深入浅出Nodejs中雪崩问题 写的例子

var EventEmitter = require('events').EventEmitter;
var proxy = new EventEmitter();
proxy.setMaxListeners(0);
var selectSqls = [];
var flags = [];
for(var i=0;i<10;i++){
    flags.push('ready');
    for(var j=0;j<10;j++){
        selectSqls.push(j);
    }
}

var count=1;
var http=require('http');
var select = function (num,callback) {
    proxy.once(''+num,callback);
    if(flags[num] === 'ready'){
        flags[num] = 'pending';
        http.get("http://www.cnblogs.com/", function(res) {
            console.log("Got response: " + count++);
            proxy.emit(''+num,num);
            flags[num] = 'ready';
            //res.resume();
        }).on('error', function(e) {
            console.log("Got error: " + e.message);
        });
    }
};

var callNum= function(num){
    console.log(num + ':ok');
};
for(var num=0;num<selectSqls.length;num++){
    var sqlNum = selectSqls[num];
    //console.log(sqlNum);
    select(sqlNum,callNum);
}