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Diffstat (limited to 'sysdeps/posix/shm_open.c')
-rw-r--r--sysdeps/posix/shm_open.c85
1 files changed, 85 insertions, 0 deletions
diff --git a/sysdeps/posix/shm_open.c b/sysdeps/posix/shm_open.c
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+++ b/sysdeps/posix/shm_open.c
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+/* shm_open -- open a POSIX shared memory object. Generic POSIX file version.
+ Copyright (C) 2001 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 Library General Public License as
+ published by the Free Software Foundation; either version 2 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
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If not,
+ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#include <unistd.h>
+
+#if ! _POSIX_MAPPED_FILES
+#include <sysdeps/generic/shm_open.c>
+
+#else
+
+#include <errno.h>
+#include <sys/mman.h>
+#include <fcntl.h>
+#include <string.h>
+#include <stdlib.h>
+#include <paths.h>
+
+#define SHMDIR (_PATH_VARRUN "shm/")
+
+/* Open shared memory object. */
+int
+shm_open (const char *name, int oflag, mode_t mode)
+{
+ size_t namelen;
+ char *fname;
+ int fd;
+
+ /* Construct the filename. */
+ while (name[0] == '/')
+ ++name;
+
+ if (name[0] == '\0')
+ {
+ /* The name "/" is not supported. */
+ __set_errno (EINVAL);
+ return -1;
+ }
+
+ namelen = strlen (name);
+ fname = (char *) __alloca (sizeof SHMDIR - 1 + namelen + 1);
+ __mempcpy (__mempcpy (fname, SHMDIR, sizeof SHMDIR - 1),
+ name, namelen + 1);
+
+ fd = open (name, oflag, mode);
+ if (fd != -1)
+ {
+ /* We got a descriptor. Now set the FD_CLOEXEC bit. */
+ int flags = fcntl (fd, F_GETFD, 0);
+
+ if (__builtin_expect (flags, 0) != -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);
+ }
+ }
+
+ return fd;
+}
+
+#endif