| // Copyright 2008, Google Inc. |
| // All rights reserved. |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following disclaimer |
| // in the documentation and/or other materials provided with the |
| // distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived from |
| // this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| #include "base/message_pump_default.h" |
| |
| #include "base/logging.h" |
| |
| namespace base { |
| |
| MessagePumpDefault::MessagePumpDefault() |
| : keep_running_(true), |
| event_(false, false) { |
| } |
| |
| void MessagePumpDefault::Run(Delegate* delegate) { |
| DCHECK(keep_running_) << "Quit must have been called outside of Run!"; |
| |
| for (;;) { |
| bool did_work = delegate->DoWork(); |
| if (!keep_running_) |
| break; |
| if (did_work) |
| continue; |
| |
| // TODO(darin): Delayed work will be starved if DoWork continues to return |
| // true. We should devise a better strategy. |
| // |
| // It is tempting to call DoWork followed by DoDelayedWork before checking |
| // did_work, but we need to make sure that any tasks that were dispatched |
| // prior to a timer actually run before the timer. Getting that right may |
| // require some additional changes. |
| |
| did_work = delegate->DoDelayedWork(&delayed_work_time_); |
| if (!keep_running_) |
| break; |
| if (did_work) |
| continue; |
| |
| did_work = delegate->DoIdleWork(); |
| if (!keep_running_) |
| break; |
| if (did_work) |
| continue; |
| |
| if (delayed_work_time_.is_null()) { |
| event_.Wait(); |
| } else { |
| TimeDelta delay = delayed_work_time_ - Time::Now(); |
| if (delay > TimeDelta()) { |
| event_.TimedWait(delay); |
| } else { |
| // It looks like delayed_work_time_ indicates a time in the past, so we |
| // need to call DoDelayedWork now. |
| delayed_work_time_ = Time(); |
| } |
| } |
| // Since event_ is auto-reset, we don't need to do anything special here |
| // other than service each delegate method. |
| } |
| |
| keep_running_ = true; |
| } |
| |
| void MessagePumpDefault::Quit() { |
| keep_running_ = false; |
| } |
| |
| void MessagePumpDefault::ScheduleWork() { |
| // Since this can be called on any thread, we need to ensure that our Run |
| // loop wakes up. |
| event_.Signal(); |
| } |
| |
| void MessagePumpDefault::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 |