Bugs item #853411, was opened at 2003-12-03 16:55 Message generated for change (Comment added) made by pymonger You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=853411&group_id=5470
Category: Threads Group: Python 2.2.3 Status: Open Resolution: None Priority: 5 Submitted By: Göran Uddeborg (goeran) Assigned to: Nobody/Anonymous (nobody) Summary: After fork in subthread, signals are blocked Initial Comment: When a Python program starts a new thread, and this new thread forks, the forked process ingores signals. It will not terminate, or dump core if that would be applicable, when it receives a signal. I attach a test case which illustrates the behaviour. In this example, the child process is sent a SEGV signal from the subthread of the parent process. This should cause the child process to die and produce a core. But execution of the parent program threads finishes, there is still a python process around, continuing to sleep. Apparently, Python subthreads blocks signals. On Linux, /proc/*/status for subthreads includes the line SigBlk: ffffffff7ffbfeff The Python documentation says one should only install signal handlers in the main thread, and only the main thread will recieve signals. So this makes sense. But when the subthread forks, the new process inherits this signal mask, which seems to be incorrect behaviour. I would assume, if Python sets this signal mask for threads, it should also reset it again after a fork. I've seen this on these two platforms: Python 2.2.3 on Red Hat Linux RHEL 3WS (IA32) Python 2.2.1 on Sun Solaris 8 (Sparc) ---------------------------------------------------------------------- Comment By: gmanipon (pymonger) Date: 2004-12-06 21:24 Message: Logged In: YES user_id=1173063 Sorry for the bother. Was there any resolution to this bug report? ---------------------------------------------------------------------- Comment By: Jack Jansen (jackjansen) Date: 2004-01-26 10:02 Message: Logged In: YES user_id=45365 I have absolutely no idea where the bug could be, someone better versed in the threading ideosyncracies of the various platforms needs to look at this, but I do want to point at hairy_flange's comment that fink-python 2.2.3 on OSX does *not* exhibit the bug (while on other platforms it does). It may be worthwhile to download a fink-python in source form, and see whether they do any configure magic. ---------------------------------------------------------------------- Comment By: Steve Muir (hairy_flange) Date: 2004-01-26 04:04 Message: Logged In: YES user_id=960132 I just submitted a bug report that is a duplicate of this bug (apologies!), I observed the same behaviour with the Python shipped with Mac OS X (Python 2.3), and Python 2.2.2 on RedHat/x86, but Fink Python 2.2.3 for OS X does not have this bug. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=853411&group_id=5470 _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
