postgresql/src/include/storage/standby.h

92 lines
3.4 KiB
C

/*-------------------------------------------------------------------------
*
* standby.h
* Definitions for hot standby mode.
*
*
* Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/storage/standby.h
*
*-------------------------------------------------------------------------
*/
#ifndef STANDBY_H
#define STANDBY_H
#include "storage/lock.h"
#include "storage/procsignal.h"
#include "storage/relfilenode.h"
#include "storage/standbydefs.h"
/* User-settable GUC parameters */
extern int vacuum_defer_cleanup_age;
extern int max_standby_archive_delay;
extern int max_standby_streaming_delay;
extern void InitRecoveryTransactionEnvironment(void);
extern void ShutdownRecoveryTransactionEnvironment(void);
extern void ResolveRecoveryConflictWithSnapshot(TransactionId latestRemovedXid,
RelFileNode node);
extern void ResolveRecoveryConflictWithTablespace(Oid tsid);
extern void ResolveRecoveryConflictWithDatabase(Oid dbid);
extern void ResolveRecoveryConflictWithLock(LOCKTAG locktag);
extern void ResolveRecoveryConflictWithBufferPin(void);
extern void CheckRecoveryConflictDeadlock(void);
extern void StandbyDeadLockHandler(void);
extern void StandbyTimeoutHandler(void);
extern void StandbyLockTimeoutHandler(void);
/*
* Standby Rmgr (RM_STANDBY_ID)
*
* Standby recovery manager exists to perform actions that are required
* to make hot standby work. That includes logging AccessExclusiveLocks taken
* by transactions and running-xacts snapshots.
*/
extern void StandbyAcquireAccessExclusiveLock(TransactionId xid, Oid dbOid, Oid relOid);
extern void StandbyReleaseLockTree(TransactionId xid,
int nsubxids, TransactionId *subxids);
extern void StandbyReleaseAllLocks(void);
extern void StandbyReleaseOldLocks(TransactionId oldxid);
#define MinSizeOfXactRunningXacts offsetof(xl_running_xacts, xids)
/*
* Declarations for GetRunningTransactionData(). Similar to Snapshots, but
* not quite. This has nothing at all to do with visibility on this server,
* so this is completely separate from snapmgr.c and snapmgr.h.
* This data is important for creating the initial snapshot state on a
* standby server. We need lots more information than a normal snapshot,
* hence we use a specific data structure for our needs. This data
* is written to WAL as a separate record immediately after each
* checkpoint. That means that wherever we start a standby from we will
* almost immediately see the data we need to begin executing queries.
*/
typedef struct RunningTransactionsData
{
int xcnt; /* # of xact ids in xids[] */
int subxcnt; /* # of subxact ids in xids[] */
bool subxid_overflow; /* snapshot overflowed, subxids missing */
TransactionId nextXid; /* xid from ShmemVariableCache->nextFullXid */
TransactionId oldestRunningXid; /* *not* oldestXmin */
TransactionId latestCompletedXid; /* so we can set xmax */
TransactionId *xids; /* array of (sub)xids still running */
} RunningTransactionsData;
typedef RunningTransactionsData *RunningTransactions;
extern void LogAccessExclusiveLock(Oid dbOid, Oid relOid);
extern void LogAccessExclusiveLockPrepare(void);
extern XLogRecPtr LogStandbySnapshot(void);
extern void LogStandbyInvalidations(int nmsgs, SharedInvalidationMessage *msgs,
bool relcacheInitFileInval);
#endif /* STANDBY_H */