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/*-------------------------------------------------------------------------
*
* lmgr.h
* POSTGRES lock manager definitions.
*
*
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: lmgr.h,v 1.34 2001/10/28 06:26:09 momjian Exp $
*
*-------------------------------------------------------------------------
*/
#ifndef LMGR_H
#define LMGR_H
#include "storage/lock.h"
#include "utils/rel.h"
/* These are the valid values of type LOCKMODE: */
/* NoLock is not a lock mode, but a flag value meaning "don't get a lock" */
#define NoLock 0
#define AccessShareLock 1 /* SELECT */
#define RowShareLock 2 /* SELECT FOR UPDATE */
#define RowExclusiveLock 3 /* INSERT, UPDATE, DELETE */
#define ShareUpdateExclusiveLock 4 /* VACUUM (non-FULL) */
#define ShareLock 5 /* CREATE INDEX */
#define ShareRowExclusiveLock 6 /* like EXCLUSIVE MODE, but allows
* ROW SHARE */
#define ExclusiveLock 7 /* blocks ROW SHARE/SELECT...FOR
* UPDATE */
#define AccessExclusiveLock 8 /* ALTER TABLE, DROP TABLE, VACUUM
* FULL, and unqualified LOCK
* TABLE */
/*
* Note: all lock mode numbers must be less than lock.h's MAX_LOCKMODES,
* so increase that if you want to add more modes.
*/
extern LOCKMETHOD LockTableId;
extern LOCKMETHOD InitLockTable(int maxBackends);
extern void RelationInitLockInfo(Relation relation);
/* Lock a relation */
extern void LockRelation(Relation relation, LOCKMODE lockmode);
extern bool ConditionalLockRelation(Relation relation, LOCKMODE lockmode);
extern void UnlockRelation(Relation relation, LOCKMODE lockmode);
extern void LockRelationForSession(LockRelId *relid, LOCKMODE lockmode);
extern void UnlockRelationForSession(LockRelId *relid, LOCKMODE lockmode);
/* Lock a page (mainly used for indices) */
extern void LockPage(Relation relation, BlockNumber blkno, LOCKMODE lockmode);
extern void UnlockPage(Relation relation, BlockNumber blkno, LOCKMODE lockmode);
/* Lock an XID (used to wait for a transaction to finish) */
extern void XactLockTableInsert(TransactionId xid);
extern void XactLockTableWait(TransactionId xid);
#endif /* LMGR_H */
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