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t_sleep.c revision 1.12
      1 /* $NetBSD: t_sleep.c,v 1.12 2025/04/06 14:24:23 riastradh 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 
     78 static volatile int sig;
     79 
     80 int sleeptest(int (*)(struct timespec *, struct timespec *), bool, bool);
     81 int do_nanosleep(struct timespec *, struct timespec *);
     82 int do_select(struct timespec *, struct timespec *);
     83 int do_poll(struct timespec *, struct timespec *);
     84 int do_sleep(struct timespec *, struct timespec *);
     85 int do_kevent(struct timespec *, struct timespec *);
     86 void sigalrm(int);
     87 
     88 void
     89 sigalrm(int s)
     90 {
     91 
     92 	sig++;
     93 }
     94 
     95 int
     96 do_nanosleep(struct timespec *delay, struct timespec *remain)
     97 {
     98 	int ret;
     99 
    100 	if (nanosleep(delay, remain) == -1)
    101 		ret = (errno == EINTR ? 0 : errno);
    102 	else
    103 		ret = 0;
    104 	return ret;
    105 }
    106 
    107 int
    108 do_select(struct timespec *delay, struct timespec *remain)
    109 {
    110 	int ret;
    111 	struct timeval tv;
    112 
    113 	TIMESPEC_TO_TIMEVAL(&tv, delay);
    114 	if (select(0, NULL, NULL, NULL, &tv) == -1)
    115 		ret = (errno == EINTR ? 0 : errno);
    116 	else
    117 		ret = 0;
    118 	return ret;
    119 }
    120 
    121 int
    122 do_poll(struct timespec *delay, struct timespec *remain)
    123 {
    124 	int ret;
    125 	struct timeval tv;
    126 
    127 	TIMESPEC_TO_TIMEVAL(&tv, delay);
    128 	if (pollts(NULL, 0, delay, NULL) == -1)
    129 		ret = (errno == EINTR ? 0 : errno);
    130 	else
    131 		ret = 0;
    132 	return ret;
    133 }
    134 
    135 int
    136 do_sleep(struct timespec *delay, struct timespec *remain)
    137 {
    138 	struct timeval tv;
    139 
    140 	TIMESPEC_TO_TIMEVAL(&tv, delay);
    141 	remain->tv_sec = sleep(delay->tv_sec);
    142 	remain->tv_nsec = 0;
    143 
    144 	return 0;
    145 }
    146 
    147 int
    148 do_kevent(struct timespec *delay, struct timespec *remain)
    149 {
    150 	struct kevent ktimer;
    151 	struct kevent kresult;
    152 	int rtc, kq, kerrno;
    153 	int tmo;
    154 
    155 	ATF_REQUIRE_MSG((kq = kqueue()) != -1, "kqueue: %s", strerror(errno));
    156 
    157 	tmo = KEVNT_TIMEOUT;
    158 
    159 	/*
    160 	 * If we expect the KEVNT_TIMEOUT to fire, and we're running
    161 	 * under QEMU, make sure the delay is long enough to account
    162 	 * for the effects of PR kern/43997 !
    163 	 */
    164 	if (isQEMU() &&
    165 	    tmo/1000 < delay->tv_sec && tmo/500 > delay->tv_sec)
    166 		delay->tv_sec = MAXSLEEP;
    167 
    168 	EV_SET(&ktimer, 1, EVFILT_TIMER, EV_ADD, 0, tmo, 0);
    169 
    170 	rtc = kevent(kq, &ktimer, 1, &kresult, 1, delay);
    171 	kerrno = errno;
    172 
    173 	(void)close(kq);
    174 
    175 	if (rtc == -1) {
    176 		ATF_REQUIRE_MSG(kerrno == EINTR, "kevent: %s",
    177 		    strerror(kerrno));
    178 		return 0;
    179 	}
    180 
    181 	if (delay->tv_sec * BILLION + delay->tv_nsec > tmo * MILLION)
    182 		ATF_REQUIRE_MSG(rtc > 0,
    183 		    "kevent: KEVNT_TIMEOUT did not cause EVFILT_TIMER event");
    184 
    185 	return 0;
    186 }
    187 
    188 ATF_TC(nanosleep);
    189 ATF_TC_HEAD(nanosleep, tc)
    190 {
    191 
    192 	atf_tc_set_md_var(tc, "descr", "Test nanosleep(2) timing");
    193 	atf_tc_set_md_var(tc, "timeout", "65");
    194 }
    195 
    196 ATF_TC_BODY(nanosleep, tc)
    197 {
    198 
    199 	sleeptest(do_nanosleep, true, false);
    200 }
    201 
    202 ATF_TC(select);
    203 ATF_TC_HEAD(select, tc)
    204 {
    205 
    206 	atf_tc_set_md_var(tc, "descr", "Test select(2) timing");
    207 	atf_tc_set_md_var(tc, "timeout", "65");
    208 }
    209 
    210 ATF_TC_BODY(select, tc)
    211 {
    212 
    213 	sleeptest(do_select, true, true);
    214 }
    215 
    216 ATF_TC(poll);
    217 ATF_TC_HEAD(poll, tc)
    218 {
    219 
    220 	atf_tc_set_md_var(tc, "descr", "Test poll(2) timing");
    221 	atf_tc_set_md_var(tc, "timeout", "65");
    222 }
    223 
    224 ATF_TC_BODY(poll, tc)
    225 {
    226 
    227 	sleeptest(do_poll, true, true);
    228 }
    229 
    230 ATF_TC(sleep);
    231 ATF_TC_HEAD(sleep, tc)
    232 {
    233 
    234 	atf_tc_set_md_var(tc, "descr", "Test sleep(3) timing");
    235 	atf_tc_set_md_var(tc, "timeout", "65");
    236 }
    237 
    238 ATF_TC_BODY(sleep, tc)
    239 {
    240 
    241 	sleeptest(do_sleep, false, false);
    242 }
    243 
    244 ATF_TC(kevent);
    245 ATF_TC_HEAD(kevent, tc)
    246 {
    247 
    248 	atf_tc_set_md_var(tc, "descr", "Test kevent(2) timing");
    249 	atf_tc_set_md_var(tc, "timeout", "65");
    250 }
    251 
    252 ATF_TC_BODY(kevent, tc)
    253 {
    254 
    255 	sleeptest(do_kevent, true, true);
    256 }
    257 
    258 int
    259 sleeptest(int (*test)(struct timespec *, struct timespec *),
    260 	   bool subsec, bool sim_remain)
    261 {
    262 	struct timespec tsa, tsb, tslp, tremain;
    263 	int64_t delta1, delta2, delta3, round;
    264 
    265 	sig = 0;
    266 	signal(SIGALRM, sigalrm);
    267 
    268 	if (subsec) {
    269 		round = 1;
    270 		delta3 = FUZZ;
    271 	} else {
    272 		round = 1000000000;
    273 		delta3 = round;
    274 	}
    275 
    276 	tslp.tv_sec = delta3 / 1000000000;
    277 	tslp.tv_nsec = delta3 % 1000000000;
    278 
    279 	while (tslp.tv_sec <= MAXSLEEP) {
    280 		/*
    281 		 * disturb sleep by signal on purpose
    282 		 */
    283 		if (tslp.tv_sec > ALARM && sig == 0)
    284 			alarm(ALARM);
    285 
    286 		clock_gettime(CLOCK_REALTIME, &tsa);
    287 		(*test)(&tslp, &tremain);
    288 		clock_gettime(CLOCK_REALTIME, &tsb);
    289 
    290 		if (sim_remain) {
    291 			timespecsub(&tsb, &tsa, &tremain);
    292 			timespecsub(&tslp, &tremain, &tremain);
    293 		}
    294 
    295 		delta1 = (int64_t)tsb.tv_sec - (int64_t)tsa.tv_sec;
    296 		delta1 *= BILLION;
    297 		delta1 += (int64_t)tsb.tv_nsec - (int64_t)tsa.tv_nsec;
    298 
    299 		delta2 = (int64_t)tremain.tv_sec * BILLION;
    300 		delta2 += (int64_t)tremain.tv_nsec;
    301 
    302 		delta3 = (int64_t)tslp.tv_sec * BILLION;
    303 		delta3 += (int64_t)tslp.tv_nsec - delta1 - delta2;
    304 
    305 		delta3 /= round;
    306 		delta3 *= round;
    307 
    308 		if (delta3 > FUZZ || delta3 < -FUZZ) {
    309 			if (!sim_remain)
    310 				atf_tc_expect_fail("Long reschedule latency "
    311 				    "due to PR kern/43997");
    312 
    313 			atf_tc_fail("Reschedule latency %"PRId64" exceeds "
    314 			    "allowable fuzz %lld", delta3, FUZZ);
    315 		}
    316 		delta3 = (int64_t)tslp.tv_sec * 2 * BILLION;
    317 		delta3 += (int64_t)tslp.tv_nsec * 2;
    318 
    319 		delta3 /= round;
    320 		delta3 *= round;
    321 		if (delta3 < FUZZ)
    322 			break;
    323 		tslp.tv_sec = delta3 / BILLION;
    324 		tslp.tv_nsec = delta3 % BILLION;
    325 	}
    326 	ATF_REQUIRE_MSG(sig == 1, "Alarm did not fire!");
    327 
    328 	atf_tc_pass();
    329 }
    330 
    331 ATF_TP_ADD_TCS(tp)
    332 {
    333 	ATF_TP_ADD_TC(tp, nanosleep);
    334 	ATF_TP_ADD_TC(tp, select);
    335 	ATF_TP_ADD_TC(tp, poll);
    336 	ATF_TP_ADD_TC(tp, sleep);
    337 	ATF_TP_ADD_TC(tp, kevent);
    338 
    339 	return atf_no_error();
    340 }
    341