gecko-dev/gfx/layers/AtomicRefCountedWithFinalize.h

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/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef MOZILLA_ATOMICREFCOUNTEDWITHFINALIZE_H_
#define MOZILLA_ATOMICREFCOUNTEDWITHFINALIZE_H_
#include "mozilla/RefPtr.h"
#include "mozilla/Likely.h"
#include "MainThreadUtils.h"
#include "base/message_loop.h"
#include "base/task.h"
#include "mozilla/gfx/Logging.h"
#define ADDREF_MANUALLY(obj) (obj)->AddRefManually(__FUNCTION__, __FILE__, __LINE__)
#define RELEASE_MANUALLY(obj) (obj)->ReleaseManually(__FUNCTION__, __FILE__, __LINE__)
namespace mozilla {
template<class U>
class StaticRefPtr;
namespace gl {
template<typename T>
class RefSet;
template<typename T>
class RefQueue;
} // namespace gl
template<typename T>
class AtomicRefCountedWithFinalize
{
protected:
AtomicRefCountedWithFinalize()
: mRecycleCallback(nullptr)
, mRefCount(0)
, mMessageLoopToPostDestructionTo(nullptr)
#ifdef DEBUG
, mSpew(false)
, mManualAddRefs(0)
, mManualReleases(0)
#endif
{}
~AtomicRefCountedWithFinalize() {
if (mRefCount >= 0) {
gfxCriticalError() << "Deleting referenced object? " << mRefCount;
}
}
void SetMessageLoopToPostDestructionTo(MessageLoop* l) {
MOZ_ASSERT(NS_IsMainThread());
mMessageLoopToPostDestructionTo = l;
}
static void DestroyToBeCalledOnMainThread(T* ptr) {
MOZ_ASSERT(NS_IsMainThread());
delete ptr;
}
public:
// Mark user classes that are considered flawless.
template<class U>
friend class ::mozilla::StaticRefPtr;
template<class U>
friend class ::RefPtr;
template<class U>
friend struct ::RunnableMethodTraits;
template<typename U>
friend class ::mozilla::gl::RefSet;
template<typename U>
friend class ::mozilla::gl::RefQueue;
//friend class mozilla::gl::SurfaceFactory;
void AddRefManually(const char* funcName, const char* fileName, uint32_t lineNum) {
#ifdef DEBUG
uint32_t count = ++mManualAddRefs;
if (mSpew) {
printf_stderr("AddRefManually() #%u in %s at %s:%u\n", count, funcName,
fileName, lineNum);
}
#else
(void)funcName;
(void)fileName;
(void)lineNum;
#endif
AddRef();
}
void ReleaseManually(const char* funcName, const char* fileName, uint32_t lineNum) {
#ifdef DEBUG
uint32_t count = ++mManualReleases;
if (mSpew) {
printf_stderr("ReleaseManually() #%u in %s at %s:%u\n", count, funcName,
fileName, lineNum);
}
#else
(void)funcName;
(void)fileName;
(void)lineNum;
#endif
Release();
}
private:
void AddRef() {
MOZ_ASSERT(mRefCount >= 0, "AddRef() during/after Finalize()/dtor.");
++mRefCount;
}
void Release() {
MOZ_ASSERT(mRefCount > 0, "Release() during/after Finalize()/dtor.");
// Read mRecycleCallback early so that it does not get set to
// deleted memory, if the object is goes away. See bug 994903.
// This saves us in the case where there is no callback, so that
// we can do the "else if" below.
RecycleCallback recycleCallback = mRecycleCallback;
int currCount = --mRefCount;
if (currCount < 0) {
gfxCriticalError() << "Invalid reference count release" << currCount;
++mRefCount;
return;
}
if (0 == currCount) {
mRefCount = detail::DEAD;
MOZ_ASSERT(IsDead());
// Recycle listeners must call ClearRecycleCallback
// before releasing their strong reference.
if (mRecycleCallback) {
gfxCriticalError() << "About to release with valid callback";
mRecycleCallback = nullptr;
}
MOZ_ASSERT(mManualAddRefs == mManualReleases);
T* derived = static_cast<T*>(this);
derived->Finalize();
if (MOZ_LIKELY(!mMessageLoopToPostDestructionTo)) {
delete derived;
} else {
if (MOZ_LIKELY(NS_IsMainThread())) {
delete derived;
} else {
mMessageLoopToPostDestructionTo->PostTask(
FROM_HERE,
NewRunnableFunction(&DestroyToBeCalledOnMainThread, derived));
}
}
} else if (1 == currCount && recycleCallback) {
// There is nothing enforcing this in the code, except how the callers
// are being careful to never let the reference count go down if there
// is a callback.
MOZ_ASSERT(!IsDead());
T* derived = static_cast<T*>(this);
recycleCallback(derived, mClosure);
}
}
public:
typedef void (*RecycleCallback)(T* aObject, void* aClosure);
/**
* Set a callback responsible for recycling this object
* before it is finalized.
*/
void SetRecycleCallback(RecycleCallback aCallback, void* aClosure)
{
MOZ_ASSERT(!IsDead());
mRecycleCallback = aCallback;
mClosure = aClosure;
}
void ClearRecycleCallback()
{
MOZ_ASSERT(!IsDead());
SetRecycleCallback(nullptr, nullptr);
}
bool HasRecycleCallback() const
{
MOZ_ASSERT(!IsDead());
return !!mRecycleCallback;
}
bool IsDead() const
{
return mRefCount < 0;
}
private:
RecycleCallback mRecycleCallback;
void *mClosure;
Atomic<int> mRefCount;
MessageLoop *mMessageLoopToPostDestructionTo;
#ifdef DEBUG
public:
bool mSpew;
private:
Atomic<uint32_t> mManualAddRefs;
Atomic<uint32_t> mManualReleases;
#endif
};
} // namespace mozilla
#endif