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120 | /**************************************************************************/
/* mutex.h */
/**************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/**************************************************************************/
/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
/* */
/* 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 {<--- The one definition rule is violated, different classes/structs have the same name '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 {<--- The one definition rule is violated, different classes/structs have the same name '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
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