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/*
* Copyright (C) 2019 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
#include <pthread.h>
// As of the end of Dec 2019, std::shared_mutex is *not* simply a pthread_rwlock, but rather a
// combination of std::mutex and std::condition variable, which is obviously less efficient. This
// immitates what std::shared_mutex should be doing and is compatible with std::shared_lock and
// std::unique_lock.
class RwLock {
public:
RwLock() {}
~RwLock() {}
void lock() { pthread_rwlock_wrlock(&rwlock_); }
void unlock() { pthread_rwlock_unlock(&rwlock_); }
void lock_shared() { pthread_rwlock_rdlock(&rwlock_); }
void unlock_shared() { pthread_rwlock_unlock(&rwlock_); }
private:
pthread_rwlock_t rwlock_ = PTHREAD_RWLOCK_INITIALIZER;
};
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