example.js

function latch(n, done, notDone) {
        return function() {
                if(--n === 0) {
                        done();
                } else if(n > 0) {
                        notDone(n);
                }
        }
}

function getRandomNumbers() {
        var n = Math.floor(Math.random() * 100);
        var a = [];
        for(var i = 0; i < n; i++) {
                a.push(Math.floor(Math.random() * 100));
        }
        return a;
}       

function step1(data, done) {
        if(done) {
                step2(data);
        } else {
                step1a(data);
        }       
}       

var randomNumbers = getRandomNumbers();

function step1a(data) {
        var cb = function() {
                if(randomNumbers.length === 0) {
                        step1(data, true);
                } else {
                        data.arr = data.arr.concat(randomNumbers.splice(0, 10));
                        step1(data);
                }
        };      
        setTimeout(cb, 1000);
}       

function step2(data) {
        var l = latch(data.arr.length, function() { console.log('done'); console.log(data.arr); }, function(n) { console.log(n + ' to go!'); });
        for(var i = 0; i < data.arr.length; i++) {
                var t = Math.floor(Math.random() * 10000) + 1000;
                var cb = (function(j) {
                        return function() {
                                console.log('Index: ' + j + ', Data: ' + data.arr[j]);
                                l();
                        };
                })(i);
                setTimeout(cb, t);
        }
}

step1({arr:[]});