var a, b, thread1, thread2 in

a := 0;
thread1 := (param) => {
  tStart(thread2, 0);
  output "After thread2 start";
  output a;
  b := 0;
  while (b < 5000) {
    b := b + 1
  };
  output "After inner loop";
  output a
};

thread2 := (param) => {
  while (a < 5000) {
    a := a + 1
  }
};

atomic {
  tStart(thread1, 0)
};

output "Final output";
output a