src/include/storage/lmgr.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * lmgr.h
   4  *        POSTGRES lock manager definitions.
   5  *
   6  *
   7  * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
   8  * Portions Copyright (c) 1994, Regents of the University of California
   9  *
  10  * src/include/storage/lmgr.h
  11  *
  12  *-------------------------------------------------------------------------
  13  */
  14 #ifndef LMGR_H
  15 #define LMGR_H
  16
  17 #include "lib/stringinfo.h"
  18 #include "storage/itemptr.h"
  19 #include "storage/lock.h"
  20 #include "utils/rel.h"
  21
  22
  23 /* XactLockTableWait operations */
  24 typedef enum XLTW_Oper
  25 {
  26         XLTW_None,
  27         XLTW_Update,
  28         XLTW_Delete,
  29         XLTW_Lock,
  30         XLTW_LockUpdated,
  31         XLTW_InsertIndex,
  32         XLTW_InsertIndexUnique,
  33         XLTW_FetchUpdated,
  34         XLTW_RecheckExclusionConstr,
  35 } XLTW_Oper;
  36
  37 extern void RelationInitLockInfo(Relation relation);
  38
  39 /* Lock a relation */
  40 extern void LockRelationOid(Oid relid, LOCKMODE lockmode);
  41 extern void LockRelationId(LockRelId *relid, LOCKMODE lockmode);
  42 extern bool ConditionalLockRelationOid(Oid relid, LOCKMODE lockmode);
  43 extern void UnlockRelationId(LockRelId *relid, LOCKMODE lockmode);
  44 extern void UnlockRelationOid(Oid relid, LOCKMODE lockmode);
  45
  46 extern void LockRelation(Relation relation, LOCKMODE lockmode);
  47 extern bool ConditionalLockRelation(Relation relation, LOCKMODE lockmode);
  48 extern void UnlockRelation(Relation relation, LOCKMODE lockmode);
  49 extern bool CheckRelationLockedByMe(Relation relation, LOCKMODE lockmode,
  50                                                                         bool orstronger);
  51 extern bool CheckRelationOidLockedByMe(Oid relid, LOCKMODE lockmode,
  52                                                                            bool orstronger);
  53 extern bool LockHasWaitersRelation(Relation relation, LOCKMODE lockmode);
  54
  55 extern void LockRelationIdForSession(LockRelId *relid, LOCKMODE lockmode);
  56 extern void UnlockRelationIdForSession(LockRelId *relid, LOCKMODE lockmode);
  57
  58 /* Lock a relation for extension */
  59 extern void LockRelationForExtension(Relation relation, LOCKMODE lockmode);
  60 extern void UnlockRelationForExtension(Relation relation, LOCKMODE lockmode);
  61 extern bool ConditionalLockRelationForExtension(Relation relation,
  62                                                                                                 LOCKMODE lockmode);
  63 extern int      RelationExtensionLockWaiterCount(Relation relation);
  64
  65 /* Lock to recompute pg_database.datfrozenxid in the current database */
  66 extern void LockDatabaseFrozenIds(LOCKMODE lockmode);
  67
  68 /* Lock a page (currently only used within indexes) */
  69 extern void LockPage(Relation relation, BlockNumber blkno, LOCKMODE lockmode);
  70 extern bool ConditionalLockPage(Relation relation, BlockNumber blkno, LOCKMODE lockmode);
  71 extern void UnlockPage(Relation relation, BlockNumber blkno, LOCKMODE lockmode);
  72
  73 /* Lock a tuple (see heap_lock_tuple before assuming you understand this) */
  74 extern void LockTuple(Relation relation, ItemPointer tid, LOCKMODE lockmode);
  75 extern bool ConditionalLockTuple(Relation relation, ItemPointer tid,
  76                                                                  LOCKMODE lockmode);
  77 extern void UnlockTuple(Relation relation, ItemPointer tid, LOCKMODE lockmode);
  78
  79 /* Lock an XID (used to wait for a transaction to finish) */
  80 extern void XactLockTableInsert(TransactionId xid);
  81 extern void XactLockTableDelete(TransactionId xid);
  82 extern void XactLockTableWait(TransactionId xid, Relation rel,
  83                                                           ItemPointer ctid, XLTW_Oper oper);
  84 extern bool ConditionalXactLockTableWait(TransactionId xid);
  85
  86 /* Lock VXIDs, specified by conflicting locktags */
  87 extern void WaitForLockers(LOCKTAG heaplocktag, LOCKMODE lockmode, bool progress);
  88 extern void WaitForLockersMultiple(List *locktags, LOCKMODE lockmode, bool progress);
  89
  90 /* Lock an XID for tuple insertion (used to wait for an insertion to finish) */
  91 extern uint32 SpeculativeInsertionLockAcquire(TransactionId xid);
  92 extern void SpeculativeInsertionLockRelease(TransactionId xid);
  93 extern void SpeculativeInsertionWait(TransactionId xid, uint32 token);
  94
  95 /* Lock a general object (other than a relation) of the current database */
  96 extern void LockDatabaseObject(Oid classid, Oid objid, uint16 objsubid,
  97                                                            LOCKMODE lockmode);
  98 extern bool ConditionalLockDatabaseObject(Oid classid, Oid objid,
  99                                                                                   uint16 objsubid, LOCKMODE lockmode);
 100 extern void UnlockDatabaseObject(Oid classid, Oid objid, uint16 objsubid,
 101                                                                  LOCKMODE lockmode);
 102
 103 /* Lock a shared-across-databases object (other than a relation) */
 104 extern void LockSharedObject(Oid classid, Oid objid, uint16 objsubid,
 105                                                          LOCKMODE lockmode);
 106 extern bool ConditionalLockSharedObject(Oid classid, Oid objid, uint16 objsubid,
 107                                                                                 LOCKMODE lockmode);
 108 extern void UnlockSharedObject(Oid classid, Oid objid, uint16 objsubid,
 109                                                            LOCKMODE lockmode);
 110
 111 extern void LockSharedObjectForSession(Oid classid, Oid objid, uint16 objsubid,
 112                                                                            LOCKMODE lockmode);
 113 extern void UnlockSharedObjectForSession(Oid classid, Oid objid, uint16 objsubid,
 114                                                                                  LOCKMODE lockmode);
 115
 116 extern void LockApplyTransactionForSession(Oid suboid, TransactionId xid, uint16 objid,
 117                                                                                    LOCKMODE lockmode);
 118 extern void UnlockApplyTransactionForSession(Oid suboid, TransactionId xid, uint16 objid,
 119                                                                                          LOCKMODE lockmode);
 120
 121 /* Describe a locktag for error messages */
 122 extern void DescribeLockTag(StringInfo buf, const LOCKTAG *tag);
 123
 124 extern const char *GetLockNameFromTagType(uint16 locktag_type);
 125
 126 #endif                                                  /* LMGR_H */