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Diffstat (limited to 'lib/libc/gen/shm_open.3')
| -rw-r--r-- | lib/libc/gen/shm_open.3 | 194 |
1 files changed, 0 insertions, 194 deletions
diff --git a/lib/libc/gen/shm_open.3 b/lib/libc/gen/shm_open.3 deleted file mode 100644 index d8af8794529ef..0000000000000 --- a/lib/libc/gen/shm_open.3 +++ /dev/null @@ -1,194 +0,0 @@ -.\" -.\" Copyright 2000 Massachusetts Institute of Technology -.\" -.\" Permission to use, copy, modify, and distribute this software and -.\" its documentation for any purpose and without fee is hereby -.\" granted, provided that both the above copyright notice and this -.\" permission notice appear in all copies, that both the above -.\" copyright notice and this permission notice appear in all -.\" supporting documentation, and that the name of M.I.T. not be used -.\" in advertising or publicity pertaining to distribution of the -.\" software without specific, written prior permission. M.I.T. makes -.\" no representations about the suitability of this software for any -.\" purpose. It is provided "as is" without express or implied -.\" warranty. -.\" -.\" THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''. M.I.T. DISCLAIMS -.\" ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE, -.\" INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF -.\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT -.\" SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, -.\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT -.\" LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF -.\" USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND -.\" ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, -.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT -.\" OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF -.\" SUCH DAMAGE. -.\" -.\" $FreeBSD$ -.\" -.Dd March 24, 2000 -.Dt SHM_OPEN 3 -.Os -.Sh NAME -.Nm shm_open -.Nd open or create a shared memory object -.Nm shm_unlink -.Nd remove a shared memory object -.Sh LIBRARY -.Lb libc -.Sh SYNOPSIS -.Fd #include <sys/types.h> -.Fd #include <sys/mman.h> -.Ft int -.Fn shm_open "const char *path" "int flags" "mode_t mode" -.Ft int -.Fn shm_unlink "const char *path" -.Sh DESCRIPTION -The -.Nm shm_open -function opens (or optionally creates) a -.Tn POSIX -shared memory object named -.Fa path . -The -.Nm shm_unlink -function removes a shared memory object named -.Fa path . -.Pp -In the -.Fx -implementation, -.Tn POSIX -shared memory objects are implemented as ordinary files. -The -.Nm shm_open -and -.Nm shm_unlink -act as wrappers around the -.Xr open 2 -and -.Xr unlink 2 -routines, and -.Fa path , -.Fa flags , -and -.Fa mode -arguments are as specified for those functions. -The -.Fa flags -argument is checked to ensure that the access mode specified is not -.Dv O_WRONLY -(which is not defined for shared memory objects). -.Pp -In addition, the -.Fx -implementation causes -.Fn mmap -of a descriptor returned by -.Nm shm_open -to behave as if the -.Dv MAP_NOSYNC -flag had been specified to -.Xr mmap 2 . -(It does so by setting a special file flag using -.Xr fcntl 2 . ) -.Pp -The -.Nm shm_unlink -function makes no effort to ensure that -.Fa path -refers to a shared memory object. -.Sh PORTABILITY -The -.Fa path -argument does not necessarily represent a pathname (although it does in this -and most other implementations). -Two processes opening the same -.Fa path -are guaranteed to access the same shared memory object if and only if -.Fa path -begins with a slash -.Pq Ql \&/ -character. -.Pp -Only the -.Dv O_RDONLY , -.Dv O_RDWR , -.Dv O_CREAT , -.Dv O_EXCL , -and -.Dv O_TRUNC -flags may be used in portable programs. -.Pp -The result of using -.Xr open 2 , -.Xr read 2 , -or -.Xr write 2 -on a shared memory object, or on the descriptor returned by -.Fn shm_open , -is undefined. -It is also undefined whether the shared memory object itself, or its -contents, persist across reboots. -.Sh RETURN VALUES -If successful, -.Fn shm_open -returns a non-negative integer; -.Fn shm_unlink -returns zero. -Both functions return -1 on failure, and set -.Va errno -to indicate the error. -.Sh ERRORS -The -.Fn shm_open -and -.Fn shm_unlink -functions can fail with any error defined for -.Fn open -and -.Fn unlink , -respectively. In addition, the following errors are defined for -.Fn shm_open : -.Bl -tag -width Er -.It Bq Er EINVAL -The object named by -.Fa path -is not a shared memory object -(i.e., it is not a regular file). -.It Bq Er EINVAL -The -.Fa flags -argument to -.Fn shm_open -specifies an access mode of -.Dv O_WRONLY . -.El -.Sh SEE ALSO -.Xr mmap 2 , -.Xr munmap 2 , -.Xr open 2 , -.Xr unlink 2 -.Sh STANDARDS -The -.Nm shm_open -and -.Nm shm_unlink -functions are believed to conform to -.St -p1003.1b . -.Sh HISTORY -The -.Nm shm_open -and -.Nm shm_unlink -functions first appeared in -.Fx 5.0 . -.Sh AUTHORS -.An Garrett A. Wollman Aq wollman@FreeBSD.org -(C library support and this manual page) -.Pp -.An Matthew Dillon Aq dillon@FreeBSD.org -.Pq Dv MAP_NOSYNC - |