bug#75275: 30.0.92; `make-thread` bug on macOS 15.2

["Gerd Möllmann" <gerd.moellmann@gmail.com>]

Alan Third <alan@idiocy.org> writes:

>> But... when I look at fd_handler, that function calls pselect directly.
>> 
>>           result = pselect (nfds, &readfds, wfds, NULL, tmo, NULL);
>> 
>> 
>> Can that be right?
>
> I think that's OK as we've already called thread_select further up.
> I've a vague memory of putting this in as a work-around.
>
> We call thread_select with a zero timeout to give other threads a
> chance to grab the lock, then carry on as normal, running the run loop
> and fd_handler which calls pselect.
>
> To be fair, though, I think when we set this up I didn't understand
> the code as well as I do now, so perhaps it was the wrong thing to do.

OK, thanks!