Optimise stub

[craff]

The function caml_polly_ctl and the three functions calling it could be called frequently in some applications. We could tag them with noalloc and untagged, raising the exception from OCaml in case of error ?

[craff]

This is not really important for
simple_httpd as I am using ET and non blocking socket, I only need to
call epoll_add once for each socket. So this may wait, but if you like the idea, I will submit a PR.

[lindig]

I have to think about this. I am motivated to support your use case because it complements our own, which is not high performance and quite limited. So I am interested how to improve performance without complicating the interface and how to improve general usability.

[craff]

My proposal will not change the interface and reduce the size of the code, because it will move code from C to OCaml which is safer and more concise. The best is probably to discuss on the PR, I wont be vexed if the PR is finally not merges ;-)

[lindig]

I looked at your code; a frequent operation is to calculate event sets. It would be possible to re-bind infix operators |, and & to make the code look more like C code instead of using land and lor

[craff]

I submitted 2 PR... This will allow precise arguments #6 and #7