1#!/bin/sh
2
3#
4# Copyright (c) 2008 Peter Holm <pho@FreeBSD.org>
5# All rights reserved.
6#
7# Redistribution and use in source and binary forms, with or without
8# modification, are permitted provided that the following conditions
9# are met:
10# 1. Redistributions of source code must retain the above copyright
11#    notice, this list of conditions and the following disclaimer.
12# 2. Redistributions in binary form must reproduce the above copyright
13#    notice, this list of conditions and the following disclaimer in the
14#    documentation and/or other materials provided with the distribution.
15#
16# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26# SUCH DAMAGE.
27#
28# $FreeBSD$
29#
30
31# Provokes a deadlock by lower priority process holding a lock and
32# never beeing run
33
34dir=/tmp
35N=5	# Number of CPUs + 1
36M=25	# Number of lower priority jobs
37
38odir=`pwd`
39cd $dir
40sed '1,/^EOF/d' < $odir/$0 > $dir/inversion.c
41cc -o inversion -Wall inversion.c
42rm -f inversion.c
43
44for i in `jot $N`; do
45	./inversion 3700&
46done
47
48while pgrep inversion > /dev/null; do
49	date '+%T'
50	(
51		for i in `jot $M`; do
52			nice -n 20 lockf -s -t 0 .lock pwd > /dev/null &
53		done
54		for i in `jot $M`; do
55			wait
56		done
57	)
58done
59
60for i in `jot $N`; do
61	wait
62done
63rm -f inversion
64exit
65
66EOF
67#include <signal.h>
68#include <stdlib.h>
69#include <unistd.h>
70
71void
72handler(int i)
73{
74	exit(0);
75}
76
77int
78main(int argc, char **argv)
79{
80
81	int t;
82	if (argc == 2)
83		t = atoi(argv[1]);
84	else
85		t = 60;
86	signal(SIGALRM, handler);
87	alarm(t);
88	for (;;)
89		;
90	return (0);
91}
92