On Apr 9, 1:24 am, Dennis Lee Bieber <[EMAIL PROTECTED]> wrote: > On Tue, 8 Apr 2008 16:49:27 -0700 (PDT), Thomas Dimson > <[EMAIL PROTECTED]> declaimed the following in comp.lang.python: > > > > > I assume there is some issue with the global interpreter lock or that > > you can't exit the infinite loop from above Python. Any suggestions on > > how I can design this so the thread will be able to issue exits/raise > > exceptions just like a regular thread? Is there a way of terminating > > this thread from the python interpreter or ctypes.pythonapi? > > No... as I recall, you can't /EXIT/ Python from a sub-thread... > Which is what sys.exit() or whatever is trying to do -- shut down the > entire program, not just the thread. The error you get indicates that > the thread doing the shutdown wants to wait for the sub-thread to finish > -- but /it/ IS the sub-thread. Even console interrupts have to be > delivered to the main program. > > The only safe way to terminate a thread is to be able to code it > such that /it/ responds to an externally set value (a boolean, read a > message off a Queue, etc.) and for IT to then exit. Based upon the > sample you showed, that would require the C main loop to be checking for > a shutdown signal... If the API to that main loop library doesn't > include a shutdown capability I'd suggest it is a less than complete > library... And the only thing I'd suggest is not using a Python thread, > but instead spawning a separate process that somehow communicates to the > parent process -- and which can be forceably killed using OS specific > capabilities... "kill -9 pid" <G> > > -- > Wulfraed Dennis Lee Bieber KD6MOG > [EMAIL PROTECTED] [EMAIL PROTECTED] > HTTP://wlfraed.home.netcom.com/ > (Bestiaria Support Staff: [EMAIL PROTECTED]) > HTTP://www.bestiaria.com/
Thanks for the response, it put me in the right direction (I didn't realize there was no way of exiting the interpreter directly from a non-main thread). If anyone ever has the same problem, the solution I ended up using went like this: I created a wrapper around the infinite loop call that had a setjmp in it, exiting if setjmp was non-zero. Inside each callback function, I had a try/except statement that caught all exceptions. If it had an exception, it would set a thread- specific exception variable to sys.exc_info() and then call a C function that did a longjmp. The thread would first call the wrapper to the infinite loop. If the wrapper returns (because of a longjmp), it would check the thread- specific exception variable for a non-None value and raise the very same exception (with the same traceback) if it found it. A fairly large hack, but it seemed to do the job. Thanks again. -- http://mail.python.org/mailman/listinfo/python-list
