63 lines
1.8 KiB
C++
63 lines
1.8 KiB
C++
// © 2016 and later: Unicode, Inc. and others.
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// License & terms of use: http://www.unicode.org/copyright.html
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/*
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******************************************************************************
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* Copyright (C) 2015, International Business Machines
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* Corporation and others. All Rights Reserved.
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******************************************************************************
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* sharedobject.cpp
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*/
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#include "sharedobject.h"
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#include "mutex.h"
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#include "uassert.h"
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#include "umutex.h"
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#include "unifiedcache.h"
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U_NAMESPACE_BEGIN
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SharedObject::~SharedObject() {}
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UnifiedCacheBase::~UnifiedCacheBase() {}
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void
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SharedObject::addRef() const {
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umtx_atomic_inc(&hardRefCount);
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}
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// removeRef Decrement the reference count and delete if it is zero.
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// Note that SharedObjects with a non-null cachePtr are owned by the
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// unified cache, and the cache will be responsible for the actual deletion.
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// The deletion could be as soon as immediately following the
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// update to the reference count, if another thread is running
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// a cache eviction cycle concurrently.
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// NO ACCESS TO *this PERMITTED AFTER REFERENCE COUNT == 0 for cached objects.
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// THE OBJECT MAY ALREADY BE GONE.
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void
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SharedObject::removeRef() const {
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const UnifiedCacheBase *cache = this->cachePtr;
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int32_t updatedRefCount = umtx_atomic_dec(&hardRefCount);
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U_ASSERT(updatedRefCount >= 0);
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if (updatedRefCount == 0) {
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if (cache) {
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cache->handleUnreferencedObject();
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} else {
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delete this;
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}
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}
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}
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int32_t
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SharedObject::getRefCount() const {
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return umtx_loadAcquire(hardRefCount);
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}
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void
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SharedObject::deleteIfZeroRefCount() const {
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if (this->cachePtr == nullptr && getRefCount() == 0) {
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delete this;
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}
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}
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U_NAMESPACE_END
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