A scalable queue for parallel callbacks.
The API is similar to https://github.com/d3/d3-queue, but without accumulating results in memory.
var Queue = require('queue-cb);
function delayedHello(callback) {
setTimeout(function() {
console.log("Hello!");
callback(null);
}, 250);
}
var q = new Queue();
q.defer(delayedHello);
q.defer(delayedHello);
q.await(function(error) {
if (error) throw error;
console.log("Goodbye!");
});