1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/os/ossrv/genericopenlibs/openenvcore/ewsd/inc/pls.h Fri Jun 15 03:10:57 2012 +0200
1.3 @@ -0,0 +1,120 @@
1.4 +/*
1.5 +* Copyright (c) 2006-2009 Nokia Corporation and/or its subsidiary(-ies).
1.6 +* All rights reserved.
1.7 +* This component and the accompanying materials are made available
1.8 +* under the terms of "Eclipse Public License v1.0"
1.9 +* which accompanies this distribution, and is available
1.10 +* at the URL "http://www.eclipse.org/legal/epl-v10.html".
1.11 +*
1.12 +* Initial Contributors:
1.13 +* Nokia Corporation - initial contribution.
1.14 +*
1.15 +* Contributors:
1.16 +*
1.17 +* Description:
1.18 +* Name : pls.h
1.19 +* Part of : Client API for ewsd library
1.20 +* Contains the client API for using the emulator WSD library
1.21 +*
1.22 +*/
1.23 +
1.24 +
1.25 +
1.26 +#ifndef __PLS_H__
1.27 +#define __PLS_H__
1.28 +
1.29 +#ifdef __WINSCW__
1.30 +
1.31 +#include <ewsd.h>
1.32 +
1.33 +// Panic strings
1.34 +_LIT(KVirtualAllocFailure, "WSD VirtualAlloc() failed");
1.35 +_LIT(KPLSInitFailed, "WSD PLS init failed");
1.36 +_LIT(KWsdArrayFull, "WSD process or lib array full");
1.37 +
1.38 +/**
1.39 +A templated function that is used by a library (DLL) that requires to use
1.40 +WSD on the emulator.
1.41 +The function returns the PLS (Process Local Storage) object of the specified library,
1.42 +for the current process. If the PLS object doesn't yet exist then it is allocated,
1.43 +initialised, stored and returned.
1.44 +The template type T is the type of the PLS object, and is supplied by the caller.
1.45 +
1.46 +Takes as a parameter the TUid of the library DLL whose PLS is to be returned for the
1.47 +current process. It also takes as a parameter a pointer to a (non-leaving, non-panicing)
1.48 +initialisation function defined by the caller which takes a pointer to T (i.e. the
1.49 +PLS object) as a parameter and returns one of the system wide error codes as a TInt.
1.50 +This parameter is optional but it should be used when necessary to ensure that if Pls()
1.51 +requires to create a PLS object then the object is completely initialised on its return.
1.52 +The initialisation function is called after the PLS object has been allocated and its
1.53 +constructor called if it is an instance of a class - neither the constructor nor the
1.54 +initialisation function should call Pls().
1.55 +
1.56 +Returns a pointer to the PLS object
1.57 +*/
1.58 +template <typename T>
1.59 +T* Pls(const TUid& aLibraryUid, TInt (*aInitFunc)(T*) = 0)
1.60 + {
1.61 + // Fetch the PLS, if it has been set
1.62 + T* p = (T*) CheckPls(aLibraryUid);
1.63 + if (p)
1.64 + {
1.65 + return p;
1.66 + }
1.67 +
1.68 + // Obtain ownership of the mutex
1.69 + TAny* mutexHandle = ObtainPlsMutex();
1.70 +
1.71 + // Check we haven't obtained the mutex from
1.72 + // another thread that has just set the same PLS!
1.73 + p = (T*) CheckPls(aLibraryUid);
1.74 + if (p)
1.75 + {
1.76 + ReleasePlsMutex(mutexHandle);
1.77 + return p;
1.78 + }
1.79 +
1.80 + // Allocate the memory for the PLS object
1.81 + p = (T*) AllocatePls(sizeof(T));
1.82 + if (!p)
1.83 + {
1.84 + ReleasePlsMutex(mutexHandle);
1.85 + User::Panic(KVirtualAllocFailure, KErrNoMemory);
1.86 + }
1.87 +
1.88 + // Do a placement new to construct the PLS object in the allocated memory
1.89 + p = new (p) T;
1.90 +
1.91 + // Call the initialisation function (if one is provided)
1.92 + // to complete initialisation of the PLS object
1.93 + if (aInitFunc)
1.94 + {
1.95 + if (((*aInitFunc)(p)) != KErrNone)
1.96 + {
1.97 + FreePls(p);
1.98 + ReleasePlsMutex(mutexHandle);
1.99 + User::Panic(KPLSInitFailed, KErrGeneral);
1.100 + }
1.101 + }
1.102 +
1.103 + // Finally, call SetPls() to store the PLS object.
1.104 + // NOTE: This step is last to ensure that a PLS object returned by
1.105 + // CheckPls() is completely constructed/initialised. This is important
1.106 + // to handle the scenario in which the thread that is creating the PLS
1.107 + // object is interrupted by another call to Pls() by another thread
1.108 + if (SetPls(p, aLibraryUid) != KErrNone)
1.109 + {
1.110 + // SetPls() failed due to a size limit being reached in the wsdArray
1.111 + FreePls(p);
1.112 + ReleasePlsMutex(mutexHandle);
1.113 + User::Panic(KWsdArrayFull, KErrNoMemory);
1.114 + }
1.115 +
1.116 + ReleasePlsMutex(mutexHandle);
1.117 + return p;
1.118 + }
1.119 +
1.120 +#endif // __WINSCW__
1.121 +
1.122 +#endif // __PLS_H__
1.123 +