Re: Return value of finished threads

[Michael Albinus]

Tom Tromey <address@hidden> writes:

> Michael> Yes, likely until a thread-join has happened. And a second
> Michael> thread-join on the same thread shall always return ni.
>
> I was wondering which semantics would be preferred here.
> Having each thread-join return the same result doesn't seem so bad either.

I have no strong preference. But returning the result only once has the
advantage, that you could remove all thread data from a dead thread,
once the result has been shown.

> Michael> How long do we keep the results of dead threads, for which no
> Michael> thread-join happens? Do we need a Lisp cleanup function, which purges
> Michael> all dead threads results? Or does this the GC, when no Lisp object 
> holds
> Michael> the dead thread any longer?
>
> I didn't look deeply but I think instead of mark_threads, alloc.c would
> need to mark any thread it runs across; and then mark_one_thread could
> handle exited threads specially.

This goes into the darkness I'm not familiar with.

> Michael> (Btw, I believe it will be much better when you implement this. It is
> Michael> still hard for me to read and modify threads.c)
>
> I will see if I can find some time.  But I think your patch is close so
> you should keep going :-)

Sure. I use my patch locally to work on Tramp threads, but I won't push
it upstream.

> Tom

Best regards, Michael.