Rename locking structure names to be clearer. Add narrative to

backend flowchart.

src/backend/storage/lmgr/multi.c

@@ -12,7 +12,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/storage/lmgr/Attic/multi.c,v 1.18 1998/06/28 21:17:35 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/storage/lmgr/Attic/multi.c,v 1.19 1998/06/30 02:33:31 momjian Exp $
  *
  * NOTES:
  *	 (1) The lock.c module assumes that the caller here is doing
@@ -30,10 +30,10 @@
 #include "miscadmin.h"			/* MyDatabaseId */
 
 static bool
-MultiAcquire(LockTableId tableId, LOCKTAG *tag, LOCKTYPE locktype,
+MultiAcquire(LOCKMETHOD lockmethod, LOCKTAG *tag, LOCKMODE lockmode,
 			 PG_LOCK_LEVEL level);
 static bool
-MultiRelease(LockTableId tableId, LOCKTAG *tag, LOCKTYPE locktype,
+MultiRelease(LOCKMETHOD lockmethod, LOCKTAG *tag, LOCKMODE lockmode,
 			 PG_LOCK_LEVEL level);
 
 /*
@@ -78,25 +78,27 @@ static int	MultiPrios[] = {
  * Lock table identifier for this lock table.  The multi-level
  * lock table is ONE lock table, not three.
  */
-LockTableId MultiTableId = (LockTableId) NULL;
-LockTableId ShortTermTableId = (LockTableId) NULL;
+LOCKMETHOD MultiTableId = (LOCKMETHOD) NULL;
+#ifdef NOT_USED
+LOCKMETHOD ShortTermTableId = (LOCKMETHOD) NULL;
+#endif
 
 /*
  * Create the lock table described by MultiConflicts and Multiprio.
  */
-LockTableId
+LOCKMETHOD
 InitMultiLevelLocks()
 {
-	int			tableId;
+	int			lockmethod;
 
-	tableId = LockTableInit("LockTable", MultiConflicts, MultiPrios, 5);
-	MultiTableId = tableId;
+	lockmethod = LockMethodTableInit("MultiLevelLockTable", MultiConflicts, MultiPrios, 5);
+	MultiTableId = lockmethod;
 	if (!(MultiTableId))
 		elog(ERROR, "InitMultiLocks: couldnt initialize lock table");
 	/* -----------------------
 	 * No short term lock table for now.  -Jeff 15 July 1991
 	 *
-	 * ShortTermTableId = LockTableRename(tableId);
+	 * ShortTermTableId = LockTableRename(lockmethod);
 	 * if (! (ShortTermTableId)) {
 	 *	 elog(ERROR,"InitMultiLocks: couldnt rename lock table");
 	 * }
@@ -111,7 +113,7 @@ InitMultiLevelLocks()
  * Returns: TRUE if the lock can be set, FALSE otherwise.
  */
 bool
-MultiLockReln(LockInfo linfo, LOCKTYPE locktype)
+MultiLockReln(LockInfo linfo, LOCKMODE lockmode)
 {
 	LOCKTAG		tag;
 
@@ -122,7 +124,7 @@ MultiLockReln(LockInfo linfo, LOCKTYPE locktype)
 	MemSet(&tag, 0, sizeof(tag));
 	tag.relId = linfo->lRelId.relId;
 	tag.dbId = linfo->lRelId.dbId;
-	return (MultiAcquire(MultiTableId, &tag, locktype, RELN_LEVEL));
+	return (MultiAcquire(MultiTableId, &tag, lockmode, RELN_LEVEL));
 }
 
 /*
@@ -134,7 +136,7 @@ MultiLockReln(LockInfo linfo, LOCKTYPE locktype)
  *		at the page and relation level.
  */
 bool
-MultiLockTuple(LockInfo linfo, ItemPointer tidPtr, LOCKTYPE locktype)
+MultiLockTuple(LockInfo linfo, ItemPointer tidPtr, LOCKMODE lockmode)
 {
 	LOCKTAG		tag;
 
@@ -149,14 +151,14 @@ MultiLockTuple(LockInfo linfo, ItemPointer tidPtr, LOCKTYPE locktype)
 
 	/* not locking any valid Tuple, just the page */
 	tag.tupleId = *tidPtr;
-	return (MultiAcquire(MultiTableId, &tag, locktype, TUPLE_LEVEL));
+	return (MultiAcquire(MultiTableId, &tag, lockmode, TUPLE_LEVEL));
 }
 
 /*
  * same as above at page level
  */
 bool
-MultiLockPage(LockInfo linfo, ItemPointer tidPtr, LOCKTYPE locktype)
+MultiLockPage(LockInfo linfo, ItemPointer tidPtr, LOCKMODE lockmode)
 {
 	LOCKTAG		tag;
 
@@ -179,7 +181,7 @@ MultiLockPage(LockInfo linfo, ItemPointer tidPtr, LOCKTYPE locktype)
 	tag.relId = linfo->lRelId.relId;
 	tag.dbId = linfo->lRelId.dbId;
 	BlockIdCopy(&(tag.tupleId.ip_blkid), &(tidPtr->ip_blkid));
-	return (MultiAcquire(MultiTableId, &tag, locktype, PAGE_LEVEL));
+	return (MultiAcquire(MultiTableId, &tag, lockmode, PAGE_LEVEL));
 }
 
 /*
@@ -189,12 +191,12 @@ MultiLockPage(LockInfo linfo, ItemPointer tidPtr, LOCKTYPE locktype)
  * Side Effects:
  */
 static bool
-MultiAcquire(LockTableId tableId,
+MultiAcquire(LOCKMETHOD lockmethod,
 			 LOCKTAG *tag,
-			 LOCKTYPE locktype,
+			 LOCKMODE lockmode,
 			 PG_LOCK_LEVEL level)
 {
-	LOCKTYPE		locks[N_LEVELS];
+	LOCKMODE		locks[N_LEVELS];
 	int			i,
 				status;
 	LOCKTAG		xxTag,
@@ -213,19 +215,19 @@ MultiAcquire(LockTableId tableId,
 	switch (level)
 	{
 		case RELN_LEVEL:
-			locks[0] = locktype;
+			locks[0] = lockmode;
 			locks[1] = NO_LOCK;
 			locks[2] = NO_LOCK;
 			break;
 		case PAGE_LEVEL:
-			locks[0] = locktype + INTENT;
-			locks[1] = locktype;
+			locks[0] = lockmode + INTENT;
+			locks[1] = lockmode;
 			locks[2] = NO_LOCK;
 			break;
 		case TUPLE_LEVEL:
-			locks[0] = locktype + INTENT;
-			locks[1] = locktype + INTENT;
-			locks[2] = locktype;
+			locks[0] = lockmode + INTENT;
+			locks[1] = lockmode + INTENT;
+			locks[2] = lockmode;
 			break;
 		default:
 			elog(ERROR, "MultiAcquire: bad lock level");
@@ -274,7 +276,7 @@ MultiAcquire(LockTableId tableId,
 					break;
 			}
 
-			status = LockAcquire(tableId, tmpTag, locks[i]);
+			status = LockAcquire(lockmethod, tmpTag, locks[i]);
 			if (!status)
 			{
 
@@ -285,7 +287,7 @@ MultiAcquire(LockTableId tableId,
 				 * the last level lock we successfully acquired
 				 */
 				retStatus = FALSE;
-				MultiRelease(tableId, tag, locktype, i);
+				MultiRelease(lockmethod, tag, lockmode, i);
 				/* now leave the loop.	Don't try for any more locks */
 				break;
 			}
@@ -300,7 +302,7 @@ MultiAcquire(LockTableId tableId,
  */
 #ifdef NOT_USED
 bool
-MultiReleasePage(LockInfo linfo, ItemPointer tidPtr, LOCKTYPE locktype)
+MultiReleasePage(LockInfo linfo, ItemPointer tidPtr, LOCKMODE lockmode)
 {
 	LOCKTAG		tag;
 
@@ -316,7 +318,7 @@ MultiReleasePage(LockInfo linfo, ItemPointer tidPtr, LOCKTYPE locktype)
 	tag.dbId = linfo->lRelId.dbId;
 	BlockIdCopy(&(tag.tupleId.ip_blkid), &(tidPtr->ip_blkid));
 
-	return (MultiRelease(MultiTableId, &tag, locktype, PAGE_LEVEL));
+	return (MultiRelease(MultiTableId, &tag, lockmode, PAGE_LEVEL));
 }
 
 #endif
@@ -326,7 +328,7 @@ MultiReleasePage(LockInfo linfo, ItemPointer tidPtr, LOCKTYPE locktype)
  * ------------------
  */
 bool
-MultiReleaseReln(LockInfo linfo, LOCKTYPE locktype)
+MultiReleaseReln(LockInfo linfo, LOCKMODE lockmode)
 {
 	LOCKTAG		tag;
 
@@ -340,7 +342,7 @@ MultiReleaseReln(LockInfo linfo, LOCKTYPE locktype)
 	tag.relId = linfo->lRelId.relId;
 	tag.dbId = linfo->lRelId.dbId;
 
-	return (MultiRelease(MultiTableId, &tag, locktype, RELN_LEVEL));
+	return (MultiRelease(MultiTableId, &tag, lockmode, RELN_LEVEL));
 }
 
 /*
@@ -349,12 +351,12 @@ MultiReleaseReln(LockInfo linfo, LOCKTYPE locktype)
  * Returns: TRUE if successful, FALSE otherwise.
  */
 static bool
-MultiRelease(LockTableId tableId,
+MultiRelease(LOCKMETHOD lockmethod,
 			 LOCKTAG *tag,
-			 LOCKTYPE locktype,
+			 LOCKMODE lockmode,
 			 PG_LOCK_LEVEL level)
 {
-	LOCKTYPE		locks[N_LEVELS];
+	LOCKMODE		locks[N_LEVELS];
 	int			i,
 				status;
 	LOCKTAG		xxTag,
@@ -366,22 +368,22 @@ MultiRelease(LockTableId tableId,
 	switch (level)
 	{
 		case RELN_LEVEL:
-			locks[0] = locktype;
+			locks[0] = lockmode;
 			locks[1] = NO_LOCK;
 			locks[2] = NO_LOCK;
 			break;
 		case PAGE_LEVEL:
-			locks[0] = locktype + INTENT;
-			locks[1] = locktype;
+			locks[0] = lockmode + INTENT;
+			locks[1] = lockmode;
 			locks[2] = NO_LOCK;
 			break;
 		case TUPLE_LEVEL:
-			locks[0] = locktype + INTENT;
-			locks[1] = locktype + INTENT;
-			locks[2] = locktype;
+			locks[0] = lockmode + INTENT;
+			locks[1] = lockmode + INTENT;
+			locks[2] = lockmode;
 			break;
 		default:
-			elog(ERROR, "MultiRelease: bad locktype");
+			elog(ERROR, "MultiRelease: bad lockmode");
 	}
 
 	/*
@@ -423,7 +425,7 @@ MultiRelease(LockTableId tableId,
 					ItemPointerCopy(&tmpTag->tupleId, &tag->tupleId);
 					break;
 			}
-			status = LockRelease(tableId, tmpTag, locks[i]);
+			status = LockRelease(lockmethod, tmpTag, locks[i]);
 			if (!status)
 				elog(ERROR, "MultiRelease: couldn't release after error");
 		}

src/backend/storage/lmgr/proc.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.38 1998/06/27 15:47:46 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.39 1998/06/30 02:33:32 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -46,7 +46,7 @@
  *		This is so that we can support more backends. (system-wide semaphore
  *		sets run out pretty fast.)				  -ay 4/95
  *
- * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.38 1998/06/27 15:47:46 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.39 1998/06/30 02:33:32 momjian Exp $
  */
 #include <sys/time.h>
 #include <unistd.h>
@@ -580,7 +580,7 @@ ProcWakeup(PROC *proc, int errType)
  *		released.
  */
 int
-ProcLockWakeup(PROC_QUEUE *queue, char *ltable, char *lock)
+ProcLockWakeup(PROC_QUEUE *queue, LOCKMETHOD lockmethod, LOCK *lock)
 {
 	PROC	   *proc;
 	int			count;
@@ -590,8 +590,8 @@ ProcLockWakeup(PROC_QUEUE *queue, char *ltable, char *lock)
 
 	proc = (PROC *) MAKE_PTR(queue->links.prev);
 	count = 0;
-	while ((LockResolveConflicts((LOCKTAB *) ltable,
-								 (LOCK *) lock,
+	while ((LockResolveConflicts(lockmethod,
+								 lock,
 								 proc->token,
 								 proc->xid) == STATUS_OK))
 	{
@@ -602,7 +602,7 @@ ProcLockWakeup(PROC_QUEUE *queue, char *ltable, char *lock)
 		 * between the time we release the lock master (spinlock) and the
 		 * time that the awoken process begins executing again.
 		 */
-		GrantLock((LOCK *) lock, proc->token);
+		GrantLock(lock, proc->token);
 		queue->size--;
 
 		/*

src/backend/storage/lmgr/single.c

@@ -13,7 +13,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/storage/lmgr/Attic/single.c,v 1.6 1998/06/28 21:17:35 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/storage/lmgr/Attic/single.c,v 1.7 1998/06/30 02:33:32 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -32,7 +32,7 @@
  * Returns: TRUE if the lock can be set, FALSE otherwise.
  */
 bool
-SingleLockReln(LockInfo linfo, LOCKTYPE locktype, int action)
+SingleLockReln(LockInfo linfo, LOCKMODE lockmode, int action)
 {
 	LOCKTAG		tag;
 
@@ -47,9 +47,9 @@ SingleLockReln(LockInfo linfo, LOCKTYPE locktype, int action)
 	tag.tupleId.ip_posid = InvalidOffsetNumber;
 
 	if (action == UNLOCK)
-		return (LockRelease(MultiTableId, &tag, locktype));
+		return (LockRelease(MultiTableId, &tag, lockmode));
 	else
-		return (LockAcquire(MultiTableId, &tag, locktype));
+		return (LockAcquire(MultiTableId, &tag, lockmode));
 }
 
 /*
@@ -63,7 +63,7 @@ SingleLockReln(LockInfo linfo, LOCKTYPE locktype, int action)
 bool
 SingleLockPage(LockInfo linfo,
 			   ItemPointer tidPtr,
-			   LOCKTYPE locktype,
+			   LOCKMODE lockmode,
 			   int action)
 {
 	LOCKTAG		tag;
@@ -80,7 +80,7 @@ SingleLockPage(LockInfo linfo,
 
 
 	if (action == UNLOCK)
-		return (LockRelease(MultiTableId, &tag, locktype));
+		return (LockRelease(MultiTableId, &tag, lockmode));
 	else
-		return (LockAcquire(MultiTableId, &tag, locktype));
+		return (LockAcquire(MultiTableId, &tag, lockmode));
 }

src/include/storage/lmgr.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: lmgr.h,v 1.11 1998/06/28 21:17:35 momjian Exp $
+ * $Id: lmgr.h,v 1.12 1998/06/30 02:33:32 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -72,10 +72,10 @@ extern void RelationSetWIntentLock(Relation relation);
 extern void RelationUnsetWIntentLock(Relation relation);
 
 /* single.c */
-extern bool SingleLockReln(LockInfo linfo, LOCKTYPE locktype, int action);
+extern bool SingleLockReln(LockInfo linfo, LOCKMODE lockmode, int action);
 extern bool
 SingleLockPage(LockInfo linfo, ItemPointer tidPtr,
-			   LOCKTYPE locktype, int action);
+			   LOCKMODE lockmode, int action);
 
 /* proc.c */
 extern void InitProcGlobal(IPCKey key);

src/include/storage/lock.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: lock.h,v 1.14 1998/06/28 21:17:35 momjian Exp $
+ * $Id: lock.h,v 1.15 1998/06/30 02:33:33 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -36,26 +36,25 @@ typedef int MASK;
 #define NLOCKS_PER_XACT 40
 #define NLOCKENTS NLOCKS_PER_XACT*NBACKENDS
 
-typedef int LOCK_TYPE;
-typedef int LOCKTYPE;
-typedef int LockTableId;
+typedef int LOCKMODE;
+typedef int LOCKMETHOD;
 
-/* MAX_LOCKTYPES cannot be larger than the bits in MASK */
-#define MAX_LOCKTYPES 6
+/* MAX_LOCKMODES cannot be larger than the bits in MASK */
+#define MAX_LOCKMODES 6
 
 /*
- * MAX_TABLES corresponds to the number of spin locks allocated in
+ * MAX_LOCK_METHODS corresponds to the number of spin locks allocated in
  * CreateSpinLocks() or the number of shared memory locations allocated
  * for lock table spin locks in the case of machines with TAS instructions.
  */
-#define MAX_TABLES 2
+#define MAX_LOCK_METHODS 2
 
 #define INVALID_TABLEID 0
 
 /*typedef struct LOCK LOCK; */
 
 
-typedef struct ltag
+typedef struct LTAG
 {
 	Oid			relId;
 	Oid			dbId;
@@ -67,31 +66,31 @@ typedef struct ltag
 /* This is the control structure for a lock table.	It
  * lives in shared memory:
  *
- * tableID -- the handle used by the lock table's clients to
- *		refer to the table.
+ * lockmethod -- the handle used by the lock table's clients to
+ *		refer to the type of lock table being used.
  *
- * nLockTypes -- number of lock types (READ,WRITE,etc) that
+ * numLockModes -- number of lock types (READ,WRITE,etc) that
  *		are defined on this lock table
  *
  * conflictTab -- this is an array of bitmasks showing lock
  *		type conflicts. conflictTab[i] is a mask with the j-th bit
  *		turned on if lock types i and j conflict.
  *
- * prio -- each locktype has a priority, so, for example, waiting
+ * prio -- each lockmode has a priority, so, for example, waiting
  *		writers can be given priority over readers (to avoid
  *		starvation).
  *
  * masterlock -- synchronizes access to the table
  *
  */
-typedef struct lockctl
+typedef struct LOCKMETHODCTL
 {
-	LockTableId tableId;
-	int			nLockTypes;
-	int			conflictTab[MAX_LOCKTYPES];
-	int			prio[MAX_LOCKTYPES];
+	LOCKMETHOD 	lockmethod;
+	int			numLockModes;
+	int			conflictTab[MAX_LOCKMODES];
+	int			prio[MAX_LOCKMODES];
 	SPINLOCK	masterLock;
-} LOCKCTL;
+} LOCKMETHODCTL;
 
 /*
  * lockHash -- hash table on lock Ids,
@@ -99,12 +98,12 @@ typedef struct lockctl
  *		multiple processes are holding the lock
  * ctl - control structure described above.
  */
-typedef struct ltable
+typedef struct LOCKMETHODTABLE
 {
 	HTAB	   *lockHash;
 	HTAB	   *xidHash;
-	LOCKCTL    *ctl;
-} LOCKTAB;
+	LOCKMETHODCTL    *ctl;
+} LOCKMETHODTABLE;
 
 /* -----------------------
  * A transaction never conflicts with its own locks.  Hence, if
@@ -148,7 +147,7 @@ typedef struct XIDLookupEnt
 	XIDTAG		tag;
 
 	/* data */
-	int			holders[MAX_LOCKTYPES];
+	int			holders[MAX_LOCKMODES];
 	int			nHolding;
 	SHM_QUEUE	queue;
 } XIDLookupEnt;
@@ -156,7 +155,7 @@ typedef struct XIDLookupEnt
 #define XID_TAGSIZE (sizeof(XIDTAG))
 
 /* originally in procq.h */
-typedef struct procQueue
+typedef struct PROC_QUEUE
 {
 	SHM_QUEUE	links;
 	int			size;
@@ -174,7 +173,7 @@ typedef struct procQueue
  *		lock.
  * nHolding -- total locks of all types.
  */
-typedef struct Lock
+typedef struct LOCK
 {
 	/* hash key */
 	LOCKTAG		tag;
@@ -182,18 +181,18 @@ typedef struct Lock
 	/* data */
 	int			mask;
 	PROC_QUEUE	waitProcs;
-	int			holders[MAX_LOCKTYPES];
+	int			holders[MAX_LOCKMODES];
 	int			nHolding;
-	int			activeHolders[MAX_LOCKTYPES];
+	int			activeHolders[MAX_LOCKMODES];
 	int			nActive;
 } LOCK;
 
 #define LockGetLock_nHolders(l) l->nHolders
 
-#define LockDecrWaitHolders(lock, locktype) \
+#define LockDecrWaitHolders(lock, lockmode) \
 ( \
   lock->nHolding--, \
-  lock->holders[locktype]-- \
+  lock->holders[lockmode]-- \
 )
 
 #define LockLockTable() SpinAcquire(LockMgrLock);
@@ -206,16 +205,16 @@ extern SPINLOCK LockMgrLock;
  */
 extern void InitLocks(void);
 extern void LockDisable(int status);
-extern LockTableId
-LockTableInit(char *tabName, MASK *conflictsP, int *prioP,
-			int ntypes);
-extern bool LockAcquire(LockTableId tableId, LOCKTAG *lockName, LOCKTYPE locktype);
+extern LOCKMETHOD
+LockMethodTableInit(char *tabName, MASK *conflictsP, int *prioP,
+			int numModes);
+extern bool LockAcquire(LOCKMETHOD lockmethod, LOCKTAG *locktag, LOCKMODE lockmode);
 extern int
-LockResolveConflicts(LOCKTAB *ltable, LOCK *lock, LOCKTYPE locktype,
+LockResolveConflicts(LOCKMETHOD lockmethod, LOCK *lock, LOCKMODE lockmode,
 					 TransactionId xid);
-extern bool LockRelease(LockTableId tableId, LOCKTAG *lockName, LOCKTYPE locktype);
-extern void GrantLock(LOCK *lock, LOCKTYPE locktype);
-extern bool LockReleaseAll(LockTableId tableId, SHM_QUEUE *lockQueue);
+extern bool LockRelease(LOCKMETHOD lockmethod, LOCKTAG *locktag, LOCKMODE lockmode);
+extern void GrantLock(LOCK *lock, LOCKMODE lockmode);
+extern bool LockReleaseAll(LOCKMETHOD lockmethod, SHM_QUEUE *lockQueue);
 extern int	LockShmemSize(void);
 extern bool LockingDisabled(void);
 extern bool DeadLockCheck(SHM_QUEUE *lockQueue, LOCK *findlock, bool skip_check);

src/include/storage/multilev.h

@@ -7,7 +7,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: multilev.h,v 1.9 1998/06/28 21:17:36 momjian Exp $
+ * $Id: multilev.h,v 1.10 1998/06/30 02:33:33 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -43,16 +43,18 @@ typedef int PG_LOCK_LEVEL;
 
 /* multi.c */
 
-extern LockTableId MultiTableId;
-extern LockTableId ShortTermTableId;
+extern LOCKMETHOD MultiTableId;
+#ifdef NOT_USED
+extern LOCKMETHOD ShortTermTableId;
+#endif
 
 /*
  * function prototypes
  */
-extern LockTableId InitMultiLevelLocks(void);
-extern bool MultiLockReln(LockInfo linfo, LOCKTYPE locktype);
-extern bool MultiLockTuple(LockInfo linfo, ItemPointer tidPtr, LOCKTYPE locktype);
-extern bool MultiLockPage(LockInfo linfo, ItemPointer tidPtr, LOCKTYPE locktype);
-extern bool MultiReleaseReln(LockInfo linfo, LOCKTYPE locktype);
+extern LOCKMETHOD InitMultiLevelLocks(void);
+extern bool MultiLockReln(LockInfo linfo, LOCKMODE lockmode);
+extern bool MultiLockTuple(LockInfo linfo, ItemPointer tidPtr, LOCKMODE lockmode);
+extern bool MultiLockPage(LockInfo linfo, ItemPointer tidPtr, LOCKMODE lockmode);
+extern bool MultiReleaseReln(LockInfo linfo, LOCKMODE lockmode);
 
 #endif							/* MULTILEV_H */

src/include/storage/proc.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: proc.h,v 1.11 1998/02/26 04:43:31 momjian Exp $
+ * $Id: proc.h,v 1.12 1998/06/30 02:33:33 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -100,7 +100,7 @@ extern void ProcQueueInit(PROC_QUEUE *queue);
 extern int
 ProcSleep(PROC_QUEUE *queue, SPINLOCK spinlock, int token,
 		  int prio, LOCK *lock);
-extern int	ProcLockWakeup(PROC_QUEUE *queue, char *ltable, char *lock);
+extern int	ProcLockWakeup(PROC_QUEUE *queue, LOCKMETHOD lockmethod, LOCK *lock);
 extern void ProcAddLock(SHM_QUEUE *elem);
 extern void ProcReleaseSpins(PROC *proc);
 extern void ProcFreeAllSemaphores(void);

src/tools/backend/index.html

@@ -25,13 +25,13 @@ structure, like
 The query is then identified as a <I>Utility</I> function or a more
 complex query.  A <I>Utility</I> query is processed by a
 query-specific function in <A HREF="../../backend/commands">
-commands.</A> A complex query, like <B>SELECT, UPDATE,</B> and
-<B>DELETE</B> requires much more handling.
+commands.</A> A complex query, like <CODE>SELECT, UPDATE,</CODE> and
+<CODE>DELETE</CODE> requires much more handling.
 <P>
 The parser takes a complex query, and creates a
 <A HREF="../../include/nodes/parsenodes.h">Query</A> structure that
 contains all the elements used by complex queries.  Query.qual holds the
-<B>WHERE</B> clause qualification, which is filled in by
+<CODE>WHERE</CODE> clause qualification, which is filled in by
 <A HREF="../../backend/parser/parse_clause.c">transformWhereClause().</A>
 Each table referenced in the query is represented by a <A
 HREF="../../include/nodes/parsenodes.h"> RangeTableEntry,</A> and they
@@ -39,19 +39,19 @@ are linked together to form the <I>range table</I> of the query, which is
 generated by <A HREF="../../backend/parser/parse_clause.c">
 makeRangeTable().</A>  Query.rtable holds the queries range table.
 <P>
-Certain queries, like <B>SELECT,</B> return columns of data.  Other
-queries, like <B>INSERT</B> and <B>UPDATE,</B> specify the columns
+Certain queries, like <CODE>SELECT,</CODE> return columns of data.  Other
+queries, like <CODE>INSERT</CODE> and <CODE>UPDATE,</CODE> specify the columns
 modified by the query.  These column references are converted to <A
 HREF="../../include/nodes/primnodes.h">Resdom</A> entries, which are
 linked together to make up the <I>target list</I> of the query. The
 target list is stored in Query.targetList, which is generated by
 <A HREF="../../backend/parser/parse_target.c">transformTargetList().</A>
 <P>
-Other query elements, like aggregates(<B>SUM()</B>), <B>GROUP BY,</B>
-<B>ORDER BY</B> are also stored in their own Query fields.
+Other query elements, like aggregates(<CODE>SUM()</CODE>), <CODE>GROUP BY,</CODE>
+<CODE>ORDER BY</CODE> are also stored in their own Query fields.
 <P>
-The next step is for the Query to be modified by any <B>VIEWS</B> or
-<B>RULES</B> that may apply to the query.  This is performed by the <A
+The next step is for the Query to be modified by any <CODE>VIEWS</CODE> or
+<CODE>RULES</CODE> that may apply to the query.  This is performed by the <A
 HREF="../../backend/rewrite">rewrite</A> system.
 <P>
 The <A HREF="../../backend/optimizer">optimizer</A> takes the Query
@@ -60,7 +60,7 @@ HREF="../..//include/nodes/plannodes.h">Plan,</A> which contains the
 operations to be performed to execute the query.  The <A
 HREF="../../backend/optimizer/path">path</A> module determines the best
 table join order and join type of each table in the RangeTable, using
-Query.qual(<B>WHERE</B> clause) to consider optimal index usage.
+Query.qual(<CODE>WHERE</CODE> clause) to consider optimal index usage.
 <P>
 The Plan is then passed to the <A
 HREF="../../backend/executor">executor</A> for execution, and the result
@@ -81,15 +81,25 @@ data/index buffer cache block
 <LI>Shared Buf Lookup Table - lookup of buffer cache block address using
 table name and block number(<A HREF="../../include/storage/buf_internals.h">
 BufferTag</A>)
-<LI><A HREF="../../include/storage/lock.h">LockTable (ctl)</A> - lock table
-structure, specifiying table, lock types, and backends holding or
-waiting on lock
-<LI>LockTable (lock hash) - lookup of LockTable structures using relation,
-database object ids
-<LI>LockTable (xid hash) - lookup of LockTable structures using
-transaction id, LockTable address
+<LI>MultiLevelLockTable (ctl) - <A
+HREF="../../include/storage/lock.h">LOCKCTL</A> control structure for
+each locking method.  Currently, only multi-level locking is used.
+<LI>MultiLevelLockTable (lock hash) - the <A
+HREF="../../include/storage/lock.h">LOCK</A> structure, looked up using
+relation, database object ids(<A
+HREF="../../include/storage/lock.h">LOCKTAG)</A>.  The lock table structure contains the
+lock modes(read, write) and circular linked list of backends (<A
+HREF="../../include/storage/proc.h">PROC</A> structure pointers) waiting
+on the lock.
+<LI>MultiLevelLockTable (xid hash) - lookup of LOCK structure address
+using transaction id, LOCK address.  It is used to quickly check if the
+current transaction already has any locks on a table, rather than having
+to search through all the held locks.  It also stores the modes
+(read/write) of the locks held by the current transaction.  The returned
+<A HREF="../../include/storage/lock.h">XIDLookupEnt</A> structure also
+contains a pointer to the backend's PROC.lockQueue.
 <LI><A HREF="../../include/storage/proc.h">Proc Header</A> - information
-about each backend, including locks held/waiting,  indexed by process id
+about each backend, including locks held/waiting, indexed by process id
 </UL>
 Each data structure is created by calling <A
 HREF="../../backend/storage/ipc/shmem.c">ShmemInitStruct(),</A> and