1/* shm_open -- open a POSIX shared memory object. Generic POSIX file version.
2 Copyright (C) 2001-2021 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <unistd.h>
20
21#if ! _POSIX_MAPPED_FILES
22
23# include <rt/shm_open.c>
24
25#else
26
27# include <fcntl.h>
28# include <pthread.h>
29# include <shm-directory.h>
30
31
32/* Open shared memory object. */
33int
34shm_open (const char *name, int oflag, mode_t mode)
35{
36 SHM_GET_NAME (EINVAL, -1, "");
37
38 oflag |= O_NOFOLLOW | O_CLOEXEC;
39
40 /* Disable asynchronous cancellation. */
41 int state;
42 pthread_setcancelstate (PTHREAD_CANCEL_DISABLE, &state);
43
44 int fd = open (shm_name, oflag, mode);
45 if (fd == -1 && __glibc_unlikely (errno == EISDIR))
46 /* It might be better to fold this error with EINVAL since
47 directory names are just another example for unsuitable shared
48 object names and the standard does not mention EISDIR. */
49 __set_errno (EINVAL);
50
51 pthread_setcancelstate (state, NULL);
52
53 return fd;
54}
55
56#endif /* _POSIX_MAPPED_FILES */
57