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/*
* Copyright (C) 2007, 2008, 2010, 2013, 2014 Apple Inc. All rights reserved.
* Copyright (C) 2007 Justin Haygood (jhaygood@reaktix.com)
*
* 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 APPLE INC. AND ITS 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 APPLE INC. OR ITS 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 <wtf/ThreadSafeRefCounted.h>
namespace WTF {
// FIXME: Safer CPP Checking cannot perform analysis globally, and it does not work well
// with some of lifetime model, in particular JSC::VM which is retained before entering
// JSC world. This class is introduced to suppress these warnings since it does not use
// ref / deref functions. Except for the function names, implementation is the copy of
// ThreadSafeRefCounted. We would like to drop this class once Safer CPP Checking supports
// suppression mechanism for the classes which cannot be handled well with the checker, or
// the checker introduces a solution which works well with JSC::VM.
class WTF_EMPTY_BASE_CLASS ThreadSafeRefCountedWithSuppressingSaferCPPCheckingBase : public RefCountDebugger {
WTF_MAKE_NONCOPYABLE(ThreadSafeRefCountedWithSuppressingSaferCPPCheckingBase);
WTF_DEPRECATED_MAKE_FAST_ALLOCATED(ThreadSafeRefCountedWithSuppressingSaferCPPCheckingBase);
public:
void refSuppressingSaferCPPChecking() const
{
willRef(m_refCount, RefCountIsThreadSafe::Yes);
++m_refCount;
}
bool hasOneRef() const { return m_refCount == 1; }
unsigned refCount() const { return m_refCount; }
protected:
ThreadSafeRefCountedWithSuppressingSaferCPPCheckingBase()
{
// FIXME: Lots of subclasses violate our adoption requirements. Migrate
// this call into only those subclasses that need it.
relaxAdoptionRequirement();
}
~ThreadSafeRefCountedWithSuppressingSaferCPPCheckingBase()
{
willDestroy(m_refCount);
// FIXME: Test performance, then change this to RELEASE_ASSERT.
ASSERT(m_refCount == 1);
}
// Returns true if the pointer should be freed.
bool derefBase() const
{
willDeref(m_refCount, RefCountIsThreadSafe::Yes);
if (!--m_refCount) [[unlikely]] {
willDelete();
m_refCount = 1;
return true;
}
return false;
}
private:
mutable std::atomic<unsigned> m_refCount { 1 };
};
template<class T, DestructionThread destructionThread = DestructionThread::Any> class ThreadSafeRefCountedWithSuppressingSaferCPPChecking : public ThreadSafeRefCountedWithSuppressingSaferCPPCheckingBase {
public:
ThreadSafeRefCountedWithSuppressingSaferCPPChecking() = default;
void derefSuppressingSaferCPPChecking() const
{
if (!derefBase())
return;
if constexpr (destructionThread == DestructionThread::Any) {
delete static_cast<const T*>(this);
} else if constexpr (destructionThread == DestructionThread::Main) {
ensureOnMainThread([this] {
delete static_cast<const T*>(this);
});
} else if constexpr (destructionThread == DestructionThread::MainRunLoop) {
ensureOnMainRunLoop([this] {
delete static_cast<const T*>(this);
});
} else
STATIC_ASSERT_NOT_REACHED_FOR_VALUE(destructionThread, "Unexpected destructionThread enumerator value");
}
} SWIFT_RETURNED_AS_UNRETAINED_BY_DEFAULT;
} // namespace WTF
using WTF::ThreadSafeRefCountedWithSuppressingSaferCPPChecking;
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