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/* See LICENSE file for copyright and license details. */
#include <sys/prctl.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "arg.h"
#define NS (1L)
#define US (1000L)
#define MS (1000L * 1000L)
#define S (1000L * 1000L * 1000L)
char *argv0;
static void
usage(void)
{
fprintf(stderr, "usage: %s [-f] ('get' | 'GET' | (('reset' | interval) command [argument] ...))\n", argv0);
exit(1);
}
int
main(int argc, char **argv)
{
int fatal;
long int slackvalue;
const char *suffix;
char *end;
int r;
ARGBEGIN {
case 'f':
fatal = 1;
break;
default:
usage();
} ARGEND;
if (!argc)
usage();
if (!strcmp(*argv, "get") || !strcmp(*argv, "GET")) {
if (argc > 1)
usage();
r = prctl(PR_GET_TIMERSLACK);
if (r < 0)
return fprintf(stderr, "%s: prctl PR_GET_TIMERSLACK: %s\n", argv0, strerror(errno)), 1;
if (!strcmp(*argv, "GET")) suffix = "";
else if (r % S == 0) suffix = "s", r /= S;
else if (r % MS == 0) suffix = "ms", r /= MS;
else if (r % US == 0) suffix = "µs", r /= US;
else suffix = "ns";
printf("%i%s\n", r, suffix);
return 0;
}
if (argc < 2)
usage();
if (!strcmp(*argv, "reset")) {
slackvalue = 0;
} else {
slackvalue = strtol(*argv, &end, 10);
if (end == *argv)
return fprintf(stderr, "%s: no slack value specified\n", argv0), 1;
if (!strcmp(end, "n") || !strcmp(end, "ns") || !strcmp(end, "")) slackvalue *= NS;
else if (!strcmp(end, "µ") || !strcmp(end, "µs")) slackvalue *= US;
else if (!strcmp(end, "u") || !strcmp(end, "us")) slackvalue *= US;
else if (!strcmp(end, "m") || !strcmp(end, "ms")) slackvalue *= MS;
else if (!strcmp(end, "s")) slackvalue *= S;
else
return fprintf(stderr, "%s: unrecognised suffix for slack value\n", argv0), 1;
if (slackvalue <= 0)
return fprintf(stderr, "%s: invalid slack value: %lins\n", argv0, slackvalue), 1;
}
r = prctl(PR_SET_TIMERSLACK, slackvalue);
if (r < 0) {
fprintf(stderr, "%s: prctl PR_SET_TIMERSLACK %li: %s\n", argv0, slackvalue, strerror(errno));
if (fatal)
return 1;
}
argv++;
execvp(*argv, argv);
fprintf(stderr, "%s: execvp %s: %s\n", argv0, *argv, strerror(errno));
return 1;
}
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