//%2004////////////////////////////////////////////////////////////////////////
//
// 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.
//
// 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: Chip Vincent (cvincent@us.ibm.com)
//
// Modified By: Yi Zhou, Hewlett-Packard Company(yi_zhou@hp.com)
//              Mike Day IBM Corporation (mdday@us.ibm.com)
//              Adrian Schuur, schuur@de.ibm.com
//              Jenny Yu, Hewlett-Packard Company (jenny_yu@hp.com)
//
//%/////////////////////////////////////////////////////////////////////////////

#include "ProviderManager.h"

#include <Pegasus/Common/Constants.h>
#include <Pegasus/Common/Tracer.h>
#include <Pegasus/Common/MessageQueueService.h>
#include <Pegasus/Common/PegasusVersion.h>

PEGASUS_NAMESPACE_BEGIN

PEGASUS_USING_STD;

ProviderManager *my_instance = 0;

ProviderManager::ProviderManager(void)
   : _idle_timeout(300), _unload_idle_flag(1)
{
   my_instance = this;

}

ProviderManager::~ProviderManager(void)
{
   PEG_METHOD_ENTER(TRC_PROVIDERMANAGER, "~ProviderManager");

   Uint32 ccode;
   
   _provider_ctrl(UNLOAD_ALL_PROVIDERS, this, &ccode);

   // clear the providerTable 
   ProviderTable::Iterator i = _providers.start();
   for(; i != 0; i++)
   {
       Provider *provider = i.value();
       delete provider;
   }

   // clear the moduleTable 
   ModuleTable::Iterator j = _modules.start();
   for(; j != 0; j++)
   {
       ProviderModule *module = j.value();
       delete module;
   }

   PEG_METHOD_EXIT();
}


Sint32 ProviderManager::_provider_ctrl(CTRL code, void *parm, void *ret)
{

   static Uint32 quantum;
   PEG_METHOD_ENTER(TRC_PROVIDERMANAGER, "_provider_ctrl");
   
   Sint32 ccode = 0;
   CTRL_STRINGS *parms = reinterpret_cast<CTRL_STRINGS *>(parm);

   switch(code)
   {

      case GET_PROVIDER:
      {
	 PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL2, 
			  "_provider_ctrl::GET_PROVIDER");

         String providerName = *(parms->providerName);
         String moduleFileName = *(parms->fileName);
         String interfaceName = *(parms->interfaceName);

	 Provider *pr = 0;
	 OpProviderHolder* ph = reinterpret_cast< OpProviderHolder* >( ret );

         // look up provider in cache
         pr = _lookupProvider(providerName);

	 // initialize provider if it is not already initialized
         if (pr->getStatus() != Provider::INITIALIZED)
	 {
	    _initProvider(pr, moduleFileName, interfaceName);
         }

         // if provider is not initialized at this time, throw an exception
         if (pr->_status != Provider::INITIALIZED)
	 {
            PEG_METHOD_EXIT();
	    //l10n done
	    //throw PEGASUS_CIM_EXCEPTION(CIM_ERR_FAILED,
            //                          "provider initialization failed.");
	    throw PEGASUS_CIM_EXCEPTION_L(CIM_ERR_FAILED,
					MessageLoaderParms("ProviderManager.ProviderManager.INITIALIZE_FAILED",
					"provider initialization failed."));
         }

         // return the provider
	 PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
                          "Returning Provider " + providerName);

         ph->SetProvider( pr );
         ph->GetProvider().update_idle_timer();
         break;
      }
      
      case UNLOAD_PROVIDER:
      {
	 PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL2, 
			  "_provider_ctrl::UNLOAD_PROVIDER");

         // Lookup  provider
	 Provider *pr = _lookupProvider(*(parms->providerName));

         if (pr->getStatus() == Provider::INITIALIZED)
	 {
	    PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
			     "Unloading Provider " + pr->_name );

            // lock the providerTable mutex
            AutoMutex lock(_providerTableMutex);

	    // unload provider
            _unloadProvider(pr);
	 }
	 break;
      }

      case LOOKUP_PROVIDER:
      {

	 PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL2, 
			  "_provider_ctrl::LOOKUP_PROVIDER");
	 
         // lock the providerTable mutex
         AutoMutex lock(_providerTableMutex);
         
	 if(true == _providers.lookup(*(parms->providerName),
                                      *(reinterpret_cast<Provider * *>(ret))))
         {
	    PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
			     "Found Provider in cache: " + 
			      *(parms->providerName));
	    
	    (*(reinterpret_cast<Provider * *>(ret)))->update_idle_timer();
	 }
	 else
	 {

	    PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
			     "Could not find  Provider in cache: " + 
			     *(parms->providerName));
	    ccode = -1;
	 }

	 break;
      }
      
      case LOOKUP_MODULE:
      {

	 PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL2, 
			  "_provider_ctrl::LOOKUP_MODULE");

         // lock the providerTable mutex
         AutoMutex lock(_providerTableMutex);

         // Lookup module
	 if(false  == _modules.lookup(*(parms->fileName), 
			              *(reinterpret_cast<ProviderModule * *>(ret))))
	 {
	    PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
			     "Could not find Provider Module in cache: " + 
			     *(parms->fileName));
	    ccode = -1;
	 }

	 break;
      }

      case INSERT_PROVIDER: 
      {
	 PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL2, 
			  "_provider_ctrl::INSERT_PROVIDER");

         // lock the providerTable mutex
         AutoMutex lock(_providerTableMutex);

         // Insert provider in provider table
         if( false  == _providers.insert( 
		*(parms->providerName),
                *reinterpret_cast<Provider * *>(parm)) )
	    ccode = -1;
	 break;
      }
      case INSERT_MODULE: 
      {
	 PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL2, 
			  "_provider_ctrl::INSERT_MODULE");

         // lock the providerTable mutex
         AutoMutex lock(_providerTableMutex);

	 if( false  == _modules.insert(
                *(parms->fileName),
		*reinterpret_cast<ProviderModule * *>(parm)) )
	    ccode = -1;
	 break;
      }

      case UNLOAD_ALL_PROVIDERS:
      {
	 PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL2, 
			  "_provider_ctrl::UNLOAD_ALL_PROVIDERS");
	 ProviderManager *myself = reinterpret_cast<ProviderManager *>(parm);
	 Provider * provider;

         // lock the providerTable mutex
         AutoMutex lock(_providerTableMutex);

	 Tracer::trace(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
             "providers in cache = %d", myself->_providers.size());

	 ProviderTable::Iterator i = myself->_providers.start();
	 try 
	 {
	    for(; i != 0; i++)
	    {
	       provider = i.value();
               PEGASUS_ASSERT(provider != 0);
               if ( provider->getStatus() == Provider::UNINITIALIZED )
	       {
		  continue;
	       }
	       else
	       {
                  _unloadProvider(provider);
               }
	    }
	 }
	 catch(...)
	 {
	    PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
			     "Unexpected Exception in UNLOAD_ALL_PROVIDERS.");
	 }
	 break;
      }

      case UNLOAD_IDLE_PROVIDERS:
      {

	 PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL2, 
			  "_provider_ctrl::UNLOAD_IDLE_PROVIDERS");
	 
         // lock the providerTable mutex
         AutoMutex lock(_providerTableMutex);

	 quantum++;
	 ProviderManager *myself = reinterpret_cast<ProviderManager *>(parm);
	 Provider * provider;
	 
	 if(myself->_providers.size())
	 {
	    try
	    {
	       struct timeval now;
	       gettimeofday(&now, NULL);
	       ProviderTable::Iterator i = myself->_providers.start();
	       for(; i != 0 ; i++)
	       {
		  provider = i.value();
                  PEGASUS_ASSERT(provider != 0);
		  if (provider->getStatus() == Provider::UNINITIALIZED)
		  {
		     continue;
		  }
		  
		  if(provider->_quantum == quantum)
		  {
		     continue;
		  }
		  
		  provider->_quantum = quantum;
		  
		  // if provider has pending requests or an indication 
		  // provider needs to serve subscriptions, do not 
		  // unload the provider
		  if( provider->_current_operations.value() || 
		      provider->_indications_enabled) 
		  {
		     PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
				      "Provider has pending operations: " + 
				      provider->getName());
		     
		     continue;
		  }

		  PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
				   "Checking timeout data for Provider: " + 
				   provider->getName());
		  struct timeval timeout = {0,0};
		  provider->get_idle_timer(&timeout);
		  PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
				   " provider->unload_ok() returns: " + 
				   provider->unload_ok() ? "true" : "false" );

		  if(provider->unload_ok() == true && 
                     (  now.tv_sec - timeout.tv_sec) > ((Sint32)myself->_idle_timeout))
		  {
                     // lock the provider mutex
                     AutoMutex pr_lock(provider->_statusMutex);

	             Logger::put(Logger::STANDARD_LOG, System::CIMSERVER, Logger::TRACE,
                                     "ProviderManager::_provider_crtl -  Unload idle provider $0",
                                      provider->getName());

		     PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
		                      "Trying to Terminate Provider " + provider->getName());
		     try 
		     {
			if(false == provider->tryTerminate())
			{
			   PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
			                    "Provider Refused Termination " + provider->getName());
			   
			   continue;
			}
			else 
			{
			   PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
			                    "Provider terminated: " +  provider->getName());
			}
		     }
		     catch(...)
		     {
			PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
					 "Exception terminating " + 
					 provider->getName());
			continue;
		     }

                     PEGASUS_ASSERT(provider->_module != 0);
                     PEG_TRACE_STRING(TRC_PROVIDERMANAGER, 
                                      Tracer::LEVEL4,
                                      "unloading provider module " +
                                      provider->getName());

                     // unload provider module
                     provider->_module->unloadModule();
		  
		     // delete cimom handle
                     PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
                                      "Destroying Provider's CIMOM Handle: " + 
                                      provider->getName());
                     delete provider->_cimom_handle;

                     // set provider status to UNINITIALIZED
                     provider->reset();
		  }
	       }
	    }
	    catch(...)
	    {
	       PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
		              "Unexpected Exception in UNLOAD_IDLE_PROVIDERS.");
	    }
	 } // if there are any providers
	 break;
      }

      default:
	 ccode = -1;
	 break;
   }
   PEG_METHOD_EXIT();
   return ccode;
}

OpProviderHolder ProviderManager::getProvider(
    const String & fileName,
    const String & providerName,
    const String & interfaceName) 
{

   OpProviderHolder ph;
   CTRL_STRINGS strings;
   Sint32 ccode;
   PEG_METHOD_ENTER(TRC_PROVIDERMANAGER, "ProviderManager::getProvider");
   strings.fileName = &fileName;
   strings.providerName = &providerName;
   strings.interfaceName = &interfaceName;
   try
   {
      ccode = _provider_ctrl( GET_PROVIDER, &strings, &ph );
   }
   catch(...)
   {
      PEG_METHOD_EXIT();
      throw;
   }
   

   PEG_METHOD_EXIT();
   return ph;
   
}

void ProviderManager::unloadProvider(
    const String & fileName,
    const String & providerName)  
{
   CTRL_STRINGS strings;
      PEG_METHOD_ENTER(TRC_PROVIDERMANAGER, "ProviderManager::unloadProvider");
   strings.fileName = &fileName;
   strings.providerName = &providerName;
   _provider_ctrl(UNLOAD_PROVIDER, &strings, (void *)0);
   PEG_METHOD_EXIT();
}

void ProviderManager::shutdownAllProviders(void) 
{

   PEG_METHOD_ENTER(TRC_PROVIDERMANAGER, "ProviderManager::shutdownAllProviders");
   _provider_ctrl(UNLOAD_ALL_PROVIDERS, (void *)this, (void *)0);
   PEG_METHOD_EXIT();
}


// << Tue Jul 29 16:51:25 2003 mdd >> change to run every 300 seconds  
void ProviderManager::unload_idle_providers(void) 
{
   static struct timeval first = {0,0}, now, last = {0,0};
   PEG_METHOD_ENTER(TRC_PROVIDERMANAGER, "ProviderManager::unload_idle_providers");
   if(first.tv_sec == 0)
      gettimeofday(&first, NULL);
   gettimeofday(&now, NULL);
   if(((now.tv_sec - first.tv_sec) > 300 ) && ( (now.tv_sec - last.tv_sec) > 300))
   {
      gettimeofday(&last, NULL);
      if(_unload_idle_flag.value() == 1 )
      { 
	 PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL2, 
                          "Unload Idle Flag Set: Starting Provider Monitor Thread");
	 _unload_idle_flag = 0;
	 MessageQueueService::get_thread_pool()->allocate_and_awaken(this, provider_monitor);

      }
   }
   PEG_METHOD_EXIT();
}


PEGASUS_THREAD_RETURN PEGASUS_THREAD_CDECL ProviderManager::provider_monitor(void *parm)
{
   Thread *th = reinterpret_cast<Thread *>(parm);
   
   PEG_METHOD_ENTER(TRC_PROVIDERMANAGER, "ProviderManager::provider_monitor");
   ProviderManager *myself =    my_instance ;
      
   PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
		    "Checking for Idle providers to unload.");
   try 
   {
      myself->_provider_ctrl(UNLOAD_IDLE_PROVIDERS, myself, (void *)0);
      myself->_unload_idle_flag = 1;
   }
   catch(...)
   {
   }
   PEG_METHOD_EXIT();
   return 0;
}

Sint16 ProviderManager::disableProvider(
    const String & fileName,
    const String & providerName)
{
   CTRL_STRINGS strings;
      PEG_METHOD_ENTER(TRC_PROVIDERMANAGER, "ProviderManager::disableProvider");

   Provider *pr = _lookupProvider(providerName);

   if (pr->getStatus() == Provider::INITIALIZED)
   {
        PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4,
                         "Disable Provider " + pr->_name );
	//
	// Check to see if there are pending requests. If there are pending
	// requests and the disable timeout has not expired, loop and wait one 
	// second until either there is no pending requests or until timeout expires.
	//
	Uint32 waitTime = PROVIDER_DISABLE_TIMEOUT;
        while ( pr->_current_operations.value() > 0  &&  waitTime > 0)
        {
	    System::sleep(1);
	    waitTime = waitTime - 1;
        }

	// There are still pending requests, do not disable
        if (pr->_current_operations.value() > 0 )
        {
            PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
                     "Disable failed since there are pending requests." );
   	    PEG_METHOD_EXIT();
	    return (0);
        }
   }
   else
   {
	PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL2,
                         "Provider " + providerName + " is not loaded.");
   	PEG_METHOD_EXIT();
	return (1);
   }

   strings.fileName = &fileName;
   strings.providerName = &providerName;
   try
   {
       _provider_ctrl(UNLOAD_PROVIDER, &strings, (void *)0);
   }
   catch (...)
   {
	PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4,
			 "Unload provider failed " + pr->_name);
   	PEG_METHOD_EXIT();
	return (-1);
   }
   PEG_METHOD_EXIT();
   return (1);
}

Provider* ProviderManager::_initProvider(
    Provider * provider,
    const String & moduleFileName,
    const String & interfaceName) 
{
    PEG_METHOD_ENTER(TRC_PROVIDERMANAGER, "_initProvider");

    ProviderModule *module = 0;
    CIMProvider *base;

    {  
	// lock the providerTable mutex
        AutoMutex lock(_providerTableMutex);

        // lookup provider module
	module = _lookupModule(moduleFileName, interfaceName);

        PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4,
                         "Loading/Linking Provider Module " + moduleFileName);

        // load the provider
        try
        {
            base = module->load(provider->_name);
        }
        catch(...)
        {
            PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4,
                           "Exception caught Loading/Linking Provider Module " +
                           moduleFileName);
            PEG_METHOD_EXIT();
            throw;
        }
    }   // unlock the providerTable mutex

    // initialize the provider 
    PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL2, 
                     "Initializing Provider " +  provider->_name);

    //
    // Set the undoModuleLoad flag to true here, so that if the
    // initialize() throws an exception, we can unload the provider 
    // module.
    //
    Boolean undoModuleLoad = true;

    {   // lock the provider mutex
        AutoMutex pr_lock(provider->_statusMutex);

        // check provider status
        if (provider->_status == Provider::UNINITIALIZED)
        {
            CIMOMHandle *cimomHandle =  new CIMOMHandle();
            provider->set(module, base, cimomHandle);
            provider->_quantum=0;

            try
            {
                provider->initialize(*(provider->_cimom_handle));
                undoModuleLoad = false;
            }
            catch(...)
            {
                // delete the cimom handle
	        delete provider->_cimom_handle;

	        // set provider status to UNINITIALIZED
                provider->reset();
            }
        }
    }  // unlock the provider mutex

    // if we did not initialize the provider, unload the provider module
    if (undoModuleLoad)
    {
	// lock the providerTable mutex
        AutoMutex lock(_providerTableMutex);

	// unload provider module
        module->unloadModule();
    }

    PEG_METHOD_EXIT();
    return(provider);
}


void ProviderManager::_unloadProvider( Provider * provider)
{
    // 
    // NOTE:  It is the caller's responsibility to make sure that
    // the ProviderTable mutex is locked before calling this method.
    //
    PEG_METHOD_ENTER(TRC_PROVIDERMANAGER, "_unloadProvider");

    PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
                     "Unloading Provider " + provider->_name );

    if ( provider->_current_operations.value())
    {
        PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
                         "Provider cannot be unloaded due to pending operations: " + 
                         provider->_name );
    }
    else
    {
        PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
                         "Terminating Provider " + provider->_name );

        // lock the provider mutex
        AutoMutex pr_lock(provider->_statusMutex);

        try 
        {
	    if (provider->_indications_enabled)
	    {
		provider->disableIndications();
	    }
	}
        catch(...)
        {
            PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL3, 
                             "Error occured disabling provider " + provider->_name );
        }

        try 
        {
            provider->terminate();
        }
        catch(...)
        {
            PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL3, 
                             "Error occured terminating provider " + provider->_name );
        }

        // delete the cimom handle
        PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
                         "Destroying Provider's CIMOM Handle " + provider->_name );
        delete provider->_cimom_handle;

        PEGASUS_ASSERT(provider->_module != 0);

        // unload provider module
        provider->_module->unloadModule();

        Logger::put(Logger::STANDARD_LOG, System::CIMSERVER, Logger::TRACE,
            "ProviderManager::_provider_crtl -  Unload provider $0", 
            provider->getName());

        // set provider status to UNINITIALIZED
	provider->reset();
    }

    PEG_METHOD_EXIT();
}

Provider * ProviderManager::_lookupProvider( 
    const String & providerName)
{
    PEG_METHOD_ENTER(TRC_PROVIDERMANAGER, "_lookupProvider");

    // lock the providerTable mutex
    AutoMutex lock(_providerTableMutex);

    // look up provider in cache
    Provider * pr = 0;
    if ( true == _providers.lookup(providerName, pr) )
    {
        PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
                         "Found Provider " + providerName + 
			 " in Provider Manager Cache");
    }
    else
    {
        // create provider 
        pr = new Provider(providerName, 0, 0);

        // insert provider in provider table
        _providers.insert(providerName, pr);
 
        PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
                         "Created provider " + pr->getName());
    }

    PEG_METHOD_EXIT();
    return (pr);
}


ProviderModule * ProviderManager::_lookupModule( 
    const String & moduleFileName,
    const String & interfaceName)
{
    PEG_METHOD_ENTER(TRC_PROVIDERMANAGER, "_lookupModule");

    // look up provider module in cache
    ProviderModule * module = 0;

    if ( true == _modules.lookup(moduleFileName, module) )
    {
	// found provider module in cache
        PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4, 
                         "Found Provider Module" + moduleFileName +
                         " in Provider Manager Cache");
      
	// if provider module is not loaded, reset the interface
	if (module->_ref_count.value() == 0)
	{
	    module->setInterfaceName(interfaceName);
        }
    }
    else
    {
	// provider module not found in cache, create provider module
        PEG_TRACE_STRING(TRC_PROVIDERMANAGER, Tracer::LEVEL4,
                         "Creating Provider Module " + moduleFileName);
	    
        module = new ProviderModule(moduleFileName, interfaceName);

	// insert provider module in module table
        _modules.insert(moduleFileName, module);
    }

    PEG_METHOD_EXIT();
    return (module);
}

PEGASUS_NAMESPACE_END