/*************************************************************************/ /* rw_lock.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 RW_LOCK_H #define RW_LOCK_H #include "core/error/error_list.h" #if !defined(NO_THREADS) #include <shared_mutex> class RWLock { mutable std::shared_timed_mutex mutex; public: // Lock the rwlock, block if locked by someone else void read_lock() const { mutex.lock_shared(); } // Unlock the rwlock, let other threads continue void read_unlock() const { mutex.unlock_shared(); } // Attempt to lock the rwlock, OK on success, ERR_BUSY means it can't lock. Error read_try_lock() const { return mutex.try_lock_shared() ? OK : ERR_BUSY; } // Lock the rwlock, block if locked by someone else void write_lock() { mutex.lock(); } // Unlock the rwlock, let other thwrites continue void write_unlock() { mutex.unlock(); } // Attempt to lock the rwlock, OK on success, ERR_BUSY means it can't lock. Error write_try_lock() { return mutex.try_lock() ? OK : ERR_BUSY; } }; #else class RWLock { public: void read_lock() const {} void read_unlock() const {} Error read_try_lock() const { return OK; } void write_lock() {} void write_unlock() {} Error write_try_lock() { return OK; } }; #endif class RWLockRead { const RWLock &lock; public: RWLockRead(const RWLock &p_lock) : lock(p_lock) { lock.read_lock(); } ~RWLockRead() { lock.read_unlock(); } }; class RWLockWrite { RWLock &lock; public: RWLockWrite(RWLock &p_lock) : lock(p_lock) { lock.write_lock(); } ~RWLockWrite() { lock.write_unlock(); } }; #endif // RW_LOCK_H