/* Compile this as follows:
 *   gcc -O0 -o raise raise.c
 * The C standard on signal() guarantees that the execution of raise will
 * terminate.
 *
 * Compile this as follows:
 *   gcc -Os -o raise raise.c
 * The C standard on signal() guarantees that the execution of raise will
 * terminate.
 *
 * Compile this as follows:
 *   gcc -O2 -o raise raise.c
 * The C standard on signal() guarantees that the execution of raise will
 * terminate.
 */

#include <signal.h>
#include <stdlib.h>
#include <time.h>

int terminated;

static void handler(int signo)
{
  terminated = 1;
}

int main(int argc, char **argv) {
  unsigned total = 0, delta = drand48() >= argc ? 1 : 0;
  /* At runtime, delta will be 0 as argc is one */

  signal(SIGUSR1, handler);

  /* This is an infinite loop unless terminated is 1 as delta is surely 0 */
  for (int i = 0; !terminated && i < 100; i += delta) {
    total += i;
    raise(SIGUSR1);
  }
  
  return total;
}