2004-05-09 15:28:58 +04:00
|
|
|
.\" $NetBSD: sa_yield.2,v 1.4 2004/05/09 11:28:58 yamt Exp $
|
2004-03-14 12:18:45 +03:00
|
|
|
.\"
|
|
|
|
|
.\" Copyright (c)2004 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.
|
|
|
|
|
.\"
|
|
|
|
|
.\" ------------------------------------------------------------
|
2004-05-09 15:28:58 +04:00
|
|
|
.Dd May 9, 2004
|
2004-03-14 12:18:45 +03:00
|
|
|
.Dt SA_YIELD 2
|
|
|
|
|
.Os
|
|
|
|
|
.Sh NAME
|
|
|
|
|
.Nm sa_yield
|
2004-03-14 13:22:06 +03:00
|
|
|
.Nd idle a virtual processor
|
2004-03-14 12:18:45 +03:00
|
|
|
.\" ------------------------------------------------------------
|
|
|
|
|
.Sh LIBRARY
|
|
|
|
|
.Lb libc
|
|
|
|
|
.\" ------------------------------------------------------------
|
|
|
|
|
.Sh SYNOPSIS
|
|
|
|
|
.In sa.h
|
|
|
|
|
.Ft int
|
|
|
|
|
.Fn sa_yield
|
|
|
|
|
.\" ------------------------------------------------------------
|
|
|
|
|
.Sh DESCRIPTION
|
|
|
|
|
.Fn sa_yield
|
2004-05-09 15:28:58 +04:00
|
|
|
is used to idle a virtual processor on which the calling thread is running.
|
|
|
|
|
It's typically used when the process's userland scheduler has no userland
|
|
|
|
|
thread to run.
|
2004-03-14 12:18:45 +03:00
|
|
|
.Pp
|
|
|
|
|
Scheduler activation should be enabled by
|
|
|
|
|
.Fn sa_enable
|
|
|
|
|
beforehand.
|
|
|
|
|
.\" ------------------------------------------------------------
|
|
|
|
|
.Sh RETURN VALUES
|
|
|
|
|
On success,
|
|
|
|
|
.Fn sa_yield
|
|
|
|
|
will not return to userland in the normal way.
|
2004-03-14 23:57:49 +03:00
|
|
|
It returns into an upcall hander with an upcall.
|
2004-03-14 12:18:45 +03:00
|
|
|
Otherwise, a value of \-1 is returned and
|
|
|
|
|
.Va errno
|
|
|
|
|
is set to indicate the error.
|
|
|
|
|
.\" ------------------------------------------------------------
|
|
|
|
|
.Sh SEE ALSO
|
|
|
|
|
.Xr sa_enable 2 ,
|
|
|
|
|
.Xr pthread 3
|
