base/synchronization/condition_variable_posix.cc

   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/threading/thread_restrictions.h"
  13 #include "base/time.h"
  14
  15 namespace base {
  16
  17 ConditionVariable::ConditionVariable(Lock* user_lock)
  18     : user_mutex_(user_lock->lock_.os_lock())
  19 #if !defined(NDEBUG)
  20     , user_lock_(user_lock)
  21 #endif
  22 {
  23   int rv = pthread_cond_init(&condition_, NULL);
  24   DCHECK_EQ(0, rv);
  25 }
  26
  27 ConditionVariable::~ConditionVariable() {
  28   int rv = pthread_cond_destroy(&condition_);
  29   DCHECK_EQ(0, rv);
  30 }
  31
  32 void ConditionVariable::Wait() {
  33   base::ThreadRestrictions::AssertWaitAllowed();
  34 #if !defined(NDEBUG)
  35   user_lock_->CheckHeldAndUnmark();
  36 #endif
  37   int rv = pthread_cond_wait(&condition_, user_mutex_);
  38   DCHECK_EQ(0, rv);
  39 #if !defined(NDEBUG)
  40   user_lock_->CheckUnheldAndMark();
  41 #endif
  42 }
  43
  44 void ConditionVariable::TimedWait(const TimeDelta& max_time) {
  45   base::ThreadRestrictions::AssertWaitAllowed();
  46   int64 usecs = max_time.InMicroseconds();
  47
  48   // The timeout argument to pthread_cond_timedwait is in absolute time.
  49   struct timeval now;
  50   gettimeofday(&now, NULL);
  51
  52   struct timespec abstime;
  53   abstime.tv_sec = now.tv_sec + (usecs / Time::kMicrosecondsPerSecond);
  54   abstime.tv_nsec = (now.tv_usec + (usecs % Time::kMicrosecondsPerSecond)) *
  55                     Time::kNanosecondsPerMicrosecond;
  56   abstime.tv_sec += abstime.tv_nsec / Time::kNanosecondsPerSecond;
  57   abstime.tv_nsec %= Time::kNanosecondsPerSecond;
  58   DCHECK_GE(abstime.tv_sec, now.tv_sec);  // Overflow paranoia
  59
  60 #if !defined(NDEBUG)
  61   user_lock_->CheckHeldAndUnmark();
  62 #endif
  63   int rv = pthread_cond_timedwait(&condition_, user_mutex_, &abstime);
  64   DCHECK(rv == 0 || rv == ETIMEDOUT);
  65 #if !defined(NDEBUG)
  66   user_lock_->CheckUnheldAndMark();
  67 #endif
  68 }
  69
  70 void ConditionVariable::Broadcast() {
  71   int rv = pthread_cond_broadcast(&condition_);
  72   DCHECK_EQ(0, rv);
  73 }
  74
  75 void ConditionVariable::Signal() {
  76   int rv = pthread_cond_signal(&condition_);
  77   DCHECK_EQ(0, rv);
  78 }
  79
  80 }  // namespace base