t_sleep.c revision 314817 
1/* $NetBSD: t_sleep.c,v 1.11 2017/01/10 15:43:59 maya Exp $ */
2
3/*-
4 * Copyright (c) 2006 Frank Kardel
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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
30#include <sys/event.h>
31#include <sys/signal.h>
32#include <sys/time.h>		/* for TIMESPEC_TO_TIMEVAL on FreeBSD */
33
34#include <atf-c.h>
35#include <errno.h>
36#include <inttypes.h>
37#include <poll.h>
38#include <stdio.h>
39#include <stdlib.h>
40#include <string.h>
41#include <time.h>
42#include <unistd.h>
43
44#include "isqemu.h"
45
46#define BILLION		1000000000LL	/* nano-seconds per second */
47#define MILLION		1000000LL	/* nano-seconds per milli-second */
48
49#define ALARM		6		/* SIGALRM after this many seconds */
50#define MAXSLEEP	22		/* Maximum delay in seconds */
51#define KEVNT_TIMEOUT	10300		/* measured in milli-seconds */
52#define FUZZ		(40 * MILLION)	/* scheduling fuzz accepted - 40 ms */
53
54/*
55 * Timer notes
56 *
57 * Most tests use FUZZ as their initial delay value, but 'sleep'
58 * starts at 1sec (since it cannot handle sub-second intervals).
59 * Subsequent passes double the previous interval, up to MAXSLEEP.
60 *
61 * The current values result in 5 passes for the 'sleep' test (at 1,
62 * 2, 4, 8, and 16 seconds) and 10 passes for the other tests (at
63 * 0.04, 0.08, 0.16, 0.32, 0.64, 1.28, 2.56, 5.12, 10.24, and 20.48
64 * seconds).
65 *
66 * The ALARM is only set if the current pass's delay is longer, and
67 * only if the ALARM has not already been triggered.
68 *
69 * The 'kevent' test needs the ALARM to be set on a different pass
70 * from when the KEVNT_TIMEOUT fires.  So set ALARM to fire on the
71 * penultimate pass, and the KEVNT_TIMEOUT on the final pass.  We
72 * set KEVNT_TIMEOUT just barely long enough to put it into the
73 * last test pass, and set MAXSLEEP a couple seconds longer than
74 * necessary, in order to avoid a QEMU bug which nearly doubles
75 * some timers.
76 */
77
78static volatile int sig;
79
80int sleeptest(int (*)(struct timespec *, struct timespec *), bool, bool);
81int do_nanosleep(struct timespec *, struct timespec *);
82int do_select(struct timespec *, struct timespec *);
83#ifdef __NetBSD__
84int do_poll(struct timespec *, struct timespec *);
85#endif
86int do_sleep(struct timespec *, struct timespec *);
87int do_kevent(struct timespec *, struct timespec *);
88void sigalrm(int);
89
90void
91sigalrm(int s)
92{
93
94	sig++;
95}
96
97int
98do_nanosleep(struct timespec *delay, struct timespec *remain)
99{
100	int ret;
101
102	if (nanosleep(delay, remain) == -1)
103		ret = (errno == EINTR ? 0 : errno);
104	else
105		ret = 0;
106	return ret;
107}
108
109int
110do_select(struct timespec *delay, struct timespec *remain)
111{
112	int ret;
113	struct timeval tv;
114
115	TIMESPEC_TO_TIMEVAL(&tv, delay);
116	if (select(0, NULL, NULL, NULL, &tv) == -1)
117		ret = (errno == EINTR ? 0 : errno);
118	else
119		ret = 0;
120	return ret;
121}
122
123#ifdef __NetBSD__
124int
125do_poll(struct timespec *delay, struct timespec *remain)
126{
127	int ret;
128	struct timeval tv;
129
130	TIMESPEC_TO_TIMEVAL(&tv, delay);
131	if (pollts(NULL, 0, delay, NULL) == -1)
132		ret = (errno == EINTR ? 0 : errno);
133	else
134		ret = 0;
135	return ret;
136}
137#endif
138
139int
140do_sleep(struct timespec *delay, struct timespec *remain)
141{
142	struct timeval tv;
143
144	TIMESPEC_TO_TIMEVAL(&tv, delay);
145	remain->tv_sec = sleep(delay->tv_sec);
146	remain->tv_nsec = 0;
147
148	return 0;
149}
150
151int
152do_kevent(struct timespec *delay, struct timespec *remain)
153{
154	struct kevent ktimer;
155	struct kevent kresult;
156	int rtc, kq, kerrno;
157	int tmo;
158
159	ATF_REQUIRE_MSG((kq = kqueue()) != -1, "kqueue: %s", strerror(errno));
160
161	tmo = KEVNT_TIMEOUT;
162
163	/*
164	 * If we expect the KEVNT_TIMEOUT to fire, and we're running
165	 * under QEMU, make sure the delay is long enough to account
166	 * for the effects of PR kern/43997 !
167	 */
168	if (isQEMU() &&
169	    tmo/1000 < delay->tv_sec && tmo/500 > delay->tv_sec)
170		delay->tv_sec = MAXSLEEP;
171
172	EV_SET(&ktimer, 1, EVFILT_TIMER, EV_ADD, 0, tmo, 0);
173
174	rtc = kevent(kq, &ktimer, 1, &kresult, 1, delay);
175	kerrno = errno;
176
177	(void)close(kq);
178
179	if (rtc == -1) {
180		ATF_REQUIRE_MSG(kerrno == EINTR, "kevent: %s",
181		    strerror(kerrno));
182		return 0;
183	}
184
185	if (delay->tv_sec * BILLION + delay->tv_nsec > tmo * MILLION)
186		ATF_REQUIRE_MSG(rtc > 0,
187		    "kevent: KEVNT_TIMEOUT did not cause EVFILT_TIMER event");
188
189	return 0;
190}
191
192ATF_TC(nanosleep);
193ATF_TC_HEAD(nanosleep, tc)
194{
195
196	atf_tc_set_md_var(tc, "descr", "Test nanosleep(2) timing");
197	atf_tc_set_md_var(tc, "timeout", "65");
198}
199
200ATF_TC_BODY(nanosleep, tc)
201{
202
203	sleeptest(do_nanosleep, true, false);
204}
205
206ATF_TC(select);
207ATF_TC_HEAD(select, tc)
208{
209
210	atf_tc_set_md_var(tc, "descr", "Test select(2) timing");
211	atf_tc_set_md_var(tc, "timeout", "65");
212}
213
214ATF_TC_BODY(select, tc)
215{
216
217	sleeptest(do_select, true, true);
218}
219
220#ifdef __NetBSD__
221ATF_TC(poll);
222ATF_TC_HEAD(poll, tc)
223{
224
225	atf_tc_set_md_var(tc, "descr", "Test poll(2) timing");
226	atf_tc_set_md_var(tc, "timeout", "65");
227}
228
229ATF_TC_BODY(poll, tc)
230{
231
232	sleeptest(do_poll, true, true);
233}
234#endif
235
236ATF_TC(sleep);
237ATF_TC_HEAD(sleep, tc)
238{
239
240	atf_tc_set_md_var(tc, "descr", "Test sleep(3) timing");
241	atf_tc_set_md_var(tc, "timeout", "65");
242}
243
244ATF_TC_BODY(sleep, tc)
245{
246
247	sleeptest(do_sleep, false, false);
248}
249
250ATF_TC(kevent);
251ATF_TC_HEAD(kevent, tc)
252{
253
254	atf_tc_set_md_var(tc, "descr", "Test kevent(2) timing");
255	atf_tc_set_md_var(tc, "timeout", "65");
256}
257
258ATF_TC_BODY(kevent, tc)
259{
260
261	sleeptest(do_kevent, true, true);
262}
263
264int
265sleeptest(int (*test)(struct timespec *, struct timespec *),
266	   bool subsec, bool sim_remain)
267{
268	struct timespec tsa, tsb, tslp, tremain;
269	int64_t delta1, delta2, delta3, round;
270
271	sig = 0;
272	signal(SIGALRM, sigalrm);
273
274	if (subsec) {
275		round = 1;
276		delta3 = FUZZ;
277	} else {
278		round = 1000000000;
279		delta3 = round;
280	}
281
282	tslp.tv_sec = delta3 / 1000000000;
283	tslp.tv_nsec = delta3 % 1000000000;
284
285	while (tslp.tv_sec <= MAXSLEEP) {
286		/*
287		 * disturb sleep by signal on purpose
288		 */
289		if (tslp.tv_sec > ALARM && sig == 0)
290			alarm(ALARM);
291
292		clock_gettime(CLOCK_REALTIME, &tsa);
293		(*test)(&tslp, &tremain);
294		clock_gettime(CLOCK_REALTIME, &tsb);
295
296		if (sim_remain) {
297			timespecsub(&tsb, &tsa, &tremain);
298			timespecsub(&tslp, &tremain, &tremain);
299		}
300
301		delta1 = (int64_t)tsb.tv_sec - (int64_t)tsa.tv_sec;
302		delta1 *= BILLION;
303		delta1 += (int64_t)tsb.tv_nsec - (int64_t)tsa.tv_nsec;
304
305		delta2 = (int64_t)tremain.tv_sec * BILLION;
306		delta2 += (int64_t)tremain.tv_nsec;
307
308		delta3 = (int64_t)tslp.tv_sec * BILLION;
309		delta3 += (int64_t)tslp.tv_nsec - delta1 - delta2;
310
311		delta3 /= round;
312		delta3 *= round;
313
314		if (delta3 > FUZZ || delta3 < -FUZZ) {
315			if (!sim_remain)
316				atf_tc_expect_fail("Long reschedule latency "
317				    "due to PR kern/43997");
318
319			atf_tc_fail("Reschedule latency %"PRId64" exceeds "
320			    "allowable fuzz %lld", delta3, FUZZ);
321		}
322		delta3 = (int64_t)tslp.tv_sec * 2 * BILLION;
323		delta3 += (int64_t)tslp.tv_nsec * 2;
324
325		delta3 /= round;
326		delta3 *= round;
327		if (delta3 < FUZZ)
328			break;
329		tslp.tv_sec = delta3 / BILLION;
330		tslp.tv_nsec = delta3 % BILLION;
331	}
332	ATF_REQUIRE_MSG(sig == 1, "Alarm did not fire!");
333
334	atf_tc_pass();
335}
336
337ATF_TP_ADD_TCS(tp)
338{
339	ATF_TP_ADD_TC(tp, nanosleep);
340	ATF_TP_ADD_TC(tp, select);
341#ifdef __NetBSD__
342	ATF_TP_ADD_TC(tp, poll);
343#endif
344	ATF_TP_ADD_TC(tp, sleep);
345	ATF_TP_ADD_TC(tp, kevent);
346
347	return atf_no_error();
348}
349