83 lines
2.7 KiB
Groff
83 lines
2.7 KiB
Groff
.\" $NetBSD: getiobuf.9,v 1.3 2008/05/06 11:32:47 yamt Exp $
|
|
.\"
|
|
.\" Copyright (c)2006,2008 YAMAMOTO Takashi,
|
|
.\" 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.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
|
|
.\" ------------------------------------------------------------
|
|
.Dd May 6, 2008
|
|
.Dt GETIOBUF 9
|
|
.Os
|
|
.Sh NAME
|
|
.Nm getiobuf ,
|
|
.Nm putiobuf
|
|
.Nd I/O descriptor allocation interface
|
|
.\" ------------------------------------------------------------
|
|
.Sh SYNOPSIS
|
|
.In sys/buf.h
|
|
.Ft struct buf *
|
|
.Fn getiobuf "struct vnode *vp" "bool waitok"
|
|
.Ft void
|
|
.Fn putiobuf "struct buf *bp"
|
|
.\" ------------------------------------------------------------
|
|
.Sh DESCRIPTION
|
|
.Bl -tag -width compact
|
|
.\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|
|
.Fn getiobuf
|
|
allocates a
|
|
.Em buf
|
|
structure.
|
|
.Pp
|
|
.Bl -tag -width waitok
|
|
.It Fa vp
|
|
The vnode to which the allocated buffer will be associated.
|
|
This can be
|
|
.Dv NULL .
|
|
.It Fa waitok
|
|
If true,
|
|
.Fa getiobuf
|
|
can sleep until enough memory is available.
|
|
Otherwise, it returns
|
|
.Dv NULL
|
|
immediately if enough memory is not available.
|
|
.El
|
|
.Pp
|
|
Note that the allocated buffer doesn't belong to buffer cache.
|
|
To free it,
|
|
.Fn putiobuf
|
|
should be used.
|
|
.Fn brelse
|
|
should not be used on it.
|
|
.Pp
|
|
.\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|
|
.Fn putiobuf
|
|
frees
|
|
.Fa bp ,
|
|
which should be a buffer allocated with
|
|
.Fn getiobuf .
|
|
.\" - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
|
|
.El
|
|
.\" ------------------------------------------------------------
|
|
.Sh SEE ALSO
|
|
.Xr buffercache 9 ,
|
|
.Xr intro 9
|