Fix use of relcache TriggerDesc field introduced by commit
The commit added code which used a relcache TriggerDesc field across
another cache access, which it shouldn't because the relcache doesn't
guarantee it won't get moved.
Diagnosed-by: Tom Lane
Author: Greg Nancarrow
Discussion:
@@ -114,7 +114,7 @@ static bool target_rel_max_parallel_hazard(max_parallel_hazard_context *context)
static bool target_rel_max_parallel_hazard_recurse(Relation relation,
CmdType command_type,
max_parallel_hazard_context *context);
-static bool target_rel_trigger_max_parallel_hazard(TriggerDesc *trigdesc,
+static bool target_rel_trigger_max_parallel_hazard(Relation rel,
max_parallel_hazard_context *context);
static bool target_rel_index_max_parallel_hazard(Relation rel,
max_parallel_hazard_context *context);
@@ -926,7 +926,7 @@ target_rel_max_parallel_hazard_recurse(Relation rel,
/*
* If any triggers exist, check that they are parallel-safe.
*/
- if (target_rel_trigger_max_parallel_hazard(rel->trigdesc, context))
+ if (target_rel_trigger_max_parallel_hazard(rel, context))
return true;
/*
@@ -952,23 +952,29 @@ target_rel_max_parallel_hazard_recurse(Relation rel,
/*
* target_rel_trigger_max_parallel_hazard
*
- * Finds the maximum parallel-mode hazard level for the specified trigger data.
+ * Finds the maximum parallel-mode hazard level for the specified relation's
+ * trigger data.
*/
static bool
-target_rel_trigger_max_parallel_hazard(TriggerDesc *trigdesc,
+target_rel_trigger_max_parallel_hazard(Relation rel,
max_parallel_hazard_context *context)
{
int i;
- if (trigdesc == NULL)
+ if (rel->trigdesc == NULL)
return false;
- for (i = 0; i < trigdesc->numtriggers; i++)
+ /*
+ * Care is needed here to avoid using the same relcache TriggerDesc field
+ * across other cache accesses, because relcache doesn't guarantee that it
+ * won't move.
+ */
+ for (i = 0; i < rel->trigdesc->numtriggers; i++)
{
int trigtype;
- Trigger *trigger = &trigdesc->triggers[i];
+ Oid tgfoid = rel->trigdesc->triggers[i].tgfoid;
- if (max_parallel_hazard_test(func_parallel(trigger->tgfoid), context))
+ if (max_parallel_hazard_test(func_parallel(tgfoid), context))
return true;
/*
@@ -977,7 +983,7 @@ target_rel_trigger_max_parallel_hazard(TriggerDesc *trigdesc,
* on insert/update and this isn't supported in a parallel worker (but
* is safe in the parallel leader).
*/
- trigtype = RI_FKey_trigger_type(trigger->tgfoid);
+ trigtype = RI_FKey_trigger_type(tgfoid);
if (trigtype == RI_TRIGGER_FK)
{
if (max_parallel_hazard_test(PROPARALLEL_RESTRICTED, context))
