vfork_freeze.sh revision 2d5ffa60a4e03056631ca117392288b9c7d94261 
1#!/bin/sh
2
3# Copyright (c) International Business Machines  Corp., 2008
4# Author: Matt Helsley <matthltc@us.ibm.com>
5#
6# This library is free software; you can redistribute it and/or
7# modify it under the terms of the GNU Lesser General Public
8# License as published by the Free Software Foundation; either
9# version 2.1 of the License, or (at your option) any later version.
10#
11# This library is distributed in the hope that it will be useful,
12# but WITHOUT ANY WARRANTY; without even the implied warranty of
13# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14# Lesser General Public License for more details.
15#
16# You should have received a copy of the GNU Lesser General Public
17# License along with this library; if not, write to the Free Software
18# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19#
20
21#
22# This bash script tests freezer code by starting a process with vfork(2).
23# vfork causes the freezer to wait until the vfork call "returns" to the
24# parent.
25#
26
27# we need the vfork test binary -- ensure it's been built
28CGROUPS_TESTROOT=${CGROUPS_TESTROOT:=$(dirname "$0")}
29
30if [ ! -x "$CGROUPS_TESTROOT/vfork" ] ; then
31
32	print_make_message=1
33
34	# Maintain ease-of-use backwards compatibility so Matt doesn't want to
35	# hang me for the script change :].
36	if type make > /dev/null ; then
37		make all && print_make_message=0
38	fi
39
40	if [ $print_make_message -eq 1 ] ; then
41		cat <<EOF
42${0##*/}: ERROR: you must run \`make all' in $CGROUPS_TESTROOT before running
43this script.
44EOF
45	exit 1
46fi
47
48. "${CGROUPS_TESTROOT}/libcgroup_freezer"
49SETS_DEFAULTS="${TCID=vfork_freeze.sh} ${TST_COUNT=1} ${TST_TOTAL=1}"
50declare -r TCID
51declare -r TST_COUNT
52declare -r TST_TOTAL
53export TCID TST_COUNT TST_TOTAL
54
55TMPDIR=${TMPDIR:=/tmp}
56
57# We replace the normal sample process with a process which uses vfork to
58# create new processes. The vfork'ed processes then sleep, causing the
59# parent process ($sample_proc) to enter the TASK_UNINTERRUPTIBLE state
60# for the duration of the sleep.
61function vfork_sleep()
62{
63	vfork -s$sample_sleep 1 > "$TMPDIR/${0##*/}.$$.txt" &
64	local rc=$?
65	export vfork_proc=$!
66	read sample_proc < /tmp/tmp.txt
67	rm -f /tmp/tmp.txt
68	export sample_proc
69
70	return $rc
71}
72
73running_cgroup_test
74mount_freezer && {
75make_sample_cgroup && {
76assert_cgroup_freezer_state "THAWED" \
77		"ERROR: cgroup freezer started in non-THAWED state" && {
78
79vfork_sleep && {
80
81while [ 1 ] ; do
82	trap 'break' ERR
83
84	add_sample_proc_to_cgroup
85	"${CG_FILE_WRITE}" $vfork_proc >> tasks # should add to the same cgroup as above
86
87	issue_freeze_cmd
88	wait_until_frozen
89	assert_sample_proc_is_frozen
90	assert_task_is_frozen $vfork_proc
91
92	issue_thaw_cmd
93	wait_until_thawed
94	assert_sample_proc_not_frozen
95	assert_task_not_frozen $vfork_proc
96
97	result=$FINISHED
98	break
99done
100trap '' ERR
101cleanup_cgroup_test
102tst_resm TINFO " Cleaning up $0"
103
104# We need to kill the sample process(es).
105kill_sample_proc ; export sample_proc=$vfork_proc ; kill_sample_proc ; }
106
107# no inverse op needed for assert
108}
109
110rm_sample_cgroup ; }
111umount_freezer ; }
112
113rm -f "$TMPDIR/${0##*/}.$$.txt"
114
115# Failsafe cleanup
116cleanup_freezer || /bin/true
117
118exit $result
119