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/**************************************************************************/
/* object_rc.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 OBJECT_RC_H
#define OBJECT_RC_H
#include "core/os/memory.h"
#include "core/typedefs.h"
#include <atomic>
class Object;
// Used to track Variants pointing to a non-Reference Object
class ObjectRC {
std::atomic<Object *> _ptr;
std::atomic<uint32_t> _users;
public:
// This is for allowing debug builds to check for instance ID validity,
// so warnings are shown in debug builds when a stray Variant (one pointing
// to a released Object) would have happened.
const ObjectID instance_id;
_FORCE_INLINE_ void increment() {
_users.fetch_add(1, std::memory_order_relaxed);
}
_FORCE_INLINE_ bool decrement() {
return _users.fetch_sub(1, std::memory_order_relaxed) == 1;
}
_FORCE_INLINE_ bool invalidate() {
_ptr.store(nullptr, std::memory_order_release);
return decrement();
}
_FORCE_INLINE_ Object *get_ptr() {
return _ptr.load(std::memory_order_acquire);
}
_FORCE_INLINE_ ObjectRC(Object *p_object) :
instance_id(p_object->get_instance_id()) {
// 1 (the Object) + 1 (the first user)
_users.store(2, std::memory_order_relaxed);
_ptr.store(p_object, std::memory_order_release);
}
};
#endif // OBJECT_RC_H
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