[Babel-users] rbtree branch for resend.c

[Dave Taht]

I learned something this past couple weeks, and particularly this
weekend at (the hackers conference)

The "Skip list" is a really, really really amazing data structure.
It's cache friendly, easy to think about and write an api for, and the
lockless threaded version was invented in 2004,

https://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-579.pdf

the initial publication, 1989.

https://www.epaperpress.com/sortsearch/download/skiplist.pdf

being a lazy programmer, the following appears to be a halfway decent
implementation of that idea.

https://github.com/greensky00/skiplist.git

I do need to go and check if the red/black thing I was doing was
actually correct, but this would drop in
and be a direct replacement/competitor to the idea.