/*  camserv - An internet streaming picture application * *  Copyright (C) 1999-2002  Jon Travis (jtravis@p00p.org) * *  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 of the License, or *  (at your option) any later version. * *  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. * *  You should have received a copy of the GNU General Public License *  along with this program; if not, write to the Free Software *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */#include <stdio.h>#include <stdlib.h>#include <string.h>#include <errno.h>#include <sys/types.h>#include <sys/ipc.h>#include <sys/shm.h>#include <unistd.h>#include "log.h"#include "camshm.h"#define MODNAME "shm"/* * shm_dest:  Destroy a shared memory segment based on a shmid. * * Arguments:  shmid = Shared memory segment to destroy */void shm_dest( int shmid ){  if( shmctl( shmid, IPC_RMID, NULL ) == -1 ){    camserv_log( MODNAME, "Unable to destroy shared memory segment");    return;  }}/* * shm_setup:  Setup a shared memory segment. * * Arguments:  pathname = Pathname to associated with shm segment. *             size     = # of bytes to allocate for shm *             addr     = Location to store pointer to new shared memory * * Return values:  Returns -1 if the shm segment could not be setup, else 0 */int shm_setup( const char *pathname, int size, char **addr ){  key_t shm_key;  int shm_res;  pid_t pid;  pid = getpid();  if( (shm_key = ftok( pathname, pid )) == -1 ){    camserv_log( MODNAME, "Failed to get shared memory key!");    return -1;  }   if( (shm_res = shmget( shm_key, size, 			 IPC_CREAT | 0600 )) == -1 ){    camserv_log( MODNAME, "Failed to create shared memory segment: %s",		 strerror( errno ));    return -1;  }  if( (*addr = shmat( shm_res, 0, 0 )) == NULL ){    camserv_log( MODNAME, "Could not attach to shared memory segment: %s",		 strerror( errno ));    shm_dest( shm_res );    return -1;  }  /* Now that we are attached, and everything is perfect, mark it for     deletion, in case we exit abnormally */  shm_dest( shm_res );  return shm_res;}