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/condition_variable.h"
6
7#include <errno.h>
8#include <sys/time.h>
9
10#include "base/lock.h"
11#include "base/lock_impl.h"
12#include "base/logging.h"
13#include "base/time.h"
14
15using base::Time;
16using base::TimeDelta;
17
18ConditionVariable::ConditionVariable(Lock* user_lock)
19    : user_mutex_(user_lock->lock_impl()->os_lock()) {
20  int rv = pthread_cond_init(&condition_, NULL);
21  DCHECK(rv == 0);
22}
23
24ConditionVariable::~ConditionVariable() {
25  int rv = pthread_cond_destroy(&condition_);
26  DCHECK(rv == 0);
27}
28
29void ConditionVariable::Wait() {
30  int rv = pthread_cond_wait(&condition_, user_mutex_);
31  DCHECK(rv == 0);
32}
33
34void ConditionVariable::TimedWait(const TimeDelta& max_time) {
35  int64 usecs = max_time.InMicroseconds();
36
37  // The timeout argument to pthread_cond_timedwait is in absolute time.
38  struct timeval now;
39  gettimeofday(&now, NULL);
40
41  struct timespec abstime;
42  abstime.tv_sec = now.tv_sec + (usecs / Time::kMicrosecondsPerSecond);
43  abstime.tv_nsec = (now.tv_usec + (usecs % Time::kMicrosecondsPerSecond)) *
44                    Time::kNanosecondsPerMicrosecond;
45  abstime.tv_sec += abstime.tv_nsec / Time::kNanosecondsPerSecond;
46  abstime.tv_nsec %= Time::kNanosecondsPerSecond;
47  DCHECK(abstime.tv_sec >= now.tv_sec);  // Overflow paranoia
48
49  int rv = pthread_cond_timedwait(&condition_, user_mutex_, &abstime);
50  DCHECK(rv == 0 || rv == ETIMEDOUT);
51}
52
53void ConditionVariable::Broadcast() {
54  int rv = pthread_cond_broadcast(&condition_);
55  DCHECK(rv == 0);
56}
57
58void ConditionVariable::Signal() {
59  int rv = pthread_cond_signal(&condition_);
60  DCHECK(rv == 0);
61}
62