| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you 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 <memory> |
| |
| #include "arrow/util/macros.h" |
| #include "arrow/util/visibility.h" |
| |
| namespace arrow { |
| namespace util { |
| |
| /// A wrapper around std::mutex since we can't use it directly in |
| /// public headers due to C++/CLI. |
| /// https://docs.microsoft.com/en-us/cpp/standard-library/mutex#remarks |
| class ARROW_EXPORT Mutex { |
| public: |
| Mutex(); |
| Mutex(Mutex&&) = default; |
| Mutex& operator=(Mutex&&) = default; |
| |
| /// A Guard is falsy if a lock could not be acquired. |
| class ARROW_EXPORT Guard { |
| public: |
| Guard() : locked_(NULLPTR, [](Mutex* mutex) {}) {} |
| Guard(Guard&&) = default; |
| Guard& operator=(Guard&&) = default; |
| |
| explicit operator bool() const { return bool(locked_); } |
| |
| void Unlock() { locked_.reset(); } |
| |
| private: |
| explicit Guard(Mutex* locked); |
| |
| std::unique_ptr<Mutex, void (*)(Mutex*)> locked_; |
| friend Mutex; |
| }; |
| |
| Guard TryLock(); |
| Guard Lock(); |
| |
| private: |
| struct Impl; |
| std::unique_ptr<Impl, void (*)(Impl*)> impl_; |
| }; |
| |
| } // namespace util |
| } // namespace arrow |