Function ExecSquelchMotion

src/backend/executor/nodeMotion.c:1388–1405

* Mark this node as "stopped." When ExecProcNode() is called on a * stopped motion node it should behave as if there are no tuples * available. * * ExecProcNode() on a stopped motion node should also notify the * "other end" of the motion node of the stoppage. * * Note: once this is called, it is possible that the motion node will * never be called again, so we *must* send the stop message

 * never be called again, so we *must* send the stop message now.
 */
void
ExecSquelchMotion(MotionState *node, bool force)
{
	Motion	   *motion;

	AssertArg(node != NULL);
	if (node->ps.squelched)
		return;
	motion = (Motion *) node->ps.plan;
	node->stopRequested = true;
	node->ps.state->active_recv_id = -1;

	/* pass down */
	SendStopMessage(node->ps.state->motionlayer_context,
					node->ps.state->interconnect_context,
					motion->motionID);
	node->ps.squelched = true;
}