What do I do when I want to limit the number of tasks that are run in parallel? I'm talking about something like the queues in the famous async.js. I've seen ta

What do I do when I want to limit the number of tasks that are run in parallel? I'm talking about something like the queues in the famous async.js. I've seen tame.js trying to solve this by a construct named rendezvous but to me it looked even messier than inline callbacks.