贴一个解决js异步并行等待的代码

var Y = YUI();
var EventProxy = function(){
this.event_list = {};
this.data_list = [];
this.callback = null;
this.trigger_flag = false;
}
EventProxy.prototype.assign = function(){
this.callback = Array.prototype.splice.call(arguments, arguments.length - 1, 1)[0];
if(typeof this.callback !== 'function'){
return false;
}
for(var i = 0,len = arguments.length; i < len; i++){
this.event_list[arguments[i]] = false;
}
}
EventProxy.prototype.trigger = function(event_name, data){
if(!this.callback || this.event_list[event_name]){
return false;
}
this.event_list[event_name] = true;
this.data_list.push(data);

this.trigger_flag = true;
for(var key in this.event_list){
if(this.event_list.hasOwnProperty(key) && !this.event_list[key]){
this.trigger_flag = false;
}
}
if(this.trigger_flag){
this.callback.apply(null, this.data_list);
}
}

var proxy = new EventProxy();
proxy.assign('event1', 'event2', 'event3', function(v1, v2, v3){
Y.log(v1 + ' ' + v2 + ' ' + v3);
})
proxy.trigger('event1', 'data1');
proxy.trigger('event2', 'data2');
proxy.trigger('event3');