diff options
Diffstat (limited to 'src/include/storage/standby.h')
| -rw-r--r-- | src/include/storage/standby.h | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/src/include/storage/standby.h b/src/include/storage/standby.h new file mode 100644 index 00000000000..45d44f60f6b --- /dev/null +++ b/src/include/storage/standby.h @@ -0,0 +1,106 @@ +/*------------------------------------------------------------------------- + * + * standby.h + * Definitions for hot standby mode. + * + * + * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * $PostgreSQL: pgsql/src/include/storage/standby.h,v 1.1 2009/12/19 01:32:44 sriggs Exp $ + * + *------------------------------------------------------------------------- + */ +#ifndef STANDBY_H +#define STANDBY_H + +#include "access/xlog.h" +#include "storage/lock.h" + +extern int vacuum_defer_cleanup_age; + +/* cancel modes for ResolveRecoveryConflictWithVirtualXIDs */ +#define CONFLICT_MODE_NOT_SET 0 +#define CONFLICT_MODE_ERROR 1 /* Conflict can be resolved by canceling query */ +#define CONFLICT_MODE_FATAL 2 /* Conflict can only be resolved by disconnecting session */ + +extern void ResolveRecoveryConflictWithVirtualXIDs(VirtualTransactionId *waitlist, + char *reason, int cancel_mode); + +extern void InitRecoveryTransactionEnvironment(void); +extern void ShutdownRecoveryTransactionEnvironment(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 removeXid); + +/* + * XLOG message types + */ +#define XLOG_STANDBY_LOCK 0x00 +#define XLOG_RUNNING_XACTS 0x10 + +typedef struct xl_standby_locks +{ + int nlocks; /* number of entries in locks array */ + xl_standby_lock locks[1]; /* VARIABLE LENGTH ARRAY */ +} xl_standby_locks; + +/* + * When we write running xact data to WAL, we use this structure. + */ +typedef struct xl_running_xacts +{ + int xcnt; /* # of xact ids in xids[] */ + bool subxid_overflow; /* snapshot overflowed, subxids missing */ + TransactionId nextXid; /* copy of ShmemVariableCache->nextXid */ + TransactionId oldestRunningXid; /* *not* oldestXmin */ + + TransactionId xids[1]; /* VARIABLE LENGTH ARRAY */ +} xl_running_xacts; + +#define MinSizeOfXactRunningXacts offsetof(xl_running_xacts, xids) + + +/* Recovery handlers for the Standby Rmgr (RM_STANDBY_ID) */ +extern void standby_redo(XLogRecPtr lsn, XLogRecord *record); +extern void standby_desc(StringInfo buf, uint8 xl_info, char *rec); + +/* + * 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[] */ + bool subxid_overflow; /* snapshot overflowed, subxids missing */ + TransactionId nextXid; /* copy of ShmemVariableCache->nextXid */ + TransactionId oldestRunningXid; /* *not* oldestXmin */ + + TransactionId *xids; /* array of (sub)xids still running */ +} RunningTransactionsData; + +typedef RunningTransactionsData *RunningTransactions; + +extern void LogAccessExclusiveLock(Oid dbOid, Oid relOid); + +extern void LogStandbySnapshot(TransactionId *oldestActiveXid, TransactionId *nextXid); + +#endif /* STANDBY_H */ |