LockedResource.hpp

/*
 *
 * LockedResource
 * ledger-core
 *
 * Created by Pierre Pollastri on 21/11/2016.
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2016 Ledger
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 */
#ifndef LEDGER_CORE_LOCKEDRESOURCE_HPP
#define LEDGER_CORE_LOCKEDRESOURCE_HPP

#include <memory>
#include "../api/Lock.hpp"

namespace ledger {
    namespace core {
        template <typename T>
        class LockedResource {
            public:
                LockedResource(std::shared_ptr<api::Lock> lock, T resource) : _lock(lock), _resource(resource) {
                    _isLocked = false;
                }

                T* operator->() {
                    lock();
                    return &_resource;
                }

                void lock() {
                    if (!_isLocked) {
                        _isLocked = true;
                        _lock->lock();
                    }
                }

                void swap(T value) {
                    lock();
                    _resource = value;
                    unlock();
                }

                void unlock() {
                    if (_isLocked) {
                        _isLocked = false;
                        _lock->unlock();
                    }
                }

                ~LockedResource() {
                    unlock();
                }

        private:
                std::shared_ptr<api::Lock> _lock;
                T _resource;
                bool _isLocked;
        };
    }
}


#endif //LEDGER_CORE_LOCKEDRESOURCE_HPP