if (cluster.isMaster) {
  // Fork workers.
  for (var i = 0; i < numCPUs; i++) {
    cluster.fork();
  }

  cluster.on('exit', function(worker, code, signal) {
    console.log('worker ' + worker.process.pid + ' died');
  });
} else {
  // Workers can share any TCP connection
  // In this case its a HTTP server
  http.createServer(function(req, res) {
    res.writeHead(200);
    res.end("hello world\n");
  }).listen(8000);
}

if (cluster.isMaster) {

  var workers=[];
  //新建worker
  function newWorker(){
    var worker=cluster.fork();

    //監(jiān)聽信息，如果type為broadcast的話，則確定為廣播
    worker.on('message', function(msg) {
      if(msg.type=='broadcast'){
        var event=msg.event;
        //向所有worker發(fā)送此條廣播
        workers.forEach(function(worker){
          worker.send(event);
        })
      }
    });
    return worker;
  }

  for (var i = 0; i < numCPUs; i++) {
    workers.push(newWorker());
  }

    cluster.on('online',function(worker){
        console.log('worker %d is online',worker.id);
    })
} else {
  var worker=cluster.worker;

  //廣播就是發(fā)送一個type為broadcast的信息，event就是廣播內(nèi)容
  worker.broadcast=function(event){
    worker.send({
      type:'broadcast',
      event:event
    });
  }

  //這里用worker.on貌似不能監(jiān)聽到返回的信息
  process.on('message',function(event){
    console.log('worker: '+worker.id+' recived event from '+event.workerId);
  })

  //發(fā)送廣播
  worker.broadcast({
    message:'online',
    workerId:worker.id
  })
}