base/message_pump_default.cc

   1 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/message_pump_default.h"
   6
   7 #include "base/logging.h"
   8 #include "base/mac/scoped_nsautorelease_pool.h"
   9
  10 namespace base {
  11
  12 MessagePumpDefault::MessagePumpDefault()
  13     : keep_running_(true),
  14       event_(false, false) {
  15 }
  16
  17 void MessagePumpDefault::Run(Delegate* delegate) {
  18   DCHECK(keep_running_) << "Quit must have been called outside of Run!";
  19
  20   for (;;) {
  21     mac::ScopedNSAutoreleasePool autorelease_pool;
  22
  23     bool did_work = delegate->DoWork();
  24     if (!keep_running_)
  25       break;
  26
  27     did_work |= delegate->DoDelayedWork(&delayed_work_time_);
  28     if (!keep_running_)
  29       break;
  30
  31     if (did_work)
  32       continue;
  33
  34     did_work = delegate->DoIdleWork();
  35     if (!keep_running_)
  36       break;
  37
  38     if (did_work)
  39       continue;
  40
  41     if (delayed_work_time_.is_null()) {
  42       event_.Wait();
  43     } else {
  44       TimeDelta delay = delayed_work_time_ - TimeTicks::Now();
  45       if (delay > TimeDelta()) {
  46         event_.TimedWait(delay);
  47       } else {
  48         // It looks like delayed_work_time_ indicates a time in the past, so we
  49         // need to call DoDelayedWork now.
  50         delayed_work_time_ = TimeTicks();
  51       }
  52     }
  53     // Since event_ is auto-reset, we don't need to do anything special here
  54     // other than service each delegate method.
  55   }
  56
  57   keep_running_ = true;
  58 }
  59
  60 void MessagePumpDefault::Quit() {
  61   keep_running_ = false;
  62 }
  63
  64 void MessagePumpDefault::ScheduleWork() {
  65   // Since this can be called on any thread, we need to ensure that our Run
  66   // loop wakes up.
  67   event_.Signal();
  68 }
  69
  70 void MessagePumpDefault::ScheduleDelayedWork(
  71     const TimeTicks& delayed_work_time) {
  72   // We know that we can't be blocked on Wait right now since this method can
  73   // only be called on the same thread as Run, so we only need to update our
  74   // record of how long to sleep when we do sleep.
  75   delayed_work_time_ = delayed_work_time;
  76 }
  77
  78 }  // namespace base