freebsd-dev/lib/libc/sys/msync.2

.\" Copyright (c) 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
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.\" modification, are permitted provided that the following conditions
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.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
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.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
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.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS 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
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.\"	@(#)msync.2	8.2 (Berkeley) 6/21/94
.\" $FreeBSD$
.\"
.Dd June 21, 1994
.Dt MSYNC 2
.Os
.Sh NAME
.Nm msync
.Nd synchronize a mapped region
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.Fd #include <sys/types.h>
.Fd #include <sys/mman.h>
.Ft int
.Fn msync "void *addr" "size_t len" "int flags"
.Sh DESCRIPTION
The
.Fn msync
system call
writes any modified pages back to the filesystem and updates
the file modification time.
If
.Fa len
is 0, all modified pages within the region containing
.Fa addr
will be flushed;
if
.Fa len
is non-zero, only those pages containing 
.Fa addr
and
.Fa len-1
succeeding locations will be examined.
The
.Fa flags
argument may be specified as follows:
.Bd -literal
MS_ASYNC	Return immediately
MS_SYNC		Perform synchronous writes
MS_INVALIDATE	Invalidate all cached data
.Ed
.Sh RETURN VALUES
If any errors occur, -1 is returned and errno is set to indicate the
error.
Otherwise, a 0 value is returned.
.Sh ERRORS
.Fn msync
will fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
.Fa addr
is not a multiple of the hardware page size.
.It Bq Er EINVAL
.Fa len
is too large or negative.
.It Bq Er EINVAL
.Fa flags
was both MS_ASYNC and MS_INVALIDATE.
Only one of these flags is allowed.
.It Bq Er EIO
An I/O error occurred while writing to the file system.
.El
.Sh SEE ALSO
.Xr madvise 2 ,
.Xr mincore 2 ,
.Xr mprotect 2 ,
.Xr munmap 2
.Sh HISTORY
The
.Fn msync
function first appeared in
.Bx 4.4 .
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.\" Copyright (c) 1991, 1993`
			`.\" The Regents of the University of California. All rights reserved.`
			`.\"`
			`.\" Redistribution and use in source and binary forms, with or without`
			`.\" modification, are permitted provided that the following conditions`
			`.\" are met:`
			`.\" 1. Redistributions of source code must retain the above copyright`
			`.\" notice, this list of conditions and the following disclaimer.`
			`.\" 2. Redistributions in binary form must reproduce the above copyright`
			`.\" notice, this list of conditions and the following disclaimer in the`
			`.\" documentation and/or other materials provided with the distribution.`
			`.\" 3. All advertising materials mentioning features or use of this software`
			`.\" must display the following acknowledgement:`
			`.\" This product includes software developed by the University of`
			`.\" California, Berkeley and its contributors.`
			`.\" 4. Neither the name of the University nor the names of its contributors`
			`.\" may be used to endorse or promote products derived from this software`
			`.\" without specific prior written permission.`
			`.\"`
			.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
			`.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE`
			`.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE`
			`.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS 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.`
			`.\"`
Merge from Lite2 onto mainline - - add undelete() and undelete.2 (requires libc minor bump some time) - man page updates 1997-03-11 11:35:56 +00:00			`.\" @(#)msync.2 8.2 (Berkeley) 6/21/94`
$Id$ -> $FreeBSD$ 1999-08-28 00:22:10 +00:00			`.\" $FreeBSD$`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.\"`
Merge from Lite2 onto mainline - - add undelete() and undelete.2 (requires libc minor bump some time) - man page updates 1997-03-11 11:35:56 +00:00			`.Dd June 21, 1994`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Dt MSYNC 2`
			`.Os`
			`.Sh NAME`
			`.Nm msync`
			`.Nd synchronize a mapped region`
Introduce ".Lb" macro to libc manpages. More libraries manpages updates following. 2000-04-21 09:42:15 +00:00			`.Sh LIBRARY`
			`.Lb libc`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Sh SYNOPSIS`
Submitted by: bruce, davidg, dyson add a BUG section for mmap with current limitation section SYNOPSIS completed 1996-02-02 05:06:29 +00:00			`.Fd #include <sys/types.h>`
			`.Fd #include <sys/mman.h>`
Minor mdoc fixes in msync.2 and munmap.2. Add RETURN VALUES and ERRORS sections to mincore. Closes PR# 1493. 1997-01-11 23:33:18 +00:00			`.Ft int`
Convert caddr_t --> void * for sys/mman.h functions. mlock, mmap, mprotect, msync, munlock, and munmap are defined by POSIX as taking void . The const modifier has been added to mlock, munlock, and mprotect as the standard dictates. minherit comes from OpenBSD and has been updated to conform with their recent change to void . madvise and mincore are not defined by POSIX, but their arguments have been modified to be consistent with the POSIX-defined functions. mincore takes a const pointer, but madvise does not due to the MADV_FREE case. Discussed with: bde 1997-12-31 01:22:01 +00:00			`.Fn msync "void *addr" "size_t len" "int flags"`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Sh DESCRIPTION`
			`The`
			`.Fn msync`
			`system call`
			`writes any modified pages back to the filesystem and updates`
			`the file modification time.`
			`If`
			`.Fa len`
			`is 0, all modified pages within the region containing`
			`.Fa addr`
			`will be flushed;`
			`if`
			`.Fa len`
Correct wording on range of addresses examined by `msync(2)'. PR: 7180 1998-07-09 06:16:22 +00:00			`is non-zero, only those pages containing`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Fa addr`
			`and`
Correct wording on range of addresses examined by `msync(2)'. PR: 7180 1998-07-09 06:16:22 +00:00			`.Fa len-1`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`succeeding locations will be examined.`
Updated manual page to indicate flags argument; added return value and errors section. 1995-03-25 17:24:47 +00:00			`The`
			`.Fa flags`
			`argument may be specified as follows:`
			`.Bd -literal`
We _do_ support MS_ASYNC Reviewed by: Matthew Dillon <dillon@apollo.backplane.com> 2000-01-24 18:35:16 +00:00			`MS_ASYNC Return immediately`
Document MS_SYNC. 1997-12-30 03:26:15 +00:00			`MS_SYNC Perform synchronous writes`
Updated manual page to indicate flags argument; added return value and errors section. 1995-03-25 17:24:47 +00:00			`MS_INVALIDATE Invalidate all cached data`
			`.Ed`
			`.Sh RETURN VALUES`
			`If any errors occur, -1 is returned and errno is set to indicate the`
Remove single-space hard sentence breaks. These degrade the quality of the typeset output, tend to make diffs harder to read and provide bad examples for new-comers to mdoc. 2000-03-02 09:14:21 +00:00			`error.`
			`Otherwise, a 0 value is returned.`
Updated manual page to indicate flags argument; added return value and errors section. 1995-03-25 17:24:47 +00:00			`.Sh ERRORS`
			`.Fn msync`
			`will fail if:`
			`.Bl -tag -width Er`
			`.It Bq Er EINVAL`
			`.Fa addr`
			`is not a multiple of the hardware page size.`
			`.It Bq Er EINVAL`
			`.Fa len`
			`is too large or negative.`
			`.It Bq Er EINVAL`
			`.Fa flags`
Remove single-space hard sentence breaks. These degrade the quality of the typeset output, tend to make diffs harder to read and provide bad examples for new-comers to mdoc. 2000-03-02 09:14:21 +00:00			`was both MS_ASYNC and MS_INVALIDATE.`
			`Only one of these flags is allowed.`
Merge from Lite2 onto mainline - - add undelete() and undelete.2 (requires libc minor bump some time) - man page updates 1997-03-11 11:35:56 +00:00			`.It Bq Er EIO`
Fix a bunch of spelling errors. PR: 6856 Submitted by: Josh Gilliam <josh@quick.net> 1998-06-04 21:06:07 +00:00			`An I/O error occurred while writing to the file system.`
Prepare for mdoc(7)NG. 2000-12-29 14:08:20 +00:00			`.El`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Sh SEE ALSO`
			`.Xr madvise 2 ,`
Minor mdoc fixes in msync.2 and munmap.2. Add RETURN VALUES and ERRORS sections to mincore. Closes PR# 1493. 1997-01-11 23:33:18 +00:00			`.Xr mincore 2 ,`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Xr mprotect 2 ,`
Sort cross references. 1997-01-20 23:23:22 +00:00			`.Xr munmap 2`
BSD 4.4 Lite Lib Sources 1994-05-27 05:00:24 +00:00			`.Sh HISTORY`
			`The`
			`.Fn msync`
Correctly use .Fn instead of .Nm to reference function names in a bunch of man pages. Use the correct .Bx (BSD UNIX) or .At (AT&T UNIX) macros instead of explicitly specifying the version in the text in a bunch of man pages. 1996-08-22 23:31:07 +00:00			`function first appeared in`
			`.Bx 4.4 .`