Passing Exceptions Across Threads

[Adam Mullins]

Hello, I'm writing a physics simulator back-end with a built-in,
threaded server that for the moment is quite simple. I've faced a few
problems in writing this code, however, as it's the first time I've
played with threading. For the moment, everything works decently, but I
need (or rather, want) a method for passing caught exceptions in
sub-threads to the main thread to be raised there. Although this
solution isn't the only one, I feel it will be the most elegant (the
thread/class will be called inside the main module within a try/except
structure, which makes the program a bit more modular, in my opinion,
and cleaner).

Here is my code so far:

http://rafb.net/paste/results/UESOWB24.html

You can see near the top where I clumsily tried to a hack a function
into threading._Main Thread, in the hopes that if it were called from a
sub-thread it would execute in the main thread. This is seemingly not
so.

Many thanks for any help.

[aurelien.campeas@free.fr]

Re: Passing Exceptions Across Threads

have you tried replacing :

main = threading._Main Thread()

with

main = threading.curre ntThread() ?

(not sure if that will be sufficient)

Well your way to pass exception between threads looks like I would have
done myself. But I am no expert.

Have you considered using stackless Python ? It provides a much safer
and efficient threading model (thinking about your physics simulator).
Of course, if you want not to block on blocking calls (socket stuff),
real threads are a way to go.

[robert]

Re: Passing Exceptions Across Threads

Adam Mullins wrote:
[color=blue]
> Hello, I'm writing a physics simulator back-end with a built-in,
> threaded server that for the moment is quite simple. I've faced a few
> problems in writing this code, however, as it's the first time I've
> played with threading. For the moment, everything works decently, but I
> need (or rather, want) a method for passing caught exceptions in
> sub-threads to the main thread to be raised there. Although this
> solution isn't the only one, I feel it will be the most elegant (the
> thread/class will be called inside the main module within a try/except
> structure, which makes the program a bit more modular, in my opinion,
> and cleaner).
>
> Here is my code so far:
> http://rafb.net/paste/results/UESOWB24.html
>
> You can see near the top where I clumsily tried to a hack a function
> into threading._Main Thread, in the hopes that if it were called from a
> sub-thread it would execute in the main thread. This is seemingly not
> so.
>
> Many thanks for any help.
>[/color]

The CallQueue and BackgroundCall. get_return() do that exception transfer
already by default:

http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/491281

http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/491280

-robert