[Python-Dev] pthread sem PyThread_acquire_lock
Hello. As this is my first post I will try to introduce myself as requested in the welcome email. If you aren't interested in my person, just continue reading at the next paragraph. I'm a student from Vienna/Austria. I attend what would match high school in the United States. I have been writing Python for about 3 years now and have just began to dig into the implementation of CPython. Now to my real question. I have noticed that PyThread_acquire_lock swallows all signals with pthread using sems. Looking at the source code it appears that this is intended, but I cannot see the reason for that. It seems the pthread sem implementation is the only one doing so. Can any of you tell me the reason why it swallows signals? I have already prepared a patch that introduces a new _noswallow function if sem are used and uses this in threadmodule.c. But if there isn't any real reason for it to swallow exceptions, I think it would be wisest to change that. Best regards, Florian Mayer ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] pthread sem PyThread_acquire_lock
Martin v. Löwis wrote: > Can you please explain what you mean by "swallowing"? The signals don't get through when acquiring the lock. > What is the sequence of actions triggering the case you are talking > about, what happens, and what do you expect to happen instead? Create a Lock object, call .acquire and try to press Ctrl-C, the keyboardinterrupt is swallowed > Also, how would you fix this (in principle, not what the specific > patch would look like)? Remove the loop that explicitly does this in a new function and use that one in threadmodule.c for lock.acquire. > > Regards, > Martin Best regards, Florian PS: Sorry for sending this message twice. ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] pthread sem PyThread_acquire_lock
Martin v. Löwis wrote: Can you please explain what you mean by "swallowing"? The signals don't get through when acquiring the lock. What is the sequence of actions triggering the case you are talking about, what happens, and what do you expect to happen instead? Easiest way is to create a Queue.Queue and call .get() on it and try to Ctrl-C it. Also, how would you fix this (in principle, not what the specific patch would look like)? Remove the loop that explicitly does this in a new function and use that one in threadmodule.c for lock.acquire. Regards, Martin Best regards, Florian PS: Excuse me, I messed up things once again. ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
