// Copyright (c) 1997-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of "Eclipse Public License v1.0"

// which accompanies this distribution, and is available

// at the URL "http://www.eclipse.org/legal/epl-v10.html".

//

// Initial Contributors:

// Nokia Corporation - initial contribution.

//

// Contributors:

//

// Description:

// Implementation of the CUnloadPolicy class

// 

//

/**

 @internalComponent

 @file

*/

#include <ecom/ecom.h>

#include <ecom/ecomerrorcodes.h>

#include <ecom/ecomresolverparams.h>

#include <ecom/implementationinformation.h>

#include "UnloadPolicy.h"

#include "TestUtilities.h"	// For __FILE__LINE__

#include "EComUidCodes.h"

// Design Note:

// 	Dll text is per process.

// 	RLibrary handles are per thread.

// 	Therefore, data related to each loaded dll is per thread so no need for any mutex on say

// 	the reference counter.

CUnloadPolicy* CUnloadPolicy::NewLC(const TEntry& aDllEntry)

	{

	CUnloadPolicy* self = new(ELeave) CUnloadPolicy();

	CleanupStack::PushL(self);

	self->ConstructL(aDllEntry);

	return self;

	}

// Default d'tor

CUnloadPolicy::~CUnloadPolicy()

	{

	// Make sure the library is unloaded

	iLibrary.Close();

	// Remove the instance variable

	delete iDllEntry;

	}

// Default c'tor

CUnloadPolicy::CUnloadPolicy()

	{

	// Do nothing here

	}

void CUnloadPolicy::ConstructL(const TEntry& aDllEntry)

	{

	iDllEntry = CEComEntry::NewL(aDllEntry.iName,aDllEntry.iType[1],aDllEntry.iType[2]);

	}

TUnloadPolicyStatus CUnloadPolicy::DecreaseReference()

	{

	// Already finished with this DLL OR

	// Note: There could be many clients per process	

	if (iReferencesInUseCount == 0 || --iReferencesInUseCount == 0)

		{

		return EDeleteMe;		

		}

	return EDontDeleteMe;

	}

void CUnloadPolicy::IncreaseReference()

	{

	++iReferencesInUseCount;

	}

TInt CUnloadPolicy::ReferenceCount() const

	{

	return iReferencesInUseCount;

	}

TLibraryFunction CUnloadPolicy::LoadDllAndReturnProxyL()

	{

	// Function at ordinal 1 is InstantiationMethodL()

	const TInt KImplementationGroupProxy = 1;

	// If we have already loaded the library

	if(iReferencesInUseCount > 0)

		{

		IncreaseReference();

		return iLibrary.Lookup(KImplementationGroupProxy);

		}

	const TDesC& libraryPath = iDllEntry->GetName();

	if(libraryPath.Length())

		{

		// Load up the specified library and its default method

		// Dynamically load DLL	

		User::LeaveIfError(iLibrary.Load(libraryPath, TUidType(KDynamicLibraryUid,iDllEntry->GetSecondUid(),iDllEntry->GetThirdUid())));

		// Add to the reference count now to keep the

		// library loaded for the instantiation call.

		// IF the client fails before instantiating an implementation

		// we can rely upon CEcomServerSession to correctly call

		// for an implementations reference to be removed.

		IncreaseReference();

		return iLibrary.Lookup(KImplementationGroupProxy);

		}

	return NULL;

	}	

const CEComEntry& CUnloadPolicy::DllEntryInformation() const

	{

	return *iDllEntry;

	}