Adjust GetLockConflicts() so that it uses TopMemoryContext when

executed InHotStandby. Cleaner solution than using malloc or palloc
depending upon situation, as proposed by Tom.

diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c
index 2c024f829933529357418e887d478316ccf112b9..cbc2070c37f01fa4e8484268e616de1af383d51c 100644 (file)
--- a/src/backend/storage/lmgr/lock.c
+++ b/src/backend/storage/lmgr/lock.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/backend/storage/lmgr/lock.c,v 1.192 2010/01/28 10:05:37 sriggs Exp $
+ *   $PostgreSQL: pgsql/src/backend/storage/lmgr/lock.c,v 1.193 2010/01/29 19:45:12 sriggs Exp $
  *
  * NOTES
  *   A lock table is a shared memory hash table.  When
@@ -1790,7 +1790,7 @@ LockReassignCurrentOwner(void)
 VirtualTransactionId *
 GetLockConflicts(const LOCKTAG *locktag, LOCKMODE lockmode)
 {
-   static VirtualTransactionId *vxids = NULL;
+   static VirtualTransactionId *vxids;
    LOCKMETHODID lockmethodid = locktag->locktag_lockmethodid;
    LockMethod  lockMethodTable;
    LOCK       *lock;
@@ -1810,24 +1810,18 @@ GetLockConflicts(const LOCKTAG *locktag, LOCKMODE lockmode)
    /*
     * Allocate memory to store results, and fill with InvalidVXID.  We only
     * need enough space for MaxBackends + a terminator, since prepared xacts
-    * don't count.
+    * don't count. InHotStandby allocate once in TopMemoryContext.
     */
-   if (!InHotStandby)
-       vxids = (VirtualTransactionId *)
-           palloc0(sizeof(VirtualTransactionId) * (MaxBackends + 1));
-   else
+   if (InHotStandby)
    {
        if (vxids == NULL)
-       {
            vxids = (VirtualTransactionId *)
-               malloc(sizeof(VirtualTransactionId) * (MaxBackends + 1));
-           if (vxids == NULL)
-               ereport(ERROR,
-                   (errcode(ERRCODE_OUT_OF_MEMORY),
-                    errmsg("out of memory")));
-
-       }
+               MemoryContextAlloc(TopMemoryContext,
+                   sizeof(VirtualTransactionId) * (MaxBackends + 1));
    }
+   else
+       vxids = (VirtualTransactionId *)
+           palloc0(sizeof(VirtualTransactionId) * (MaxBackends + 1));
 
    /*
     * Look up the lock object matching the tag.