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/* See LICENSE file for copyright and license details. */
#include <sys/timerfd.h>
#include <errno.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
int
main(int argc, char *argv[])
{
char *argv0;
char float_part[10];
struct itimerspec value;
struct itimerspec largest_value;
int i, fd = -1, clocks = 0;
uint64_t overrun;
int clockid = CLOCK_REALTIME;
const char *clockstr = "CLOCK_REALTIME";
char *p1, *p2, excess;
size_t len;
argv0 = *argv++, argc--;
if (*argv && **argv == '-') {
if (argv[0][1] == '-' && !argv[0][2]) {
argv++, argc--;
} else {
fprintf(stderr, "usage: %s [clock | timepoint] ...", argv0);
return 1;
}
}
if (!argc)
return 0;
memset(&value, 0, sizeof(value));
float_part[9] = '\0';
for (i = 0; i < argc; i++) {
p1 = argv[i];
if (strstr(p1, "CLOCK_") != p1)
goto parse_time;
#define X(C)\
else if (!strcmp(p1, #C))\
clockid = C, clockstr = #C;
#include "clocks.h"
#undef X
else
clockid = -1, clockstr = "invalid";
clocks++;
continue;
parse_time:
if ((p2 = strchr(p1, '.')))
*p2++ = '\0';
value.it_value.tv_sec = (time_t)atoll(p1);
if (p2) {
len = strlen(p2);
memset(float_part, '0', 9 * sizeof(char));
excess = len > 9 ? p2[9] : '0';
len = len > 9 ? 9 : len;
memcpy(float_part + 9 - len, p2, len * sizeof(char));
value.it_value.tv_nsec = atol(float_part);
if ((excess >= '5') && (value.it_value.tv_nsec++ == 999999999L))
value.it_value.tv_nsec = 0, value.it_value.tv_sec++;
}
if (i == clocks)
largest_value = value;
else if (value.it_value.tv_sec > largest_value.it_value.tv_sec)
largest_value = value;
else if (value.it_value.tv_sec == largest_value.it_value.tv_sec)
if (value.it_value.tv_nsec > largest_value.it_value.tv_nsec)
largest_value = value;
}
if (clocks == argc)
return 0;
fd = timerfd_create(clockid, 0);
if (fd < 0)
goto fail;
if (timerfd_settime(fd, TFD_TIMER_ABSTIME, &largest_value, NULL))
goto fail;
if (clock_gettime(clockid, &(value.it_value)) == 0)
fprintf(stderr, "%s: sleeping until %lli.%09li (current time: %lli.%09li, clock: %s)\n",
argv0, (long long int)(largest_value.it_value.tv_sec), largest_value.it_value.tv_nsec,
(long long int)(value.it_value.tv_sec), value.it_value.tv_nsec, clockstr);
for (;;) {
if (clock_gettime(clockid, &(value.it_value)))
goto fail;
if (value.it_value.tv_sec > largest_value.it_value.tv_sec)
break;
if (value.it_value.tv_sec == largest_value.it_value.tv_sec)
if (value.it_value.tv_nsec >= largest_value.it_value.tv_nsec)
break;
if (read(fd, &overrun, (size_t)8) < 8) {
if (errno == EINTR)
continue;
goto fail;
}
}
close(fd);
return 0;
fail:
perror(argv0);
if (fd >= 0)
close(fd);
return 1;
}
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