From 6e89233b7427b0797a01b6b77bf3bb5dd5eaa601 Mon Sep 17 00:00:00 2001
From: "A. Unique TensorFlower" <nobody@tensorflow.org>
Date: Wed, 25 May 2016 14:00:41 -0800
Subject: [PATCH] Make the gput_allocator_retry_test *Fail test cases more
 reliable by having each consumer thread pause for 1 msec between getting its
 memory and returning it.

Logged failures for the NoRetryFail case suggest that on OS/X thread
scheduling is such that without this delay it's possible not to experience
a race condition failure within 10 seconds.
Change: 123257296
---
 .../core/common_runtime/gpu/gpu_allocator_retry_test.cc  | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/tensorflow/core/common_runtime/gpu/gpu_allocator_retry_test.cc b/tensorflow/core/common_runtime/gpu/gpu_allocator_retry_test.cc
index c03cb27df50..c911290f28b 100644
--- a/tensorflow/core/common_runtime/gpu/gpu_allocator_retry_test.cc
+++ b/tensorflow/core/common_runtime/gpu/gpu_allocator_retry_test.cc
@@ -81,6 +81,9 @@ class GPUAllocatorRetryTest : public ::testing::Test {
                   return;
                 }
               }
+              // Failures are more likely to occur if each consumer
+              // delays for a while before returning the memory.
+              Env::Default()->SleepForMicroseconds(500);
               ++consumer_count_[i];
               for (int j = 0; j < cap_needed; ++j) {
                 alloc_->DeallocateRaw(ptr);
@@ -141,9 +144,10 @@ TEST_F(GPUAllocatorRetryTest, RetrySuccess) {
   EXPECT_GT(consumer_count_[2], 0);
 }
 
-/* Disabled due to flakiness.  b/24738751
 // Verifies OutOfMemory failure when memory is slightly overcommitted
-// and retry is not allowed.
+// and retry is not allowed.  Note that this test will fail, i.e. no
+// memory alloc failure will be detected, if it is run in a context that
+// does not permit real multi-threaded execution.
 TEST_F(GPUAllocatorRetryTest, NoRetryFail) {
   // Support up to 2 allocations simultaneously, waits up to 0 msec for
   // a chance to alloc.
@@ -162,7 +166,6 @@ TEST_F(GPUAllocatorRetryTest, NoRetryFail) {
     EXPECT_TRUE(has_failed_);
   }
 }
-*/
 
 // Verifies OutOfMemory failure when retry is allowed but memory capacity
 // is too low even for retry.