src/include/storage/lmgr.h

   1 /*-------------------------------------------------------------------------
   2  *
   3  * lmgr.h
   4  *        POSTGRES lock manager definitions.
   5  *
   6  *
   7  * Portions Copyright (c) 1996-2022, 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 LockHasWaitersRelation(Relation relation, LOCKMODE lockmode);
  52
  53 extern void LockRelationIdForSession(LockRelId *relid, LOCKMODE lockmode);
  54 extern void UnlockRelationIdForSession(LockRelId *relid, LOCKMODE lockmode);
  55
  56 /* Lock a relation for extension */
  57 extern void LockRelationForExtension(Relation relation, LOCKMODE lockmode);
  58 extern void UnlockRelationForExtension(Relation relation, LOCKMODE lockmode);
  59 extern bool ConditionalLockRelationForExtension(Relation relation,
  60                                                                                                 LOCKMODE lockmode);
  61 extern int      RelationExtensionLockWaiterCount(Relation relation);
  62
  63 /* Lock to recompute pg_database.datfrozenxid in the current database */
  64 extern void LockDatabaseFrozenIds(LOCKMODE lockmode);
  65
  66 /* Lock a page (currently only used within indexes) */
  67 extern void LockPage(Relation relation, BlockNumber blkno, LOCKMODE lockmode);
  68 extern bool ConditionalLockPage(Relation relation, BlockNumber blkno, LOCKMODE lockmode);
  69 extern void UnlockPage(Relation relation, BlockNumber blkno, LOCKMODE lockmode);
  70
  71 /* Lock a tuple (see heap_lock_tuple before assuming you understand this) */
  72 extern void LockTuple(Relation relation, ItemPointer tid, LOCKMODE lockmode);
  73 extern bool ConditionalLockTuple(Relation relation, ItemPointer tid,
  74                                                                  LOCKMODE lockmode);
  75 extern void UnlockTuple(Relation relation, ItemPointer tid, LOCKMODE lockmode);
  76
  77 /* Lock an XID (used to wait for a transaction to finish) */
  78 extern void XactLockTableInsert(TransactionId xid);
  79 extern void XactLockTableDelete(TransactionId xid);
  80 extern void XactLockTableWait(TransactionId xid, Relation rel,
  81                                                           ItemPointer ctid, XLTW_Oper oper);
  82 extern bool ConditionalXactLockTableWait(TransactionId xid);
  83
  84 /* Lock VXIDs, specified by conflicting locktags */
  85 extern void WaitForLockers(LOCKTAG heaplocktag, LOCKMODE lockmode, bool progress);
  86 extern void WaitForLockersMultiple(List *locktags, LOCKMODE lockmode, bool progress);
  87
  88 /* Lock an XID for tuple insertion (used to wait for an insertion to finish) */
  89 extern uint32 SpeculativeInsertionLockAcquire(TransactionId xid);
  90 extern void SpeculativeInsertionLockRelease(TransactionId xid);
  91 extern void SpeculativeInsertionWait(TransactionId xid, uint32 token);
  92
  93 /* Lock a general object (other than a relation) of the current database */
  94 extern void LockDatabaseObject(Oid classid, Oid objid, uint16 objsubid,
  95                                                            LOCKMODE lockmode);
  96 extern void UnlockDatabaseObject(Oid classid, Oid objid, uint16 objsubid,
  97                                                                  LOCKMODE lockmode);
  98
  99 /* Lock a shared-across-databases object (other than a relation) */
 100 extern void LockSharedObject(Oid classid, Oid objid, uint16 objsubid,
 101                                                          LOCKMODE lockmode);
 102 extern void UnlockSharedObject(Oid classid, Oid objid, uint16 objsubid,
 103                                                            LOCKMODE lockmode);
 104
 105 extern void LockSharedObjectForSession(Oid classid, Oid objid, uint16 objsubid,
 106                                                                            LOCKMODE lockmode);
 107 extern void UnlockSharedObjectForSession(Oid classid, Oid objid, uint16 objsubid,
 108                                                                                  LOCKMODE lockmode);
 109
 110 /* Describe a locktag for error messages */
 111 extern void DescribeLockTag(StringInfo buf, const LOCKTAG *tag);
 112
 113 extern const char *GetLockNameFromTagType(uint16 locktag_type);
 114
 115 #endif                                                  /* LMGR_H */