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/*
* Copyright (c) 2020, Ford Motor Company
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following
* disclaimer in the documentation and/or other materials provided with the
* distribution.
*
* Neither the name of the Ford Motor Company nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef SRC_COMPONENTS_INCLUDE_UTILS_MUTABLE_DATA_ACCESSOR_H
#define SRC_COMPONENTS_INCLUDE_UTILS_MUTABLE_DATA_ACCESSOR_H
#include "utils/lock.h"
// This class is for thread-safe mutable access to data
template <class T>
class MutableDataAccessor {
public:
MutableDataAccessor(T& data,
const std::shared_ptr<sync_primitives::BaseLock>& lock)
: data_(data), lock_(lock), counter_(new uint32_t(0)) {
lock_->Acquire();
}
MutableDataAccessor(const MutableDataAccessor<T>& other)
: data_(other.data_), lock_(other.lock_), counter_(other.counter_) {
++(*counter_);
}
~MutableDataAccessor() {
if (0 == *counter_) {
lock_->Release();
} else {
--(*counter_);
}
}
const T& GetData() const {
return data_;
}
T& GetMutableData() {
return data_;
}
private:
void* operator new(size_t size);
T& data_;
// Require that the lock lives at least as long as the DataAccessor
const std::shared_ptr<sync_primitives::BaseLock> lock_;
std::shared_ptr<uint32_t> counter_;
};
#endif // SRC_COMPONENTS_INCLUDE_UTILS_MUTABLE_DATA_ACCESSOR_H
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