From 93509133add8c4a2b2796d3b6587173aff7aef98 Mon Sep 17 00:00:00 2001
From: "A.J. Beamon" <ajbeamon@apple.com>
Date: Fri, 26 May 2017 10:47:37 -0700
Subject: [PATCH] =?UTF-8?q?Attempt=20to=20eliminate=20a=20race=20in=20DLSi?=
 =?UTF-8?q?ngleAssignmentVar=20between=20cancelling=20a=20future=20and=20c?=
 =?UTF-8?q?hecking=20its=20ref=20count.=20Reduce=20the=20amount=20of=20ite?=
 =?UTF-8?q?rations=20in=20the=20test=20because=20it=E2=80=99s=20timing=20o?=
 =?UTF-8?q?ut=20on=20the=20pie=20workers.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 fdbclient/MultiVersionTransaction.actor.cpp | 24 +++++++++++++++------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/fdbclient/MultiVersionTransaction.actor.cpp b/fdbclient/MultiVersionTransaction.actor.cpp
index b5685932ab..daad55dd77 100644
--- a/fdbclient/MultiVersionTransaction.actor.cpp
+++ b/fdbclient/MultiVersionTransaction.actor.cpp
@@ -1522,14 +1522,24 @@ THREAD_FUNC cancel(void *arg) {
 
 ACTOR Future<Void> checkUndestroyedFutures(std::vector<ThreadSingleAssignmentVar<int>*> undestroyed) {
 	state int fNum;
+	state ThreadSingleAssignmentVar<int>* f;
+	state double start = now();
+
 	for(fNum = 0; fNum < undestroyed.size(); ++fNum) {
-		state ThreadSingleAssignmentVar<int>* f = undestroyed[fNum];
-		state double start = now();
-		while(!f->isReady()) {
-			ASSERT(now() < start+60);
-			Void _ = wait(delay(5.0));
+		f = undestroyed[fNum];
+		
+		while(!f->isReady() && start+5 >= now()) {
+			Void _ = wait(delay(1.0));
 		}
 
+		ASSERT(f->isReady());
+	}
+
+	Void _ = wait(delay(1.0));
+
+	for(fNum = 0; fNum < undestroyed.size(); ++fNum) {
+		f = undestroyed[fNum];
+
 		ASSERT(f->debugGetReferenceCount() == 1);
 		ASSERT(f->isReady());
 
@@ -1545,7 +1555,7 @@ THREAD_FUNC runSingleAssignmentVarTest(void *arg) {
 
 	volatile bool *done = (volatile bool*)arg;
 	try {
-		for(int i = 0; i < 100; ++i) {
+		for(int i = 0; i < 25; ++i) {
 			FutureInfo f = createVarOnMainThread(false);
 			FutureInfo tf = T::createThreadFuture(f);
 			tf.validate();
@@ -1553,7 +1563,7 @@ THREAD_FUNC runSingleAssignmentVarTest(void *arg) {
 			tf.future.extractPtr(); // leaks
 		}
 
-		for(int numRuns = 0; numRuns < 100; ++numRuns) {
+		for(int numRuns = 0; numRuns < 25; ++numRuns) {
 			std::vector<ThreadSingleAssignmentVar<int>*> undestroyed;
 			std::vector<THREAD_HANDLE> threads;
 			for(int i = 0; i < 10; ++i) {