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BUG#: 5314
TITLE: IPC Refactoring

DESCRIPTION: This patch cleans up the IPC related classes. It (1) reorganizes
related classes into their own headers, (2) makes the mutex class recursive to
eliminate recursive lock exclusion logic, (3) reimplements condition variables,
renames dozens of global functions.

//%2006////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2000, 2001, 2002 BMC Software; Hewlett-Packard Development
// Company, L.P.; IBM Corp.; The Open Group; Tivoli Systems.
// Copyright (c) 2003 BMC Software; Hewlett-Packard Development Company, L.P.;
// IBM Corp.; EMC Corporation, The Open Group.
// Copyright (c) 2004 BMC Software; Hewlett-Packard Development Company, L.P.;
// IBM Corp.; EMC Corporation; VERITAS Software Corporation; The Open Group.
// Copyright (c) 2005 Hewlett-Packard Development Company, L.P.; IBM Corp.;
// EMC Corporation; VERITAS Software Corporation; The Open Group.
// Copyright (c) 2006 Hewlett-Packard Development Company, L.P.; IBM Corp.;
// EMC Corporation; Symantec Corporation; The Open Group.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// THE ABOVE COPYRIGHT NOTICE AND THIS PERMISSION NOTICE SHALL BE INCLUDED IN
// ALL COPIES OR SUBSTANTIAL PORTIONS OF THE SOFTWARE. THE SOFTWARE IS PROVIDED
// "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
// LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
// ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
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//==============================================================================
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// Author: Heather Sterling (hsterl@us.ibm.com)
//
// Modified By: 
//
//%/////////////////////////////////////////////////////////////////////////////

#ifndef Pegasus_Dynamic_Consumer_h
#define Pegasus_Dynamic_Consumer_h

#include <Pegasus/Common/Config.h>
#include <Pegasus/Common/ArrayInternal.h>
#include <Pegasus/Common/System.h>
#include <Pegasus/Common/Thread.h>
#include <Pegasus/Common/List.h>
#include <Pegasus/Common/Mutex.h>
#include <Pegasus/DynListener/Linkage.h>
#include <Pegasus/Provider/CIMOMHandle.h>
#include "DynamicConsumerFacade.h"
#include "ConsumerModule.h"

PEGASUS_NAMESPACE_BEGIN


/** The IndicationDispatchEvent class encapsulates an event and all of the information associated with the event.
 *  The operation context, URL, and the CIM indication instance are the parameters to the consumeIndication() method
 *  of the CIMIndicationConsumer interface.  Additionally, we need to store the number of retries in order to resend
 *  indications if the consumer fails.
 */ 
class PEGASUS_DYNLISTENER_LINKAGE IndicationDispatchEvent : public Linkable
{
public:
    
	IndicationDispatchEvent();

    IndicationDispatchEvent(OperationContext context,
                            String url,
                            CIMInstance instance);

    IndicationDispatchEvent(const IndicationDispatchEvent &event);

    ~IndicationDispatchEvent();

    OperationContext getContext() const;

    String getURL() const;

    CIMInstance getIndicationInstance() const;

    Uint32 getRetries();

    void increaseRetries();

    CIMDateTime getLastAttemptTime();

	IndicationDispatchEvent& operator=(const IndicationDispatchEvent &event);

    Boolean operator==(const IndicationDispatchEvent &event) const;

private:
    OperationContext _context;
    String _url;
    CIMInstance _instance;
    AtomicInt _retries;
    CIMDateTime _lastAttemptTime;

};



/** The DynamicConsumer class represents the logical consumer extracted from a
 * consumer module. It is wrapped in a facade to stabalize the interface
 * and is directly tied to a module.
 * 
 * The synchronization of these actions is left up to the caller.  For example,
 * the caller must ensure that terminate is not called while initialize is executing.  
 * The ConsumerManager uses a consumer table mutex to ensure that no mutually exclusive
 * operations occur at the same time. The exception to this is the operation of the worker 
 * thread, which is signalled during a shutdown operation or when a new event occurs.
 */

class PEGASUS_DYNLISTENER_LINKAGE DynamicConsumer : public DynamicConsumerFacade
{
public:

    typedef DynamicConsumerFacade Base;

    DynamicConsumer();

    DynamicConsumer(const String& name);

    DynamicConsumer(const String & name,
                    ConsumerModule* consumerModule,
                    CIMIndicationConsumerProvider* consumerRef);

    ~DynamicConsumer(void);

    virtual void initialize(void);

    virtual void terminate(void);

    void enqueueEvent(IndicationDispatchEvent* event);

    void sendShutdownSignal();

    String getName(void) const;

    Boolean isInitialized(void) const;

    Boolean isLoaded(void) const;

    void waitForEventThread(void);

    Boolean isIdle(void);

    virtual void getIdleTimer(struct timeval *);

    virtual void updateIdleTimer(void);

    Uint32 getPendingIndications(void);

    void set(ConsumerModule* consumerModule,
             CIMIndicationConsumerProvider* consumerRef);

    Semaphore* getShutdownSemaphore();

    void setShutdownSemaphore(Semaphore* shutdownSempahore);

    void reset();

    String toString();

protected:
    ConsumerModule* _module;

private:
    friend class ConsumerManager;

    //indication queue
    List<IndicationDispatchEvent,Mutex> _eventqueue;

    //this mutex controls the state of the consumer to ensure it is not initializing, terminating, etc at the same time
    //ATTN: Do we need this?  The ConsumerManager will be controlling the status of the consumers.
    //Check back here when doing global queue
    Mutex _statusMutex;

    //physical consumer variables
    CIMIndicationConsumerProvider* getConsumer();
    ConsumerModule* getModule(void) const;

    String _name;
    String _fileName;

    //state variables
    Boolean _initialized;
    Boolean _dieNow;        //indicates we are shutting down

    // we must keep track of this ourself, since we cannot use the cimomhandle
    struct timeval _idleTime;
    Mutex _idleTimeMutex;
    Boolean _no_unload;

    //Signals the worker thread to wake up and check the queue.
    //This is signalled in the following scenarios:
    //  1) shutdown event
    //  2) event was placed in queue
    // This allows for a simulated "WaitForMultipleObjects"
    Semaphore* _check_queue;

    //Signals that the event thread is listening and can now be signalled.
    //This eliminates any synchronization issues that may occur when the first event comes in or if shutdown is called
    //right as the consumer thread is being started
    Semaphore* _listeningSemaphore;

    //ATTN: For now, we must store the shutdown semaphore on the consumer, in order to be able to gracefully
    //unload it during a normal shutdown OR an idle shutdown.  Pegasus's ThreadPool does not provide
    //a way to access any thread information once it is spawned; the only option is to pass a blocking
    //semaphore in, which will signal when the thread completes.  Since we are using one dedicated thread
    //per consumer for now, we can store one shutdown semaphore per consumer.  We'll change the implementation
    //when we go to a global queue.

    //This is used to tell the consumer manager that the worker thread has indeed stopped
    //it's passed in from the manager during initialization and can be checked to determine
    //whether the consumer can be unloaded.  This setup will change as the global queueing is
    //set up.
    Semaphore* _shutdownSemaphore;

    //these functions are used to serialize and deserialize outstanding indications
    void _loadOutstandingIndications(Array<IndicationDispatchEvent> indications);

    Array<IndicationDispatchEvent> _retrieveOutstandingIndications();

};

PEGASUS_NAMESPACE_END

#endif