Interesting Thread Gotcha

[Hendrik van Rooyen]

"Bjoern Schliessmann" <usenet-ourmet.com> wrote:

Hendrik van Rooyen wrote:
> Absolutely! - well spotted!

This is no threading problem at all; not even a syntax problem. If
you don't know exactly what start_new_thread and kbd_driver
functions do it's impossible to tell if your code does what is
intended.

> It would have been nice, however, to have gotten something like:
>
> TypeError - This routine needs a tuple.
>
> instead of the silent in line calling of the routine in question,
> while failing actually to start a new thread.

Exactly which part of the code should give you this warning?

I am obviously missing something.

My understanding is that, to start a new thread, one does:

NewThreadID = thread.start_new_thread(NameOfRoutineToStart,
(ArgumentToCall_it_with,secondArg,Etc))

This calls start_new_thread with the name and the arguments to pass.

If one omits the comma, then start_new_thread is surely stilled called,
but with an argument that is now a call to the routine in question, which
somehow causes the problem.

So start_new_thread is the code that that is executed, with a bad set of
arguments - one thing, (a call to a routine) instead of two things -
a routine and a tuple of arguments.

Everywhere else in Python if you give a routine the incorrect number of
arguments, you get an exception.  Why not here?

- Hendrik