time/clocktest.c

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