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shm.cc

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#include "rcs_defs.hh"

#include "shm.hh"
#include "_shm.h"               /* rcs_shm_open(), rcs_shm_close() */
#include "rcs_prnt.hh"          // rcs_print_error()


extern "C"
{
#ifndef NO_STDIO
#include <stdio.h>              /* fprintf(), stderr */
#endif
#ifndef UNDER_CE
#include <sys/types.h>          /* key_t */
#include <stddef.h>             /* size_t */
#include <errno.h>              // errno
#endif
#if !defined(VXWORKS) && !defined(WIN32)
#include <sys/ipc.h>            // IPC_CREAT
#endif
}

#ifdef WIN32
#if defined(WIN32) && !defined(USE_OLD_WINSOCK)
// Lame problem if windows.h is included before winsock2.h many redefined
// compiler errors result.
#include <winsock2.h>
#endif
#include <windows.h>            // GetLastError()
#endif

RCS_SHAREDMEM::RCS_SHAREDMEM (key_t key, size_t size, int oflag, int mode)
{
  shm = NULL;
  addr = NULL;
  delete_totally = 0;
  create_errno = 0;
  created = 0;

  if (oflag & RCS_SHAREDMEM_CREATE)
    {
      /* create shared memory */
#if defined(VXWORKS) || defined(_Windows)
      shm = rcs_shm_open (key, size, 1);
#else
#ifdef USE_POSIX_SHAREDMEM
      shm = rcs_shm_open (key, size, O_CREAT, mode);
#else
      shm = rcs_shm_open (key, size, IPC_CREAT, mode);
#endif
#endif
      if (shm == NULL)
        {
          create_errno = errno;
          rcs_print_error ("can't create shared memory\n");
          return;
        }
    }
  else
    {
      /* attach to existing shared memory */
      shm = rcs_shm_open (key, size, 0);
      if (shm == NULL)
        {
          create_errno = errno;
          rcs_print_error
            ("can't attach to shared memory-- is master started?\n");
          return;
        }
    }
  create_errno = shm->create_errno;
  created = shm->created;
  /* duplicate the pointer, so users don't
     have to dig into shm->addr */
  addr = shm->addr;
}

RCS_SHAREDMEM::~RCS_SHAREDMEM ()
{
  if (shm == NULL)
    {
      return;
    }
  else
    {
      if (delete_totally)
        {
          rcs_shm_delete (shm);
        }
      else
        {
          rcs_shm_close (shm);
        }
      shm = NULL;
    }
}

int
RCS_SHAREDMEM::nattch ()
{
  if (shm == NULL)
    {
      return -1;
    }
  else
    {
      return rcs_shm_nattch (shm);
    }
}

// This constructor declared private to prevent copying
RCS_SHAREDMEM::RCS_SHAREDMEM (RCS_SHAREDMEM & shm)
{
}

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