#include #include #include #include #include #include #include #include typedef unsigned long long uint64; struct rusage rstart; struct timeval tstart, tstop; uint64 ttime = 0; void start() { gettimeofday (&tstart, NULL); getrusage (RUSAGE_SELF, &rstart); } uint64 usecs (struct timeval *tv) { return tv->tv_sec * 1000000 + tv->tv_usec; } uint64 stop() { struct rusage rend; getrusage (RUSAGE_SELF, &rend); gettimeofday (&tstop, NULL); uint64 utime = usecs(&rend.ru_utime) - usecs(&rstart.ru_utime); uint64 stime = usecs(&rend.ru_stime) - usecs(&rstart.ru_stime); ttime = usecs(&tstop) - usecs(&tstart); return utime + stime; } void usage(char *name) { printf ("Usage %s [time]\nWhere \"time\" is millions of times to loop.\n", name); exit(1); } int main(int argc, char *argv[]) { int i, n = 1; uint64 nsecs; if (argc > 2) usage(argv[0]); if (argc == 2) { n = strtol(argv[1], NULL, 10); if (n == 0) usage(argv[0]); } start(); for (i = 0; i < n * 1000000; i++) getuid(); nsecs = stop() / (n * 1000); /* returns nanosecs per call (user + system time) elapsed usecs (real time) */ printf("%lld %.2f\n", nsecs, ttime/1000000.0); return 0; }