Fix WaitableEvent and ConditionVariable::TimedWait to use monotonic time on non-mac posix

base/synchronization/condition_variable_unittest.cc

Index: base/synchronization/condition_variable_unittest.cc
diff --git a/base/synchronization/condition_variable_unittest.cc b/base/synchronization/condition_variable_unittest.cc
index 4230e635495962d7990bbf79070fcc4e37a059dd..65e153cd7909e254ae941f8afcd82c472d0ccae2 100644
--- a/base/synchronization/condition_variable_unittest.cc
+++ b/base/synchronization/condition_variable_unittest.cc
@@ -8,12 +8,14 @@
 #include <algorithm>
 #include <vector>
 
+#include "base/bind.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/synchronization/condition_variable.h"
 #include "base/synchronization/lock.h"
 #include "base/synchronization/spin_wait.h"
 #include "base/threading/platform_thread.h"
+#include "base/threading/thread.h"
 #include "base/threading/thread_collision_warner.h"
 #include "base/time/time.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -188,6 +190,57 @@ TEST_F(ConditionVariableTest, TimeoutTest) {
   lock.Release();
 }
 
+#if defined(OS_POSIX)
+const int kDiscontinuitySeconds = 2;
+
+void BackInTime(Lock* lock) {
+  AutoLock auto_lock(*lock);
+
+  timeval tv;
+  gettimeofday(&tv, NULL);
+  tv.tv_sec -= kDiscontinuitySeconds;
+  settimeofday(&tv, NULL);
+}
+
+// Tests that TimedWait ignores changes to the system clock.
+// Test is disabled by default, because it needs to run as root to muck with the
+// system clock.
+// http://crbug.com/293736
+TEST_F(ConditionVariableTest, DISABLED_TimeoutAcrossSetTimeOfDay) {

[Alexander Potapenko, 2013/10/03 09:16:17]

A disabled test will rot in no time, because nobody is going to run it.
Also, the comment references a bug which is already marked as fixed and which
doesn't contain any details relevant to this test.

+  timeval tv;
+  gettimeofday(&tv, NULL);
+  tv.tv_sec += kDiscontinuitySeconds;
+  if (settimeofday(&tv, NULL) < 0) {
+    PLOG(ERROR) << "Could not set time of day. Run as root?";
+    return;
+  }
+
+  Lock lock;
+  ConditionVariable cv(&lock);
+  lock.Acquire();
+
+  Thread thread("Helper");
+  thread.Start();
+  thread.message_loop()->PostTask(FROM_HERE, base::Bind(&BackInTime, &lock));
+
+  TimeTicks start = TimeTicks::Now();
+  const TimeDelta kWaitTime = TimeDelta::FromMilliseconds(300);
+  // Allow for clocking rate granularity.
+  const TimeDelta kFudgeTime = TimeDelta::FromMilliseconds(50);
+
+  cv.TimedWait(kWaitTime + kFudgeTime);
+  TimeDelta duration = TimeTicks::Now() - start;
+
+  thread.Stop();
+  // We can't use EXPECT_GE here as the TimeDelta class does not support the
+  // required stream conversion.
+  EXPECT_TRUE(duration >= kWaitTime);
+  EXPECT_TRUE(duration <= TimeDelta::FromSeconds(kDiscontinuitySeconds));
+
+  lock.Release();
+}
+#endif
+
 
 // Suddenly got flaky on Win, see http://crbug.com/10607 (starting at
 // comment #15)