/*************************************************************************/ /* mutex.h */ /*************************************************************************/ /* This file is part of: */ /* GODOT ENGINE */ /* https://godotengine.org */ /*************************************************************************/ /* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur. */ /* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md). */ /* */ /* 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 MUTEX_H #define MUTEX_H #include "core/error_list.h" #include "core/typedefs.h" #if !defined(NO_THREADS) #include <mutex> template <class StdMutexT> class MutexImpl { mutable StdMutexT mutex; friend class MutexLock; public: _ALWAYS_INLINE_ void lock() const { mutex.lock(); } _ALWAYS_INLINE_ void unlock() const { mutex.unlock(); } _ALWAYS_INLINE_ Error try_lock() const { return mutex.try_lock() ? OK : ERR_BUSY; } }; // This is written this way instead of being a template to overcome a limitation of C++ pre-17 // that would require MutexLock to be used like this: MutexLock<Mutex> lock; class MutexLock { union { std::recursive_mutex *recursive_mutex; std::mutex *mutex; }; bool recursive; public: _ALWAYS_INLINE_ explicit MutexLock(const MutexImpl<std::recursive_mutex> &p_mutex) : recursive_mutex(&p_mutex.mutex), recursive(true) { recursive_mutex->lock(); } _ALWAYS_INLINE_ explicit MutexLock(const MutexImpl<std::mutex> &p_mutex) : mutex(&p_mutex.mutex), recursive(false) { mutex->lock(); } _ALWAYS_INLINE_ ~MutexLock() { if (recursive) { recursive_mutex->unlock(); } else { mutex->unlock(); } } }; using Mutex = MutexImpl<std::recursive_mutex>; // Recursive, for general use using BinaryMutex = MutexImpl<std::mutex>; // Non-recursive, handle with care extern template class MutexImpl<std::recursive_mutex>; extern template class MutexImpl<std::mutex>; #else class FakeMutex { FakeMutex() {} }; template <class MutexT> class MutexImpl { public: _ALWAYS_INLINE_ void lock() const {} _ALWAYS_INLINE_ void unlock() const {} _ALWAYS_INLINE_ Error try_lock() const { return OK; } }; class MutexLock { public: explicit MutexLock(const MutexImpl<FakeMutex> &p_mutex) {} }; using Mutex = MutexImpl<FakeMutex>; using BinaryMutex = MutexImpl<FakeMutex>; // Non-recursive, handle with care #endif // !NO_THREADS #endif // MUTEX_H