cluster进程间通讯精简版

var cluster = require('cluster');if (cluster.isMaster) {console.log('I am master');var numCPUs = require('os').cpus().length;for (var i = 0; i < numCPUs; i++) {         cluster.fork();    }for (var id in cluster.workers) {        cluster.workers[id].on('message', function(msg){            console.log('[master] ' + 'message ' + msg);        });}    setTimeout(function () {        for (var id in cluster.workers) {            cluster.workers[id].send('[master] ' + 'send message to worker' + id);        }    }, 3000);} else if (cluster.isWorker) {console.log('I am worker #' + cluster.worker.id);    process.on('message', function(msg) {        console.log('[worker] '+msg);        process.send('[worker] worker'+cluster.worker.id+' received!');    });}