1// Copyright (c) 2011 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/synchronization/condition_variable.h"
6
7#include <errno.h>
8#include <sys/time.h>
9
10#include "base/logging.h"
11#include "base/synchronization/lock.h"
12#include "base/time.h"
13
14namespace base {
15
16ConditionVariable::ConditionVariable(Lock* user_lock)
17    : user_mutex_(user_lock->lock_.os_lock())
18#if !defined(NDEBUG)
19    , user_lock_(user_lock)
20#endif
21{
22  int rv = pthread_cond_init(&condition_, NULL);
23  DCHECK_EQ(0, rv);
24}
25
26ConditionVariable::~ConditionVariable() {
27  int rv = pthread_cond_destroy(&condition_);
28  DCHECK_EQ(0, rv);
29}
30
31void ConditionVariable::Wait() {
32#if !defined(NDEBUG)
33  user_lock_->CheckHeldAndUnmark();
34#endif
35  int rv = pthread_cond_wait(&condition_, user_mutex_);
36  DCHECK_EQ(0, rv);
37#if !defined(NDEBUG)
38  user_lock_->CheckUnheldAndMark();
39#endif
40}
41
42void ConditionVariable::TimedWait(const TimeDelta& max_time) {
43  int64 usecs = max_time.InMicroseconds();
44
45  // The timeout argument to pthread_cond_timedwait is in absolute time.
46  struct timeval now;
47  gettimeofday(&now, NULL);
48
49  struct timespec abstime;
50  abstime.tv_sec = now.tv_sec + (usecs / Time::kMicrosecondsPerSecond);
51  abstime.tv_nsec = (now.tv_usec + (usecs % Time::kMicrosecondsPerSecond)) *
52                    Time::kNanosecondsPerMicrosecond;
53  abstime.tv_sec += abstime.tv_nsec / Time::kNanosecondsPerSecond;
54  abstime.tv_nsec %= Time::kNanosecondsPerSecond;
55  DCHECK_GE(abstime.tv_sec, now.tv_sec);  // Overflow paranoia
56
57#if !defined(NDEBUG)
58  user_lock_->CheckHeldAndUnmark();
59#endif
60  int rv = pthread_cond_timedwait(&condition_, user_mutex_, &abstime);
61  DCHECK(rv == 0 || rv == ETIMEDOUT);
62#if !defined(NDEBUG)
63  user_lock_->CheckUnheldAndMark();
64#endif
65}
66
67void ConditionVariable::Broadcast() {
68  int rv = pthread_cond_broadcast(&condition_);
69  DCHECK_EQ(0, rv);
70}
71
72void ConditionVariable::Signal() {
73  int rv = pthread_cond_signal(&condition_);
74  DCHECK_EQ(0, rv);
75}
76
77}  // namespace base
78