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77 lines
2.0 KiB
C
77 lines
2.0 KiB
C
/* shm_open -- open a POSIX shared memory object. Generic POSIX file version.
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Copyright (C) 2001-2015 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<http://www.gnu.org/licenses/>. */
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#include <unistd.h>
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#if ! _POSIX_MAPPED_FILES
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# include <rt/shm_open.c>
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#else
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# include <fcntl.h>
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# include <shm-directory.h>
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/* Open shared memory object. */
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int
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shm_open (const char *name, int oflag, mode_t mode)
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{
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SHM_GET_NAME (EINVAL, -1, "");
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# ifdef O_NOFOLLOW
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oflag |= O_NOFOLLOW;
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# endif
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# ifdef O_CLOEXEC
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oflag |= O_CLOEXEC;
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# endif
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int fd = open (shm_name, oflag, mode);
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if (fd == -1 && __glibc_unlikely (errno == EISDIR))
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/* It might be better to fold this error with EINVAL since
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directory names are just another example for unsuitable shared
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object names and the standard does not mention EISDIR. */
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__set_errno (EINVAL);
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# ifndef O_CLOEXEC
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if (fd != -1)
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{
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/* We got a descriptor. Now set the FD_CLOEXEC bit. */
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int flags = fcntl (fd, F_GETFD, 0);
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if (__glibc_likely (flags != -1))
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{
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flags |= FD_CLOEXEC;
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flags = fcntl (fd, F_SETFD, flags);
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}
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if (flags == -1)
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{
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/* Something went wrong. We cannot return the descriptor. */
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int save_errno = errno;
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close (fd);
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fd = -1;
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__set_errno (save_errno);
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}
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}
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# endif
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return fd;
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}
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#endif /* _POSIX_MAPPED_FILES */
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