1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/layers/AtomicRefCountedWithFinalize.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,73 @@
1.4 +/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
1.5 + * This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef MOZILLA_ATOMICREFCOUNTEDWITHFINALIZE_H_
1.10 +#define MOZILLA_ATOMICREFCOUNTEDWITHFINALIZE_H_
1.11 +
1.12 +#include "mozilla/RefPtr.h"
1.13 +#include "mozilla/NullPtr.h"
1.14 +
1.15 +namespace mozilla {
1.16 +
1.17 +template<typename T>
1.18 +class AtomicRefCountedWithFinalize
1.19 +{
1.20 + protected:
1.21 + AtomicRefCountedWithFinalize()
1.22 + : mRecycleCallback(nullptr)
1.23 + , mRefCount(0)
1.24 + {}
1.25 +
1.26 + ~AtomicRefCountedWithFinalize() {}
1.27 +
1.28 + public:
1.29 + void AddRef() {
1.30 + MOZ_ASSERT(mRefCount >= 0);
1.31 + ++mRefCount;
1.32 + }
1.33 +
1.34 + void Release() {
1.35 + MOZ_ASSERT(mRefCount > 0);
1.36 + // Read mRecycleCallback early so that it does not get set to
1.37 + // deleted memory, if the object is goes away.
1.38 + RecycleCallback recycleCallback = mRecycleCallback;
1.39 + int currCount = --mRefCount;
1.40 + if (0 == currCount) {
1.41 + // Recycle listeners must call ClearRecycleCallback
1.42 + // before releasing their strong reference.
1.43 + MOZ_ASSERT(mRecycleCallback == nullptr);
1.44 +#ifdef DEBUG
1.45 + mRefCount = detail::DEAD;
1.46 +#endif
1.47 + T* derived = static_cast<T*>(this);
1.48 + derived->Finalize();
1.49 + delete derived;
1.50 + } else if (1 == currCount && recycleCallback) {
1.51 + T* derived = static_cast<T*>(this);
1.52 + recycleCallback(derived, mClosure);
1.53 + }
1.54 + }
1.55 +
1.56 + typedef void (*RecycleCallback)(T* aObject, void* aClosure);
1.57 + /**
1.58 + * Set a callback responsible for recycling this object
1.59 + * before it is finalized.
1.60 + */
1.61 + void SetRecycleCallback(RecycleCallback aCallback, void* aClosure)
1.62 + {
1.63 + mRecycleCallback = aCallback;
1.64 + mClosure = aClosure;
1.65 + }
1.66 + void ClearRecycleCallback() { SetRecycleCallback(nullptr, nullptr); }
1.67 +
1.68 +private:
1.69 + RecycleCallback mRecycleCallback;
1.70 + void *mClosure;
1.71 + Atomic<int> mRefCount;
1.72 +};
1.73 +
1.74 +}
1.75 +
1.76 +#endif
