Function ShutdownExprContext

src/backend/executor/execUtils.c:1039–1067

* Call all the shutdown callbacks registered in an ExprContext. * * The callback list is emptied (important in case this is only a rescan * reset, and not deletion of the ExprContext). * * If isCommit is false, just clean the callback list but don't call 'em. * (See comment for FreeExprContext.) */

 * (See comment for FreeExprContext.)
 */
static void
ShutdownExprContext(ExprContext *econtext, bool isCommit)
{
	ExprContext_CB *ecxt_callback;
	MemoryContext oldcontext;

	/* Fast path in normal case where there's nothing to do. */
	if (econtext->ecxt_callbacks == NULL)
		return;

	/*
	 * Call the callbacks in econtext's per-tuple context.  This ensures that
	 * any memory they might leak will get cleaned up.
	 */
	oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_tuple_memory);

	/*
	 * Call each callback function in reverse registration order.
	 */
	while ((ecxt_callback = econtext->ecxt_callbacks) != NULL)
	{
		econtext->ecxt_callbacks = ecxt_callback->next;
		if (isCommit)
			ecxt_callback->function(ecxt_callback->arg);
		pfree(ecxt_callback);
	}

	MemoryContextSwitchTo(oldcontext);
}

/*
 *		GetAttributeByName