[hunchentoot-devel] Server sporadically hanging

[Jeff Cunningham]

Edi Weitz wrote:
>> That one went over my head. Does it mean that if I put a function
>> like this:
>>
>> (defun cancel-all-threads ()
>>   (mapcar (lambda (thread)
>>         (sb-thread:interrupt-thread thread
>>                             (lambda ()
>>                             (throw 'hunchentoot::handler-done
>>                               ""))))
>>         (sb-thread:list-all-threads)))
>>
>> into, say, request.lisp (in hunchentoot), that it would find the
>> tag?
>>     
>
> Why don't you try it out yourself?
>
>   CL-USER> (defun endless ()
>              (format #.*standard-output*
>                      "Interrupted by someone throwing ~S.~%"
>                      (catch 'foo
>                        (loop (sleep 1)))))
>   ENDLESS
>   CL-USER> (defun stop ()
>              (throw 'foo 42))
>   STOP
>   CL-USER> (sb-thread:make-thread 'endless)
>   #<SB-THREAD:THREAD {AEB0E11}>
>   CL-USER> (sb-thread:interrupt-thread * 'stop)
>   Interrupted by someone throwing 42.
>
> But as I already said the catch tag has to be established for this to
> work.  Look at the code, specifically at server.lisp, and you'll see
> that you can't simply throw HANDLER-DONE at any time during the
> lifetime of a Hunchentoot thread.  Or simply read the docs where it
> says that you can throw this tag "during the lifetime of a handler."
>   
I didn't try it out at that point because I didn't understand it well 
enough to formulate an intelligent test case. Thank you for providing one.

I have in place some machinery now that should enable me to identify all 
the threads in play and their state the next time it hangs as per Zach's 
suggestions, so I'll have to wait and see. Can't troubleshoot it until 
it breaks unfortunately.

Thanks for the ideas.
--Jeff