Function XactLockTableWait

src/backend/storage/lmgr/lmgr.c:676–765

* XactLockTableWait * * Wait for the specified transaction to commit or abort. If an operation * is specified, an error context callback is set up. If 'oper' is passed as * None, no error context callback is set up. * * Note that this does the right thing for subtransactions: if we wait on a * subtransaction, we will exit as soon as it aborts or its top parent commits. * It takes some e

 * and if so wait for its parent.
 */
void
XactLockTableWait(TransactionId xid, Relation rel, ItemPointer ctid,
				  XLTW_Oper oper)
{
	LOCKTAG		tag;
	XactLockTableWaitInfo info;
	ErrorContextCallback callback;
	bool		first = true;

	/*
	 * Concurrent update and delete will wait on segment when GDD is enabled (or
	 * the corner case that utility mode delete|update in segment which does not hold
	 * gxid), need to report the waited transactions to QD to make sure the they have
	 * the same transaction order on the master.
	 */
	if (Gp_role == GP_ROLE_EXECUTE)
	{
		MemoryContext oldContext;
		DistributedTransactionId gxid = LocalXidGetDistributedXid(xid);

		if (gxid != InvalidDistributedTransactionId)
		{
			/*
			 * allocate waitGxids in TopMemoryContext since it's used in
			 * 'commit prepared' and the TopTransactionContext has been delete
			 * after 'prepare'
			 */
			oldContext = MemoryContextSwitchTo(TopMemoryContext);
			MyTmGxactLocal->waitGxids = lappend_int(MyTmGxactLocal->waitGxids, gxid);
			MemoryContextSwitchTo(oldContext);
		}
	}

	/*
	 * If an operation is specified, set up our verbose error context
	 * callback.
	 */
	if (oper != XLTW_None)
	{
		Assert(RelationIsValid(rel));
		Assert(ItemPointerIsValid(ctid));

		info.rel = rel;
		info.ctid = ctid;
		info.oper = oper;

		callback.callback = XactLockTableWaitErrorCb;
		callback.arg = &info;
		callback.previous = error_context_stack;
		error_context_stack = &callback;
	}

	for (;;)
	{
		Assert(TransactionIdIsValid(xid));
		Assert(!TransactionIdEquals(xid, GetTopTransactionIdIfAny()));

		SET_LOCKTAG_TRANSACTION(tag, xid);