fix: handle only the latest waker

[geofmureithi]

This attempts to resolve #477

[sjmiller609]

Thank you! I will set the polling rate back to 100ms, then use this version on my server. I'll report back once I have the information.

[sjmiller609]

Started the server with the new version at 1:08 ET. Checking on it at 1:37 ET, CPU looks flat so far.

Zooming in on that, yes it looks flat.

CPU profile look good: no single function takes up a majority of the CPU load, and add_waker is not seen.

I think it works!

EDIT: I did not update the polling rate to 100ms, it's still at 1 second. I think it works, just FYI.