'\" te
.\"  Copyright 1989 AT&T
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.TH biowait 9F "11 Apr 1991" "SunOS 5.11" "Kernel Functions for Drivers"
.SH NAME
biowait \- suspend processes pending completion of block I/O
.SH SYNOPSIS
.LP
.nf
#include <sys/types.h>
#include <sys/buf.h>



\fBint\fR \fBbiowait\fR(\fBstruct buf *\fR\fIbp\fR);
.fi

.SH INTERFACE LEVEL
.sp
.LP
Architecture independent level 1 (DDI/DKI).
.SH PARAMETERS
.sp
.ne 2
.mk
.na
\fB\fIbp\fR \fR
.ad
.RS 7n
.rt  
Pointer to the \fBbuf\fR structure describing the transfer.
.RE

.SH DESCRIPTION
.sp
.LP
Drivers allocating their own  \fBbuf\fR structures with  \fBgetrbuf\fR(9F) can
use the \fBbiowait()\fR function to suspend the current thread and wait for
completion of  the transfer.
.sp
.LP
Drivers  must call \fBbiodone\fR(9F) when the transfer is complete to notify
the thread blocked by \fBbiowait()\fR. \fBbiodone()\fR is usually called in the
interrupt routine.
.SH RETURN VALUES
.sp
.ne 2
.mk
.na
\fB\fB0\fR \fR
.ad
.RS 12n
.rt  
Upon success
.RE

.sp
.ne 2
.mk
.na
\fB\fBnon-zero\fR\fR
.ad
.RS 12n
.rt  
Upon \fBI/O\fR failure.  \fBbiowait()\fR calls \fBgeterror\fR(9F) to retrieve
the error number which it returns.
.RE

.SH CONTEXT
.sp
.LP
\fBbiowait()\fR can be called from user context only.
.SH SEE ALSO
.sp
.LP
\fBbiodone\fR(9F), \fBgeterror\fR(9F), \fBgetrbuf\fR(9F), \fBbuf\fR(9S)
.sp
.LP
\fIWriting Device Drivers\fR