* relations are held open with locks for the transaction duration, preventing
* relcache invalidation. The entry itself is torn down at batch end by
* ri_FastPathEndBatch(); on abort, ResourceOwner releases the cached
- * relations and the XactCallback/SubXactCallback NULL the static cache pointer
- * to prevent any subsequent access.
+ * relations and the XactCallback NULLs the static cache pointer to prevent
+ * any subsequent access.
*/
typedef struct RI_FastPathEntry
{
static HTAB *ri_fastpath_cache = NULL;
static bool ri_fastpath_callback_registered = false;
+static bool ri_fastpath_flushing = false;
/*
* Local function prototypes
*/
if (ri_fastpath_is_applicable(riinfo))
{
- if (AfterTriggerIsActive())
+ if (AfterTriggerIsActive() &&
+ GetCurrentTransactionNestLevel() == 1 &&
+ !ri_fastpath_flushing)
{
/* Batched path: buffer and probe in groups */
ri_FastPathBatchAdd(riinfo, fk_rel, newslot);
}
else
{
- /* ALTER TABLE validation: per-row, no cache */
+ /*
+ * Per-row path, used when batching is not safe or not applicable:
+ *
+ * - ALTER TABLE validation, where no after-trigger firing is
+ * active;
+ *
+ * - any FK check inside a subtransaction, since the batch cache
+ * is confined to the top transaction level (it cannot be cleanly
+ * unwound on subxact abort);
+ *
+ * - a re-entrant check from user cast/operator code running
+ * during a batch flush, since adding a cache entry while
+ * ri_FastPathEndBatch is iterating the cache could leave it
+ * unflushed.
+ */
ri_FastPathCheck(riinfo, fk_rel, newslot);
}
return PointerGetDatum(NULL);
if (ri_fastpath_cache == NULL)
return;
- /* Flush any partial batches -- can throw ERROR */
- hash_seq_init(&status, ri_fastpath_cache);
- while ((entry = hash_seq_search(&status)) != NULL)
+ /*
+ * Set a flag for the duration of the scan so that any FK check triggered
+ * by user cast or operator code during a flush takes the per-row path
+ * instead of adding a new entry to the cache we are iterating. A new
+ * entry could land in an already-scanned bucket and then be torn down
+ * unflushed below.
+ *
+ * The flush can throw ERROR (a reported constraint violation, or an error
+ * from the user code it runs). In that case ri_FastPathTeardown below is
+ * skipped; the ResourceOwner and the transaction-end callback handle
+ * resource cleanup on the abort path. The PG_FINALLY only resets the
+ * flag and deliberately does not attempt teardown.
+ */
+ Assert(!ri_fastpath_flushing);
+ ri_fastpath_flushing = true;
+ PG_TRY();
{
- if (entry->batch_count > 0)
+ hash_seq_init(&status, ri_fastpath_cache);
+ while ((entry = hash_seq_search(&status)) != NULL)
{
- Relation fk_rel = table_open(entry->fk_relid, AccessShareLock);
- RI_ConstraintInfo *riinfo = ri_LoadConstraintInfo(entry->conoid);
+ if (entry->batch_count > 0)
+ {
+ Relation fk_rel = table_open(entry->fk_relid, AccessShareLock);
+ RI_ConstraintInfo *riinfo = ri_LoadConstraintInfo(entry->conoid);
- ri_FastPathBatchFlush(entry, fk_rel, riinfo);
- table_close(fk_rel, NoLock);
+ ri_FastPathBatchFlush(entry, fk_rel, riinfo);
+ table_close(fk_rel, NoLock);
+ }
}
}
+ PG_FINALLY();
+ {
+ ri_fastpath_flushing = false;
+ }
+ PG_END_TRY();
ri_FastPathTeardown();
}
*/
ri_fastpath_cache = NULL;
ri_fastpath_callback_registered = false;
-}
-static void
-ri_FastPathSubXactCallback(SubXactEvent event, SubTransactionId mySubid,
- SubTransactionId parentSubid, void *arg)
-{
- if (event == SUBXACT_EVENT_ABORT_SUB)
- {
- /*
- * ResourceOwner already released relations. NULL the static pointers
- * so the still-registered batch callback becomes a no-op for the rest
- * of this transaction.
- */
- ri_fastpath_cache = NULL;
- ri_fastpath_callback_registered = false;
- }
+ /*
+ * Also clear the in-flush flag. ri_FastPathEndBatch() already clears it
+ * via PG_FINALLY, so this is just defensive: it keeps a stale flag from
+ * surviving into the next transaction should any future path leave it
+ * set.
+ */
+ ri_fastpath_flushing = false;
}
/*
if (!ri_fastpath_xact_callback_registered)
{
RegisterXactCallback(ri_FastPathXactCallback, NULL);
- RegisterSubXactCallback(ri_FastPathSubXactCallback, NULL);
ri_fastpath_xact_callback_registered = true;
}
(1 row)
DROP TABLE fp_reentry_fk2, fp_reentry_pk2;
+-- Subtransaction abort during after-trigger firing must not drop FK checks
+-- for rows buffered earlier in the same statement. Batching is confined to
+-- the top transaction level and the buffered batch is no longer discarded on
+-- subxact abort, so the violating rows are detected.
+CREATE TABLE fp_subxact_pk (id int PRIMARY KEY);
+INSERT INTO fp_subxact_pk SELECT g FROM generate_series(1, 10) g;
+CREATE TABLE fp_subxact_fk (a int, tag text);
+ALTER TABLE fp_subxact_fk ADD CONSTRAINT fp_subxact_fk_fkey
+ FOREIGN KEY (a) REFERENCES fp_subxact_pk (id);
+CREATE FUNCTION fp_abort_subxact() RETURNS trigger LANGUAGE plpgsql AS $$
+BEGIN
+ IF NEW.tag = 'boom' THEN
+ BEGIN PERFORM 1/0; EXCEPTION WHEN division_by_zero THEN NULL; END;
+ END IF;
+ RETURN NEW;
+END$$;
+CREATE TRIGGER fp_subxact_trg AFTER INSERT ON fp_subxact_fk
+ FOR EACH ROW EXECUTE FUNCTION fp_abort_subxact();
+INSERT INTO fp_subxact_fk VALUES (999, 'bad'), (0, 'boom'), (1, 'ok');
+ERROR: insert or update on table "fp_subxact_fk" violates foreign key constraint "fp_subxact_fk_fkey"
+DETAIL: Key (a)=(999) is not present in table "fp_subxact_pk".
+DROP TRIGGER fp_subxact_trg ON fp_subxact_fk;
+DROP FUNCTION fp_abort_subxact();
+DROP TABLE fp_subxact_fk, fp_subxact_pk;
END$$;
SELECT count(*), max(a) FROM fp_reentry_fk2; -- 64 rows, max 1
DROP TABLE fp_reentry_fk2, fp_reentry_pk2;
+
+-- Subtransaction abort during after-trigger firing must not drop FK checks
+-- for rows buffered earlier in the same statement. Batching is confined to
+-- the top transaction level and the buffered batch is no longer discarded on
+-- subxact abort, so the violating rows are detected.
+CREATE TABLE fp_subxact_pk (id int PRIMARY KEY);
+INSERT INTO fp_subxact_pk SELECT g FROM generate_series(1, 10) g;
+CREATE TABLE fp_subxact_fk (a int, tag text);
+ALTER TABLE fp_subxact_fk ADD CONSTRAINT fp_subxact_fk_fkey
+ FOREIGN KEY (a) REFERENCES fp_subxact_pk (id);
+CREATE FUNCTION fp_abort_subxact() RETURNS trigger LANGUAGE plpgsql AS $$
+BEGIN
+ IF NEW.tag = 'boom' THEN
+ BEGIN PERFORM 1/0; EXCEPTION WHEN division_by_zero THEN NULL; END;
+ END IF;
+ RETURN NEW;
+END$$;
+CREATE TRIGGER fp_subxact_trg AFTER INSERT ON fp_subxact_fk
+ FOR EACH ROW EXECUTE FUNCTION fp_abort_subxact();
+INSERT INTO fp_subxact_fk VALUES (999, 'bad'), (0, 'boom'), (1, 'ok');
+DROP TRIGGER fp_subxact_trg ON fp_subxact_fk;
+DROP FUNCTION fp_abort_subxact();
+DROP TABLE fp_subxact_fk, fp_subxact_pk;
projects / thirdparty / postgresql.git / commitdiff
