Cancel unused timeout events. Without this change they can

accumulate for a while, wasting memory and causing unneeded wakeups.
BUG=25641
TEST=green valgrind or heapchecker on net_unittests

Previously reviewed as
http://codereview.chromium.org/370005/

TBR=timurrrr
Review URL: http://codereview.chromium.org/372033

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@31306 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 14 insertions, 1 deletions

diff --git a/base/message_pump_libevent.cc b/base/message_pump_libevent.cc
index ddb2a2d..eae77f4 100644
--- a/base/message_pump_libevent.cc
+++ b/base/message_pump_libevent.cc
@@ -215,6 +215,12 @@ void MessagePumpLibevent::OnLibeventNotification(int fd, short flags,
   }
 }
 
+// Tell libevent to break out of inner loop.
+static void timer_callback(int fd, short events, void *context)
+{
+  event_base_loopbreak((struct event_base *)context);
+}
+
 // Reentrant!
 void MessagePumpLibevent::Run(Delegate* delegate) {
   DCHECK(keep_running_) << "Quit must have been called outside of Run!";
@@ -222,6 +228,10 @@ void MessagePumpLibevent::Run(Delegate* delegate) {
   bool old_in_run = in_run_;
   in_run_ = true;
 
+  // event_base_loopexit() + EVLOOP_ONCE is leaky, see http://crbug.com/25641.
+  // Instead, make our own timer and reuse it on each call to event_base_loop().
+  scoped_ptr<event> timer_event(new event);
+
   for (;;) {
     ScopedNSAutoreleasePool autorelease_pool;
 
@@ -253,8 +263,11 @@ void MessagePumpLibevent::Run(Delegate* delegate) {
         struct timeval poll_tv;
         poll_tv.tv_sec = delay.InSeconds();
         poll_tv.tv_usec = delay.InMicroseconds() % Time::kMicrosecondsPerSecond;
-        event_base_loopexit(event_base_, &poll_tv);
+        event_set(timer_event.get(), -1, 0, timer_callback, event_base_);
+        event_base_set(event_base_, timer_event.get());
+        event_add(timer_event.get(), &poll_tv);
         event_base_loop(event_base_, EVLOOP_ONCE);
+        event_del(timer_event.get());
       } else {
         // It looks like delayed_work_time_ indicates a time in the past, so we
         // need to call DoDelayedWork now.