From: Robert Haas <rhaas@postgresql.org>
Date: Fri, 27 Jul 2012 16:34:50 +0000 (+0000)
Subject: Thinko: of course, invalid CHashPtrs can also be delete-marked.
X-Git-Url: http://git.postgresql.org/gitweb/static/gitweb.js?a=commitdiff_plain;h=50a0f6747c5fbe5fcc9555101e936b6935a3f4fc;p=users%2Fandresfreund%2Fpostgres.git

Thinko: of course, invalid CHashPtrs can also be delete-marked.
---

diff --git a/src/backend/utils/hash/chash.c b/src/backend/utils/hash/chash.c
index cfef6d5745..a076da07c2 100644
--- a/src/backend/utils/hash/chash.c
+++ b/src/backend/utils/hash/chash.c
@@ -105,6 +105,7 @@
  */
 typedef uint32 CHashPtr;
 #define InvalidCHashPtr				((uint32) -2)
+#define CHashPtrIsInvalid(x)		((x) >= InvalidCHashPtr)
 #define CHashPtrIsMarked(x)			((x) & 1)
 #define CHashPtrGetOffset(x)		((x) >> 1)
 #define CHashPtrMark(x)				((x) | 1)
@@ -160,7 +161,7 @@ typedef struct CHashTableData
 	(AssertMacro((offset) < (table)->arena_limit), \
 	 (CHashNode *) ((table)->arena + (table)->arena_stride * (offset)))
 #define CHashTableGetNode(table, ptr) \
-	(AssertMacro((ptr) != InvalidCHashPtr), \
+	(AssertMacro(!CHashPtrIsInvalid(ptr)), \
 	 CHashTableGetRaw((table), CHashPtrGetOffset((ptr))))
 
 /*
@@ -580,7 +581,7 @@ retry:
 		 * If we've reached the end of the bucket chain, stop; otherwise,
 		 * figure out the actual address of the next item.
 		 */
-		if (target == InvalidCHashPtr)
+		if (CHashPtrIsInvalid(target))
 		{
 			res->found = false;
 			break;
@@ -748,7 +749,7 @@ CHashAllocate(CHashTable table)
 		/* Try to pop a buffer from a freelist using compare-and-swap. */
 		b = &table->freelist[f_current];
 		new = *b;
-		if (new != InvalidCHashPtr)
+		if (!CHashPtrIsInvalid(new))
 		{
 			CHashNode  *n = CHashTableGetNode(table, new);
 
@@ -766,7 +767,7 @@ CHashAllocate(CHashTable table)
 		table->gc_next = (table->gc_next + 1) % table->ngarbage;
 		b = &table->garbage[table->gc_next];
 		garbage = *b;
-		if (garbage != InvalidCHashPtr &&
+		if (!CHashPtrIsInvalid(garbage) &&
 			__sync_bool_compare_and_swap(b, garbage, InvalidCHashPtr))
 		{
 			uint64		chash_bucket;
@@ -801,7 +802,7 @@ CHashAllocate(CHashTable table)
 			fhead = n->un.gcnext;
 
 			/* Put any remaining elements back on the free list. */
-			if (fhead != InvalidCHashPtr)
+			if (!CHashPtrIsInvalid(fhead))
 			{
 				CHashPtr	fcurrent;
 				CHashPtr	fnext;
@@ -813,7 +814,7 @@ CHashAllocate(CHashTable table)
 				{
 					n = CHashTableGetNode(table, fcurrent);
 					fnext = n->un.gcnext;
-					if (fnext == InvalidCHashPtr)
+					if (CHashPtrIsInvalid(fnext))
 						break;
 					fcurrent = fnext;
 				}
@@ -922,7 +923,7 @@ retry:
 		 * If we've reached the end of the bucket chain, stop; otherwise,
 		 * figure out the actual address of the next item.
 		 */
-		if (target == InvalidCHashPtr)
+		if (CHashPtrIsInvalid(target))
 			break;
 		target_node = CHashTableGetNode(table, target);