Function AssertPendingSyncs_RelationCache

src/backend/utils/cache/relcache.c:3228–3280

* AssertPendingSyncs_RelationCache * * Assert that relcache.c and storage.c agree on whether to skip WAL. */

 *	Assert that relcache.c and storage.c agree on whether to skip WAL.
 */
void
AssertPendingSyncs_RelationCache(void)
{
	HASH_SEQ_STATUS status;
	LOCALLOCK  *locallock;
	Relation   *rels;
	int			maxrels;
	int			nrels;
	RelIdCacheEnt *idhentry;
	int			i;

	/*
	 * Open every relation that this transaction has locked.  If, for some
	 * relation, storage.c is skipping WAL and relcache.c is not skipping WAL,
	 * a CommandCounterIncrement() typically yields a local invalidation
	 * message that destroys the relcache entry.  By recreating such entries
	 * here, we detect the problem.
	 */
	PushActiveSnapshot(GetTransactionSnapshot());
	maxrels = 1;
	rels = palloc(maxrels * sizeof(*rels));
	nrels = 0;
	hash_seq_init(&status, GetLockMethodLocalHash());
	while ((locallock = (LOCALLOCK *) hash_seq_search(&status)) != NULL)
	{
		Oid			relid;
		Relation	r;

		if (locallock->nLocks <= 0)
			continue;
		if ((LockTagType) locallock->tag.lock.locktag_type !=
			LOCKTAG_RELATION)
			continue;
		relid = ObjectIdGetDatum(locallock->tag.lock.locktag_field2);
		r = RelationIdGetRelation(relid);
		if (!RelationIsValid(r))
			continue;
		if (nrels >= maxrels)
		{
			maxrels *= 2;
			rels = repalloc(rels, maxrels * sizeof(*rels));
		}
		rels[nrels++] = r;
	}

	hash_seq_init(&status, RelationIdCache);
	while ((idhentry = (RelIdCacheEnt *) hash_seq_search(&status)) != NULL)
		AssertPendingSyncConsistency(idhentry->reldesc);

	for (i = 0; i < nrels; i++)
		RelationClose(rels[i]);
	PopActiveSnapshot();
}
#endif

/*