[issue1215] documentation doesn't say that you can't handle C segfaults from python
Georg Brandl added the comment: I see not much to be done here, except from committing Martin's patch updated to the current trunk. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1215 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1215] documentation doesn't say that you can't handle C segfaults from python
Roundup Robot added the comment: New changeset bd16e333 by Georg Brandl in branch '3.3': Closes #1215: document better why it is not a good idea to catch e.g. SIGSEGV and refer to faulthandler. http://hg.python.org/cpython/rev/bd16e333 -- nosy: +python-dev resolution: - fixed stage: - committed/rejected status: open - closed ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1215 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1215] documentation doesn't say that you can't handle C segfaults from python
STINNER Victor victor.stin...@haypocalc.com added the comment: Le mercredi 31 août 2011 02:52:01, vous avez écrit : What do you want to do on a SIGSEGV? On a real fault, you cannot rely on Python internal state, you cannot use any Python object. To handle a real SIGSEGV fault, you have to implement a signal handler using only *signal safe* functions in C. Well, strictly speaking, it is very hard or impossible to write C code that's guaranteed to be safe after an unexpected segv too It is possible if you only use signal safe functions. I think that no Python function is signal safe :-) -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1215 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1215] documentation doesn't say that you can't handle C segfaults from python
Changes by Éric Araujo mer...@netwok.org: -- nosy: +eric.araujo, haypo versions: +Python 3.3 -Python 2.6, Python 2.7, Python 3.1, Python 3.2 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1215 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1215] documentation doesn't say that you can't handle C segfaults from python
STINNER Victor victor.stin...@haypocalc.com added the comment: def handler(signal, stackframe): print OUCH stdout.flush() _exit(1) What do you want to do on a SIGSEGV? On a real fault, you cannot rely on Python internal state, you cannot use any Python object. To handle a real SIGSEGV fault, you have to implement a signal handler using only *signal safe* functions in C. See faulthandler_fatal_error() function: https://github.com/haypo/faulthandler/blob/master/faulthandler.c#L257 The documentation for this can now point to the faulthandler module (in Python 3). For your information, faulthandler is available for Python older than 3.3 as a third party module: http://pypi.python.org/pypi/faulthandler segfault is the following C module: For tests, you can use ctypes.string_at(0) to read a word from NULL. -- faulthandler installs a signal handler for SIGSEGV, SIGFPE, SIGABRT, SIGBUS and SIGILL signals: http://docs.python.org/dev/library/faulthandler.html -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1215 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1215] documentation doesn't say that you can't handle C segfaults from python
Martin Pool m...@sourcefrog.net added the comment: On 31 August 2011 07:56, STINNER Victor rep...@bugs.python.org wrote: STINNER Victor victor.stin...@haypocalc.com added the comment: def handler(signal, stackframe): print OUCH stdout.flush() _exit(1) What do you want to do on a SIGSEGV? On a real fault, you cannot rely on Python internal state, you cannot use any Python object. To handle a real SIGSEGV fault, you have to implement a signal handler using only *signal safe* functions in C. Well, strictly speaking, it is very hard or impossible to write C code that's guaranteed to be safe after an unexpected segv too; who knows what might have caused it. The odds are probably better that it will work in in C than in Python. At any rate I think it's agreed that the original code is not supported and it's just the docs that need to change. So what do you think of http://bugs.python.org/file22989/20110822-1525-signal-doc.diff ? -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1215 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1215] documentation doesn't say that you can't handle C segfaults from python
Changes by Martin Pool m...@sourcefrog.net: -- title: Python hang when catching a segfault - documentation doesn't say that you can't handle C segfaults from python ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1215 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue1215] documentation doesn't say that you can't handle C segfaults from python
Martin Pool m...@sourcefrog.net added the comment: This patch tries to improve the documentation a bit more to address the issue that confused tebeka and to advertise faulthandler. Could someone review or apply it? -- keywords: +patch Added file: http://bugs.python.org/file22989/20110822-1525-signal-doc.diff ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue1215 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
