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