godot/core/object_rc.h
Pedro J. Estébanez 26edc6cd41 Promote object validity checks to release builds
Extra:
- Optimized the debug-only check about why the object is null to determine if it's because it has been deleted (the RC is enough; no need to check the ObjectDB).
- Because of the previous point. the debugger being attached is not required anymore for giving the "Object was deleted" error; from now, it only matters that it's a debug build.
- `is_instance_valid()` is now trustworthy. It will return `true` if, and only if, the last object assigned to a `Variant` is still alive (and not if a new object happened to be created at the same memory address of the old one).
- Replacements of `instance_validate()` are used where possible `Variant::is_invalid_object()` is introduced to help with that. (GDScript's `is_instance_valid()` is good.)
2021-09-21 10:39:04 +02:00

78 lines
3.3 KiB
C++

/*************************************************************************/
/* object_rc.h */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md). */
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#ifndef OBJECTRC_H
#define OBJECTRC_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