how fast can we count?

counting.c

#include <string.h>
#include <signal.h>
#include <stdio.h>

long i;

static void signal_handler ( int data ) {
  printf("%ld\n", i);
}

static void install_signal_handler() {
  struct sigaction sa;

  memset(&sa, '\0', sizeof(sa));
  sa.sa_handler = signal_handler;
  sigemptyset(&(sa.sa_mask));
  sa.sa_flags = SA_RESTART;

  if ( sigaction(SIGUSR2, &sa, NULL) == -1 ) {
    printf("unable to install signal handler\n");
  } else {
    printf("installed signal handler\n");
  }
}

int main ( int arfc, char ** arfv ) {

  install_signal_handler();

  i = 0;
  while ( 1 ) {
    i ++;
  }

  return 0;
}