base/condition_variable_posix.cc

   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
  15 using base::Time;
  16 using base::TimeDelta;
  17
  18 ConditionVariable::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
  24 ConditionVariable::~ConditionVariable() {
  25   int rv = pthread_cond_destroy(&condition_);
  26   DCHECK(rv == 0);
  27 }
  28
  29 void ConditionVariable::Wait() {
  30   int rv = pthread_cond_wait(&condition_, user_mutex_);
  31   DCHECK(rv == 0);
  32 }
  33
  34 void 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
  53 void ConditionVariable::Broadcast() {
  54   int rv = pthread_cond_broadcast(&condition_);
  55   DCHECK(rv == 0);
  56 }
  57
  58 void ConditionVariable::Signal() {
  59   int rv = pthread_cond_signal(&condition_);
  60   DCHECK(rv == 0);
  61 }