How to create a sleep/delay in nodejs that is Blocking?

Node is asynchronous by nature, and that’s what’s great about it, so you really shouldn’t be blocking the thread, but as this seems to be for a project controlling LED’s, I’ll post a workaraound anyway, even if it’s not a very good one and shouldn’t be used (seriously).

A while loop will block the thread, so you can create your own sleep function

function sleep(time, callback) {
    var stop = new Date().getTime();
    while(new Date().getTime() < stop + time) {
        ;
    }
    callback();
}

to be used as

sleep(1000, function() {
   // executes after one second, and blocks the thread
});

I think this is the only way to block the thread (in principle), keeping it busy in a loop, as Node doesn’t have any blocking functionality built in, as it would sorta defeat the purpose of the async behaviour.

Leave a Comment