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

base/synchronization/condition_variable_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Multi-threaded tests of ConditionVariable class.
 
 #include <time.h>
 #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"
 #include "testing/platform_test.h"
 
 namespace base {
 
 namespace {
 //------------------------------------------------------------------------------
 // Define our test class, with several common variables.
@@ skipping 154 matching lines @@
 
   cv.TimedWait(WAIT_TIME + FUDGE_TIME);
   TimeDelta duration = TimeTicks::Now() - start;
   // We can't use EXPECT_GE here as the TimeDelta class does not support the
   // required stream conversion.
   EXPECT_TRUE(duration >= WAIT_TIME);
 
   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)
 #if defined(OS_WIN)
 #define MAYBE_MultiThreadConsumerTest DISABLED_MultiThreadConsumerTest
 #else
 #define MAYBE_MultiThreadConsumerTest MultiThreadConsumerTest
 #endif
 // Test serial task servicing, as well as two parallel task servicing methods.
 TEST_F(ConditionVariableTest, MAYBE_MultiThreadConsumerTest) {
@@ skipping 505 matching lines @@
       base::AutoLock auto_lock(lock_);
       // Send notification that we completed our "work."
       WorkIsCompleted(thread_id);
     }
   }
 }
 
 }  // namespace
 
 }  // namespace base