142 lines
2.5 KiB
C++
142 lines
2.5 KiB
C++
/*
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* Copyright 2015, Mozilla Foundation and contributors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifndef __RefCount_h__
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#define __RefCount_h__
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#include <stdint.h>
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#include <assert.h>
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extern GMPPlatformAPI* g_platform_api;
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inline GMPMutex* GMPCreateMutex() {
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GMPMutex* mutex;
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if (!g_platform_api) {
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return nullptr;
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}
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GMPErr err = g_platform_api->createmutex(&mutex);
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assert(mutex);
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return GMP_FAILED(err) ? nullptr : mutex;
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}
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class AutoLock {
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public:
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explicit AutoLock(GMPMutex* aMutex)
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: mMutex(aMutex)
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{
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assert(aMutex);
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if (mMutex) {
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mMutex->Acquire();
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}
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}
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~AutoLock() {
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if (mMutex) {
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mMutex->Release();
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}
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}
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private:
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GMPMutex* mMutex;
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};
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class AtomicRefCount {
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public:
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explicit AtomicRefCount(uint32_t aValue)
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: mCount(aValue)
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, mMutex(GMPCreateMutex())
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{
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assert(mMutex);
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}
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~AtomicRefCount()
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{
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if (mMutex) {
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mMutex->Destroy();
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}
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}
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uint32_t operator--() {
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AutoLock lock(mMutex);
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return --mCount;
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}
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uint32_t operator++() {
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AutoLock lock(mMutex);
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return ++mCount;
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}
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operator uint32_t() {
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AutoLock lock(mMutex);
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return mCount;
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}
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private:
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uint32_t mCount;
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GMPMutex* mMutex;
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};
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// Note: Thread safe.
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class RefCounted {
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public:
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void AddRef() {
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++mRefCount;
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}
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uint32_t Release() {
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uint32_t newCount = --mRefCount;
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if (!newCount) {
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delete this;
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}
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return newCount;
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}
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protected:
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RefCounted()
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: mRefCount(0)
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{
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}
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virtual ~RefCounted()
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{
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assert(!mRefCount);
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}
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AtomicRefCount mRefCount;
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};
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template<class T>
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class RefPtr {
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public:
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explicit RefPtr(T* aPtr) : mPtr(nullptr) {
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Assign(aPtr);
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}
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~RefPtr() {
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Assign(nullptr);
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}
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T* operator->() const { return mPtr; }
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RefPtr& operator=(T* aVal) {
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Assign(aVal);
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return *this;
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}
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private:
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void Assign(T* aPtr) {
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if (mPtr) {
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mPtr->Release();
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}
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mPtr = aPtr;
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if (mPtr) {
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aPtr->AddRef();
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}
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}
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T* mPtr;
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};
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#endif // __RefCount_h__
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