time/clocktest.c

   1 #include <signal.h>
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <time.h>
   5 #include <unistd.h>
   6 #include <stdint.h>
   7
   8 volatile int gotit = 0;
   9
  10 static void
  11 alarm_handler (int signal)
  12 {
  13     gotit = 1;
  14 }
  15
  16
  17 int
  18 main (int argc, char ** argv)
  19 {
  20   clock_t start, stop;
  21
  22   if (signal(SIGALRM, alarm_handler) == SIG_ERR)
  23     {
  24       perror ("signal");
  25       exit (1);
  26     }
  27   alarm(1);
  28   start = clock ();
  29   while (!gotit);
  30   stop = clock ();
  31
  32   printf ("%jd clock ticks per second (start=%jd,stop=%jd)\n",
  33           (intmax_t) (stop - start), (intmax_t) start, (intmax_t) stop);
  34   printf ("CLOCKS_PER_SEC=%jd, sysconf(_SC_CLK_TCK)=%ld\n",
  35           (intmax_t) CLOCKS_PER_SEC, sysconf(_SC_CLK_TCK));
  36   return 0;
  37 }