Switched flaky ProfilerTest to use fake clock

webrtc/base/profiler_unittest.cc

Index: webrtc/base/profiler_unittest.cc
diff --git a/webrtc/base/profiler_unittest.cc b/webrtc/base/profiler_unittest.cc
index 2448fce2de62e52f3ce569d96eae5ea5aed9ada9..ff62f5edec9a0c4cf787a1595c49be887724f85a 100644
--- a/webrtc/base/profiler_unittest.cc
+++ b/webrtc/base/profiler_unittest.cc
@@ -8,8 +8,10 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
+#include "webrtc/base/fakeclock.h"
 #include "webrtc/base/gunit.h"
 #include "webrtc/base/profiler.h"
+#include "webrtc/base/timedelta.h"
 #include "webrtc/base/thread.h"
 
 namespace {
@@ -18,9 +20,9 @@ const int kWaitMs = 250;
 const double kWaitSec = 0.250;
 const double kTolerance = 0.1;
 
-const char* TestFunc() {
+const char* TestFunc(rtc::FakeClock* clock) {
   PROFILE_F();
-  rtc::Thread::SleepMs(kWaitMs);
+  clock->AdvanceTime(rtc::TimeDelta::FromMilliseconds(kWaitMs));
   return __FUNCTION__;
 }
 
@@ -28,17 +30,12 @@ const char* TestFunc() {
 
 namespace rtc {
 
-// Disable this test due to flakiness; see bug 5947.
-#if defined(WEBRTC_LINUX)
-#define MAYBE_TestFunction DISABLED_TestFunction
-#else
-#define MAYBE_TestFunction TestFunction
-#endif
-TEST(ProfilerTest, MAYBE_TestFunction) {
+TEST(ProfilerTest, TestFunction) {
+  rtc::ScopedFakeClock fake_clock;
   ASSERT_TRUE(Profiler::Instance()->Clear());
 
   // Profile a long-running function.
-  const char* function_name = TestFunc();
+  const char* function_name = TestFunc(&fake_clock);
   const ProfilerEvent* event = Profiler::Instance()->GetEvent(function_name);
   ASSERT_TRUE(event != NULL);
   EXPECT_FALSE(event->is_started());
@@ -46,7 +43,7 @@ TEST(ProfilerTest, MAYBE_TestFunction) {
   EXPECT_NEAR(kWaitSec, event->mean(), kTolerance * 3);

[Taylor Brandstetter, 2016/10/04 00:48:53]

If the time is now 100% predictable, can we get rid of "EXPECT_NEAR" and
kTolerance? If not here, we should at least add a TODO and P3 bug to track it.

[skvlad, 2016/10/04 01:17:45]

Good point. I've replaced them all with EXPECT_EQ.

 
   // Run it a second time.
-  TestFunc();
+  TestFunc(&fake_clock);
   EXPECT_FALSE(event->is_started());
   EXPECT_EQ(2, event->event_count());
   EXPECT_NEAR(kWaitSec, event->mean(), kTolerance);
@@ -55,6 +52,7 @@ TEST(ProfilerTest, MAYBE_TestFunction) {
 }
 
 TEST(ProfilerTest, TestScopedEvents) {
+  rtc::ScopedFakeClock fake_clock;
   const std::string kEvent1Name = "Event 1";
   const std::string kEvent2Name = "Event 2";
   const int kEvent2WaitMs = 150;
@@ -68,7 +66,7 @@ TEST(ProfilerTest, TestScopedEvents) {
     ASSERT_TRUE(event1 != NULL);
     EXPECT_TRUE(event1->is_started());
     EXPECT_EQ(0, event1->event_count());
-    rtc::Thread::SleepMs(kWaitMs);
+    fake_clock.AdvanceTime(rtc::TimeDelta::FromMilliseconds(kWaitMs));
     EXPECT_TRUE(event1->is_started());
   }
   // Check the result.
@@ -81,7 +79,7 @@ TEST(ProfilerTest, TestScopedEvents) {
     ASSERT_TRUE(event2 != NULL);
     EXPECT_FALSE(event1->is_started());
     EXPECT_TRUE(event2->is_started());
-    rtc::Thread::SleepMs(kEvent2WaitMs);
+    fake_clock.AdvanceTime(rtc::TimeDelta::FromMilliseconds(kEvent2WaitMs));
   }
   // Check the result.
   EXPECT_FALSE(event2->is_started());
@@ -95,7 +93,7 @@ TEST(ProfilerTest, TestScopedEvents) {
   {  // Run another event 1.
     PROFILE(kEvent1Name);
     EXPECT_TRUE(event1->is_started());
-    rtc::Thread::SleepMs(kWaitMs);
+    fake_clock.AdvanceTime(rtc::TimeDelta::FromMilliseconds(kWaitMs));
   }
   // Check the result.
   EXPECT_FALSE(event1->is_started());