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/* ****************************************************************************
* eID Middleware Project.
* Copyright (C) 2008-2009 FedICT.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License version
* 3.0 as published by the Free Software Foundation.
*
* This software 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 software; if not, see
* http://www.gnu.org/licenses/.
**************************************************************************** */
#include "errno.h"
#include "SharedMem.h"
#include "Log.h"
#include "MWException.h"
#include "eidErrors.h"
namespace eIDMW
{
SharedMem::SharedMem()
{
}
SharedMem::~SharedMem()
{
Delete(m_iShmid);
}
void SharedMem::Attach(size_t tMemorySize,
const char *csReadableFilePath,
void ** content)
{
m_csFilename = csReadableFilePath;
// create a key on the base of the file name passed
m_tKey = ftok(csReadableFilePath, 0666 | IPC_CREAT);
if(m_tKey == -1)
{
MWLOG(LEV_ERROR, MOD_DLG, L" SharedMem::Attach ftok: %s", strerror(errno) );
throw CMWEXCEPTION(EIDMW_ERR_MEMORY);
}
// create the memory segment and get its ID
m_iShmid = shmget(m_tKey,tMemorySize, 0666 | IPC_CREAT );
if(m_iShmid == -1)
{
MWLOG(LEV_ERROR, MOD_DLG, L" SharedMem::Attach shmid: %s",strerror(errno));
throw CMWEXCEPTION(EIDMW_ERR_MEMORY);
}
// attach the pointer
*content = shmat(m_iShmid,0,0) ;
MWLOG(LEV_DEBUG, MOD_DLG, L" SharedMem::Attach attached segment with ID %d",m_iShmid);
}
void SharedMem::Detach(void* content)
{
MWLOG(LEV_DEBUG, MOD_DLG, L" SharedMem::Detach segment with ID %d",m_iShmid);
if( shmdt(content) == -1)
{
MWLOG(LEV_ERROR, MOD_DLG, L" SharedMem::Detach shmdt: %s", strerror(errno) );
throw CMWEXCEPTION(EIDMW_ERR_MEMORY);
}
}
int SharedMem::getNAttached(int iSegmentID)
{
shmid_ds tResult;
if( shmctl(iSegmentID, IPC_STAT, &tResult) == -1)
{
MWLOG(LEV_DEBUG, MOD_DLG, L" SharedMem::getNAttached shmctl: %s",strerror(errno) );
return -1;
}
return tResult.shm_nattch;
}
void SharedMem::Delete(int iSegmentID)
{
// delete the shared memory area
// once all processes have detached from this segment
int iAttachedProcs = getNAttached(iSegmentID);
if( iAttachedProcs > -1 )
{
MWLOG(LEV_DEBUG, MOD_DLG, L" SharedMem::Delete : request to delete memory segment with ID %d. N proc = %d", iSegmentID,iAttachedProcs);
// check that no process is attached to this segment
if( iAttachedProcs == 0)
{
if( shmctl(iSegmentID,IPC_RMID,NULL) == 1)
{
MWLOG(LEV_ERROR, MOD_DLG, L" SharedMem::Delete shmctl: %s", strerror(errno) );
throw CMWEXCEPTION(EIDMW_ERR_MEMORY);
}
MWLOG(LEV_DEBUG, MOD_DLG, L" SharedMem::Delete : deleted memory segment with ID %d", iSegmentID);
}
}
}
}
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