xref: /openbsd/regress/lib/libc/sys/t_clock_gettime.c (revision 49a6e16f)
1 /*	$OpenBSD: t_clock_gettime.c,v 1.3 2021/12/13 16:56:48 deraadt Exp $	*/
2 /* $NetBSD: t_clock_gettime.c,v 1.3 2017/01/13 21:30:41 christos Exp $ */
3 
4 /*-
5  * Copyright (c) 2008 The NetBSD Foundation, Inc.
6  * All rights reserved.
7  *
8  * This code is derived from software contributed to The NetBSD Foundation
9  * by Frank Kardel.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /*-
34  * Copyright (c) 2006 Frank Kardel
35  * All rights reserved.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  *
46  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
47  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
48  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
49  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
50  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
51  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
52  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
53  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
54  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
55  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
56  * POSSIBILITY OF SUCH DAMAGE.
57  */
58 
59 #include "macros.h"
60 
61 #include <sys/sysctl.h>
62 
63 
64 #include "atf-c.h"
65 #include <errno.h>
66 #include <limits.h>
67 #include <stdio.h>
68 #include <stdint.h>
69 #include <stdlib.h>
70 #include <string.h>
71 #include <time.h>
72 #include <unistd.h>
73 
74 #include "h_macros.h"
75 
76 #define MINPOSDIFF	15000000	/* 15 ms for now */
77 #define TIMEOUT		5
78 
79 #define TC_HARDWARE	"kern.timecounter.hardware"
80 #define TC_CHOICE	"kern.timecounter.choice"
81 
82 static void
check_timecounter(void)83 check_timecounter(void)
84 {
85 	struct timespec tsa, tsb, tsl, res;
86 	long long mindiff = INTMAX_MAX;
87 	time_t endlimit;
88 
89 #define CL(x) \
90 	do { \
91 		if ((x) != -1) \
92 			break; \
93 		atf_tc_fail_nonfatal("%s: %s", #x, strerror(errno)); \
94 		return; \
95 	} while (0)
96 
97 	CL(clock_gettime(CLOCK_REALTIME, &tsa));
98 	tsl = tsa;
99 
100 	CL(time(&endlimit));
101 	endlimit += TIMEOUT + 1;
102 
103 	while ((time_t)tsa.tv_sec < endlimit) {
104 		long long diff;
105 
106 		CL(clock_gettime(CLOCK_REALTIME, &tsb));
107 		diff = 1000000000LL * (tsb.tv_sec - tsa.tv_sec)
108 		    + tsb.tv_nsec - tsa.tv_nsec;
109 
110 		if (diff > 0 && mindiff > diff)
111 			mindiff = diff;
112 
113 		if (diff < 0 || diff > MINPOSDIFF) {
114 			long long elapsed;
115 			(void)printf("%stime TSA: 0x%jx.%08jx, TSB: 0x%jx.%08jx, "
116 			    "diff = %lld nsec, ", (diff < 0) ? "BAD " : "",
117 			    (uintmax_t)tsa.tv_sec, (uintmax_t)tsa.tv_nsec,
118 			    (uintmax_t)tsb.tv_sec, (uintmax_t)tsb.tv_nsec, diff);
119 
120 			elapsed = 1000000000LL * (tsb.tv_sec - tsl.tv_sec)
121 			    + tsb.tv_nsec - tsl.tv_nsec;
122 
123 
124 			(void)printf("%lld nsec\n", elapsed);
125 			tsl = tsb;
126 
127 			ATF_CHECK(diff >= 0);
128 			if (diff < 0)
129 				return;
130 		}
131 
132 		tsa.tv_sec = tsb.tv_sec;
133 		tsa.tv_nsec = tsb.tv_nsec;
134 	}
135 
136 	if (clock_getres(CLOCK_REALTIME, &res) == 0) {
137 		long long r = res.tv_sec * 1000000000 + res.tv_nsec;
138 
139 		(void)printf("Claimed resolution: %lld nsec (%f Hz) or "
140 		    "better\n", r, 1.0 / r * 1e9);
141 		(void)printf("Observed minimum non zero delta: %lld "
142 		    "nsec\n", mindiff);
143 	}
144 
145 #undef CL
146 }
147 
148 ATF_TC(clock_gettime_real);
ATF_TC_HEAD(clock_gettime_real,tc)149 ATF_TC_HEAD(clock_gettime_real, tc)
150 {
151 	atf_tc_set_md_var(tc, "require.user", "root");
152 	atf_tc_set_md_var(tc, "descr",
153 	    "Checks the monotonicity of the CLOCK_REALTIME implementation");
154 	atf_tc_set_md_var(tc, "timeout", "300");
155 }
156 
ATF_TC_BODY(clock_gettime_real,tc)157 ATF_TC_BODY(clock_gettime_real, tc)
158 {
159 	char name[128], cbuf[512], ctrbuf[10240];
160 	size_t cbufsiz = sizeof(cbuf);
161 	size_t ctrbufsiz = sizeof(ctrbuf);
162 	const char *p;
163 	char *save;
164 	int quality, n;
165 
166 	if (sysctlbyname(TC_HARDWARE, cbuf, &cbufsiz, NULL, 0) != 0) {
167 		(void)printf("\nChecking legacy time implementation "
168 		    "for %d seconds\n", TIMEOUT);
169 		check_timecounter();
170 		return;
171 		/* NOTREACHED */
172 	}
173 	(void)printf("%s = %s\n", TC_HARDWARE, cbuf);
174 	REQUIRE_LIBC(save = strdup(cbuf), NULL);
175 
176 	RL(sysctlbyname(TC_CHOICE, ctrbuf, &ctrbufsiz, NULL, 0));
177 	(void)printf("%s = %s\n", TC_CHOICE, ctrbuf);
178 
179 	for (p = ctrbuf, n = 0; sscanf(p, "%127[^(](q=%d, f=%*u Hz)%*[ ]%n",
180 	    name, &quality, &n) == 2; p += n) {
181 		struct timespec ts;
182 		int ret;
183 
184 		if (quality < 0)
185 			continue;
186 
187 		(void)printf("\nChecking %s for %d seconds\n", name, TIMEOUT);
188 		CHECK_LIBC(ret = sysctlbyname(TC_HARDWARE, NULL, 0,
189 		    name, strlen(name)), -1);
190 		if (ret == -1)
191 			continue;
192 
193 		/* wait a bit to select new counter in clockinterrupt */
194 		ts.tv_sec = 0;
195 		ts.tv_nsec = 100000000;
196 		(void)nanosleep(&ts, NULL);
197 
198 		check_timecounter();
199 	}
200 
201 	RL(sysctlbyname(TC_HARDWARE, NULL, 0, save, strlen(save)));
202 }
203 
ATF_TP_ADD_TCS(tp)204 ATF_TP_ADD_TCS(tp)
205 {
206 
207 	ATF_TP_ADD_TC(tp, clock_gettime_real);
208 
209 	return atf_no_error();
210 }
211