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Diffstat (limited to 'static/netbsd/man9/rt_timer.9')
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diff --git a/static/netbsd/man9/rt_timer.9 b/static/netbsd/man9/rt_timer.9 new file mode 100644 index 00000000..ed57331c --- /dev/null +++ b/static/netbsd/man9/rt_timer.9 @@ -0,0 +1,135 @@ +.\" $NetBSD: rt_timer.9,v 1.15 2016/06/01 08:17:47 wiz Exp $ +.\" +.\" Copyright (c) 1998 The NetBSD Foundation, Inc. +.\" All rights reserved. +.\" +.\" This code is derived from software contributed to The NetBSD Foundation +.\" by Kevin M. Lahey of the Numerical Aerospace Simulation Facility, +.\" NASA Ames Research Center. +.\" +.\" 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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 June 1, 2016 +.Dt RT_TIMER 9 +.Os +.Sh NAME +.Nm rt_timer , +.Nm rt_timer_add , +.Nm rt_timer_queue_create , +.Nm rt_timer_queue_change , +.Nm rt_timer_queue_destroy , +.Nm rt_timer_remove_all +.Nd route callout functions +.Sh SYNOPSIS +.In net/route.h +.Ft "struct rttimer_queue *" +.Fn rt_timer_queue_create "time_t timeout" +.Ft void +.Fn rt_timer_queue_change "struct rttimer_queue *q" "time_t timeout" +.Ft void +.Fn rt_timer_queue_destroy "struct rttimer_queue *q" "int destroy" +.Ft int +.Fn rt_timer_add "struct rtentry *rt" \ +"void(*f)(struct rtentry *, struct rttimer *)" "struct rttimer_queue *q" +.Ft void +.Fn rt_timer_remove_all "struct rtentry *rt" +.Sh DESCRIPTION +The +.Nm +functions provide a generic route callout functionality. +They allow a function to be called for a route at any time. +This was originally intended to be used to remove routes added +by path MTU discovery code. +.Pp +For maximum efficiency, a separate queue should be defined for each +timeout period. +For example, one queue should be created for the 10 minute path MTU +discovery timeouts, another for 20 minute ARP timeouts after 20 +minutes, and so on. +This permits extremely fast queue manipulations so that the timeout +functions remain scalable, even in the face of thousands of route +manipulations per minute. +.Pp +It is possible to create only a single timeout queue for all possible +timeout values, but doing so is not scalable as queue manipulations +become quite expensive if the timeout deltas are not roughly constant. +.Pp +The +.Nm +interface provides the following functions: +.Bl -tag -width compact +.It Fn rt_timer_queue_create "time_t timeout" +This function creates a new timer queue with the specified timeout period +.Fa timeout , +expressed in seconds. +.It Fn rt_timer_queue_change "rttimer_queue *q" "time_t timeout" +This function modifies the timeout period for a timer queue. +Any value, including 0, is valid. +The next time the timer queue's timeout expires (based on the previous +timeout value), all entries which are valid to execute based on the new +timeout will be executed, and the new timeout period scheduled. +.It Fn rt_timer_queue_destroy "rttimer_queue *q" "int destroy" +This function destroys a timeout queue. +All entries are removed, and if the +.Fa destroy +argument is non-zero, the timeout action is performed for each entry. +.It Fn rt_timer_add "struct rtentry *rt" \ +"void(*f)(struct rtentry *, struct rttimer *)" "struct rttimer_queue *q" +This function adds an entry to a timeout queue. +The function +.Fa f +will be called after the timeout period for queue +.Fa q +has elapsed. +If +.Fa f +is NULL +the route will be deleted when the timeout expires. +.It Fn rt_timer_remove_all "struct rtentry *rt" +This function removes all references to the given route from the +.Nm +subsystem. +This is used when a route is deleted to ensure that no dangling +references remain. +.El +.Sh CODE REFERENCES +The +.Nm +interface is implemented in +.Pa sys/net/route.h +and +.Pa sys/net/route.c . +.Sh SEE ALSO +.Xr netstat 1 , +.Xr arp 9 +.Sh HISTORY +The +.Nm +interface appeared in +.Nx 1.4 . +.Sh AUTHORS +.An -nosplit +This interface is roughly based on (but, alas, not compatible with) one +designed by David Borman of BSDI. +This implementation is by +.An Kevin Lahey +of the Numerical Aerospace Simulation Facility, NASA Ames Research Center. |