mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-30 00:31:08 +00:00
77 lines
2.0 KiB
C
77 lines
2.0 KiB
C
/* shm_open -- open a POSIX shared memory object. Generic POSIX file version.
|
|
Copyright (C) 2001-2016 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 <shm-directory.h>
|
|
|
|
|
|
/* Open shared memory object. */
|
|
int
|
|
shm_open (const char *name, int oflag, mode_t mode)
|
|
{
|
|
SHM_GET_NAME (EINVAL, -1, "");
|
|
|
|
# ifdef O_NOFOLLOW
|
|
oflag |= O_NOFOLLOW;
|
|
# endif
|
|
# ifdef O_CLOEXEC
|
|
oflag |= O_CLOEXEC;
|
|
# endif
|
|
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);
|
|
|
|
# ifndef O_CLOEXEC
|
|
if (fd != -1)
|
|
{
|
|
/* We got a descriptor. Now set the FD_CLOEXEC bit. */
|
|
int flags = fcntl (fd, F_GETFD, 0);
|
|
|
|
if (__glibc_likely (flags != -1))
|
|
{
|
|
flags |= FD_CLOEXEC;
|
|
flags = fcntl (fd, F_SETFD, flags);
|
|
}
|
|
|
|
if (flags == -1)
|
|
{
|
|
/* Something went wrong. We cannot return the descriptor. */
|
|
int save_errno = errno;
|
|
close (fd);
|
|
fd = -1;
|
|
__set_errno (save_errno);
|
|
}
|
|
}
|
|
# endif
|
|
|
|
return fd;
|
|
}
|
|
|
|
#endif /* _POSIX_MAPPED_FILES */
|