Hi, I need to create a infinite (but breakable) cycle where I can slow down the cycle by awaiting promises inside. While cycle should be able to do this, but as you can see in the image, the duration is all over the place.
Why is this happening? Is there a way to make it close to the original sleep duration?
JS is a single threaded language, so there’s just one long line of instructions, there’s no actual background tasks.
A promise just runs at the next available slot the event loop provides so it’s just as soon as it can run.
In this case I’m guessing other part of the code running in your JS engine is blocking the event loop preventing your code to run just after one second.
Where are you running it? Browser or server?
Are you using a framework? If so, have you tried just this piece of code without any other imported code?
Here’s a talk at JSConf to help understand this
Jake Archibald on the web browser event loop, setTimeout, micro tasks, requestAnimationFrame, …
https://youtu.be/cCOL7MC4Pl0
This talk explains everything I had always wondered about concurrency in JS, but could never be bothered to read about.