Make critical sections (elog->crash) and interrupt holdoff sections

into distinct concepts, per recent discussion on pghackers.

src/backend/storage/buffer/bufmgr.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/storage/buffer/bufmgr.c,v 1.104 2001/01/14 05:08:15 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/storage/buffer/bufmgr.c,v 1.105 2001/01/19 22:08:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -873,10 +873,10 @@ WaitIO(BufferDesc *buf, SPINLOCK spinlock)
 	while ((buf->flags & BM_IO_IN_PROGRESS) != 0)
 	{
 		SpinRelease(spinlock);
-		START_CRIT_SECTION();	/* don't want to die() holding the lock... */
+		HOLD_INTERRUPTS();		/* don't want to die() holding the lock... */
 		S_LOCK(&(buf->io_in_progress_lock));
 		S_UNLOCK(&(buf->io_in_progress_lock));
-		END_CRIT_SECTION();
+		RESUME_INTERRUPTS();
 		SpinAcquire(spinlock);
 	}
 }
@@ -1027,14 +1027,14 @@ BufmgrCommit(void)
  *		Returns the block number associated with a buffer.
  *
  * Note:
- *		Assumes that the buffer is valid.
+ *		Assumes that the buffer is valid and pinned, else the
+ *		value may be obsolete immediately...
  */
 BlockNumber
 BufferGetBlockNumber(Buffer buffer)
 {
 	Assert(BufferIsValid(buffer));
 
-	/* XXX should be a critical section */
 	if (BufferIsLocal(buffer))
 		return LocalBufferDescriptors[-buffer - 1].tag.blockNum;
 	else
@@ -1956,7 +1956,7 @@ UnlockBuffers(void)
 		Assert(BufferIsValid(i + 1));
 		buf = &(BufferDescriptors[i]);
 
-		START_CRIT_SECTION();	/* don't want to die() holding the lock... */
+		HOLD_INTERRUPTS();		/* don't want to die() holding the lock... */
 
 		S_LOCK(&(buf->cntx_lock));
 
@@ -1986,7 +1986,7 @@ UnlockBuffers(void)
 
 		BufferLocks[i] = 0;
 
-		END_CRIT_SECTION();
+		RESUME_INTERRUPTS();
 	}
 }
 
@@ -2003,7 +2003,7 @@ LockBuffer(Buffer buffer, int mode)
 	buf = &(BufferDescriptors[buffer - 1]);
 	buflock = &(BufferLocks[buffer - 1]);
 
-	START_CRIT_SECTION();		/* don't want to die() holding the lock... */
+	HOLD_INTERRUPTS();			/* don't want to die() holding the lock... */
 
 	S_LOCK(&(buf->cntx_lock));
 
@@ -2028,7 +2028,7 @@ LockBuffer(Buffer buffer, int mode)
 		else
 		{
 			S_UNLOCK(&(buf->cntx_lock));
-			END_CRIT_SECTION();
+			RESUME_INTERRUPTS();
 			elog(ERROR, "UNLockBuffer: buffer %lu is not locked", buffer);
 		}
 	}
@@ -2040,9 +2040,9 @@ LockBuffer(Buffer buffer, int mode)
 		while (buf->ri_lock || buf->w_lock)
 		{
 			S_UNLOCK(&(buf->cntx_lock));
-			END_CRIT_SECTION();
+			RESUME_INTERRUPTS();
 			S_LOCK_SLEEP(&(buf->cntx_lock), i++);
-			START_CRIT_SECTION();
+			HOLD_INTERRUPTS();
 			S_LOCK(&(buf->cntx_lock));
 		}
 		(buf->r_locks)++;
@@ -2068,9 +2068,9 @@ LockBuffer(Buffer buffer, int mode)
 				buf->ri_lock = true;
 			}
 			S_UNLOCK(&(buf->cntx_lock));
-			END_CRIT_SECTION();
+			RESUME_INTERRUPTS();
 			S_LOCK_SLEEP(&(buf->cntx_lock), i++);
-			START_CRIT_SECTION();
+			HOLD_INTERRUPTS();
 			S_LOCK(&(buf->cntx_lock));
 		}
 		buf->w_lock = true;
@@ -2092,12 +2092,12 @@ LockBuffer(Buffer buffer, int mode)
 	else
 	{
 		S_UNLOCK(&(buf->cntx_lock));
-		END_CRIT_SECTION();
+		RESUME_INTERRUPTS();
 		elog(ERROR, "LockBuffer: unknown lock mode %d", mode);
 	}
 
 	S_UNLOCK(&(buf->cntx_lock));
-	END_CRIT_SECTION();
+	RESUME_INTERRUPTS();
 }
 
 /*
@@ -2118,7 +2118,7 @@ static bool IsForInput;
  *	BM_IO_IN_PROGRESS mask is not set for the buffer
  *	The buffer is Pinned
  *
- * Because BufMgrLock is held, we are already in a CRIT_SECTION here,
+ * Because BufMgrLock is held, we are already in an interrupt holdoff here,
  * and do not need another.
  */
 static void
@@ -2152,7 +2152,7 @@ StartBufferIO(BufferDesc *buf, bool forInput)
  *	BufMgrLock is held
  *	The buffer is Pinned
  *
- * Because BufMgrLock is held, we are already in a CRIT_SECTION here,
+ * Because BufMgrLock is held, we are already in an interrupt holdoff here,
  * and do not need another.
  */
 static void
@@ -2170,7 +2170,7 @@ TerminateBufferIO(BufferDesc *buf)
  *	BufMgrLock is held
  *	The buffer is Pinned
  *
- * Because BufMgrLock is held, we are already in a CRIT_SECTION here,
+ * Because BufMgrLock is held, we are already in an interrupt holdoff here,
  * and do not need another.
  */
 static void

src/backend/storage/ipc/ipc.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/storage/ipc/ipc.c,v 1.60 2001/01/14 05:08:15 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/storage/ipc/ipc.c,v 1.61 2001/01/19 22:08:46 tgl Exp $
  *
  * NOTES
  *
@@ -136,7 +136,8 @@ proc_exit(int code)
 	QueryCancelPending = false;
 	/* And let's just make *sure* we're not interrupted ... */
 	ImmediateInterruptOK = false;
-	CritSectionCount = 1;
+	InterruptHoldoffCount = 1;
+	CritSectionCount = 0;
 
 	if (DebugLvl > 1)
 		elog(DEBUG, "proc_exit(%d)", code);

src/backend/storage/ipc/spin.c

@@ -14,7 +14,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/storage/ipc/Attic/spin.c,v 1.29 2001/01/14 05:08:15 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/storage/ipc/Attic/spin.c,v 1.30 2001/01/19 22:08:47 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -148,19 +148,19 @@ SpinAcquire(SPINLOCK lockid)
 	PRINT_SLDEBUG("SpinAcquire", lockid, slckP);
 	/*
 	 * Acquire the lock, then record that we have done so (for recovery
-	 * in case of elog(ERROR) during the critical section).  Note we assume
+	 * in case of elog(ERROR) while holding the lock).  Note we assume
 	 * here that S_LOCK will not accept cancel/die interrupts once it has
 	 * acquired the lock.  However, interrupts should be accepted while
-	 * waiting, if CritSectionCount is zero.
+	 * waiting, if InterruptHoldoffCount is zero.
 	 */
 	S_LOCK(&(slckP->shlock));
 	PROC_INCR_SLOCK(lockid);
 	/*
-	 * Lock out cancel/die interrupts until we exit the critical section
+	 * Lock out cancel/die interrupts until we exit the code section
 	 * protected by the spinlock.  This ensures that interrupts will not
 	 * interfere with manipulations of data structures in shared memory.
 	 */
-	START_CRIT_SECTION();
+	HOLD_INTERRUPTS();
 
     PRINT_SLDEBUG("SpinAcquire/done", lockid, slckP);
 }
@@ -182,9 +182,9 @@ SpinRelease(SPINLOCK lockid)
 	PROC_DECR_SLOCK(lockid);
 	S_UNLOCK(&(slckP->shlock));
 	/*
-	 * Exit the critical section entered in SpinAcquire().
+	 * Exit the interrupt holdoff entered in SpinAcquire().
 	 */
-	END_CRIT_SECTION();
+	RESUME_INTERRUPTS();
 
     PRINT_SLDEBUG("SpinRelease/done", lockid, slckP);
 }
@@ -329,7 +329,7 @@ SpinAcquire(SPINLOCK lock)
 	 */
 	IpcSemaphoreLock(SpinLockIds[0], lock, false);
 	PROC_INCR_SLOCK(lock);
-	START_CRIT_SECTION();
+	HOLD_INTERRUPTS();
 }
 
 /*
@@ -351,7 +351,7 @@ SpinRelease(SPINLOCK lock)
     Assert(!MyProc || MyProc->sLocks[lockid] > 0);
 	PROC_DECR_SLOCK(lock);
 	IpcSemaphoreUnlock(SpinLockIds[0], lock);
-	END_CRIT_SECTION();
+	RESUME_INTERRUPTS();
 }
 
 /*