1 /*-------------------------------------------------------------------------
4 * POSTGRES lock manager definitions.
7 * Portions Copyright (c) 1996-2014, PostgreSQL Global Development Group
8 * Portions Copyright (c) 1994, Regents of the University of California
10 * src/include/storage/lmgr.h
12 *-------------------------------------------------------------------------
17 #include "lib/stringinfo.h"
18 #include "storage/itemptr.h"
19 #include "storage/lock.h"
20 #include "utils/rel.h"
23 /* XactLockTableWait operations */
24 typedef enum XLTW_Oper
32 XLTW_InsertIndexUnique,
34 XLTW_RecheckExclusionConstr
37 extern void RelationInitLockInfo(Relation relation);
40 extern void LockRelationOid(Oid relid, LOCKMODE lockmode);
41 extern bool ConditionalLockRelationOid(Oid relid, LOCKMODE lockmode);
42 extern void UnlockRelationId(LockRelId *relid, LOCKMODE lockmode);
43 extern void UnlockRelationOid(Oid relid, LOCKMODE lockmode);
45 extern void LockRelation(Relation relation, LOCKMODE lockmode);
46 extern bool ConditionalLockRelation(Relation relation, LOCKMODE lockmode);
47 extern void UnlockRelation(Relation relation, LOCKMODE lockmode);
48 extern bool LockHasWaitersRelation(Relation relation, LOCKMODE lockmode);
50 extern void LockRelationIdForSession(LockRelId *relid, LOCKMODE lockmode);
51 extern void UnlockRelationIdForSession(LockRelId *relid, LOCKMODE lockmode);
53 /* Lock a relation for extension */
54 extern void LockRelationForExtension(Relation relation, LOCKMODE lockmode);
55 extern void UnlockRelationForExtension(Relation relation, LOCKMODE lockmode);
57 /* Lock a page (currently only used within indexes) */
58 extern void LockPage(Relation relation, BlockNumber blkno, LOCKMODE lockmode);
59 extern bool ConditionalLockPage(Relation relation, BlockNumber blkno, LOCKMODE lockmode);
60 extern void UnlockPage(Relation relation, BlockNumber blkno, LOCKMODE lockmode);
62 /* Lock a tuple (see heap_lock_tuple before assuming you understand this) */
63 extern void LockTuple(Relation relation, ItemPointer tid, LOCKMODE lockmode);
64 extern bool ConditionalLockTuple(Relation relation, ItemPointer tid,
66 extern void UnlockTuple(Relation relation, ItemPointer tid, LOCKMODE lockmode);
68 /* Lock an XID (used to wait for a transaction to finish) */
69 extern void XactLockTableInsert(TransactionId xid);
70 extern void XactLockTableDelete(TransactionId xid);
71 extern void XactLockTableWait(TransactionId xid, Relation rel,
72 ItemPointer ctid, XLTW_Oper oper);
73 extern bool ConditionalXactLockTableWait(TransactionId xid);
75 /* Lock VXIDs, specified by conflicting locktags */
76 extern void WaitForLockers(LOCKTAG heaplocktag, LOCKMODE lockmode);
77 extern void WaitForLockersMultiple(List *locktags, LOCKMODE lockmode);
79 /* Lock a general object (other than a relation) of the current database */
80 extern void LockDatabaseObject(Oid classid, Oid objid, uint16 objsubid,
82 extern void UnlockDatabaseObject(Oid classid, Oid objid, uint16 objsubid,
85 /* Lock a shared-across-databases object (other than a relation) */
86 extern void LockSharedObject(Oid classid, Oid objid, uint16 objsubid,
88 extern void UnlockSharedObject(Oid classid, Oid objid, uint16 objsubid,
91 extern void LockSharedObjectForSession(Oid classid, Oid objid, uint16 objsubid,
93 extern void UnlockSharedObjectForSession(Oid classid, Oid objid, uint16 objsubid,
96 /* Describe a locktag for error messages */
97 extern void DescribeLockTag(StringInfo buf, const LOCKTAG *tag);