* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/utils/cache/plancache.c,v 1.8 2007/04/16 18:21:07 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/cache/plancache.c,v 1.9 2007/05/14 18:13:21 tgl Exp $
*
*-------------------------------------------------------------------------
*/
static void StoreCachedPlan(CachedPlanSource *plansource, List *stmt_list,
MemoryContext plan_context);
+static List *do_planning(List *querytrees, int cursorOptions);
static void AcquireExecutorLocks(List *stmt_list, bool acquire);
static void AcquirePlannerLocks(List *stmt_list, bool acquire);
static void LockRelid(Oid relid, LOCKMODE lockmode, void *arg);
if (plansource->fully_planned)
{
- /*
- * Generate plans for queries. Assume snapshot is not set yet
- * (XXX this may be wasteful, won't all callers have done that?)
- */
- slist = pg_plan_queries(slist, plansource->cursor_options, NULL,
- true);
+ /* Generate plans for queries */
+ slist = do_planning(slist, plansource->cursor_options);
}
/*
}
/*
+ * Invoke the planner on some rewritten queries. This is broken out of
+ * RevalidateCachedPlan just to avoid plastering "volatile" all over that
+ * function's variables.
+ */
+static List *
+do_planning(List *querytrees, int cursorOptions)
+{
+ List *stmt_list;
+
+ /*
+ * If a snapshot is already set (the normal case), we can just use that
+ * for planning. But if it isn't, we have to tell pg_plan_queries to make
+ * a snap if it needs one. In that case we should arrange to reset
+ * ActiveSnapshot afterward, to ensure that RevalidateCachedPlan has no
+ * caller-visible effects on the snapshot. Having to replan is an unusual
+ * case, and it seems a really bad idea for RevalidateCachedPlan to affect
+ * the snapshot only in unusual cases. (Besides, the snap might have
+ * been created in a short-lived context.)
+ */
+ if (ActiveSnapshot != NULL)
+ stmt_list = pg_plan_queries(querytrees, cursorOptions, NULL, false);
+ else
+ {
+ PG_TRY();
+ {
+ stmt_list = pg_plan_queries(querytrees, cursorOptions, NULL, true);
+ }
+ PG_CATCH();
+ {
+ /* Restore global vars and propagate error */
+ ActiveSnapshot = NULL;
+ PG_RE_THROW();
+ }
+ PG_END_TRY();
+
+ ActiveSnapshot = NULL;
+ }
+
+ return stmt_list;
+}
+
+
+/*
* ReleaseCachedPlan: release active use of a cached plan.
*
* This decrements the reference count, and frees the plan if the count