/*
* Copyright (c) 2005-2009 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:
* Template class implementation for creating RChunk object with memory for sharing data
* Construction of template object for sharing data requires
* Name for RChunk memory, size of data and null pointer of the object type to be shared
* Construction of template class for accessing the shared data requires
* Name for RChunk memory and null pointer of the object type already shared
*
*/
/**
@file TEFSharedData.inl
@prototype
@test
*/
template <class T>
inline CTEFSharedData<T>::CTEFSharedData()
/**
* Constructor
*/
: iPtr(NULL)
{
// Intialising member data
iSharedChunkName.Zero();
iSharedMutexName.Zero();
}
template <class T>
inline CTEFSharedData<T>* CTEFSharedData<T>::NewL(T*& aPtr, const TInt aLength, const TDesC& aName)
/**
* Updates the null pointer with address of RChunk base for user to copy data
* Two phase construction
*
* @param aPtr - Address of null pointer to object that needs to be shared as a global chunk
* @param aLength - Size to be allocated in RChunk base for the object to be shared
* @param aName - Descriptor containing the name to be assigned to the global chunk
*
* @leave system wide error
*
* @return Instance of the TEFSharedData template class object
*/
{
CTEFSharedData<T>* self=CTEFSharedData<T>::NewLC(aPtr,aLength,aName);
CleanupStack::Pop();
return self;
}
template <class T>
inline CTEFSharedData<T>* CTEFSharedData<T>::NewL(T*& aPtr, const TDesC& aName)
/**
* Updates the null pointer with address of RChunk base for user to update data
* Two phase construction
*
* @param aPtr - Address of null pointer to object that is shared in a global chunk
* @param aName - Descriptor containing the name assigned to the global chunk
*
* @leave system wide error
*
* @return Instance of the TEFSharedData template class object
*/
{
CTEFSharedData<T>* self=CTEFSharedData<T>::NewLC(aPtr,aName);
CleanupStack::Pop();
return self;
}
template <class T>
inline CTEFSharedData<T>* CTEFSharedData<T>::NewLC(T*& aPtr, const TInt aLength, const TDesC& aName)
/**
* Updates the null pointer with address of RChunk base for user to copy data
* Two phase construction
*
* @param aPtr - Address of null pointer to object that needs to be shared as a global chunk
* @param aLength - Size to be allocated in RChunk base for the object to be shared
* @param aName - Descriptor containing the name to be assigned to the global chunk
*
* @leave system wide error
*
* @return Instance of the TEFSharedData template class object and pushes to CleanupStack
*/
{
CTEFSharedData<T>* self=new (ELeave) CTEFSharedData<T>();
CleanupStack::PushL(self);
self->ConstructL(aPtr,aLength,aName);
return self;
}
template <class T>
inline CTEFSharedData<T>* CTEFSharedData<T>::NewLC(T*& aPtr, const TDesC& aName)
/**
* Updates the null pointer with address of RChunk base for user to update data
* Two phase construction
*
* @param aPtr - Address of null pointer to object that is shared in a global chunk
* @param aName - Descriptor containing the name assigned to the global chunk
*
* @leave system wide error
*
* @return Instance of the TEFSharedData template class object and pushes to CleanupStack
*/
{
CTEFSharedData<T>* self=new (ELeave) CTEFSharedData<T>();
CleanupStack::PushL(self);
self->ConstructL( aPtr, aName );
return self;
}
template <class T>
inline void CTEFSharedData<T>::ConstructL(T*& aPtr, const TInt aLength, const TDesC& aName)
/**
* Opens up a handle and retrieves base address of the created chunk memory to iPtr
* Updates the null pointer with address of RChunk base for user to copy data
*
* @param aPtr - Address of null pointer to object that needs to be shared in a global chunk
* @param aLength - Size to be allocated in RChunk base for the object to be shared
* @param aName - Descriptor containing the name to be assigned to the global chunk
*
* @leave system wide error
*/
{
iSharedChunkName.Zero();
iSharedChunkName.Copy(_L("TEF"));
iSharedChunkName.Append(aName);
iSharedMutexName.Zero();
iSharedMutexName.Copy(_L("TEFMutex"));
iSharedMutexName.Append(aName);
TInt error = KErrNone;
error = iSharedDataChunk.CreateGlobal(iSharedChunkName, aLength, aLength + 1);
if( error == KErrAlreadyExists )
{
// Chunk memory already created by another process
// Open a handle to already created global chunk
error = iSharedDataChunk.OpenGlobal(iSharedChunkName,EFalse);
if( error != KErrNone )
{
User::Leave(error);
}
// Open a mutex handle to existing global chunk
error = iMutex.OpenGlobal(iSharedMutexName);
if( error != KErrNone )
{
User::Leave(error);
}
// If we have looked up a shared RChunk we will need to update it
// with the object passed into the constructor
T* baseAddress = (T*)iSharedDataChunk.Base();
iPtr = baseAddress;
aPtr = iPtr;
}
else if( error == KErrNone )
{
// Global chunk created by current process
// Copy the object to be shared to Chunks base address
T* baseAddress = (T*)iSharedDataChunk.Base();
iPtr = baseAddress;
aPtr = iPtr;
// Create a mutex object for the newly created global chunk
error = iMutex.CreateGlobal(iSharedMutexName);
if( error != KErrNone )
{
User::Leave(error);
}
}
else
{
User::Leave(error);
}
}
template <class T>
inline void CTEFSharedData<T>::ConstructL(T*& aPtr, const TDesC& aName)
/**
* Opens up a handle and retrieves base address of the created chunk memory to iPtr
* Updates the null pointer with address of RChunk base for user to update data
*
* @param aPtr - Address of null pointer to object type shared in a global chunk
* @param aName - Descriptor containing the name assigned to the global chunk
*
* @leave system wide error
*/
{
SetNameL( aName );
aPtr = Ptr();
}
template <class T>
inline T* CTEFSharedData<T>::Ptr()
/**
* @return - Pointer to the base of the RChunk object memory in heap
*/
{
// Since we are using RChunk::Close() the pointer will always be valid
// The shared RChunk can not have been deleted as it is a reference counting object
return iPtr;
}
template <class T>
inline void CTEFSharedData<T>::SetNameL( const TDesC& aName )
/**
* Opens up a handle to the existing chunk & retrieves the base address to iPtr
*
* @param aName - Name of the global chunk memory for a shared object
*/
{
// Check to see if we already have a handle to a shared RChunk
if( iPtr != NULL )
{
// Close this before searching for the new one
TInt handle = 0;
handle = iSharedDataChunk.Handle();
if(handle != 0)
{
iPtr = NULL;
iMutex.Close();
iSharedDataChunk.Close();
}
}
// Now search for and open the new shared RChunk
iSharedChunkName.Zero();
iSharedChunkName.Copy(_L("TEF"));
iSharedChunkName.Append(aName);
iSharedMutexName.Zero();
iSharedMutexName.Copy(_L("TEFMutex"));
iSharedMutexName.Append(aName);
TInt error = KErrNone;
// Open a handle to a existing chunk memory
error = iSharedDataChunk.OpenGlobal(iSharedChunkName,EFalse);
if( error == KErrNone )
{
// Open a mutex handle for the chunk memory
error = iMutex.OpenGlobal(iSharedMutexName);
if( error == KErrNone )
{
// Retrieve base address of chunk memory & assign it to iPtr
T* baseAddress = reinterpret_cast<T*>(iSharedDataChunk.Base());
iPtr = baseAddress;
}
}
if( error != KErrNone )
{
User::Leave(error);
}
}
template <class T>
inline void CTEFSharedData<T>::EnterCriticalSection()
/**
* Establishes a lock to global chunk access
* Makes other proces to wait for a signal
*/
{
iMutex.Wait();
}
template <class T>
inline void CTEFSharedData<T>::ExitCriticalSection()
/**
* Releases the lock to global chunk access
* Signals for a process to establish a lock
*/
{
iMutex.Signal();
}
template <class T>
inline CTEFSharedData<T>::~CTEFSharedData()
/**
* Destructor
*/
{
// Cleanup everything.
TInt handle = 0;
// Checks for an existing handle to the global chunk
// Ensures global objects are not closed already by another process
handle = iMutex.Handle();
if (handle != 0)
{
iMutex.Close();
}
handle = iSharedDataChunk.Handle();
if (handle != 0)
{
iSharedDataChunk.Close();
}
iPtr = NULL;
}