/* Copyright (c) 1997-2010
   Ewgenij Gawrilow, Michael Joswig (Technische Universitaet Darmstadt, Germany)
   http://www.polymake.de

   This program is free software; you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published by the
   Free Software Foundation; either version 2, or (at your option) any
   later version: http://www.gnu.org/licenses/gpl.txt.

   This program 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 General Public License for more details.
--------------------------------------------------------------------------------
   $Project: polymake $$Id: SharedMemoryMatrix.cc 9991 2010-12-12 23:36:28Z gawrilow $
*/

#include "polymake/SharedMemoryMatrix.h"
#include <sys/ipc.h>
#include <sys/shm.h>
#include <sstream>
#include <cerrno>

namespace pm {

void SharedMemorySegment::resize(size_t size)
{
   shmid=shmget(IPC_PRIVATE, size, 0600);
   if (shmid<0) {
      std::ostringstream err;
      err << "shmget error " << errno;
      throw std::runtime_error(err.str());
   }
   shmaddr=shmat(shmid,0,0);
   if (shmaddr==(void*)-1L) {
      shmaddr=0;
      std::ostringstream err;
      err << "shmat error " << errno;
      shmctl(shmid,IPC_RMID,0);
      throw std::runtime_error(err.str());
   }
}

SharedMemorySegment::~SharedMemorySegment()
{
   if (shmaddr) {
      shmdt(shmaddr);
      shmctl(shmid,IPC_RMID,0);
   }
}

}

// Local Variables:
// mode:C++
// c-basic-offset:3
// indent-tabs-mode:nil
// End:
