2020-01-18 11:38:21 +03:00
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/*
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* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
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*
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2021-04-22 11:24:48 +03:00
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* SPDX-License-Identifier: BSD-2-Clause
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2020-01-18 11:38:21 +03:00
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*/
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2018-10-10 12:53:07 +03:00
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#pragma once
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2020-02-09 17:50:13 +03:00
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#include <AK/Assertions.h>
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2020-06-12 16:38:24 +03:00
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#include <AK/Atomic.h>
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2020-06-12 16:44:17 +03:00
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#include <AK/Checked.h>
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2020-06-12 16:46:47 +03:00
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#include <AK/Noncopyable.h>
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2020-05-20 15:13:39 +03:00
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#include <AK/Platform.h>
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2020-02-09 17:50:13 +03:00
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#include <AK/StdLibExtras.h>
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2018-10-10 12:53:07 +03:00
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namespace AK {
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2018-12-20 00:28:09 +03:00
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template<class T>
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2020-12-06 05:47:20 +03:00
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constexpr auto call_will_be_destroyed_if_present(const T* object) -> decltype(const_cast<T*>(object)->will_be_destroyed(), TrueType {})
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2018-12-20 00:28:09 +03:00
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{
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2020-04-17 13:41:45 +03:00
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const_cast<T*>(object)->will_be_destroyed();
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2019-05-28 12:53:16 +03:00
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return {};
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2018-12-20 00:28:09 +03:00
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}
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constexpr auto call_will_be_destroyed_if_present(...) -> FalseType
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{
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2019-05-28 12:53:16 +03:00
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return {};
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2018-12-20 00:28:09 +03:00
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}
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2019-01-01 04:38:09 +03:00
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template<class T>
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2020-12-06 05:47:20 +03:00
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constexpr auto call_one_ref_left_if_present(const T* object) -> decltype(const_cast<T*>(object)->one_ref_left(), TrueType {})
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2019-01-01 04:38:09 +03:00
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{
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const_cast<T*>(object)->one_ref_left();
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2019-05-28 12:53:16 +03:00
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return {};
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2019-01-01 04:38:09 +03:00
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}
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2019-06-21 16:29:31 +03:00
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constexpr auto call_one_ref_left_if_present(...) -> FalseType
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2019-01-01 04:38:09 +03:00
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{
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2019-05-28 12:53:16 +03:00
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return {};
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2019-01-01 04:38:09 +03:00
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}
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2019-06-21 16:29:31 +03:00
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class RefCountedBase {
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2020-08-26 22:52:24 +03:00
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AK_MAKE_NONCOPYABLE(RefCountedBase);
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AK_MAKE_NONMOVABLE(RefCountedBase);
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2018-10-10 12:53:07 +03:00
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public:
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2020-11-12 01:21:01 +03:00
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using RefCountType = unsigned int;
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2020-11-03 17:51:56 +03:00
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using AllowOwnPtr = FalseType;
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2020-06-12 16:33:38 +03:00
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2021-05-29 17:04:58 +03:00
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void ref() const;
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[[nodiscard]] bool try_ref() const;
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[[nodiscard]] RefCountType ref_count() const;
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2018-10-10 12:53:07 +03:00
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protected:
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RefCountedBase() = default;
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~RefCountedBase();
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2018-10-10 12:53:07 +03:00
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2021-05-29 17:04:58 +03:00
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RefCountType deref_base() const;
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2019-03-16 15:48:56 +03:00
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2020-06-12 16:38:24 +03:00
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mutable Atomic<RefCountType> m_ref_count { 1 };
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2018-10-10 12:53:07 +03:00
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};
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2019-03-16 14:47:19 +03:00
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template<typename T>
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class RefCounted : public RefCountedBase {
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public:
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bool unref() const
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{
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2020-06-12 16:38:24 +03:00
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auto new_ref_count = deref_base();
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if (new_ref_count == 0) {
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2020-04-17 13:41:45 +03:00
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call_will_be_destroyed_if_present(static_cast<const T*>(this));
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delete static_cast<const T*>(this);
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2020-12-29 23:14:21 +03:00
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return true;
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2020-06-12 16:38:24 +03:00
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} else if (new_ref_count == 1) {
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call_one_ref_left_if_present(static_cast<const T*>(this));
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2019-03-16 14:47:19 +03:00
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}
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2020-12-29 23:14:21 +03:00
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return false;
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2019-03-16 14:47:19 +03:00
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}
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};
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2018-10-10 12:53:07 +03:00
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}
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2019-06-21 16:29:31 +03:00
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using AK::RefCounted;
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