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t_clock_gettime.c revision 1.1
      1 /* $NetBSD: t_clock_gettime.c,v 1.1 2011/10/15 06:42:16 jruoho 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 1.1 2011/10/15 06:42:16 jruoho Exp $");
     62 
     63 #include <sys/param.h>
     64 #include <sys/sysctl.h>
     65 
     66 #include <machine/int_limits.h>
     67 
     68 #include <atf-c.h>
     69 #include <errno.h>
     70 #include <stdio.h>
     71 #include <stdlib.h>
     72 #include <string.h>
     73 #include <time.h>
     74 #include <unistd.h>
     75 
     76 #include "../../../h_macros.h"
     77 
     78 #define MINPOSDIFF	15000000	/* 15 ms for now */
     79 #define TIMEOUT		5
     80 
     81 #define TC_HARDWARE	"kern.timecounter.hardware"
     82 #define TC_CHOICE	"kern.timecounter.choice"
     83 
     84 static void
     85 check_timecounter(void)
     86 {
     87 	struct timespec tsa, tsb, tsl, res;
     88 	long long mindiff = INTMAX_MAX;
     89 	time_t endlimit;
     90 
     91 #define CL(x) \
     92 	do { \
     93 		if ((x) != -1) \
     94 			break; \
     95 		atf_tc_fail_nonfatal("%s: %s", #x, strerror(errno)); \
     96 		return; \
     97 	} while (0)
     98 
     99 	CL(clock_gettime(CLOCK_REALTIME, &tsa));
    100 	tsl = tsa;
    101 
    102 	CL(time(&endlimit));
    103 	endlimit += TIMEOUT + 1;
    104 
    105 	while ((time_t)tsa.tv_sec < endlimit) {
    106 		long long diff;
    107 
    108 		CL(clock_gettime(CLOCK_REALTIME, &tsb));
    109 		diff = 1000000000LL * (tsb.tv_sec - tsa.tv_sec)
    110 		    + tsb.tv_nsec - tsa.tv_nsec;
    111 
    112 		if (diff > 0 && mindiff > diff)
    113 			mindiff = diff;
    114 
    115 		if (diff < 0 || diff > MINPOSDIFF) {
    116 			long long elapsed;
    117 			(void)printf("%stime TSA: 0x%jx.%08jx, TSB: 0x%jx.%08jx, "
    118 			    "diff = %lld nsec, ", (diff < 0) ? "BAD " : "",
    119 			    (uintmax_t)tsa.tv_sec, (uintmax_t)tsa.tv_nsec,
    120 			    (uintmax_t)tsb.tv_sec, (uintmax_t)tsb.tv_nsec, diff);
    121 
    122 			elapsed = 1000000000LL * (tsb.tv_sec - tsl.tv_sec)
    123 			    + tsb.tv_nsec - tsl.tv_nsec;
    124 
    125 
    126 			(void)printf("%lld nsec\n", elapsed);
    127 			tsl = tsb;
    128 
    129 			ATF_CHECK(diff >= 0);
    130 			if (diff < 0)
    131 				return;
    132 		}
    133 
    134 		tsa.tv_sec = tsb.tv_sec;
    135 		tsa.tv_nsec = tsb.tv_nsec;
    136 	}
    137 
    138 	if (clock_getres(CLOCK_REALTIME, &res) == 0) {
    139 		long long r = res.tv_sec * 1000000000 + res.tv_nsec;
    140 
    141 		(void)printf("Claimed resolution: %lld nsec (%f Hz) or "
    142 		    "better\n", r, 1.0 / r * 1e9);
    143 		(void)printf("Observed minimum non zero delta: %lld "
    144 		    "nsec\n", mindiff);
    145 	}
    146 
    147 #undef CL
    148 }
    149 
    150 ATF_TC(clock_gettime_real);
    151 ATF_TC_HEAD(clock_gettime_real, tc)
    152 {
    153 	atf_tc_set_md_var(tc, "require.user", "root");
    154 	atf_tc_set_md_var(tc, "descr",
    155 	    "Checks the monotonicity of the CLOCK_REALTIME implementation");
    156 	atf_tc_set_md_var(tc, "timeout", "300");
    157 }
    158 
    159 ATF_TC_BODY(clock_gettime_real, tc)
    160 {
    161 	char name[128], cbuf[512], ctrbuf[10240];
    162 	size_t cbufsiz = sizeof(cbuf);
    163 	size_t ctrbufsiz = sizeof(ctrbuf);
    164 	const char *p;
    165 	char *save;
    166 	int quality, n;
    167 
    168 	if (sysctlbyname(TC_HARDWARE, cbuf, &cbufsiz, NULL, 0) != 0) {
    169 		(void)printf("\nChecking legacy time implementation "
    170 		    "for %d seconds\n", TIMEOUT);
    171 		check_timecounter();
    172 		return;
    173 		/* NOTREACHED */
    174 	}
    175 	(void)printf("%s = %s\n", TC_HARDWARE, cbuf);
    176 	REQUIRE_LIBC(save = strdup(cbuf), NULL);
    177 
    178 	RL(sysctlbyname(TC_CHOICE, ctrbuf, &ctrbufsiz, NULL, 0));
    179 	(void)printf("%s = %s\n", TC_CHOICE, ctrbuf);
    180 
    181 	for (p = ctrbuf, n = 0; sscanf(p, "%127[^(](q=%d, f=%*u Hz)%*[ ]%n",
    182 	    name, &quality, &n) == 2; p += n) {
    183 		struct timespec ts;
    184 		int ret;
    185 
    186 		if (quality < 0)
    187 			continue;
    188 
    189 		(void)printf("\nChecking %s for %d seconds\n", name, TIMEOUT);
    190 		CHECK_LIBC(ret = sysctlbyname(TC_HARDWARE, NULL, 0,
    191 		    name, strlen(name)), -1);
    192 		if (ret == -1)
    193 			continue;
    194 
    195 		/* wait a bit to select new counter in clockinterrupt */
    196 		ts.tv_sec = 0;
    197 		ts.tv_nsec = 100000000;
    198 		(void)nanosleep(&ts, NULL);
    199 
    200 		check_timecounter();
    201 	}
    202 
    203 	RL(sysctlbyname(TC_HARDWARE, NULL, 0, save, strlen(save)));
    204 }
    205 
    206 ATF_TP_ADD_TCS(tp)
    207 {
    208 
    209 	ATF_TP_ADD_TC(tp, clock_gettime_real);
    210 
    211 	return atf_no_error();
    212 }
    213