125 lines
3.7 KiB
Groff
125 lines
3.7 KiB
Groff
.\" 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.
|
|
.\"
|
|
.\" @(#)msync.2 8.2 (Berkeley) 6/21/94
|
|
.\" $FreeBSD: src/lib/libc/sys/msync.2,v 1.17 2000/04/21 09:41:53 phantom Exp $
|
|
.\"
|
|
.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/mman.h>
|
|
.Ft int
|
|
.Fo msync
|
|
.Fa "void *addr"
|
|
.Fa "size_t len"
|
|
.Fa "int flags"
|
|
.Fc
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn msync
|
|
system call writes modified whole pages back to the filesystem
|
|
and updates the file modification time.
|
|
Only those pages containing
|
|
.Fa addr
|
|
and
|
|
.Fa len-1
|
|
succeeding locations will be examined.
|
|
.Pp
|
|
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
|
|
.Pp
|
|
The
|
|
.Fa MS_ASYNC
|
|
flag is not permitted to be combined with other flags.
|
|
.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 EBUSY
|
|
Some of the specified addresses are locked
|
|
and MS_INVALIDATE is specified.
|
|
.\" ===========
|
|
.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 less than 1.
|
|
.\" ===========
|
|
.It Bq Er EINVAL
|
|
.Fa flags
|
|
is invalid
|
|
(e.g., it combines MS_ASYNC with another flag,
|
|
which is not permitted).
|
|
.\" ===========
|
|
.It Bq Er EIO
|
|
An I/O error occurs while writing to the file system.
|
|
.\" ===========
|
|
.It Bq Er ENOMEM
|
|
The specified address range is outside of the address range
|
|
of the process or includes an unmapped page.
|
|
.El
|
|
.Sh LEGACY SYNOPSIS
|
|
.Fd #include <sys/types.h>
|
|
.Fd #include <sys/mman.h>
|
|
.Pp
|
|
The include file
|
|
.In sys/types.h
|
|
is necessary.
|
|
.Sh SEE ALSO
|
|
.Xr madvise 2 ,
|
|
.Xr mincore 2 ,
|
|
.Xr mprotect 2 ,
|
|
.Xr munmap 2 ,
|
|
.Xr compat 5
|
|
.Sh HISTORY
|
|
The
|
|
.Fn msync
|
|
function first appeared in
|
|
.Bx 4.4 .
|