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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
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
//==============================================================================
//
// Author: Heather Sterling (hsterl@us.ibm.com)
//
// Modified By: 
//
//%/////////////////////////////////////////////////////////////////////////////

#include "DynamicConsumer.h"
#include "DynamicConsumerFacade.h"

#include <Pegasus/Common/Config.h>
#include <Pegasus/Common/Time.h>
#include <Pegasus/Common/System.h>
#include <Pegasus/Common/Tracer.h>
#include <Pegasus/Common/XmlWriter.h>
#include <Pegasus/Common/XmlReader.h>
#include <Pegasus/Common/XmlParser.h>
#include <Pegasus/Common/FileSystem.h>

PEGASUS_NAMESPACE_BEGIN
PEGASUS_USING_STD;


DynamicConsumer::DynamicConsumer(): Base(0)
{
}

DynamicConsumer::DynamicConsumer(const String& name): 
Base(0),
_module(0),
_eventqueue(),
_name(name),
_initialized(false),
_dieNow(0),
_no_unload(0)
{
    _check_queue = new Semaphore(0);
    _shutdownSemaphore = new Semaphore(0);
    _listeningSemaphore = new Semaphore(0);
}

//ATTN: For migration from old listener -- do we want to support it?
DynamicConsumer::DynamicConsumer(const String & name,
                                 ConsumerModule* consumerModule,
                                 CIMIndicationConsumerProvider* consumerRef) :
Base(consumerRef),
_module(consumerModule),
_eventqueue(),
_name(name),
_initialized(false),
_dieNow(0),
_no_unload(0)
{
    _check_queue = new Semaphore(0);
    _shutdownSemaphore = new Semaphore(0);
    _listeningSemaphore = new Semaphore(0);
}

DynamicConsumer::~DynamicConsumer(void)
{
    //delete any outstanding events
    IndicationDispatchEvent* event;
    while (_eventqueue.size())
    {
        event = _eventqueue.remove_front();
        delete event;
    }

    //delete semaphores
    delete _check_queue;

    delete _shutdownSemaphore;

    delete _listeningSemaphore;
}

CIMIndicationConsumerProvider* DynamicConsumer::getConsumer()
{
    return(_consumer);
}

ConsumerModule* DynamicConsumer::getModule(void) const
{
    return(_module);
}

String DynamicConsumer::getName(void) const
{
    return(_name);
}

Boolean DynamicConsumer::isLoaded(void) const
{
    return(_module == 0 ? false : true);
}

Boolean DynamicConsumer::isInitialized(void) const
{
    return(_initialized);
}

/** Initializes the consumer.
 *  Caller assumes responsibility for catching exceptions thrown by this method.
 */ 
void DynamicConsumer::initialize()
{
    PEG_METHOD_ENTER(TRC_LISTENER, "DynamicConsumer::initialize");

    if (!_initialized)
    {
        // yield before a potentially lengthy operation.
        Threads::yield();

        try
        {
            //there is no cimom handle in the listener, so pass null
            CIMOMHandle* handle = 0;
            DynamicConsumerFacade::initialize(*(handle));

            updateIdleTimer();
            _initialized = true;

            PEG_TRACE_STRING(TRC_LISTENER, Tracer::LEVEL3, "Successfully initialized consumer.");

        } catch (...)
        {
            PEG_TRACE_STRING(TRC_LISTENER, Tracer::LEVEL4,
                             "Exception caught in DynamicConsumerFacade::initialize for " +
                             _name);
            throw;
        }
    }

    PEG_METHOD_EXIT();
}

void DynamicConsumer::setShutdownSemaphore(Semaphore* shutdownSemaphore)
{
    PEG_METHOD_ENTER(TRC_LISTENER, "DynamicConsumer::setShutdownSemaphore");

    _shutdownSemaphore = shutdownSemaphore;

    PEG_METHOD_EXIT();
}

Semaphore* DynamicConsumer::getShutdownSemaphore()
{
    return _shutdownSemaphore;
}

void DynamicConsumer::sendShutdownSignal()
{
    PEG_METHOD_ENTER(TRC_LISTENER, "DynamicConsumer::sendShutdownSignal");

    _dieNow = true;
    _check_queue->signal();

    PEG_METHOD_EXIT();
}

void DynamicConsumer::terminate(void)
{
    PEG_METHOD_ENTER(TRC_LISTENER, "DynamicConsumer::terminate");

    if (_initialized)
    {
        // yield before a potentially lengthy operation.
        Threads::yield();

        //terminate consumer
        try
        {
            DynamicConsumerFacade::terminate();

        } catch (...)
        {
            PEG_TRACE_STRING(TRC_LISTENER, Tracer::LEVEL4,
                             "Exception caught in DynamicConsumerFacade::Terminate for " +
                             _name);
            throw;
        }

        //update status
        _initialized = false;
        _dieNow = false;
    }

    PEG_METHOD_EXIT();
}

/** This method should be called after the physical consumer is loaded and before initialization.  
 */ 
void DynamicConsumer::set(ConsumerModule* consumerModule,
                          CIMIndicationConsumerProvider* consumerRef)
{
    PEG_METHOD_ENTER(TRC_LISTENER, "DynamicConsumer::set");

    if (_initialized)
    {
        throw Exception(MessageLoaderParms("DynListener.DynamicConsumer.CONSUMER_INVALID_STATE",
                                           "Error: The consumer is not in the correct state to perform the operation."));
    }

    _module = consumerModule;
    _consumer = consumerRef;

    PEG_METHOD_EXIT();
}

/** This method should be called after the consumer is terminated and the module is unloaded.  Note that we cannot test
 * for a loaded condition, since the _module reference here may still exist (if more than one consumer is using the module).
 * Simply test whether the consumer is initialized.  If it was terminated properly, initialized will be false and the _module
 * ref count will be decremented.
 */
void DynamicConsumer::reset()
{
    PEG_METHOD_ENTER(TRC_LISTENER, "DynamicConsumer::reset");

    if (_initialized)
    {
        throw Exception(MessageLoaderParms("DynListener.DynamicConsumer.CONSUMER_INVALID_STATE",
                                           "Error: The consumer is not in the correct state to perform the operation."));
    }

    _module = 0;    // do not delete it, that is taken care of in ConsumerModule itself 
    _consumer = 0;  // ATTN: attempting to delete this causes an exception -- why??

    Tracer::trace(__FILE__,__LINE__,TRC_LISTENER,Tracer::LEVEL4,
                  "Deleting %d outstanding requests for %s",
                  _eventqueue.size(),
                  (const char*)_name.getCString());

    //delete outstanding requests
    IndicationDispatchEvent* event = 0;
    for (Uint32 i = 0; i < _eventqueue.size(); i++)
    {
        event = _eventqueue.remove_front();
        delete event;
    }

    PEG_METHOD_EXIT();
}

void DynamicConsumer::enqueueEvent(IndicationDispatchEvent* event)
{
    PEG_METHOD_ENTER(TRC_LISTENER, "DynamicConsumer::enqueueEvent");

    if (!isLoaded())
    {
        PEG_TRACE_STRING(TRC_LISTENER, Tracer::LEVEL3, "Error: The consumer is not loaded and therefore cannot handle events.");
        return;
    }

    try
    {
        PEG_TRACE_STRING(TRC_LISTENER, Tracer::LEVEL4, "enqueueEvent before " + _name);
        // Our event queue is first in first out.
        _eventqueue.insert_back(event);
        _check_queue->signal();

        PEG_TRACE_STRING(TRC_LISTENER, Tracer::LEVEL4, "enqueueEvent after " + _name);

    } catch (Exception& ex)
    {
        //ATTN: Log missed indication
        PEGASUS_STD(cout) << "Error enqueueing event" << ex.getMessage() << "\n";

    } catch (...)
    {
        //ATTN: Log missed indication
        PEGASUS_STD(cout) << "Unknown exception";
    }

    PEG_METHOD_EXIT();
}

void DynamicConsumer::getIdleTimer(struct timeval *tv)
{
    if (tv == 0)
    {
        return;
    }

    try
    {
        AutoMutex lock(_idleTimeMutex);
        memcpy(tv, &_idleTime, sizeof(struct timeval));
    } catch (...)
    {
        Time::gettimeofday(tv);
    }
}

void DynamicConsumer::updateIdleTimer()
{
    try
    {
        AutoMutex lock(_idleTimeMutex);
        Time::gettimeofday(&_idleTime);

    } catch (...)
    {
    }
}

Uint32 DynamicConsumer::getPendingIndications()
{
    return _eventqueue.size();
}

String DynamicConsumer::toString()
{
    PEG_METHOD_ENTER(TRC_LISTENER, "DynamicConsumer::toString");

    String buffer = String::EMPTY;
    if (_initialized)
    {
        buffer.append("Consumer " + _name + " is initialized.\n");
        buffer.append("Module name " + _module->getFileName() + "\n");
    }

    PEG_METHOD_EXIT();
    return buffer;
}

/** Returns true if the consumer has been inactive for longer than the idle period.
 */ 
Boolean DynamicConsumer::isIdle() 
{
    PEG_METHOD_ENTER(TRC_LISTENER, "DynamicConsumer::isIdle");

    if (!isLoaded())
    {
        PEG_TRACE_STRING(TRC_LISTENER, Tracer::LEVEL4, "Consumer is not loaded.");
        return false;
    }

    struct timeval now;
    Time::gettimeofday(&now);

    struct timeval timeout = {0,0};
    getIdleTimer(&timeout);

	//if no consumer is currently being served and there's no consumer that has pending indications, we are idle
    if (!_current_operations.get() && !getPendingIndications())
    {
        PEG_METHOD_EXIT();
        return true;
    }

    PEG_METHOD_EXIT();
    return false;
}

/** This method waits until the event thread is ready to accept incoming indications.  Otherwise, there is a miniscule chance that 
 * the first event will be enqueued before the consumer is waiting for it and the first indication after loading the consumer will be lost.
 */ 
void DynamicConsumer::waitForEventThread()
{
    _listeningSemaphore->wait();
}

/** This method is called when the consumer is initialized for the first time.
 *  It reads the outstanding requests from the dat file and enqueues them.
 * 
 * ATTN: This method will only get called when a consumer is initialized.  Therefore,
 * when the listener starts, the outstanding indications for this consumer will not get sent
 * UNTIL a new indication comes in.  This is not really an acceptable scenario.  Maybe the consumer
 * manager needs to check the .dat files upon startup and load if they are not empty.
 * 
 */ 
void DynamicConsumer::_loadOutstandingIndications(Array<IndicationDispatchEvent> indications)
{
    PEG_METHOD_ENTER(TRC_LISTENER, "DynamicConsumer::_loadOutstandingIndications");

    //create dispatch events from the instances
    IndicationDispatchEvent* event = 0;
    for (Uint32 i=0; i < indications.size(); i++)
    {
		
        event = new IndicationDispatchEvent(OperationContext(),  //ATTN: Do we need to store this?
                                            indications[i].getURL(),
                                            indications[i].getIndicationInstance());
		
        _eventqueue.insert_back(event);
    }

    //signal the worker thread so it falls into the queue processing code
    if (_eventqueue.size())
    {
        _check_queue->signal();
    }

    PEG_METHOD_EXIT();
}

/** This method serializes the remaining indications in the queue. It should be called when the
 * consumer is shutting down.  Each time the consumer is loaded, these indications will be
 * reloaded into the queue.  Therefore, the file should be overwritten each time to eliminate
 * duplicating outstanding indications.
 * 
 * ATTN: Should we let another method delete the instances?
 */ 
Array<IndicationDispatchEvent> DynamicConsumer::_retrieveOutstandingIndications()
{
    PEG_METHOD_ENTER(TRC_LISTENER, "DynamicConsumer::_retrieveOutstandingIndications");

    Array<IndicationDispatchEvent> indications;
    IndicationDispatchEvent* temp = 0;

    try
    {
        _eventqueue.try_lock();
        temp = _eventqueue.front();
        while (temp)
        {
            PEG_TRACE_STRING(TRC_LISTENER, Tracer::LEVEL4, "retrieving");
			indications.append(*temp);
            temp = _eventqueue.next_of(temp);
        }
        _eventqueue.unlock();

    } catch (...)
    {
        PEG_TRACE_STRING(TRC_LISTENER, Tracer::LEVEL4, "Unknown Exception");
    }

    PEG_METHOD_EXIT();
    return indications;
}


////////////////////////////////
// IndicationDispatchEvent
////////////////////////////////

IndicationDispatchEvent::IndicationDispatchEvent()
{
}

IndicationDispatchEvent::IndicationDispatchEvent(OperationContext context,
                                                 String url,
                                                 CIMInstance instance) :
_context(context),
_url(url),
_instance(instance),
_retries(0),
_lastAttemptTime(CIMDateTime())
{
}

IndicationDispatchEvent::IndicationDispatchEvent(
    const IndicationDispatchEvent &event) : Linkable(event)
{
    _context = event._context;
    _url = event._url;
    _instance = event._instance;
    _retries = event._retries.get();
    _lastAttemptTime = event._lastAttemptTime;
}

IndicationDispatchEvent::~IndicationDispatchEvent()
{
}

OperationContext IndicationDispatchEvent::getContext() const
{
    return _context;
}

String IndicationDispatchEvent::getURL() const
{
    return _url;
}

CIMInstance IndicationDispatchEvent::getIndicationInstance() const
{
    return _instance;
}

Uint32 IndicationDispatchEvent::getRetries()
{
    return _retries.get();
}

void IndicationDispatchEvent::increaseRetries()
{
    PEG_TRACE_STRING(TRC_LISTENER, Tracer::LEVEL4, "Increasing retries\n");
    _retries++;
    _lastAttemptTime = CIMDateTime::getCurrentDateTime();
    PEG_TRACE_STRING(TRC_LISTENER, Tracer::LEVEL4, "Last attempt time " + _lastAttemptTime.toString());
}

CIMDateTime IndicationDispatchEvent::getLastAttemptTime()
{
    return _lastAttemptTime;
}


IndicationDispatchEvent& IndicationDispatchEvent::operator=(const IndicationDispatchEvent &event)
{
	_context = event._context;
	_url = event._url;
	_instance = event._instance;
	_retries = event._retries.get();
	_lastAttemptTime = event._lastAttemptTime;

    return *this;
}

Boolean IndicationDispatchEvent::operator==(const IndicationDispatchEvent& event) const
{
    if (String::equal(this->_url, event._url) && 
        (this->_instance.identical(event._instance)))
    {
        return true;
    }
    return false;
}

PEGASUS_NAMESPACE_END