#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/time.h>
#include <unistd.h>
#include <errno.h>
#include <assert.h>
#include <string.h>

volatile int Z = 0;
volatile int Z2 = 0;

volatile int C = 0;
volatile int C2 = 0;

static void handler(int sig) {
  (void)sig;

  char buff[] = { (char)('0' + C++ % 10), '\n' };
  write(2, buff, 2);

  for(int i = 1; i < 10000000; i++)  {
    Z2 *= i;
  }
}

void loop() {
  for(int i = 1; i < 10000000; i++)  {
    Z *= i;
  }

  char buff[] = { '*', (char)('0' + C2++ % 10), '\n' };
  write(2, buff, 3);
}

int main() {
  struct sigaction act = {};
  act.sa_handler = &handler;
  sigemptyset(&act.sa_mask);
  if (sigaction(SIGPROF, &act, 0)) {
    assert(0);
  }

  itimerval t;
  t.it_value.tv_sec = 0;
  t.it_value.tv_usec = 100;
  t.it_interval = t.it_value;
  if (setitimer(ITIMER_PROF, &t, 0)) {
    assert(0);
  }

  for(int i = 0; i < 2000000; i++)  {
    loop();
  }

  fprintf(stderr, "DONE\n");

  return 0;
}