/* shm_open -- open a POSIX shared memory object.  Generic POSIX file version.

   Copyright (C) 2001-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C 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 the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <unistd.h>

#if ! _POSIX_MAPPED_FILES

# include <rt/shm_open.c>

#else

# include <fcntl.h>

# include <pthread.h>

# include <shm-directory.h>

/* Open shared memory object.  */

int

shm_open (const char *name, int oflag, mode_t mode)

{

  SHM_GET_NAME (EINVAL, -1, "");

  oflag |= O_NOFOLLOW | O_CLOEXEC;

  /* Disable asynchronous cancellation.  */

  int state;

  pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &state);

  int fd = open (shm_name, oflag, mode);

  if (fd == -1 && __glibc_unlikely (errno == EISDIR))

    /* It might be better to fold this error with EINVAL since

       directory names are just another example for unsuitable shared

       object names and the standard does not mention EISDIR.  */

    __set_errno (EINVAL);

  pthread_setcancelstate (state, NULL);

  return fd;

}

#endif  /* _POSIX_MAPPED_FILES */