childRunner

process.on('message', function(msg){

  require(msg.path)();

});

funcA

module.exports = function(){
  var count = 0;
  while (true){
    if (count++ % 1000000000 === 0){
      console.log('while true');
    }
  }
};

funcB

module.exports = function(){
  setInterval(function(){
    console.log('running fine');
  }, 1000);
};

parallel-solution

var async = require('async');
var cp = require('child_process');

async.parallel([
	function(){
		var c = cp.fork('./childRunner');
		c.send({path: './funcA'});
	},
	function(){
		var c = cp.fork('./childRunner');
		c.send({path: './funcB'});
	}
], function(){
	console.log('doesnt have to reach there');
});