Re: the state of the concurrency branch

[Tom Tromey]

>> The basic issue is that only one thread can select on a given fd at a
>> time.

Stefan> Why?

To me it seemed like the simplest approach, not requiring changes
anywhere else in Emacs: if select says data is available, the thread can
proceed to read it and handle it.  Maybe another choice is to make the
reading code robust to failures here; and also audit to make sure there
aren't any possible races (readers have to really read all the data when
given a chance or else you could have different threads reading
different bits from the fd, possibly processing them in the wrong
order).

This approach was also convenient since it enabled thread-locking of
processes, something I think is desirable anyway.

Tom