Cancel unused timeout events. Without this change they can...

base/message_pump_libevent.cc

 // Copyright (c) 2008 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.
 
 #include "base/message_pump_libevent.h"
 
 #include <errno.h>
 #include <fcntl.h>
 
 #include "eintr_wrapper.h"
@@ skipping 197 matching lines @@
   Watcher* watcher = static_cast<Watcher*>(context);
 
   if (flags & EV_WRITE) {
     watcher->OnFileCanWriteWithoutBlocking(fd);
   }
   if (flags & EV_READ) {
     watcher->OnFileCanReadWithoutBlocking(fd);
   }
 }
 
+// Tell libevent to break out of inner loop.

[jeremy, 2009/11/05 22:51:37]

nit: expand the comment to point at the bug.

+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!";
 
   bool old_in_run = in_run_;
   in_run_ = true;
 
+  scoped_ptr<event> timer_event(new event);
+
   for (;;) {
     ScopedNSAutoreleasePool autorelease_pool;
 
     bool did_work = delegate->DoWork();
     if (!keep_running_)
       break;
 
     did_work |= delegate->DoDelayedWork(&delayed_work_time_);
     if (!keep_running_)
       break;
@@ skipping 11 matching lines @@
     // EVLOOP_ONCE tells libevent to only block once,
     // but to service all pending events when it wakes up.
     if (delayed_work_time_.is_null()) {
       event_base_loop(event_base_, EVLOOP_ONCE);
     } else {
       TimeDelta delay = delayed_work_time_ - Time::Now();
       if (delay > TimeDelta()) {
         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.
         delayed_work_time_ = Time();
       }
     }
   }
 
   keep_running_ = true;
   in_run_ = old_in_run;
@@ skipping 15 matching lines @@
 }
 
 void MessagePumpLibevent::ScheduleDelayedWork(const Time& delayed_work_time) {
   // We know that we can't be blocked on Wait right now since this method can
   // only be called on the same thread as Run, so we only need to update our
   // record of how long to sleep when we do sleep.
   delayed_work_time_ = delayed_work_time;
 }
 
 }  // namespace base