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/time.h" 14 15 namespace base { 16 17 ConditionVariable::ConditionVariable(Lock* user_lock) 18 : user_mutex_(user_lock->lock_.native_handle()) 19 #if !defined(NDEBUG) || defined(DCHECK_ALWAYS_ON) 20 , user_lock_(user_lock) 21 #endif 22 { 23 int rv = 0; 24 // http://crbug.com/293736 25 // NaCl doesn't support monotonic clock based absolute deadlines. 26 // On older Android platform versions, it's supported through the 27 // non-standard pthread_cond_timedwait_monotonic_np. Newer platform 28 // versions have pthread_condattr_setclock. 29 // Mac can use relative time deadlines. 30 #if !defined(OS_MACOSX) && !defined(OS_NACL) && \ 31 !(defined(OS_ANDROID) && defined(HAVE_PTHREAD_COND_TIMEDWAIT_MONOTONIC)) 32 pthread_condattr_t attrs; 33 rv = pthread_condattr_init(&attrs); 34 DCHECK_EQ(0, rv); 35 pthread_condattr_setclock(&attrs, CLOCK_MONOTONIC); 36 rv = pthread_cond_init(&condition_, &attrs); 37 pthread_condattr_destroy(&attrs); 38 #else 39 rv = pthread_cond_init(&condition_, NULL); 40 #endif 41 DCHECK_EQ(0, rv); 42 } 43 44 ConditionVariable::~ConditionVariable() { 45 int rv = pthread_cond_destroy(&condition_); 46 DCHECK_EQ(0, rv); 47 } 48 49 void ConditionVariable::Wait() { 50 base::ThreadRestrictions::AssertWaitAllowed(); 51 #if !defined(NDEBUG) || defined(DCHECK_ALWAYS_ON) 52 user_lock_->CheckHeldAndUnmark(); 53 #endif 54 int rv = pthread_cond_wait(&condition_, user_mutex_); 55 DCHECK_EQ(0, rv); 56 #if !defined(NDEBUG) || defined(DCHECK_ALWAYS_ON) 57 user_lock_->CheckUnheldAndMark(); 58 #endif 59 } 60 61 void ConditionVariable::TimedWait(const TimeDelta& max_time) { 62 base::ThreadRestrictions::AssertWaitAllowed(); 63 int64 usecs = max_time.InMicroseconds(); 64 struct timespec relative_time; 65 relative_time.tv_sec = usecs / Time::kMicrosecondsPerSecond; 66 relative_time.tv_nsec = 67 (usecs % Time::kMicrosecondsPerSecond) * Time::kNanosecondsPerMicrosecond; 68 69 #if !defined(NDEBUG) || defined(DCHECK_ALWAYS_ON) 70 user_lock_->CheckHeldAndUnmark(); 71 #endif 72 73 #if defined(OS_MACOSX) 74 int rv = pthread_cond_timedwait_relative_np( 75 &condition_, user_mutex_, &relative_time); 76 #else 77 // The timeout argument to pthread_cond_timedwait is in absolute time. 78 struct timespec absolute_time; 79 #if defined(OS_NACL) 80 // See comment in constructor for why this is different in NaCl. 81 struct timeval now; 82 gettimeofday(&now, NULL); 83 absolute_time.tv_sec = now.tv_sec; 84 absolute_time.tv_nsec = now.tv_usec * Time::kNanosecondsPerMicrosecond; 85 #else 86 struct timespec now; 87 clock_gettime(CLOCK_MONOTONIC, &now); 88 absolute_time.tv_sec = now.tv_sec; 89 absolute_time.tv_nsec = now.tv_nsec; 90 #endif 91 92 absolute_time.tv_sec += relative_time.tv_sec; 93 absolute_time.tv_nsec += relative_time.tv_nsec; 94 absolute_time.tv_sec += absolute_time.tv_nsec / Time::kNanosecondsPerSecond; 95 absolute_time.tv_nsec %= Time::kNanosecondsPerSecond; 96 DCHECK_GE(absolute_time.tv_sec, now.tv_sec); // Overflow paranoia 97 98 #if defined(OS_ANDROID) && defined(HAVE_PTHREAD_COND_TIMEDWAIT_MONOTONIC) 99 int rv = pthread_cond_timedwait_monotonic_np( 100 &condition_, user_mutex_, &absolute_time); 101 #else 102 int rv = pthread_cond_timedwait(&condition_, user_mutex_, &absolute_time); 103 #endif // OS_ANDROID && HAVE_PTHREAD_COND_TIMEDWAIT_MONOTONIC 104 #endif // OS_MACOSX 105 106 DCHECK(rv == 0 || rv == ETIMEDOUT); 107 #if !defined(NDEBUG) || defined(DCHECK_ALWAYS_ON) 108 user_lock_->CheckUnheldAndMark(); 109 #endif 110 } 111 112 void ConditionVariable::Broadcast() { 113 int rv = pthread_cond_broadcast(&condition_); 114 DCHECK_EQ(0, rv); 115 } 116 117 void ConditionVariable::Signal() { 118 int rv = pthread_cond_signal(&condition_); 119 DCHECK_EQ(0, rv); 120 } 121 122 } // namespace base 123
