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// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/synchronization/lock_impl.h"
#include <errno.h>
#include "base/logging.h"
namespace base {
namespace internal {
LockImpl::LockImpl() {
#ifdef LOCK_IMPL_CHECK_LIVENESS
liveness_token_ = LT_ALIVE;
#endif
#ifndef NDEBUG
// In debug, setup attributes for lock error checking.
pthread_mutexattr_t mta;
int rv = pthread_mutexattr_init(&mta);
DCHECK_EQ(rv, 0);
rv = pthread_mutexattr_settype(&mta, PTHREAD_MUTEX_ERRORCHECK);
DCHECK_EQ(rv, 0);
rv = pthread_mutex_init(&os_lock_, &mta);
DCHECK_EQ(rv, 0);
rv = pthread_mutexattr_destroy(&mta);
DCHECK_EQ(rv, 0);
#else
// In release, go with the default lock attributes.
pthread_mutex_init(&os_lock_, NULL);
#endif
}
LockImpl::~LockImpl() {
#ifdef LOCK_IMPL_CHECK_LIVENESS
CheckIsAlive();
liveness_token_ = LT_DELETED;
#endif
int rv = pthread_mutex_destroy(&os_lock_);
DCHECK_EQ(rv, 0);
}
bool LockImpl::Try() {
#ifdef LOCK_IMPL_CHECK_LIVENESS
CheckIsAlive();
#endif
int rv = pthread_mutex_trylock(&os_lock_);
DCHECK(rv == 0 || rv == EBUSY);
return rv == 0;
}
void LockImpl::Lock() {
#ifdef LOCK_IMPL_CHECK_LIVENESS
CheckIsAlive();
#endif
int rv = pthread_mutex_lock(&os_lock_);
DCHECK_EQ(rv, 0);
}
void LockImpl::Unlock() {
#ifdef LOCK_IMPL_CHECK_LIVENESS
CheckIsAlive();
#endif
int rv = pthread_mutex_unlock(&os_lock_);
DCHECK_EQ(rv, 0);
}
#ifdef LOCK_IMPL_CHECK_LIVENESS
void LockImpl::CheckIsAlive() {
CHECK_EQ(LT_ALIVE, liveness_token_)
<< "Lock was invalid. Please see: http://crbug.com/102161";
}
#endif
} // namespace internal
} // namespace base
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