Fix regression where high resolution timers could be activated even under
battery power. Add unit test to protect chromium from developers like me
in the future.
The fix is a one-liner in hi_res_timer_manager_win.cc. The rest of the code
change is the mechanics to enable the unit test.
BUG=59528
TEST=HiResTimerManagerTest.ToggleOnOff
Review URL: http://codereview.chromium.org/3848002
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@63176 0039d316-1c4b-4281-b951-d872f2087c98
CrOS-Libchrome-Original-Commit: 8f31f41edbe94651e1df889993be0704954942db
diff --git a/base/message_loop.cc b/base/message_loop.cc
index 8f6c997..0b03d3c 100644
--- a/base/message_loop.cc
+++ b/base/message_loop.cc
@@ -179,6 +179,16 @@
// OK, now make it so that no one can find us.
lazy_tls_ptr.Pointer()->Set(NULL);
+
+#if defined(OS_WIN)
+ // If we left the high-resolution timer activated, deactivate it now.
+ // Doing this is not-critical, it is mainly to make sure we track
+ // the high resolution timer activations properly in our unit tests.
+ if (!high_resolution_timer_expiration_.is_null()) {
+ Time::ActivateHighResolutionTimer(false);
+ high_resolution_timer_expiration_ = base::TimeTicks();
+ }
+#endif
}
void MessageLoop::AddDestructionObserver(
@@ -337,9 +347,10 @@
bool needs_high_res_timers =
delay_ms < (2 * Time::kMinLowResolutionThresholdMs);
if (needs_high_res_timers) {
- Time::ActivateHighResolutionTimer(true);
- high_resolution_timer_expiration_ = base::TimeTicks::Now() +
- TimeDelta::FromMilliseconds(kHighResolutionTimerModeLeaseTimeMs);
+ if (Time::ActivateHighResolutionTimer(true)) {
+ high_resolution_timer_expiration_ = base::TimeTicks::Now() +
+ TimeDelta::FromMilliseconds(kHighResolutionTimerModeLeaseTimeMs);
+ }
}
}
#endif
diff --git a/base/time.h b/base/time.h
index 79e30b4..305ca6b 100644
--- a/base/time.h
+++ b/base/time.h
@@ -283,10 +283,16 @@
// Activates or deactivates the high resolution timer based on the |activate|
// flag. If the HighResolutionTimer is not Enabled (see
// EnableHighResolutionTimer), this function will return false. Otherwise
- // returns true.
+ // returns true. Each successful activate call must be paired with a
+ // subsequent deactivate call.
// All callers to activate the high resolution timer must eventually call
// this function to deactivate the high resolution timer.
static bool ActivateHighResolutionTimer(bool activate);
+
+ // Returns true if the high resolution timer is both enabled and activated.
+ // This is provided for testing only, and is not tracked in a thread-safe
+ // way.
+ static bool IsHighResolutionTimerInUse();
#endif
// Converts an exploded structure representing either the local time or UTC
@@ -405,6 +411,9 @@
// when using battery power, we might elect to prevent high speed timers
// which would draw more power.
static bool high_resolution_timer_enabled_;
+ // Count of activations on the high resolution timer. Only use in tests
+ // which are single threaded.
+ static int high_resolution_timer_activated_;
#endif
// Time in microseconds in UTC.