90 lines
2.8 KiB
Groff
90 lines
2.8 KiB
Groff
.\" Copyright (c) 2000-2001 John H. Baldwin <jhb@FreeBSD.org>
|
|
.\" 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 DEVELOPERS ``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 DEVELOPERS 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.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd November 3, 2000
|
|
.Dt SLEEPQUEUE 9
|
|
.Os
|
|
.Sh NAME
|
|
.Nm endtsleep ,
|
|
.Nm sleepinit ,
|
|
.Nm unsleep
|
|
.Nd manage the queues of sleeping processes
|
|
.Sh SYNOPSIS
|
|
.Fd #include <sys/param.h>
|
|
.Fd #include <sys/proc.h>
|
|
.Ft void
|
|
.Fn endtsleep "void *arg"
|
|
.Ft void
|
|
.Fn sleepinit "void"
|
|
.Ft void
|
|
.Fn unsleep "struct proc *p"
|
|
.Sh DESCRIPTION
|
|
The sleep queues used by
|
|
.Xr msleep 9
|
|
and friends are stored in a hash array.
|
|
The address of the wait channel is used to generate an index into the array.
|
|
Each entry in the array is a queue of processes that are sleeping on wait
|
|
channels that hash to that index.
|
|
.Xr msleep 9
|
|
places processes into their appropriate queues directly.
|
|
To handle timeouts, the
|
|
.Fn endtsleep
|
|
function is registered as a
|
|
.Xr timeout 9 .
|
|
When the process is woken by either
|
|
.Fn wakeup
|
|
or
|
|
.Fn wakeup_one ,
|
|
the timeout is revoked via
|
|
.Xr untimeout 9 .
|
|
If the process is not awakened soon enough, then
|
|
.Fn endtsleep
|
|
is called with
|
|
.Fa arg
|
|
pointing to the
|
|
.Vt "struct proc"
|
|
of the process that timed out.
|
|
.Fn endtsleep
|
|
undoes the sleep and makes the process runnable if it is in the
|
|
.Dv SSLEEP
|
|
state.
|
|
The sleep queues and the hash array are protected internally by the
|
|
.Va sched_lock
|
|
mutex.
|
|
.Pp
|
|
.Fn unsleep
|
|
simply removes the process
|
|
.Fa p
|
|
from its sleep queue.
|
|
.Pp
|
|
.Fn sleepinit
|
|
is called during system startup and initializes the scheduler quantum
|
|
.Pq Va sched_quantum
|
|
and the sleep queues.
|
|
.Sh SEE ALSO
|
|
.Xr msleep 9 ,
|
|
.Xr runqueue 9 ,
|
|
.Xr scheduler 9
|