freebsd-dev/usr.bin/time/time.c
Alan Somers 8a9ab04279 time(1): use the monotonic clock
The monotonic clock is more appropriate than the realtime clock for
measuring durations.

Reviewed by:	ken, jilles
Differential Revision:	https://reviews.freebsd.org/D14032
2018-05-04 14:39:32 +00:00

314 lines
8.4 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1987, 1988, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1987, 1988, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
#if 0
static char sccsid[] = "@(#)time.c 8.1 (Berkeley) 6/6/93";
#endif
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
#include <sys/types.h>
#include <sys/resource.h>
#include <sys/signal.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <err.h>
#include <errno.h>
#include <locale.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
static int getstathz(void);
static void humantime(FILE *, long, long);
static void showtime(FILE *, struct timespec *, struct timespec *,
struct rusage *);
static void siginfo(int);
static void usage(void);
static sig_atomic_t siginfo_recvd;
static char decimal_point;
static struct timespec before_ts;
static int hflag, pflag;
int
main(int argc, char **argv)
{
int aflag, ch, lflag, status;
int exitonsig;
pid_t pid;
struct rlimit rl;
struct rusage ru;
struct timespec after;
char *ofn = NULL;
FILE *out = stderr;
(void) setlocale(LC_NUMERIC, "");
decimal_point = localeconv()->decimal_point[0];
aflag = hflag = lflag = pflag = 0;
while ((ch = getopt(argc, argv, "ahlo:p")) != -1)
switch((char)ch) {
case 'a':
aflag = 1;
break;
case 'h':
hflag = 1;
break;
case 'l':
lflag = 1;
break;
case 'o':
ofn = optarg;
break;
case 'p':
pflag = 1;
break;
case '?':
default:
usage();
}
if (!(argc -= optind))
exit(0);
argv += optind;
if (ofn) {
if ((out = fopen(ofn, aflag ? "ae" : "we")) == NULL)
err(1, "%s", ofn);
setvbuf(out, (char *)NULL, _IONBF, (size_t)0);
}
if (clock_gettime(CLOCK_MONOTONIC, &before_ts))
err(1, "clock_gettime");
switch(pid = fork()) {
case -1: /* error */
err(1, "time");
/* NOTREACHED */
case 0: /* child */
execvp(*argv, argv);
err(errno == ENOENT ? 127 : 126, "%s", *argv);
/* NOTREACHED */
}
/* parent */
(void)signal(SIGINT, SIG_IGN);
(void)signal(SIGQUIT, SIG_IGN);
siginfo_recvd = 0;
(void)signal(SIGINFO, siginfo);
(void)siginterrupt(SIGINFO, 1);
while (wait4(pid, &status, 0, &ru) != pid) {
if (siginfo_recvd) {
siginfo_recvd = 0;
if (clock_gettime(CLOCK_MONOTONIC, &after))
err(1, "clock_gettime");
getrusage(RUSAGE_CHILDREN, &ru);
showtime(stdout, &before_ts, &after, &ru);
}
}
if (clock_gettime(CLOCK_MONOTONIC, &after))
err(1, "clock_gettime");
if ( ! WIFEXITED(status))
warnx("command terminated abnormally");
exitonsig = WIFSIGNALED(status) ? WTERMSIG(status) : 0;
showtime(out, &before_ts, &after, &ru);
if (lflag) {
int hz = getstathz();
u_long ticks;
ticks = hz * (ru.ru_utime.tv_sec + ru.ru_stime.tv_sec) +
hz * (ru.ru_utime.tv_usec + ru.ru_stime.tv_usec) / 1000000;
/*
* If our round-off on the tick calculation still puts us at 0,
* then always assume at least one tick.
*/
if (ticks == 0)
ticks = 1;
fprintf(out, "%10ld %s\n",
ru.ru_maxrss, "maximum resident set size");
fprintf(out, "%10ld %s\n",
ru.ru_ixrss / ticks, "average shared memory size");
fprintf(out, "%10ld %s\n",
ru.ru_idrss / ticks, "average unshared data size");
fprintf(out, "%10ld %s\n",
ru.ru_isrss / ticks, "average unshared stack size");
fprintf(out, "%10ld %s\n",
ru.ru_minflt, "page reclaims");
fprintf(out, "%10ld %s\n",
ru.ru_majflt, "page faults");
fprintf(out, "%10ld %s\n",
ru.ru_nswap, "swaps");
fprintf(out, "%10ld %s\n",
ru.ru_inblock, "block input operations");
fprintf(out, "%10ld %s\n",
ru.ru_oublock, "block output operations");
fprintf(out, "%10ld %s\n",
ru.ru_msgsnd, "messages sent");
fprintf(out, "%10ld %s\n",
ru.ru_msgrcv, "messages received");
fprintf(out, "%10ld %s\n",
ru.ru_nsignals, "signals received");
fprintf(out, "%10ld %s\n",
ru.ru_nvcsw, "voluntary context switches");
fprintf(out, "%10ld %s\n",
ru.ru_nivcsw, "involuntary context switches");
}
/*
* If the child has exited on a signal, exit on the same
* signal, too, in order to reproduce the child's exit status.
* However, avoid actually dumping core from the current process.
*/
if (exitonsig) {
if (signal(exitonsig, SIG_DFL) == SIG_ERR)
warn("signal");
else {
rl.rlim_max = rl.rlim_cur = 0;
if (setrlimit(RLIMIT_CORE, &rl) == -1)
warn("setrlimit");
kill(getpid(), exitonsig);
}
}
exit (WIFEXITED(status) ? WEXITSTATUS(status) : EXIT_FAILURE);
}
static void
usage(void)
{
fprintf(stderr,
"usage: time [-al] [-h | -p] [-o file] utility [argument ...]\n");
exit(1);
}
/*
* Return the frequency of the kernel's statistics clock.
*/
static int
getstathz(void)
{
int mib[2];
size_t size;
struct clockinfo clockrate;
mib[0] = CTL_KERN;
mib[1] = KERN_CLOCKRATE;
size = sizeof clockrate;
if (sysctl(mib, 2, &clockrate, &size, NULL, 0) == -1)
err(1, "sysctl kern.clockrate");
return clockrate.stathz;
}
static void
humantime(FILE *out, long sec, long centisec)
{
long days, hrs, mins;
days = sec / (60L * 60 * 24);
sec %= (60L * 60 * 24);
hrs = sec / (60L * 60);
sec %= (60L * 60);
mins = sec / 60;
sec %= 60;
fprintf(out, "\t");
if (days)
fprintf(out, "%ldd", days);
if (hrs)
fprintf(out, "%ldh", hrs);
if (mins)
fprintf(out, "%ldm", mins);
fprintf(out, "%ld%c%02lds", sec, decimal_point, centisec);
}
static void
showtime(FILE *out, struct timespec *before, struct timespec *after,
struct rusage *ru)
{
after->tv_sec -= before->tv_sec;
after->tv_nsec -= before->tv_nsec;
if (after->tv_nsec < 0)
after->tv_sec--, after->tv_nsec += 1000000000;
if (pflag) {
/* POSIX wants output that must look like
"real %f\nuser %f\nsys %f\n" and requires
at least two digits after the radix. */
fprintf(out, "real %jd%c%02ld\n",
(intmax_t)after->tv_sec, decimal_point,
after->tv_nsec/10000000);
fprintf(out, "user %jd%c%02ld\n",
(intmax_t)ru->ru_utime.tv_sec, decimal_point,
ru->ru_utime.tv_usec/10000);
fprintf(out, "sys %jd%c%02ld\n",
(intmax_t)ru->ru_stime.tv_sec, decimal_point,
ru->ru_stime.tv_usec/10000);
} else if (hflag) {
humantime(out, after->tv_sec, after->tv_nsec/10000000);
fprintf(out, " real\t");
humantime(out, ru->ru_utime.tv_sec, ru->ru_utime.tv_usec/10000);
fprintf(out, " user\t");
humantime(out, ru->ru_stime.tv_sec, ru->ru_stime.tv_usec/10000);
fprintf(out, " sys\n");
} else {
fprintf(out, "%9jd%c%02ld real ",
(intmax_t)after->tv_sec, decimal_point,
after->tv_nsec/10000000);
fprintf(out, "%9jd%c%02ld user ",
(intmax_t)ru->ru_utime.tv_sec, decimal_point,
ru->ru_utime.tv_usec/10000);
fprintf(out, "%9jd%c%02ld sys\n",
(intmax_t)ru->ru_stime.tv_sec, decimal_point,
ru->ru_stime.tv_usec/10000);
}
}
static void
siginfo(int sig __unused)
{
siginfo_recvd = 1;
}