[llvm] r256056 - Remove possibility of failures to due race in ThreadPool unittest

[Teresa Johnson via llvm-commits]

Author: tejohnson
Date: Fri Dec 18 16:59:35 2015
New Revision: 256056

URL: http://llvm.org/viewvc/llvm-project?rev=256056&view=rev
Log:
Remove possibility of failures to due race in ThreadPool unittest

Remove all checks that required main thread to run faster than tasks in
ThreadPool, and yields which are now unnecessary. This should fix some
bot failures.

Modified:
    llvm/trunk/unittests/Support/ThreadPool.cpp

Modified: llvm/trunk/unittests/Support/ThreadPool.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/Support/ThreadPool.cpp?rev=256056&r1=256055&r2=256056&view=diff
==============================================================================
--- llvm/trunk/unittests/Support/ThreadPool.cpp (original)
+++ llvm/trunk/unittests/Support/ThreadPool.cpp Fri Dec 18 16:59:35 2015
@@ -18,18 +18,6 @@
 #include "gtest/gtest.h"
 
 using namespace llvm;
-using namespace std::chrono;
-
-/// Try best to make this thread not progress faster than the main thread
-static void yield() {
-#ifdef LLVM_ENABLE_THREADS
-  std::this_thread::yield();
-#endif
-  std::this_thread::sleep_for(milliseconds(200));
-#ifdef LLVM_ENABLE_THREADS
-  std::this_thread::yield();
-#endif
-}
 
 // Fixture for the unittests, allowing to *temporarily* disable the unittests
 // on a particular platform
@@ -83,11 +71,9 @@ TEST_F(ThreadPoolTest, AsyncBarrier) {
   ThreadPool Pool;
   for (size_t i = 0; i < 5; ++i) {
     Pool.async([&checked_in, i] {
-      yield();
       ++checked_in;
     });
   }
-  ASSERT_EQ(0, checked_in);
   Pool.wait();
   ASSERT_EQ(5, checked_in);
 }
@@ -111,13 +97,10 @@ TEST_F(ThreadPoolTest, Async) {
   CHECK_UNSUPPORTED();
   ThreadPool Pool;
   std::atomic_int i{0};
-  // sleep here just to ensure that the not-equal is correct.
   Pool.async([&i] {
-    yield();
     ++i;
   });
   Pool.async([&i] { ++i; });
-  ASSERT_NE(2, i.load());
   Pool.wait();
   ASSERT_EQ(2, i.load());
 }
@@ -126,14 +109,11 @@ TEST_F(ThreadPoolTest, GetFuture) {
   CHECK_UNSUPPORTED();
   ThreadPool Pool;
   std::atomic_int i{0};
-  // sleep here just to ensure that the not-equal is correct.
   Pool.async([&i] {
-    yield();
     ++i;
   });
   // Force the future using get()
   Pool.async([&i] { ++i; }).get();
-  ASSERT_NE(2, i.load());
   Pool.wait();
   ASSERT_EQ(2, i.load());
 }
@@ -147,11 +127,9 @@ TEST_F(ThreadPoolTest, PoolDestruction)
     ThreadPool Pool;
     for (size_t i = 0; i < 5; ++i) {
       Pool.async([&checked_in, i] {
-        yield();
         ++checked_in;
       });
     }
-    ASSERT_EQ(0, checked_in);
   }
   ASSERT_EQ(5, checked_in);
 }