问极限NodeJS setImmediate

EN

var Physics = {
    lastTime: (new Date().getTime()),
    upsCounter: 0,
    ups: 0,

    init: function() {
        Physics.loop();
    },

    loop: function() {
        var currentTime = (new Date().getTime());
        Physics.upsCounter += 1;

        if((currentTime - Physics.lastTime) >= 1000) {
            Physics.ups = Physics.upsCounter;
            Physics.upsCounter = 0;
            Physics.lastTime = currentTime;

            console.log('UPS: ' + Physics.getUPS());
        }

        setImmediate(Physics.loop);
    },

    getUPS: function() {
        return this.ups;
    }

};