From 7939f913ee610ece749fa4c5acacb0301308f503 Mon Sep 17 00:00:00 2001
From: Kyotaro Horiguchi <horiguchi.kyotaro@lab.ntt.co.jp>
Date: Tue, 25 Oct 2016 19:04:04 +0900
Subject: [PATCH 7/7] Add instrumentation to async execution

Make explain analyze give sane result when async execution has taken
place.
---
 src/backend/executor/execAsync.c  | 19 +++++++++++++++++++
 src/backend/executor/instrument.c |  2 +-
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/backend/executor/execAsync.c b/src/backend/executor/execAsync.c
index 40e3f67..588ba18 100644
--- a/src/backend/executor/execAsync.c
+++ b/src/backend/executor/execAsync.c
@@ -46,6 +46,9 @@ ExecAsyncRequest(EState *estate, PlanState *requestor, int request_index,
 	PendingAsyncRequest *areq = NULL;
 	int		nasync = estate->es_num_pending_async;

+	if (requestee->instrument)
+		InstrStartNode(requestee->instrument);
+
 	/*
 	 * If the number of pending asynchronous nodes exceeds the number of
 	 * available slots in the es_pending_async array, expand the array.
@@ -121,11 +124,17 @@ ExecAsyncRequest(EState *estate, PlanState *requestor, int request_index,
 	if (areq->state == ASYNC_COMPLETE)
 	{
 		Assert(areq->result == NULL || IsA(areq->result, TupleTableSlot));
+
 		ExecAsyncResponse(estate, areq);
+		if (areq->requestee->instrument)
+			InstrStopNode(requestee->instrument,
+						  TupIsNull((TupleTableSlot*)areq->result) ? 0.0 : 1.0);

 		return;
 	}

+	if (areq->requestee->instrument)
+		InstrStopNode(requestee->instrument, 0);
 	/* No result available now, make this node pending */
 	estate->es_num_pending_async++;
 }
@@ -193,6 +202,9 @@ ExecAsyncEventLoop(EState *estate, PlanState *requestor, long timeout)
 		{
 			PendingAsyncRequest *areq = estate->es_pending_async[i];

+			if (areq->requestee->instrument)
+				InstrStartNode(areq->requestee->instrument);
+
 			/* Skip it if not pending. */
 			if (areq->state == ASYNC_CALLBACK_PENDING)
 			{
@@ -211,7 +223,14 @@ ExecAsyncEventLoop(EState *estate, PlanState *requestor, long timeout)
 				if (requestor == areq->requestor)
 					requestor_done = true;
 				ExecAsyncResponse(estate, areq);
+
+				if (areq->requestee->instrument)
+					InstrStopNode(areq->requestee->instrument,
+								  TupIsNull((TupleTableSlot*)areq->result) ?
+								  0.0 : 1.0);
 			}
+			else if (areq->requestee->instrument)
+				InstrStopNode(areq->requestee->instrument, 0);
 		}

 		/* If any node completed, compact the array. */
diff --git a/src/backend/executor/instrument.c b/src/backend/executor/instrument.c
index 6ec96ec..959ee90 100644
--- a/src/backend/executor/instrument.c
+++ b/src/backend/executor/instrument.c
@@ -102,7 +102,7 @@ InstrStopNode(Instrumentation *instr, double nTuples)
 							 &pgBufferUsage, &instr->bufusage_start);

 	/* Is this the first tuple of this cycle? */
-	if (!instr->running)
+	if (!instr->running && nTuples > 0)
 	{
 		instr->running = true;
 		instr->firsttuple = INSTR_TIME_GET_DOUBLE(instr->counter);
-- 
2.9.2