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// **********************************************************************
//
// Copyright (c) 2003-2009 ZeroC, Inc. All rights reserved.
//
// This copy of Ice is licensed to you under the terms described in the
// ICE_LICENSE file included in this distribution.
//
// **********************************************************************
#ifndef FREEZE_BACKGROUND_SAVE_EVICTOR_I_H
#define FREEZE_BACKGROUND_SAVE_EVICTOR_I_H
#include <Freeze/EvictorI.h>
#include <Freeze/BackgroundSaveEvictor.h>
namespace Freeze
{
#if defined(_MSC_VER) && (_MSC_VER <= 1200) || defined(__IBMCPP__)
enum
{
clean = 0,
created = 1,
modified = 2,
destroyed = 3,
dead = 4
};
#else
//
// Clean object; can become modified or destroyed
//
static const Ice::Byte clean = 0;
//
// New object; can become clean, dead or destroyed
//
static const Ice::Byte created = 1;
//
// Modified object; can become clean or destroyed
//
static const Ice::Byte modified = 2;
//
// Being saved. Can become dead or created
//
static const Ice::Byte destroyed = 3;
//
// Exists only in the Evictor; for example the object was created
// and later destroyed (without a save in between), or it was
// destroyed on disk but is still in use. Can become created.
//
static const Ice::Byte dead = 4;
#endif
class BackgroundSaveEvictorI;
//
// The WatchDogThread is used by the saving thread to ensure the
// streaming of some object does not take more than timeout ms.
// We only measure the time necessary to acquire the lock on the
// object (servant), not the streaming itself.
//
class WatchDogThread : public IceUtil::Thread, private IceUtil::Monitor<IceUtil::Mutex>
{
public:
WatchDogThread(long, BackgroundSaveEvictorI&);
void run();
void activate();
void deactivate();
void terminate();
private:
const IceUtil::Time _timeout;
BackgroundSaveEvictorI& _evictor;
bool _done;
bool _active;
};
typedef IceUtil::Handle<WatchDogThread> WatchDogThreadPtr;
struct BackgroundSaveEvictorElement;
typedef IceUtil::Handle<BackgroundSaveEvictorElement> BackgroundSaveEvictorElementPtr;
struct BackgroundSaveEvictorElement : public Ice::LocalObject
{
BackgroundSaveEvictorElement(ObjectRecord&, ObjectStore<BackgroundSaveEvictorElement>&);
BackgroundSaveEvictorElement(ObjectStore<BackgroundSaveEvictorElement>&);
~BackgroundSaveEvictorElement();
void init(ObjectStore<BackgroundSaveEvictorElement>::Position);
//
// Immutable
//
ObjectStore<BackgroundSaveEvictorElement>& store;
//
// Immutable once set
//
ObjectStore<BackgroundSaveEvictorElement>::Position cachePosition;
//
// Protected by EvictorI
//
std::list<BackgroundSaveEvictorElementPtr>::iterator evictPosition;
int usageCount;
int keepCount;
bool stale;
//
// Protected by mutex
//
IceUtil::Mutex mutex;
ObjectRecord rec;
Ice::Byte status;
};
class BackgroundSaveEvictorI : public BackgroundSaveEvictor, public EvictorI<BackgroundSaveEvictorElement>,
public IceUtil::Thread
{
public:
BackgroundSaveEvictorI(const Ice::ObjectAdapterPtr&, const std::string&, DbEnv*, const std::string&,
const ServantInitializerPtr&, const std::vector<IndexPtr>&, bool);
virtual Ice::ObjectPrx addFacet(const Ice::ObjectPtr&, const Ice::Identity&, const std::string&);
virtual Ice::ObjectPtr removeFacet(const Ice::Identity&, const std::string&);
virtual void keep(const Ice::Identity&);
virtual void keepFacet(const Ice::Identity&, const std::string&);
virtual void release(const Ice::Identity&);
virtual void releaseFacet(const Ice::Identity&, const std::string&);
virtual bool hasFacet(const Ice::Identity&, const std::string&);
virtual void finished(const Ice::Current&, const Ice::ObjectPtr&, const Ice::LocalObjectPtr&);
virtual void deactivate(const std::string&);
virtual ~BackgroundSaveEvictorI();
virtual TransactionIPtr beforeQuery();
//
// Thread
//
virtual void run();
struct StreamedObject
{
Key key;
Value value;
Ice::Byte status;
ObjectStore<BackgroundSaveEvictorElement>* store;
};
protected:
virtual bool hasAnotherFacet(const Ice::Identity&, const std::string&);
virtual Ice::ObjectPtr locateImpl(const Ice::Current&, Ice::LocalObjectPtr&);
virtual void evict();
private:
void saveNow();
void evict(const BackgroundSaveEvictorElementPtr&);
void addToModifiedQueue(const BackgroundSaveEvictorElementPtr&);
void fixEvictPosition(const BackgroundSaveEvictorElementPtr&);
void stream(const BackgroundSaveEvictorElementPtr&, Ice::Long, StreamedObject&);
//
// The _evictorList contains a list of all objects we keep,
// with the most recently used first.
//
std::list<BackgroundSaveEvictorElementPtr> _evictorList;
std::list<BackgroundSaveEvictorElementPtr>::size_type _currentEvictorSize;
//
// The _modifiedQueue contains a queue of all modified objects
// Each element in the queue "owns" a usage count, to ensure the
// element containing the pointed element remains in the cache.
//
std::deque<BackgroundSaveEvictorElementPtr> _modifiedQueue;
bool _savingThreadDone;
WatchDogThreadPtr _watchDogThread;
//
// Threads that have requested a "saveNow" and are waiting for
// its completion
//
std::deque<IceUtil::ThreadControl> _saveNowThreads;
Ice::Int _saveSizeTrigger;
Ice::Int _maxTxSize;
IceUtil::Time _savePeriod;
};
}
#endif
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