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
14 namespace base {
15
ConditionVariable(Lock * user_lock)16 ConditionVariable::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
~ConditionVariable()26 ConditionVariable::~ConditionVariable() {
27 int rv = pthread_cond_destroy(&condition_);
28 DCHECK_EQ(0, rv);
29 }
30
Wait()31 void 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
TimedWait(const TimeDelta & max_time)42 void 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
Broadcast()67 void ConditionVariable::Broadcast() {
68 int rv = pthread_cond_broadcast(&condition_);
69 DCHECK_EQ(0, rv);
70 }
71
Signal()72 void ConditionVariable::Signal() {
73 int rv = pthread_cond_signal(&condition_);
74 DCHECK_EQ(0, rv);
75 }
76
77 } // namespace base
78