BG_WORKER)
#define AmWalSenderProcess() (MyBackendType == B_WAL_SENDER)
#define AmLogicalSlotSyncWorkerProcess() (MyBackendType == B_SLOTSYNC_WORKER)
#define AmArchiverProcess() (MyBackendType == B_ARCHIVER)
#define AmBackgroundWriterProcess() (MyBackendType == B_BG_WRITER)
#define AmCheckpointerProcess() (MyBackendType == B_CHECKPOINTER)
#define AmStartupProcess() (MyBackendType == B_STARTUP)
#define AmWalReceiverProcess() (MyBackendType == B_WAL_RECEIVER)
#define AmWalSummarizerProcess() (MyBackendType == B_WAL_SUMMARIZER)
#define AmWalWriterProcess() (MyBackendType == B_WAL_WRITER)
extern const char *GetBackendTypeDesc(BackendType backendType);
extern void SetDatabasePath(const char *path);
extern void checkDataDir(void);
extern void SetDataDir(const char *dir);
extern void ChangeToDataDir(void);
extern char *GetUserNameFromId(Oid roleid, bool noerr);
extern Oid GetUserId(void);
extern Oid GetOuterUserId(void);
extern Oid GetSessionUserId(void);
extern Oid GetAuthenticatedUserId(void);
extern void GetUserIdAndSecContext(Oid *userid, int *sec_context);
extern void SetUserIdAndSecContext(Oid userid, int sec_context);
extern bool InLocalUserIdChange(void);
extern bool InSecurityRestrictedOperation(void);
extern bool InNoForceRLSOperation(void);
extern void GetUserIdAndContext(Oid *userid, bool *sec_def_context);
extern void SetUserIdAndContext(Oid userid, bool sec_def_context);
extern void InitializeSessionUserId(const char *rolename, Oid roleid,
bool bypass_login_check);
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 InitializeSystemUser(const char *authn_id,
const char *auth_method);
extern const char *GetSystemUser(void);
/* 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 backend process 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 PGDLLIMPORT ProcessingMode Mode;
#define IsBootstrapProcessingMode() (Mode == BootstrapProcessing)
#define IsInitProcessingMode() (Mode == InitProcessing)
#define IsNormalProcessingMode() (Mode == NormalProcessing)
#define GetProcessingMode() Mode
#define SetProcessingMode(mode) \
do { \
Assert((mode) == BootstrapProcessing || \
(mode) == InitProcessing || \
(mode) == NormalProcessing); \
Mode = (mode); \
} while(0)
/*****************************************************************************
* pinit.h -- *
* POSTGRES initialization and cleanup definitions. *
*****************************************************************************/
/* in utils/init/postinit.c */
/* flags for InitPostgres() */
#define INIT_PG_LOAD_SESSION_LIBS 0x0001
#define INIT_PG_OVERRIDE_ALLOW_CONNS 0x0002
#define INIT_PG_OVERRIDE_ROLE_LOGIN 0x0004
extern void pg_split_opts(char **argv, int *argcp, const char *optstr);
extern void InitializeMaxBackends(void);
extern void InitPostgres(const char *in_dbname, Oid dboid,
const char *username, Oid useroid,
bits32 flags,
char *out_dbname);
extern void BaseInit(void);
/* in utils/init/miscinit.c */
extern PGDLLIMPORT bool IgnoreSystemIndexes;
extern PGDLLIMPORT bool process_shared_preload_libraries_in_progress;
extern PGDLLIMPORT bool process_shared_preload_libraries_done;
extern PGDLLIMPORT bool process_shmem_requests_in_progress;
extern PGDLLIMPORT char *session_preload_libraries_string;
extern PGDLLIMPORT char *shared_preload_libraries_string;
extern PGDLLIMPORT char *local_preload_libraries_string;
extern void CreateDataDirLockFile(bool amPostmaster);
extern void CreateSocketLockFile(const char *socketfile, bool amPostmaster,
const char *socketDir);
extern void TouchSocketLockFiles(void);
extern void AddToDataDirLockFile(int target_line, const char *str);
extern bool RecheckDataDirLockFile(void);
extern void ValidatePgVersion(const char *path);
extern void process_shared_preload_libraries(void);
extern void process_session_preload_libraries(void);
extern void process_shmem_requests(void);
extern void pg_bindtextdomain(const char *domain);
extern bool has_rolreplication(Oid roleid);
typedef void (*shmem_request_hook_type) (void);
extern PGDLLIMPORT shmem_request_hook_type shmem_request_hook;
extern Size EstimateClientConnectionInfoSpace(void);
extern void SerializeClientConnectionInfo(Size maxsize, char *start_address);
extern void RestoreClientConnectionInfo(char *conninfo);
/* in executor/nodeHash.c */
extern size_t get_hash_memory_limit(void);
#endif /* MISCADMIN_H */
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