IO fork/join more

io-fork-join2.js

var _ = require('underscore'),
    http = require('http'),
    URI = require('uri'),
    async = require('async');

var sendReq = function (s, cb) {
    // send a HTTP req, and pass error or result to the function arg
    // content omitted for brevity
};

var sendMany = function (sources, cb) {
    var funcs = [];
    _.each(sources, function (source) {
        funcs.push(function (s) {
            return function (callback) {
                sendReq(s, callback);
            };
        }(source));
    });
    async.parallel(funcs, cb);
}

var sources = ['http://www.google.com', 'http://twitter.com', 'http://www.ebay.com'];

sendMulti(sources, function(e, r) {
    // process, decide and repeast
    sendMulti(sources, function(e1, r1) {
       // ...
       sendReq(s1, function(e2, r2)  {
           // ...
       });
       // ...
       sendMulti([..], function(e3, r3) {
          // ...
       });
    });
})