[Async-sig] Feedback, loop.load() function

[Pau Freixes]

> One approach would be to add a generic instrumentation API. Trio has
> something like this, that I think is expressive enough to let Pau
> implement their busyness checking as a library:
>
>     https://trio.readthedocs.io/en/latest/reference-core.html#instrument-api
>
> This has several advantages over subclassing: multiple libraries can
> define their own instrumentation without interfering with each other,
> you don't have to redefine the instrumentation for every loop
> implementation, and you don't have to hook up the instrumentation when
> setting up the loop, e.g. you could just do something like:
>
>     import toobusy
>     with toobusy.Monitor(loop) as monitor:
>         if monitor.toobusy():
>             ...

It will help also other loops to meet the same contract making them
compatibles with already implemented instruments. Maybe the major
concern here is the performance penalty, do you have some numbers
about how negligible is have all of these signals available to be
used?
-- 
--pau