t_clock_gettime.c revision 314817 
1/* $NetBSD: t_clock_gettime.c,v 1.3 2017/01/13 21:30:41 christos Exp $ */
2
3/*-
4 * Copyright (c) 2008 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Frank Kardel.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32/*-
33 * Copyright (c) 2006 Frank Kardel
34 * All rights reserved.
35 *
36 * Redistribution and use in source and binary forms, with or without
37 * modification, are permitted provided that the following conditions
38 * are met:
39 * 1. Redistributions of source code must retain the above copyright
40 *    notice, this list of conditions and the following disclaimer.
41 * 2. Redistributions in binary form must reproduce the above copyright
42 *    notice, this list of conditions and the following disclaimer in the
43 *    documentation and/or other materials provided with the distribution.
44 *
45 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
46 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
47 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
48 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
49 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
50 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
51 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
52 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
53 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
54 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
55 * POSSIBILITY OF SUCH DAMAGE.
56 */
57
58#include <sys/cdefs.h>
59__COPYRIGHT("@(#) Copyright (c) 2008\
60 The NetBSD Foundation, inc. All rights reserved.");
61__RCSID("$NetBSD: t_clock_gettime.c,v 1.3 2017/01/13 21:30:41 christos Exp $");
62
63#include <sys/param.h>
64#include <sys/sysctl.h>
65
66
67#include <atf-c.h>
68#include <errno.h>
69#include <limits.h>
70#include <stdio.h>
71#include <stdint.h>
72#include <stdlib.h>
73#include <string.h>
74#include <time.h>
75#include <unistd.h>
76
77#include "h_macros.h"
78
79#define MINPOSDIFF	15000000	/* 15 ms for now */
80#define TIMEOUT		5
81
82#define TC_HARDWARE	"kern.timecounter.hardware"
83#define TC_CHOICE	"kern.timecounter.choice"
84
85static void
86check_timecounter(void)
87{
88	struct timespec tsa, tsb, tsl, res;
89	long long mindiff = INTMAX_MAX;
90	time_t endlimit;
91
92#define CL(x) \
93	do { \
94		if ((x) != -1) \
95			break; \
96		atf_tc_fail_nonfatal("%s: %s", #x, strerror(errno)); \
97		return; \
98	} while (0)
99
100	CL(clock_gettime(CLOCK_REALTIME, &tsa));
101	tsl = tsa;
102
103	CL(time(&endlimit));
104	endlimit += TIMEOUT + 1;
105
106	while ((time_t)tsa.tv_sec < endlimit) {
107		long long diff;
108
109		CL(clock_gettime(CLOCK_REALTIME, &tsb));
110		diff = 1000000000LL * (tsb.tv_sec - tsa.tv_sec)
111		    + tsb.tv_nsec - tsa.tv_nsec;
112
113		if (diff > 0 && mindiff > diff)
114			mindiff = diff;
115
116		if (diff < 0 || diff > MINPOSDIFF) {
117			long long elapsed;
118			(void)printf("%stime TSA: 0x%jx.%08jx, TSB: 0x%jx.%08jx, "
119			    "diff = %lld nsec, ", (diff < 0) ? "BAD " : "",
120			    (uintmax_t)tsa.tv_sec, (uintmax_t)tsa.tv_nsec,
121			    (uintmax_t)tsb.tv_sec, (uintmax_t)tsb.tv_nsec, diff);
122
123			elapsed = 1000000000LL * (tsb.tv_sec - tsl.tv_sec)
124			    + tsb.tv_nsec - tsl.tv_nsec;
125
126
127			(void)printf("%lld nsec\n", elapsed);
128			tsl = tsb;
129
130			ATF_CHECK(diff >= 0);
131			if (diff < 0)
132				return;
133		}
134
135		tsa.tv_sec = tsb.tv_sec;
136		tsa.tv_nsec = tsb.tv_nsec;
137	}
138
139	if (clock_getres(CLOCK_REALTIME, &res) == 0) {
140		long long r = res.tv_sec * 1000000000 + res.tv_nsec;
141
142		(void)printf("Claimed resolution: %lld nsec (%f Hz) or "
143		    "better\n", r, 1.0 / r * 1e9);
144		(void)printf("Observed minimum non zero delta: %lld "
145		    "nsec\n", mindiff);
146	}
147
148#undef CL
149}
150
151ATF_TC(clock_gettime_real);
152ATF_TC_HEAD(clock_gettime_real, tc)
153{
154	atf_tc_set_md_var(tc, "require.user", "root");
155	atf_tc_set_md_var(tc, "descr",
156	    "Checks the monotonicity of the CLOCK_REALTIME implementation");
157	atf_tc_set_md_var(tc, "timeout", "300");
158}
159
160ATF_TC_BODY(clock_gettime_real, tc)
161{
162	char name[128], cbuf[512], ctrbuf[10240];
163	size_t cbufsiz = sizeof(cbuf);
164	size_t ctrbufsiz = sizeof(ctrbuf);
165	const char *p;
166	char *save;
167	int quality, n;
168
169	if (sysctlbyname(TC_HARDWARE, cbuf, &cbufsiz, NULL, 0) != 0) {
170		(void)printf("\nChecking legacy time implementation "
171		    "for %d seconds\n", TIMEOUT);
172		check_timecounter();
173		return;
174		/* NOTREACHED */
175	}
176	(void)printf("%s = %s\n", TC_HARDWARE, cbuf);
177	REQUIRE_LIBC(save = strdup(cbuf), NULL);
178
179	RL(sysctlbyname(TC_CHOICE, ctrbuf, &ctrbufsiz, NULL, 0));
180	(void)printf("%s = %s\n", TC_CHOICE, ctrbuf);
181
182	for (p = ctrbuf, n = 0; sscanf(p, "%127[^(](q=%d, f=%*u Hz)%*[ ]%n",
183	    name, &quality, &n) == 2; p += n) {
184		struct timespec ts;
185		int ret;
186
187		if (quality < 0)
188			continue;
189
190		(void)printf("\nChecking %s for %d seconds\n", name, TIMEOUT);
191		CHECK_LIBC(ret = sysctlbyname(TC_HARDWARE, NULL, 0,
192		    name, strlen(name)), -1);
193		if (ret == -1)
194			continue;
195
196		/* wait a bit to select new counter in clockinterrupt */
197		ts.tv_sec = 0;
198		ts.tv_nsec = 100000000;
199		(void)nanosleep(&ts, NULL);
200
201		check_timecounter();
202	}
203
204	RL(sysctlbyname(TC_HARDWARE, NULL, 0, save, strlen(save)));
205}
206
207ATF_TP_ADD_TCS(tp)
208{
209
210	ATF_TP_ADD_TC(tp, clock_gettime_real);
211
212	return atf_no_error();
213}
214