Fix LMGR for MVCC.

Get rid of Extend lock mode.

src/backend/access/heap/hio.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Id: hio.c,v 1.18 1999/05/01 15:04:46 vadim Exp $
+ *	  $Id: hio.c,v 1.19 1999/05/07 01:22:53 vadim Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -111,14 +111,13 @@ RelationPutHeapTupleAtEnd(Relation relation, HeapTuple tuple)
 	Item		item;
 
 	/*
-	 * Actually, we lock _relation_ here, not page, but I believe
-	 * that locking page is faster... Obviously, we could get rid
-	 * of ExtendLock mode at all and use ExclusiveLock mode on
-	 * page 0, as long as we use page-level locking for indices only,
-	 * but we are in 6.5-beta currently...	- vadim 05/01/99
+	 * Lock relation for extention. We can use LockPage here as long as 
+	 * in all other places we use page-level locking for indices only.
+	 * Alternatevely, we could define pseudo-table as we do for
+	 * transactions with XactLockTable.
 	 */
 	if (!relation->rd_myxactonly)
-		LockPage(relation, 0, ExtendLock);
+		LockPage(relation, 0, ExclusiveLock);
 
 	/*
 	 * XXX This does an lseek - VERY expensive - but at the moment it is
@@ -166,7 +165,7 @@ RelationPutHeapTupleAtEnd(Relation relation, HeapTuple tuple)
 	}
 
 	if (!relation->rd_myxactonly)
-		UnlockPage(relation, 0, ExtendLock);
+		UnlockPage(relation, 0, ExclusiveLock);
 
 	offnum = PageAddItem((Page) pageHeader, (Item) tuple->t_data,
 						 tuple->t_len, InvalidOffsetNumber, LP_USED);

src/backend/storage/lmgr/lmgr.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/storage/lmgr/lmgr.c,v 1.22 1999/02/13 23:18:24 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/storage/lmgr/lmgr.c,v 1.23 1999/05/07 01:23:02 vadim Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -79,9 +79,6 @@ static MASK LockConflicts[] = {
 	(1 << RowExclusiveLock) | (1 << RowShareLock) | (1 << AccessExclusiveLock) | 
 	(1 << AccessShareLock),
 
-/* ExtendLock */
-	(1 << ExtendLock)
-
 };
 
 static int	LockPrios[] = {
@@ -92,8 +89,7 @@ static int	LockPrios[] = {
 	4,
 	5,
 	6,
-	7,
-	1
+	7
 };
 
 LOCKMETHOD	LockTableId = (LOCKMETHOD) NULL;

src/backend/storage/lmgr/proc.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.53 1999/04/30 02:04:51 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.54 1999/05/07 01:23:04 vadim 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 1.53 1999/04/30 02:04:51 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.54 1999/05/07 01:23:04 vadim Exp $
  */
 #include <sys/time.h>
 #include <unistd.h>
@@ -106,6 +106,8 @@ static void ProcKill(int exitStatus, int pid);
 static void ProcGetNewSemKeyAndNum(IPCKey *key, int *semNum);
 static void ProcFreeSem(IpcSemaphoreKey semKey, int semNum);
 
+static char *DeadLockMessage = "Deadlock detected -- See the lock(l) manual page for a possible cause.";
+
 /*
  * InitProcGlobal -
  *	  initializes the global process table. We put it here so that
@@ -488,68 +490,80 @@ ProcQueueInit(PROC_QUEUE *queue)
  */
 int
 ProcSleep(PROC_QUEUE *waitQueue,/* lock->waitProcs */
-		  SPINLOCK spinlock,
+		  LOCKMETHODCTL *lockctl,
 		  int token,			/* lockmode */
-		  int prio,
-		  LOCK *lock,
-		  TransactionId xid)	/* needed by user locks, see below */
+		  LOCK *lock)
 {
 	int			i;
+	SPINLOCK	spinlock = lockctl->masterLock;
 	PROC	   *proc;
+	int			myMask = (1 << token);
+	int			waitMask = lock->waitMask;
+	int			aheadHolders[MAX_LOCKMODES];
+	bool		selfConflict = (lockctl->conflictTab[token] & myMask),
+				prevSame = false;
 	bool		deadlock_checked = false;
 	struct itimerval timeval,
 				dummy;
 
-	/*
-	 * If the first entries in the waitQueue have a greater priority than
-	 * we have, we must be a reader, and they must be a writers, and we
-	 * must be here because the current holder is a writer or a reader but
-	 * we don't share shared locks if a writer is waiting. We put
-	 * ourselves after the writers.  This way, we have a FIFO, but keep
-	 * the readers together to give them decent priority, and no one
-	 * starves.  Because we group all readers together, a non-empty queue
-	 * only has a few possible configurations:
-	 *
-	 * [readers] [writers] [readers][writers] [writers][readers]
-	 * [writers][readers][writers]
-	 *
-	 * In a full queue, we would have a reader holding a lock, then a writer
-	 * gets the lock, then a bunch of readers, made up of readers who
-	 * could not share the first readlock because a writer was waiting,
-	 * and new readers arriving while the writer had the lock.  bjm
-	 */
+	MyProc->token = token;
+	MyProc->waitLock = lock;
+
 	proc = (PROC *) MAKE_PTR(waitQueue->links.prev);
 
-	/* If we are a reader, and they are writers, skip past them */
-	for (i = 0; i < waitQueue->size && proc->prio > prio; i++)
-		proc = (PROC *) MAKE_PTR(proc->links.prev);
+	/* if we don't conflict with any waiter - be first in queue */
+	if (!(lockctl->conflictTab[token] & waitMask))
+		goto ins;
 
-	/* The rest of the queue is FIFO, with readers first, writers last */
-	for (; i < waitQueue->size && proc->prio <= prio; i++)
-		proc = (PROC *) MAKE_PTR(proc->links.prev);
+	for (i = 1; i < MAX_LOCKMODES; i++)
+		aheadHolders[i] = lock->activeHolders[i];
+	(aheadHolders[token])++;
 
-	MyProc->prio = prio;
-	MyProc->token = token;
-	MyProc->waitLock = lock;
+	for (i = 0; i < waitQueue->size; i++)
+	{
+		/* am I waiting for him ? */
+		if (lockctl->conflictTab[token] & proc->holdLock)
+		{
+			/* is he waiting for me ? */
+			if (lockctl->conflictTab[proc->token] & MyProc->holdLock)
+			{
+				MyProc->errType = STATUS_ERROR;
+				elog(NOTICE, DeadLockMessage);
+				goto rt;
+			}
+			/* being waiting for him - go past */
+		}
+		/* if he waits for me */
+		else if (lockctl->conflictTab[proc->token] & MyProc->holdLock)
+		{
+			break;
+		}
+		/* if conflicting locks requested */
+		else if (lockctl->conflictTab[proc->token] & myMask)
+		{
+			/*
+			 * If I request non self-conflicting lock and there
+			 * are others requesting the same lock just before me -
+			 * stay here.
+			 */
+			if (!selfConflict && prevSame)
+				break;
+		}
+		/*
+		 * Last attempt to don't move any more: if we don't conflict
+		 * with rest waiters in queue.
+		 */
+		else if (!(lockctl->conflictTab[token] & waitMask))
+			break;
 
-#ifdef USER_LOCKS
-	/* -------------------
-	 * Currently, we only need this for the ProcWakeup routines.
-	 * This must be 0 for user lock, so we can't just use the value
-	 * from GetCurrentTransactionId().
-	 * -------------------
-	 */
-	TransactionIdStore(xid, &MyProc->xid);
-#else
-#ifndef LowLevelLocking
-	/* -------------------
-	 * currently, we only need this for the ProcWakeup routines
-	 * -------------------
-	 */
-	TransactionIdStore((TransactionId) GetCurrentTransactionId(), &MyProc->xid);
-#endif
-#endif
+		prevSame = (proc->token == token);
+		(aheadHolders[proc->token])++;
+		if (aheadHolders[proc->token] == lock->holders[proc->token])
+			waitMask &= ~ (1 << proc->token);
+		proc = (PROC *) MAKE_PTR(proc->links.prev);
+	}
 
+ins:;
 	/* -------------------
 	 * assume that these two operations are atomic (because
 	 * of the spinlock).
@@ -558,6 +572,7 @@ ProcSleep(PROC_QUEUE *waitQueue,/* lock->waitProcs */
 	SHMQueueInsertTL(&(proc->links), &(MyProc->links));
 	waitQueue->size++;
 
+	lock->waitMask |= myMask;
 	SpinRelease(spinlock);
 
 	/* --------------
@@ -608,6 +623,8 @@ ProcSleep(PROC_QUEUE *waitQueue,/* lock->waitProcs */
 	 */
 	SpinAcquire(spinlock);
 
+rt:;
+
 #ifdef LOCK_MGR_DEBUG
 	/* Just to get meaningful debug messages from DumpLocks() */
 	MyProc->waitLock = (LOCK *) NULL;
@@ -655,9 +672,9 @@ int
 ProcLockWakeup(PROC_QUEUE *queue, LOCKMETHOD lockmethod, LOCK *lock)
 {
 	PROC	   *proc;
-	int			count;
+	int			count = 0;
 	int			trace_flag;
-	int			last_locktype = -1;
+	int			last_locktype = 0;
 	int			queue_size = queue->size;
 
 	Assert(queue->size >= 0);
@@ -666,7 +683,6 @@ ProcLockWakeup(PROC_QUEUE *queue, LOCKMETHOD lockmethod, LOCK *lock)
 		return STATUS_NOT_FOUND;
 
 	proc = (PROC *) MAKE_PTR(queue->links.prev);
-	count = 0;
 	while ((queue_size--) && (proc))
 	{
 
@@ -678,7 +694,7 @@ ProcLockWakeup(PROC_QUEUE *queue, LOCKMETHOD lockmethod, LOCK *lock)
 			continue;
 
 		/*
-		 * This proc conflicts with locks held by others, ignored.
+		 * Does this proc conflict with locks held by others ?
 		 */
 		if (LockResolveConflicts(lockmethod,
 								 lock,
@@ -686,6 +702,8 @@ ProcLockWakeup(PROC_QUEUE *queue, LOCKMETHOD lockmethod, LOCK *lock)
 								 proc->xid,
 								 (XIDLookupEnt *) NULL) != STATUS_OK)
 		{
+			if (count != 0)
+				break;
 			last_locktype = proc->token;
 			continue;
 		}
@@ -828,7 +846,7 @@ HandleDeadLock(int sig)
 	 */
 	UnlockLockTable();
 
-	elog(NOTICE, "Deadlock detected -- See the lock(l) manual page for a possible cause.");
+	elog(NOTICE, DeadLockMessage);
 	return;
 }
 

src/include/storage/lmgr.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: lmgr.h,v 1.18 1999/02/19 06:06:34 tgl Exp $
+ * $Id: lmgr.h,v 1.19 1999/05/07 01:23:05 vadim Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -25,8 +25,6 @@
 #define ExclusiveLock			6
 #define AccessExclusiveLock		7
 
-#define ExtendLock				8
-
 extern LOCKMETHOD LockTableId;
 
 

src/include/storage/lock.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: lock.h,v 1.24 1999/03/06 21:17:43 tgl Exp $
+ * $Id: lock.h,v 1.25 1999/05/07 01:23:07 vadim Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -41,7 +41,7 @@ typedef int LOCKMODE;
 typedef int LOCKMETHOD;
 
 /* MAX_LOCKMODES cannot be larger than the bits in MASK */
-#define MAX_LOCKMODES	9
+#define MAX_LOCKMODES	8
 
 /*
  * MAX_LOCK_METHODS corresponds to the number of spin locks allocated in
@@ -204,6 +204,7 @@ typedef struct LOCK
 
 	/* data */
 	int			mask;
+	int			waitMask;
 	PROC_QUEUE	waitProcs;
 	int			holders[MAX_LOCKMODES];
 	int			nHolding;

src/include/storage/proc.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: proc.h,v 1.20 1999/02/19 07:10:47 tgl Exp $
+ * $Id: proc.h,v 1.21 1999/05/07 01:23:07 vadim Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -48,8 +48,9 @@ typedef struct proc
 								 * were starting our xact: vacuum must not
 								 * remove tuples deleted by xid >= xmin ! */
 
-	LOCK	   *waitLock;		/* Lock we're sleeping on */
-	int			token;			/* info for proc wakeup routines */
+	LOCK	   *waitLock;		/* Lock we're sleeping on ... */
+	int			token;			/* type of lock we sleeping for */
+	int			holdLock;		/* while holding these locks */
 	int			pid;			/* This procs process id */
 	short		sLocks[MAX_SPINS];		/* Spin lock stats */
 	SHM_QUEUE	lockQueue;		/* locks associated with current
@@ -116,8 +117,8 @@ extern bool ProcRemove(int pid);
 /* make static in storage/lmgr/proc.c -- jolly */
 
 extern void ProcQueueInit(PROC_QUEUE *queue);
-extern int ProcSleep(PROC_QUEUE *queue, SPINLOCK spinlock, int token,
-		  int prio, LOCK *lock, TransactionId xid);
+extern int ProcSleep(PROC_QUEUE *queue, LOCKMETHODCTL *lockctl, int token, 
+					LOCK *lock);
 extern int ProcLockWakeup(PROC_QUEUE *queue, LOCKMETHOD lockmethod,
 			   LOCK *lock);
 extern void ProcAddLock(SHM_QUEUE *elem);