index 94fbf1aa190c42cf77e2ce494da2bd92488fb9f2..5dac9f0696012655d502ef9578838a17101bf09d 100644 (file)
/* First time through: initialize the opclass cache */
HASHCTL ctl;
+ /* Also make sure CacheMemoryContext exists */
+ if (!CacheMemoryContext)
+ CreateCacheMemoryContext();
+
ctl.keysize = sizeof(Oid);
ctl.entrysize = sizeof(OpClassCacheEnt);
OpClassCache = hash_create("Operator class cache", 64,
&ctl, HASH_ELEM | HASH_BLOBS);
-
- /* Also make sure CacheMemoryContext exists */
- if (!CacheMemoryContext)
- CreateCacheMemoryContext();
}
opcentry = (OpClassCacheEnt *) hash_search(OpClassCache,
if (!found)
{
- /* Need to allocate memory for new entry */
+ /* Initialize new entry */
opcentry->valid = false; /* until known OK */
opcentry->numSupport = numSupport;
-
- if (numSupport > 0)
- opcentry->supportProcs = (RegProcedure *)
- MemoryContextAllocZero(CacheMemoryContext,
- (numSupport + 1) * sizeof(RegProcedure));
- else
- opcentry->supportProcs = NULL;
+ opcentry->supportProcs = NULL; /* filled below */
}
else
{
}
/*
- * When testing for cache-flush hazards, we intentionally disable the
- * operator class cache and force reloading of the info on each call. This
- * is helpful because we want to test the case where a cache flush occurs
- * while we are loading the info, and it's very hard to provoke that if
- * this happens only once per opclass per backend.
+ * When aggressively testing cache-flush hazards, we disable the operator
+ * class cache and force reloading of the info on each call. This models
+ * no real-world behavior, since the cache entries are never invalidated
+ * otherwise. However it can be helpful for detecting bugs in the cache
+ * loading logic itself, such as reliance on a non-nailed index. Given
+ * the limited use-case and the fact that this adds a great deal of
+ * expense, we enable it only for high values of
+ * debug_invalidate_system_caches_always.
*/
#ifdef CLOBBER_CACHE_ENABLED
- if (debug_invalidate_system_caches_always > 0)
+ if (debug_invalidate_system_caches_always > 2)
opcentry->valid = false;
#endif
return opcentry;
/*
- * Need to fill in new entry.
- *
+ * Need to fill in new entry. First allocate space, unless we already did
+ * so in some previous attempt.
+ */
+ if (opcentry->supportProcs == NULL && numSupport > 0)
+ opcentry->supportProcs = (RegProcedure *)
+ MemoryContextAllocZero(CacheMemoryContext,
+ numSupport * sizeof(RegProcedure));
+
+ /*
* To avoid infinite recursion during startup, force heap scans if we're
* looking up info for the opclasses used by the indexes we would like to
* reference here.