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 <stdint.h>
#include <assert.h>
#include "ClearKeyUtils.h"
#if defined(_MSC_VER)
#include <atomic>
typedef std::atomic<uint32_t> AtomicRefCount;
#else
class AtomicRefCount {
public:
explicit AtomicRefCount(uint32_t aValue)
: mCount(aValue)
, mMutex(GMPCreateMutex())
{
assert(mMutex);
}
~AtomicRefCount()
{
if (mMutex) {
mMutex->Destroy();
}
}
uint32_t operator--() {
AutoLock lock(mMutex);
return --mCount;
}
uint32_t operator++() {
AutoLock lock(mMutex);
return ++mCount;
}
operator uint32_t() {
AutoLock lock(mMutex);
return mCount;
}
private:
uint32_t mCount;
GMPMutex* mMutex;
};
#endif
// 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);
}
AtomicRefCount mRefCount;
};
template<class T>
class RefPtr {
public:
explicit RefPtr(T* aPtr) : mPtr(nullptr) {
Assign(aPtr);
}
~RefPtr() {
Assign(nullptr);
}
T* operator->() const { return mPtr; }
RefPtr& operator=(T* aVal) {
Assign(aVal);
return *this;
}
private:
void Assign(T* aPtr) {
if (mPtr) {
mPtr->Release();
}
mPtr = aPtr;
if (mPtr) {
aPtr->AddRef();
}
}
T* mPtr;
};
#endif // __RefCount_h__