license.bot | f003cfe | 2008-08-24 09:55:55 +0900 | [diff] [blame^] | 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. |
darin@google.com | c62bf35 | 2008-08-11 23:35:15 +0900 | [diff] [blame] | 4 | |
| 5 | #include "base/waitable_event.h" |
| 6 | |
| 7 | namespace base { |
| 8 | |
| 9 | WaitableEvent::WaitableEvent(bool manual_reset, bool signaled) |
| 10 | : lock_(), |
| 11 | cvar_(&lock_), |
| 12 | signaled_(signaled), |
| 13 | manual_reset_(manual_reset) { |
| 14 | } |
| 15 | |
| 16 | WaitableEvent::~WaitableEvent() { |
| 17 | // Members are destroyed in the reverse of their initialization order, so we |
| 18 | // should not have to worry about lock_ being destroyed before cvar_. |
| 19 | } |
| 20 | |
| 21 | void WaitableEvent::Reset() { |
| 22 | AutoLock locked(lock_); |
| 23 | signaled_ = false; |
| 24 | } |
| 25 | |
| 26 | void WaitableEvent::Signal() { |
| 27 | AutoLock locked(lock_); |
| 28 | if (!signaled_) { |
| 29 | signaled_ = true; |
| 30 | if (manual_reset_) { |
| 31 | cvar_.Broadcast(); |
| 32 | } else { |
| 33 | cvar_.Signal(); |
| 34 | } |
| 35 | } |
| 36 | } |
| 37 | |
| 38 | bool WaitableEvent::IsSignaled() { |
| 39 | return TimedWait(TimeDelta::FromMilliseconds(0)); |
| 40 | } |
| 41 | |
| 42 | bool WaitableEvent::Wait() { |
| 43 | AutoLock locked(lock_); |
| 44 | while (!signaled_) |
| 45 | cvar_.Wait(); |
| 46 | if (!manual_reset_) |
| 47 | signaled_ = false; |
| 48 | return true; |
| 49 | } |
| 50 | |
| 51 | bool WaitableEvent::TimedWait(const TimeDelta& max_time) { |
| 52 | AutoLock locked(lock_); |
| 53 | // In case of spurious wake-ups, we need to adjust the amount of time that we |
| 54 | // spend sleeping. |
| 55 | TimeDelta total_time; |
| 56 | for (;;) { |
| 57 | TimeTicks start = TimeTicks::Now(); |
| 58 | cvar_.TimedWait(max_time - total_time); |
| 59 | if (signaled_) |
| 60 | break; |
| 61 | total_time += TimeTicks::Now() - start; |
| 62 | if (total_time >= max_time) |
| 63 | break; |
| 64 | } |
| 65 | bool result = signaled_; |
| 66 | if (!manual_reset_) |
| 67 | signaled_ = false; |
| 68 | return result; |
| 69 | } |
| 70 | |
| 71 | } // namespace base |
license.bot | f003cfe | 2008-08-24 09:55:55 +0900 | [diff] [blame^] | 72 | |