| // 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/waitable_event.h" |
| |
| namespace base { |
| |
| WaitableEvent::WaitableEvent(bool manual_reset, bool signaled) |
| : lock_(), |
| cvar_(&lock_), |
| signaled_(signaled), |
| manual_reset_(manual_reset) { |
| } |
| |
| WaitableEvent::~WaitableEvent() { |
| // Members are destroyed in the reverse of their initialization order, so we |
| // should not have to worry about lock_ being destroyed before cvar_. |
| } |
| |
| void WaitableEvent::Reset() { |
| AutoLock locked(lock_); |
| signaled_ = false; |
| } |
| |
| void WaitableEvent::Signal() { |
| AutoLock locked(lock_); |
| if (!signaled_) { |
| signaled_ = true; |
| if (manual_reset_) { |
| cvar_.Broadcast(); |
| } else { |
| cvar_.Signal(); |
| } |
| } |
| } |
| |
| bool WaitableEvent::IsSignaled() { |
| return TimedWait(TimeDelta::FromMilliseconds(0)); |
| } |
| |
| bool WaitableEvent::Wait() { |
| AutoLock locked(lock_); |
| while (!signaled_) |
| cvar_.Wait(); |
| if (!manual_reset_) |
| signaled_ = false; |
| return true; |
| } |
| |
| bool WaitableEvent::TimedWait(const TimeDelta& max_time) { |
| AutoLock locked(lock_); |
| // In case of spurious wake-ups, we need to adjust the amount of time that we |
| // spend sleeping. |
| TimeDelta total_time; |
| for (;;) { |
| TimeTicks start = TimeTicks::Now(); |
| cvar_.TimedWait(max_time - total_time); |
| if (signaled_) |
| break; |
| total_time += TimeTicks::Now() - start; |
| if (total_time >= max_time) |
| break; |
| } |
| bool result = signaled_; |
| if (!manual_reset_) |
| signaled_ = false; |
| return result; |
| } |
| |
| } // namespace base |