[ltk-user] Mysterious breakage

[Kenneth Tilton]

On 10/4/2010 9:27 PM, Daniel Herring wrote:
> On Tue, 5 Oct 2010, Jonathan Johansen wrote:
>
>> I tried using Ltk a while back (running Phil's Able editor), and
>> immediately ran into the kind of problem you report.  I found that
>> bringing up a msgbox as the first thing to do, and dismissing it by
>> pressing Enter (not by clicking)
>> was one way to avoid the hang.  Unfortunately that's all I can add.
>>  I'm pretty sure there are a few more people that would be very happy
>> to see this bug get fixed.  I hit it and just stopped trying to do GUI
>> programming, so if it
>> get's fixed, I'll be very happy, and willing to test things on my
>> 'eerie' computer.
>
> So the patches I sent several months ago make things work 100% on my xp
> box. It is my belief that the problem is some oddity of how
> ms-broken-windows handles process creation and/or stream i/o.
>
> What I saw (e.g. the ABLE window not appearing until after I terminated
> clisp) lead me to believe that ltk was writing everything to the wish
> shell before it entered the Tk event loop; thus Tk never received
> notification of pending data until the stream was closed. Strategic
> placement of a (sleep 1) solved my problem and reinforced my belief.
>
> That said, I did a bunch of tinkering, never breaking out proper debug
> tools. Its possible I just moved a race condition away from my computer
> and towards others. To diagnose this properly, someone needs to break
> out the debuggers and attach to both lisp and wish after the startup
> hang. Backtraces should show what each is doing, hopefully pointing out
> where the deadlock occurs.
>
> These links may help.
> http://msdn.microsoft.com/en-us/library/c6wf8e4z.aspx
> http://www.microsoft.com/whdc/devtools/debugging/default.mspx

This link might help: http://common-lisp.net/project/cffi/

It's time for LTk to lose the stream crutch. FFI isn't /that/ hard, and 
it only needs to be done by the LTk maintainers.

kt

-- 
http://www.stuckonalgebra.com
"The best Algebra tutorial program I have seen... in a class by itself." 
Macworld