277 lines
12 KiB
C++
277 lines
12 KiB
C++
/*************************************************************************
|
|
*
|
|
* OpenOffice.org - a multi-platform office productivity suite
|
|
*
|
|
* $RCSfile: writeguard.hxx,v $
|
|
*
|
|
* $Revision: 1.6 $
|
|
*
|
|
* last change: $Author: hr $ $Date: 2006-06-19 11:02:28 $
|
|
*
|
|
* The Contents of this file are made available subject to
|
|
* the terms of GNU Lesser General Public License Version 2.1.
|
|
*
|
|
*
|
|
* GNU Lesser General Public License Version 2.1
|
|
* =============================================
|
|
* Copyright 2005 by Sun Microsystems, Inc.
|
|
* 901 San Antonio Road, Palo Alto, CA 94303, USA
|
|
*
|
|
* This library is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License version 2.1, as published by the Free Software Foundation.
|
|
*
|
|
* This library 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 for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with this library; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
|
|
* MA 02111-1307 USA
|
|
*
|
|
************************************************************************/
|
|
|
|
#ifndef __FRAMEWORK_THREADHELP_WRITEGUARD_HXX_
|
|
#define __FRAMEWORK_THREADHELP_WRITEGUARD_HXX_
|
|
|
|
//_________________________________________________________________________________________________________________
|
|
// my own includes
|
|
//_________________________________________________________________________________________________________________
|
|
|
|
#ifndef __FRAMEWORK_THREADHELP_INONCOPYABLE_H_
|
|
#include <threadhelp/inoncopyable.h>
|
|
#endif
|
|
|
|
#ifndef __FRAMEWORK_THREADHELP_IRWLOCK_H_
|
|
#include <threadhelp/irwlock.h>
|
|
#endif
|
|
|
|
//#ifndef __FRAMEWORK_THREADHELP_THREADHELPBASE_HXX_
|
|
//#include <threadhelp/threadhelpbase.hxx>
|
|
//#endif
|
|
|
|
//_________________________________________________________________________________________________________________
|
|
// interface includes
|
|
//_________________________________________________________________________________________________________________
|
|
|
|
//_________________________________________________________________________________________________________________
|
|
// other includes
|
|
//_________________________________________________________________________________________________________________
|
|
|
|
//_________________________________________________________________________________________________________________
|
|
// namespace
|
|
//_________________________________________________________________________________________________________________
|
|
|
|
namespace framework{
|
|
|
|
//_________________________________________________________________________________________________________________
|
|
// const
|
|
//_________________________________________________________________________________________________________________
|
|
|
|
//_________________________________________________________________________________________________________________
|
|
// declarations
|
|
//_________________________________________________________________________________________________________________
|
|
|
|
/*-************************************************************************************************************//**
|
|
@short implement a guard to set write locks
|
|
@descr This guard should be used to set a lock for reading AND writing object internal member.
|
|
We never need a own mutex to safe our internal member access - because
|
|
a guard is used as function-local member only. There exist no multithreaded access to it realy ...
|
|
|
|
@attention a) To prevent us against wrong using, the default ctor, copy ctor and the =operator are maked private!
|
|
b) Use interface "IRWLock" of set LockHelper only - because we must support a finer granularity of locking.
|
|
Interface "IMutex" should be used by easier guard implementations ... like "ResetableGuard"!
|
|
|
|
@implements -
|
|
@base INonCopyable
|
|
|
|
@devstatus ready to use
|
|
*//*-*************************************************************************************************************/
|
|
class WriteGuard : private INonCopyable
|
|
{
|
|
//-------------------------------------------------------------------------------------------------------------
|
|
// public methods
|
|
//-------------------------------------------------------------------------------------------------------------
|
|
public:
|
|
|
|
/*-****************************************************************************************************//**
|
|
@short ctor
|
|
@descr These ctors initialize the guard with a reference to used lock member of object to protect.
|
|
Null isn't allowed as value!
|
|
|
|
@seealso -
|
|
|
|
@param "pLock" ,reference to used lock member of object to protect
|
|
@param "rLock" ,reference to used lock member of object to protect
|
|
@return -
|
|
|
|
@onerror -
|
|
*//*-*****************************************************************************************************/
|
|
inline WriteGuard( IRWLock* pLock )
|
|
: m_pLock ( pLock )
|
|
, m_eMode ( E_NOLOCK )
|
|
{
|
|
lock();
|
|
}
|
|
|
|
//*********************************************************************************************************
|
|
inline WriteGuard( IRWLock& rLock )
|
|
: m_pLock ( &rLock )
|
|
, m_eMode ( E_NOLOCK )
|
|
{
|
|
lock();
|
|
}
|
|
|
|
/*-****************************************************************************************************//**
|
|
@short dtor
|
|
@descr We unlock the used lock member automaticly if user forget it.
|
|
|
|
@seealso -
|
|
|
|
@param -
|
|
@return -
|
|
|
|
@onerror -
|
|
*//*-*****************************************************************************************************/
|
|
inline ~WriteGuard()
|
|
{
|
|
unlock();
|
|
}
|
|
|
|
/*-****************************************************************************************************//**
|
|
@short set write lock
|
|
@descr Call this method to set the write lock. The call will block till all current threads are synchronized!
|
|
|
|
@seealso method unlock()
|
|
|
|
@param -
|
|
@return -
|
|
|
|
@onerror -
|
|
*//*-*****************************************************************************************************/
|
|
inline void lock()
|
|
{
|
|
switch( m_eMode )
|
|
{
|
|
case E_NOLOCK : {
|
|
// Acquire write access and set return state.
|
|
// Mode is set later if it was successful!
|
|
m_pLock->acquireWriteAccess();
|
|
m_eMode = E_WRITELOCK;
|
|
}
|
|
break;
|
|
case E_READLOCK : {
|
|
// User has downgrade to read access before!
|
|
// We must release it before we can set a new write access!
|
|
m_pLock->releaseReadAccess();
|
|
m_pLock->acquireWriteAccess();
|
|
m_eMode = E_WRITELOCK;
|
|
}
|
|
break;
|
|
default: break; // nothing to do
|
|
}
|
|
}
|
|
|
|
/*-****************************************************************************************************//**
|
|
@short unset write lock
|
|
@descr Call this method to unlock the rw-lock temp.!
|
|
Normaly we do it at dtor automaticly for you ...
|
|
|
|
@seealso method lock()
|
|
|
|
@param -
|
|
@return -
|
|
|
|
@onerror -
|
|
*//*-*****************************************************************************************************/
|
|
inline void unlock()
|
|
{
|
|
switch( m_eMode )
|
|
{
|
|
case E_READLOCK : {
|
|
// User has downgraded to a read lock before!
|
|
// => There isn't realy a write lock ...
|
|
m_pLock->releaseReadAccess();
|
|
m_eMode = E_NOLOCK;
|
|
}
|
|
break;
|
|
case E_WRITELOCK : {
|
|
m_pLock->releaseWriteAccess();
|
|
m_eMode = E_NOLOCK;
|
|
}
|
|
break;
|
|
default: break; // nothing to do
|
|
}
|
|
}
|
|
|
|
/*-****************************************************************************************************//**
|
|
@short downgrade write access to read access without new blocking!
|
|
@descr If this write lock is set you can change it to a "read lock".
|
|
An "upgrade" is the same like new calling "lock()"!
|
|
|
|
@seealso -
|
|
|
|
@param -
|
|
@return -
|
|
|
|
@onerror -
|
|
*//*-*****************************************************************************************************/
|
|
inline void downgrade()
|
|
{
|
|
if( m_eMode == E_WRITELOCK )
|
|
{
|
|
m_pLock->downgradeWriteAccess();
|
|
m_eMode = E_READLOCK;
|
|
}
|
|
}
|
|
|
|
/*-****************************************************************************************************//**
|
|
@short return internal states
|
|
@descr For user they dont know what they are doing ...
|
|
|
|
@seealso -
|
|
|
|
@param -
|
|
@return Current set lock mode.
|
|
|
|
@onerror No error should occure.
|
|
*//*-*****************************************************************************************************/
|
|
inline ELockMode getMode() const
|
|
{
|
|
return m_eMode;
|
|
}
|
|
|
|
//-------------------------------------------------------------------------------------------------------------
|
|
// 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 -
|
|
*//*-*****************************************************************************************************/
|
|
WriteGuard();
|
|
|
|
//-------------------------------------------------------------------------------------------------------------
|
|
// private member
|
|
//-------------------------------------------------------------------------------------------------------------
|
|
private:
|
|
|
|
IRWLock* m_pLock ; /// reference to lock-member of protected object
|
|
ELockMode m_eMode ; /// protection against multiple lock calls without unlock and difference between supported lock modi
|
|
|
|
}; // class WriteGuard
|
|
|
|
} // namespace framework
|
|
|
|
#endif // #ifndef __FRAMEWORK_THREADHELP_WRITEGUARD_HXX_
|