Re: Return value of finished threads

[Eli Zaretskii <eliz@gnu.org>]

> From: Michael Albinus <michael.albinus@gmx.de>
> Date: Fri, 20 Jul 2018 16:56:48 +0200
> 
> What I'm missing is a simple possibility to collect the return values of
> the respective finished threads (`find-file-noselect' calls), which is a
> buffer or a list of buffers. The documentation recommends the use of
> global variables, which would be inconvenient for many threads to supervise.
> 
> So I'm wondering if we could extend thread support by an indication of
> the thread result, when finished. One idea would be that `thread-join'
> returns with that value.
> 
> Another idea, even broader, would be to extend `condition-notify' by an
> argument, which passes a Lisp object to another thread. The
> corresponding `condition-wait' would return that value.

Do you have an implementation in mind?  Because in general, passing
variables between threads in C also needs global variables...