bug#25265: make-thread crashes in OS X 10.6

[Alan Third]

On Sat, Dec 24, 2016 at 12:06:45PM +0100, Charles A. Roelli wrote:
> Running Emacs -Q on the latest commit (e36a3882),
> 
> M-: (make-thread (lambda () "string"))
> 
> appears to hang Emacs immediately.

I’ve been working on this on and off for a while now, and I just can’t
fix it.

I’ve attached two patches that together are the best I’ve managed to
achieve, but unfortunately it randomly freezes up with 100% CPU usage.

I’ve not yet managed to work out what it’s doing when it goes into the
100% CPU loop. I can only assume I’ve missed some crucial case in
ns_select or something.

The first patch stops the NS port from using SIGIO, as it seems to be
the source of a number of problems. The second removes the NS event
loop in ns_select as it requires block_input/unblock_input wrapped
around it, but that’s what’s causing the crash in make-thread.

Instead it just looks for whether there is a new NS event as I don’t
think that requires blocking input.

-- 
Alan Third

0001-Don-t-use-SIGIO-in-NS.patch
Description: Remove SIGIO stuff

0001-Remove-event-loop-from-ns_select.patch
Description: Remove NS event loop from ns_select