xref: /aoo41x/main/framework/inc/threadhelp/resetableguard.hxx (revision cdf0e10c)

/*************************************************************************
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * Copyright 2000, 2010 Oracle and/or its affiliates.
 *
 * OpenOffice.org - a multi-platform office productivity suite
 *
 * This file is part of OpenOffice.org.
 *
 * OpenOffice.org is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License version 3
 * only, as published by the Free Software Foundation.
 *
 * OpenOffice.org is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License version 3 for more details
 * (a copy is included in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU Lesser General Public License
 * version 3 along with OpenOffice.org.  If not, see
 * <http://www.openoffice.org/license.html>
 * for a copy of the LGPLv3 License.
 *
 ************************************************************************/

#ifndef __FRAMEWORK_THREADHELP_RESETABLEGUARD_HXX_
#define __FRAMEWORK_THREADHELP_RESETABLEGUARD_HXX_

//_________________________________________________________________________________________________________________
//	my own includes
//_________________________________________________________________________________________________________________

#include <threadhelp/inoncopyable.h>
#include <framework/imutex.hxx>

//#ifndef __FRAMEWORK_THREADHELP_THREADHELPBASE_HXX_
//#include <threadhelp/threadhelpbase.hxx>
//#endif

//_________________________________________________________________________________________________________________
//	interface includes
//_________________________________________________________________________________________________________________

//_________________________________________________________________________________________________________________
//	other includes
//_________________________________________________________________________________________________________________
#include <sal/types.h>

//_________________________________________________________________________________________________________________
//	namespace
//_________________________________________________________________________________________________________________

namespace framework{

//_________________________________________________________________________________________________________________
//	const
//_________________________________________________________________________________________________________________

//_________________________________________________________________________________________________________________
//	declarations
//_________________________________________________________________________________________________________________

/*-************************************************************************************************************//**
	@short          implement a guard for implementing save thread access
	@descr			These guard has an additional feature to well known one ::osl::Guard.
					You can lock() and unlock() it very often!
					A set bool flag inside protect this implementation against multiple lock() calls
					without any unlock()! So the increasing of guarded mutex couldn't be greater then 1 ...

    @attention      a) To prevent us against wrong using, the default ctor, copy ctor and the =operator are maked private!
                    b) Use interface "IMutex" of set LockHelper only - because we must support an exclusiv locking.
                       Interface "IRWLock" should be used by special guard implementations ... like "ReadGuard" or "WriteGuard"!

	@implements		-
    @base           INonCopyable

	@devstatus		ready to use
*//*-*************************************************************************************************************/
class ResetableGuard : private INonCopyable
{
	//-------------------------------------------------------------------------------------------------------------
	//	public methods
	//-------------------------------------------------------------------------------------------------------------
	public:

		/*-****************************************************************************************************//**
			@short		ctors
			@descr		Use these ctor methods to initialize the guard right.
                        Given lock reference must be valid - otherwise crashes could occure!

			@seealso	-

            @param      "pLock", pointer to lock helper of user
            @param      "rLock", reference to lock helper of user
			@return		-

			@onerror	-
		*//*-*****************************************************************************************************/
        inline ResetableGuard( IMutex* pLock )
            :   m_pLock    ( pLock     )
            ,   m_bLocked  ( sal_False )
        {
            lock();
        }

        //*********************************************************************************************************
        inline ResetableGuard( IMutex& rLock )
            :   m_pLock    ( &rLock    )
            ,   m_bLocked  ( sal_False )
        {
            lock();
        }

		/*-****************************************************************************************************//**
			@short		dtor
			@descr		We must release set mutex if programmer forget it ...

			@seealso	-

			@param		-
			@return		-

			@onerror	-
		*//*-*****************************************************************************************************/
        inline ~ResetableGuard()
        {
            unlock();
        }

		/*-****************************************************************************************************//**
			@short		enable/disable the lock
			@descr		Use this methods to lock or unlock the mutex.
						You can do it so often you wish to do that ...

            @attention  We use another member to prevent us against multiple acquire calls of the same guard
                        without suitable release calls!
                        You don't must protect access at these bool member by using an own mutex ....
                        because nobody use the same guard instance from different threads!
                        It will be a function-local object every time.

			@seealso	-

			@param		-
			@return		-

			@onerror	-
		*//*-*****************************************************************************************************/
        inline void lock()
        {
            if( m_bLocked == sal_False )
            {
                m_pLock->acquire();
                m_bLocked = sal_True;
            }
        }

        //*********************************************************************************************************
        inline void unlock()
        {
            if( m_bLocked == sal_True )
            {
                m_pLock->release();
                m_bLocked = sal_False;
            }
        }

	//-------------------------------------------------------------------------------------------------------------
	//	private methods
	//-------------------------------------------------------------------------------------------------------------
	private:

		/*-****************************************************************************************************//**
			@short		disable using of these functions!
			@descr		It's not allowed to use this methods. Different problem can occure otherwise.
						Thats why we disable it by make it private.

			@seealso	other ctor

			@param		-
			@return		-

			@onerror	-
		*//*-*****************************************************************************************************/
		ResetableGuard();

	//-------------------------------------------------------------------------------------------------------------
	//	private member
	//-------------------------------------------------------------------------------------------------------------
	private:

        IMutex*         m_pLock     ;   /// pointer to safed lock member of user
		sal_Bool		m_bLocked	;	/// protection against multiple lock() calls without unlock()

};		//	class ResetableGuard

}		//	namespace framework

#endif	//	#ifndef __FRAMEWORK_THREADHELP_RESETABLEGUARD_HXX_