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Diffstat (limited to 'src/components/include/utils/mutable_data_accessor.h')
-rw-r--r-- | src/components/include/utils/mutable_data_accessor.h | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/src/components/include/utils/mutable_data_accessor.h b/src/components/include/utils/mutable_data_accessor.h new file mode 100644 index 0000000000..0e03345a45 --- /dev/null +++ b/src/components/include/utils/mutable_data_accessor.h @@ -0,0 +1,78 @@ +/* + * 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 |