mirror of
https://github.com/SerenityOS/serenity
synced 2024-07-21 18:15:58 +00:00
5d180d1f99
(...and ASSERT_NOT_REACHED => VERIFY_NOT_REACHED) Since all of these checks are done in release builds as well, let's rename them to VERIFY to prevent confusion, as everyone is used to assertions being compiled out in release. We can introduce a new ASSERT macro that is specifically for debug checks, but I'm doing this wholesale conversion first since we've accumulated thousands of these already, and it's not immediately obvious which ones are suitable for ASSERT.
131 lines
4.1 KiB
C++
131 lines
4.1 KiB
C++
/*
|
|
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions are met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright notice, this
|
|
* list of conditions and the following disclaimer.
|
|
*
|
|
* 2. Redistributions in binary form must reproduce the above copyright notice,
|
|
* this list of conditions and the following disclaimer in the documentation
|
|
* and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
|
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
|
|
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
|
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
|
|
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <AK/Assertions.h>
|
|
#include <AK/Atomic.h>
|
|
#include <AK/Checked.h>
|
|
#include <AK/Noncopyable.h>
|
|
#include <AK/Platform.h>
|
|
#include <AK/StdLibExtras.h>
|
|
|
|
namespace AK {
|
|
|
|
template<class T>
|
|
constexpr auto call_will_be_destroyed_if_present(const T* object) -> decltype(const_cast<T*>(object)->will_be_destroyed(), TrueType {})
|
|
{
|
|
const_cast<T*>(object)->will_be_destroyed();
|
|
return {};
|
|
}
|
|
|
|
constexpr auto call_will_be_destroyed_if_present(...) -> FalseType
|
|
{
|
|
return {};
|
|
}
|
|
|
|
template<class T>
|
|
constexpr auto call_one_ref_left_if_present(const T* object) -> decltype(const_cast<T*>(object)->one_ref_left(), TrueType {})
|
|
{
|
|
const_cast<T*>(object)->one_ref_left();
|
|
return {};
|
|
}
|
|
|
|
constexpr auto call_one_ref_left_if_present(...) -> FalseType
|
|
{
|
|
return {};
|
|
}
|
|
|
|
class RefCountedBase {
|
|
AK_MAKE_NONCOPYABLE(RefCountedBase);
|
|
AK_MAKE_NONMOVABLE(RefCountedBase);
|
|
|
|
public:
|
|
using RefCountType = unsigned int;
|
|
using AllowOwnPtr = FalseType;
|
|
|
|
ALWAYS_INLINE void ref() const
|
|
{
|
|
auto old_ref_count = m_ref_count.fetch_add(1, AK::MemoryOrder::memory_order_relaxed);
|
|
VERIFY(old_ref_count > 0);
|
|
VERIFY(!Checked<RefCountType>::addition_would_overflow(old_ref_count, 1));
|
|
}
|
|
|
|
[[nodiscard]] ALWAYS_INLINE bool try_ref() const
|
|
{
|
|
RefCountType expected = m_ref_count.load(AK::MemoryOrder::memory_order_relaxed);
|
|
for (;;) {
|
|
if (expected == 0)
|
|
return false;
|
|
VERIFY(!Checked<RefCountType>::addition_would_overflow(expected, 1));
|
|
if (m_ref_count.compare_exchange_strong(expected, expected + 1, AK::MemoryOrder::memory_order_acquire))
|
|
return true;
|
|
}
|
|
}
|
|
|
|
ALWAYS_INLINE RefCountType ref_count() const
|
|
{
|
|
return m_ref_count.load(AK::MemoryOrder::memory_order_relaxed);
|
|
}
|
|
|
|
protected:
|
|
RefCountedBase() = default;
|
|
ALWAYS_INLINE ~RefCountedBase()
|
|
{
|
|
VERIFY(m_ref_count.load(AK::MemoryOrder::memory_order_relaxed) == 0);
|
|
}
|
|
|
|
ALWAYS_INLINE RefCountType deref_base() const
|
|
{
|
|
auto old_ref_count = m_ref_count.fetch_sub(1, AK::MemoryOrder::memory_order_acq_rel);
|
|
VERIFY(old_ref_count > 0);
|
|
return old_ref_count - 1;
|
|
}
|
|
|
|
mutable Atomic<RefCountType> m_ref_count { 1 };
|
|
};
|
|
|
|
template<typename T>
|
|
class RefCounted : public RefCountedBase {
|
|
public:
|
|
bool unref() const
|
|
{
|
|
auto new_ref_count = deref_base();
|
|
if (new_ref_count == 0) {
|
|
call_will_be_destroyed_if_present(static_cast<const T*>(this));
|
|
delete static_cast<const T*>(this);
|
|
return true;
|
|
} else if (new_ref_count == 1) {
|
|
call_one_ref_left_if_present(static_cast<const T*>(this));
|
|
}
|
|
return false;
|
|
}
|
|
};
|
|
|
|
}
|
|
|
|
using AK::RefCounted;
|