gecko-dev/media/gmp-clearkey/0.1/RefCounted.h

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/*
* Copyright 2015, Mozilla Foundation and contributors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef __RefCount_h__
#define __RefCount_h__
#include <assert.h>
#include <stdint.h>
#include <atomic>
#include "ClearKeyUtils.h"
// Note: Thread safe.
class RefCounted {
public:
void AddRef() { ++mRefCount; }
uint32_t Release() {
uint32_t newCount = --mRefCount;
if (!newCount) {
delete this;
}
return newCount;
}
protected:
RefCounted() : mRefCount(0) {}
virtual ~RefCounted() { assert(!mRefCount); }
std::atomic<uint32_t> mRefCount;
};
template <class T>
class RefPtr {
public:
RefPtr(const RefPtr& src) { Set(src.mPtr); }
explicit RefPtr(T* aPtr) { Set(aPtr); }
RefPtr() { Set(nullptr); }
~RefPtr() { Set(nullptr); }
T* operator->() const { return mPtr; }
T** operator&() { return &mPtr; }
T* operator->() { return mPtr; }
operator T*() { return mPtr; }
T* Get() const { return mPtr; }
RefPtr& operator=(T* aVal) {
Set(aVal);
return *this;
}
private:
T* Set(T* aPtr) {
if (mPtr == aPtr) {
return aPtr;
}
if (mPtr) {
mPtr->Release();
}
mPtr = aPtr;
if (mPtr) {
aPtr->AddRef();
}
return mPtr;
}
T* mPtr = nullptr;
};
#endif // __RefCount_h__