test.js

var fork = require('child_process').fork;

if (process.argv[2] === 'child') {
  setInterval(function () {
    console.log('alive ... ');
  }, 200);

  setTimeout(function () {
    console.log('exit child');
    process.exit(0);
    process.exit(0);
  }, 500);
} else {
  var child = fork(process.argv[1], ['child'], {thread: true});
}