feedback loops - different methods

Question

Im trying to get an understanding of different coding methods to manage feedback loops. There are a variety of languages I can use (js being the most desired)

Essentially, I have multiple threads of data coming in and going out like so:

direction id   float
in        31   0.2313
out       32   0.4564
in        33   0.2656
out       31   0.5464

Notice the two id's for 31? I need to filter the "out" direction.

I'm a bit lost with this and trying to figure the right method to use. I'm guessing I need some kind of timing switch, to wait for a certain period (like a gate).

Any thoughts would be much appreciated.

Heres a diagram to explain better

Cheers

Ke