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