freebsd-skq/share/man/man9/at_exit.9
Poul-Henning Kamp 93efcae809 The at_exit and at_fork functions currently use a 'roll your own'
linked list to store the callbak routines.  The patch converts the
lists to queue(3) TAILQs, making the code slightly clearer and ensuring
that callbacks are executed in FIFO order.

Man page also updated as necesary.

(discontinued use of M_TEMP malloc type while here anyway /phk)

Submitted by:   Jake Burkholder jake@checker.org
PR:             14912
1999-11-19 21:29:03 +00:00

76 lines
2.4 KiB
Groff

.\"
.\" Copyright (c) 1996 Julian Elischer
.\"
.\" All rights reserved.
.\"
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.\" modification, are permitted provided that the following conditions
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.\" $FreeBSD$
.\" "
.Dd August 15, 1996
.Os
.Dt AT_EXIT 9
.Sh NAME
.Nm at_exit ,
.Nm rm_at_exit
.Nd ask that a function be run at exit.
.Sh SYNOPSIS
.Fd #include <sys/types.h>
.Fd #include <sys/systm.h>
.Ft typedef void \*(lp*exitlist_fn\*(rp \*(lpstruct proc *\*(rp;
.Ft int
.Fn at_exit "exitlist_fn func"
.Ft int
.Fn rm_at_exit "exitlist_fn func"
.Sh DESCRIPTION
The
.Nm at_exit
facility allows a kernel module to ensure that it is notified
at any process exit.
The function
.Fa func
is called with the a pointer to the exiting process's proc structure.
.Pp
If the requirement for notification is removed, then the function
.Fn rm_at_exit
must be called with the exact
.Fa func
argument as the corresponding call to
.Fn at_exit .
.Pp
.Sh RETURN VALUES
The
.Fa at_exit
function returns an errno, 0 meaning success. The
.Fn rm_at_exit
function returns the number of items removed (should be 0 or 1).
.Sh SEE ALSO
.Xr _exit 2
.Sh HISTORY
The
.Fn at_exit
function appeared in
.Fx 2.2 .
.Sh AUTHORS
The function was written by
.An Julian Elischer Aq julian@FreeBSD.org .