async queue callback test

index.js

var async = require('async'), concurrency = 1, i, timestart = Date.now();

var testQueue = async.queue(function(task, callback) {
	var _runonce = false;

	console.log('running number '+task.number+', time: '+(Date.now() - timestart));

	var cb = function() {
		if (_runonce) return;

		/*
			Uncomment this line to show the difference between running the callback
			only once and multiple times.
		 */
		//_runonce = true;
		callback();
	}

	setTimeout(function() {
		if (task.number == 2 || task.number == 10) {
			cb();
			cb();
		} else {
			cb();
		}
	}, 1000);
}, concurrency);

testQueue.saturated = function() {
	console.log('testQueue: is saturated');
}

testQueue.empty = function() {
	console.log('testQueue: is now empty');
}

testQueue.drain = function() {
	console.log('testQueue: has finished processing all queued tasks');
}

for (i = 0; i <= 20; i++) {
	testQueue.push({number: i});
}