godot/core/os/spin_lock.h

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/**************************************************************************/
/* spin_lock.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 SPIN_LOCK_H
#define SPIN_LOCK_H
#include "core/typedefs.h"
#if defined(__APPLE__)
#include <os/lock.h>
class SpinLock {
mutable os_unfair_lock _lock = OS_UNFAIR_LOCK_INIT;
public:
_ALWAYS_INLINE_ void lock() const {
os_unfair_lock_lock(&_lock);
}
_ALWAYS_INLINE_ void unlock() const {
os_unfair_lock_unlock(&_lock);
}
};
#else
#include <atomic>
class SpinLock {
mutable std::atomic_flag locked = ATOMIC_FLAG_INIT;
public:
_ALWAYS_INLINE_ void lock() const {
while (locked.test_and_set(std::memory_order_acquire)) {
// Continue.
}
}
_ALWAYS_INLINE_ void unlock() const {
locked.clear(std::memory_order_release);
}
};
#endif // __APPLE__
#endif // SPIN_LOCK_H