Fix another recently-changed place that was messing with spinlock-

tglsfdc · tglsfdc · commit fa7212159453 · 2005-10-12T16:55:59.000Z
protected data structures and not using a volatile pointer for same.
diff --git a/src/backend/storage/lmgr/lwlock.c b/src/backend/storage/lmgr/lwlock.c
@@ -15,7 +15,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/storage/lmgr/lwlock.c,v 1.32 2005/10/07 21:42:38 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/storage/lmgr/lwlock.c,v 1.33 2005/10/12 16:55:59 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -226,7 +226,8 @@ LWLockId
 LWLockAssign(void)
 {
 	LWLockId	result;
-	int		   *LWLockCounter;
+	/* use volatile pointer to prevent code rearrangement */
+	volatile int *LWLockCounter;
 
 	LWLockCounter = (int *) ((char *) LWLockArray - 2 * sizeof(int));
 	SpinLockAcquire(ShmemLock);

Original file line number	Diff line number	Diff line change
`@@ -15,7 +15,7 @@`
`15`	`15`	`* Portions Copyright (c) 1994, Regents of the University of California`
`16`	`16`	`*`
`17`	`17`	`* IDENTIFICATION`
`18`		`- * $PostgreSQL: pgsql/src/backend/storage/lmgr/lwlock.c,v 1.32 2005/10/07 21:42:38 tgl Exp $`
	`18`	`+ * $PostgreSQL: pgsql/src/backend/storage/lmgr/lwlock.c,v 1.33 2005/10/12 16:55:59 tgl Exp $`
`19`	`19`	`*`
`20`	`20`	`*-------------------------------------------------------------------------`
`21`	`21`	`*/`
`@@ -226,7 +226,8 @@ LWLockId`
`226`	`226`	`LWLockAssign(void)`
`227`	`227`	`{`
`228`	`228`	`LWLockId result;`
`229`		`- int *LWLockCounter;`
	`229`	`+ /* use volatile pointer to prevent code rearrangement */`
	`230`	`+ volatile int *LWLockCounter;`
`230`	`231`
`231`	`232`	`LWLockCounter = (int ) ((char ) LWLockArray - 2 * sizeof(int));`
`232`	`233`	`SpinLockAcquire(ShmemLock);`