On Sep 21, 4:04 pm, Fredrik Lundh <[EMAIL PROTECTED]> wrote: > Diez B. Roggisch wrote: > >> I wonder why something like myThread.exit() or myThread.quit() or > >> threading.kill(myThread) can't be implemented? > >> Is something like that present in Python 3000? > > > Not that I'm aware of it (which doesn't mean to much though). > > > However I *am* aware of the bazillions discussions that have been held > > over this here - and the short answer is: it is a generally very bad > > idea to terminate threads hard, as it can cause all kinds of corruption. > > the problem is that you have no idea what the thread is doing, so just > killing it dead it may make one big mess out of the application's > internal state; see e.g. this post > > http://mail.python.org/pipermail/python-list/2006-August/400256.html > > That's wise ;-) Stopping a thread asynchronously is in /general/ a > dangerous thing to do, and for obvious reasons. For example, perhaps > the victim thread is running in a library routine at the time the > asynch exception is raised, and getting forcibly ejected from the > normal control flow leaves a library-internal mutex locked forever. > Or perhaps a catch-all "finally:" clause in the library manages to > release the mutex, but leaves the internals in an inconsistent state. > > which links to a FAQ from Sun on this very topic: > > http://java.sun.com/j2se/1.3/docs/guide/misc/threadPrimitiveDeprecati... > > (note that Java releases all mutexes when a thread is killed, but that's > not much better, as the FAQ explains) > > so as usual, the right thing to do is to do things in the right way. > > </F>
Often you know terminated a thread would be perfectly safe - and not being able to is very frustrating - particularly if your calculation is coarse grained and there is no convenient point to regularly poll for a stop signal. .NET solves the 'you might interrupt important stuff' by guaranteeing that an asynchronous ThreadAbortException won't be raised inside a finally block. Michael http://www.ironpythoninaction.com/ -- http://mail.python.org/mailman/listinfo/python-list
