diff -r 000000000000 -r bde4ae8d615e os/ossrv/genericopenlibs/openenvcore/ewsd/inc/pls.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/os/ossrv/genericopenlibs/openenvcore/ewsd/inc/pls.h Fri Jun 15 03:10:57 2012 +0200 @@ -0,0 +1,120 @@ +/* +* Copyright (c) 2006-2009 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: +* Name : pls.h +* Part of : Client API for ewsd library +* Contains the client API for using the emulator WSD library +* +*/ + + + +#ifndef __PLS_H__ +#define __PLS_H__ + +#ifdef __WINSCW__ + +#include + +// Panic strings +_LIT(KVirtualAllocFailure, "WSD VirtualAlloc() failed"); +_LIT(KPLSInitFailed, "WSD PLS init failed"); +_LIT(KWsdArrayFull, "WSD process or lib array full"); + +/** +A templated function that is used by a library (DLL) that requires to use +WSD on the emulator. +The function returns the PLS (Process Local Storage) object of the specified library, +for the current process. If the PLS object doesn't yet exist then it is allocated, +initialised, stored and returned. +The template type T is the type of the PLS object, and is supplied by the caller. + +Takes as a parameter the TUid of the library DLL whose PLS is to be returned for the +current process. It also takes as a parameter a pointer to a (non-leaving, non-panicing) +initialisation function defined by the caller which takes a pointer to T (i.e. the +PLS object) as a parameter and returns one of the system wide error codes as a TInt. +This parameter is optional but it should be used when necessary to ensure that if Pls() +requires to create a PLS object then the object is completely initialised on its return. +The initialisation function is called after the PLS object has been allocated and its +constructor called if it is an instance of a class - neither the constructor nor the +initialisation function should call Pls(). + +Returns a pointer to the PLS object +*/ +template +T* Pls(const TUid& aLibraryUid, TInt (*aInitFunc)(T*) = 0) + { + // Fetch the PLS, if it has been set + T* p = (T*) CheckPls(aLibraryUid); + if (p) + { + return p; + } + + // Obtain ownership of the mutex + TAny* mutexHandle = ObtainPlsMutex(); + + // Check we haven't obtained the mutex from + // another thread that has just set the same PLS! + p = (T*) CheckPls(aLibraryUid); + if (p) + { + ReleasePlsMutex(mutexHandle); + return p; + } + + // Allocate the memory for the PLS object + p = (T*) AllocatePls(sizeof(T)); + if (!p) + { + ReleasePlsMutex(mutexHandle); + User::Panic(KVirtualAllocFailure, KErrNoMemory); + } + + // Do a placement new to construct the PLS object in the allocated memory + p = new (p) T; + + // Call the initialisation function (if one is provided) + // to complete initialisation of the PLS object + if (aInitFunc) + { + if (((*aInitFunc)(p)) != KErrNone) + { + FreePls(p); + ReleasePlsMutex(mutexHandle); + User::Panic(KPLSInitFailed, KErrGeneral); + } + } + + // Finally, call SetPls() to store the PLS object. + // NOTE: This step is last to ensure that a PLS object returned by + // CheckPls() is completely constructed/initialised. This is important + // to handle the scenario in which the thread that is creating the PLS + // object is interrupted by another call to Pls() by another thread + if (SetPls(p, aLibraryUid) != KErrNone) + { + // SetPls() failed due to a size limit being reached in the wsdArray + FreePls(p); + ReleasePlsMutex(mutexHandle); + User::Panic(KWsdArrayFull, KErrNoMemory); + } + + ReleasePlsMutex(mutexHandle); + return p; + } + +#endif // __WINSCW__ + +#endif // __PLS_H__ +