epoc32/include/pls.h
branchSymbian2
changeset 2 2fe1408b6811
parent 0 061f57f2323e
child 4 837f303aceeb
     1.1 --- a/epoc32/include/pls.h	Tue Nov 24 13:55:44 2009 +0000
     1.2 +++ b/epoc32/include/pls.h	Tue Mar 16 16:12:26 2010 +0000
     1.3 @@ -1,1 +1,140 @@
     1.4 -pls.h
     1.5 +/*
     1.6 +* Copyright (c) 2006-2009 Nokia Corporation and/or its subsidiary(-ies).
     1.7 +* All rights reserved.
     1.8 +* This component and the accompanying materials are made available
     1.9 +* under the terms of the License "Symbian Foundation License v1.0" to Symbian Foundation members and "Symbian Foundation End User License Agreement v1.0" to non-members
    1.10 +* which accompanies this distribution, and is available
    1.11 +* at the URL "http://www.symbianfoundation.org/legal/licencesv10.html".
    1.12 +*
    1.13 +* Initial Contributors:
    1.14 +* Nokia Corporation - initial contribution.
    1.15 +*
    1.16 +* Contributors:
    1.17 +*
    1.18 +* Description:
    1.19 +* Name        : pls.h
    1.20 +* Part of     : Client API for ewsd library
    1.21 +* Contains the client API for using the emulator WSD library
    1.22 +* Redistribution and use in source and binary forms, with or without 
    1.23 +* modification, are permitted provided that the following conditions are met:
    1.24 +* Redistributions of source code must retain the above copyright notice, this 
    1.25 +* list of conditions and the following disclaimer. 
    1.26 +* Redistributions in binary form must reproduce the above copyright notice, 
    1.27 +* this list of conditions and the following disclaimer in the documentation 
    1.28 +* and/or other materials provided with the distribution. 
    1.29 +* Neither the name of the <ORGANIZATION> nor the names of its contributors 
    1.30 +* may be used to endorse or promote products derived from this software 
    1.31 +* without specific prior written permission. 
    1.32 +* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
    1.33 +* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
    1.34 +* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
    1.35 +* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
    1.36 +* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
    1.37 +* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 
    1.38 +* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
    1.39 +* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
    1.40 +* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
    1.41 +* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    1.42 +*
    1.43 +*/
    1.44 +
    1.45 +
    1.46 + 
    1.47 +#ifndef __PLS_H__
    1.48 +#define __PLS_H__
    1.49 +
    1.50 +#ifdef __WINSCW__
    1.51 + 
    1.52 +#include <ewsd.h>
    1.53 +
    1.54 +// Panic strings
    1.55 +_LIT(KVirtualAllocFailure, "WSD VirtualAlloc() failed");
    1.56 +_LIT(KPLSInitFailed, "WSD PLS init failed");
    1.57 +_LIT(KWsdArrayFull, "WSD process or lib array full");	
    1.58 +
    1.59 +/**  
    1.60 +A templated function that is used by a library (DLL) that requires to use
    1.61 +WSD on the emulator.
    1.62 +The function returns the PLS (Process Local Storage) object of the specified library, 
    1.63 +for the current process. If the PLS object doesn't yet exist then it is allocated, 
    1.64 +initialised, stored and returned.
    1.65 +The template type T is the type of the PLS object, and is supplied by the caller.
    1.66 +
    1.67 +Takes as a parameter the TUid of the library DLL whose PLS is to be returned for the 
    1.68 +current process. It also takes as a parameter a pointer to a (non-leaving, non-panicing) 
    1.69 +initialisation function defined by the caller which takes a pointer to T (i.e. the 
    1.70 +PLS object) as a parameter and returns one of the system wide error codes as a TInt.
    1.71 +This parameter is optional but it should be used when necessary to ensure that if Pls() 
    1.72 +requires to create a PLS object then the object is completely initialised on its return. 
    1.73 +The initialisation function is called after the PLS object has been allocated and its 
    1.74 +constructor called if it is an instance of a class - neither the constructor nor the 
    1.75 +initialisation function should call Pls().
    1.76 +
    1.77 +Returns a pointer to the PLS object					
    1.78 +*/
    1.79 +template <typename T>
    1.80 +T* Pls(const TUid& aLibraryUid, TInt (*aInitFunc)(T*) = 0)
    1.81 +	{
    1.82 +	// Fetch the PLS, if it has been set
    1.83 +	T* p = (T*) CheckPls(aLibraryUid);
    1.84 +	if (p)
    1.85 +		{
    1.86 +		return p;
    1.87 +		}
    1.88 +	
    1.89 +	// Obtain ownership of the mutex
    1.90 +	TAny* mutexHandle = ObtainPlsMutex(); 
    1.91 +			
    1.92 +	// Check we haven't obtained the mutex from 
    1.93 +	// another thread that has just set the same PLS!
    1.94 +	p = (T*) CheckPls(aLibraryUid);
    1.95 +	if (p) 
    1.96 +		{
    1.97 +		ReleasePlsMutex(mutexHandle);				
    1.98 +		return p;
    1.99 +		}
   1.100 +	
   1.101 +	// Allocate the memory for the PLS object
   1.102 +	p = (T*) AllocatePls(sizeof(T));
   1.103 +	if (!p)
   1.104 +		{
   1.105 +		ReleasePlsMutex(mutexHandle);
   1.106 +		User::Panic(KVirtualAllocFailure, KErrNoMemory);
   1.107 +		}
   1.108 +			
   1.109 +	// Do a placement new to construct the PLS object in the allocated memory
   1.110 +	p = new (p) T;
   1.111 +	
   1.112 +	// Call the initialisation function (if one is provided)
   1.113 +	// to complete initialisation of the PLS object
   1.114 +	if (aInitFunc)
   1.115 +		{
   1.116 +		 if (((*aInitFunc)(p)) != KErrNone) 
   1.117 +		 	{
   1.118 +		 	 FreePls(p);			
   1.119 +			 ReleasePlsMutex(mutexHandle);
   1.120 +			 User::Panic(KPLSInitFailed, KErrGeneral);
   1.121 +		 	}
   1.122 +		}
   1.123 +		
   1.124 +	// Finally, call SetPls() to store the PLS object.
   1.125 +	// NOTE: This step is last to ensure that a PLS object returned by 
   1.126 +	// CheckPls() is completely constructed/initialised. This is important 
   1.127 +	// to handle the scenario in which the thread that is creating the PLS 
   1.128 +	// object is interrupted by another call to Pls() by another thread
   1.129 +	if (SetPls(p, aLibraryUid) != KErrNone)
   1.130 +		{
   1.131 +		// SetPls() failed due to a size limit being reached in the wsdArray
   1.132 +		FreePls(p);
   1.133 +		ReleasePlsMutex(mutexHandle);
   1.134 +		User::Panic(KWsdArrayFull, KErrNoMemory);				
   1.135 +		}
   1.136 +
   1.137 +	ReleasePlsMutex(mutexHandle);		
   1.138 +	return p;
   1.139 +	}
   1.140 +
   1.141 +#endif // __WINSCW__
   1.142 +
   1.143 +#endif // __PLS_H__
   1.144 +