New submission from Guido van Rossum: I was writing a new Tulip example (a cache client and server, not yet public) and I noticed that when I interrupted the client with ^C I got a traceback (expected) followed by a segfault (unexpected). This is on OSX 10.8 but I don't think it is platform dependent.
A little experiment showed that this only happened with Python 3.4 and only with the latest Tulip, where Future has a __del__ method. According to gdb, the segfault happens on the first line of PyModule_GetState(), because the argument 'm' is NULL. Putting a NULL check in this function averts the segfault but give the following disturbing extra traceback: --- Logging error --- Traceback (most recent call last): Exception ignored in: <bound method Task.__del__ of Task(<testing>)<exception=KeyboardInterrupt()>> Traceback (most recent call last): File "/Users/guido/tulip/asyncio/futures.py", line 177, in __del__ File "/Users/guido/cpython/Lib/logging/__init__.py", line 1278, in error File "/Users/guido/cpython/Lib/logging/__init__.py", line 1384, in _log File "/Users/guido/cpython/Lib/logging/__init__.py", line 1394, in handle File "/Users/guido/cpython/Lib/logging/__init__.py", line 1456, in callHandlers File "/Users/guido/cpython/Lib/logging/__init__.py", line 835, in handle File "/Users/guido/cpython/Lib/logging/__init__.py", line 959, in emit File "/Users/guido/cpython/Lib/logging/__init__.py", line 888, in handleError File "/Users/guido/cpython/Lib/traceback.py", line 169, in print_exception File "/Users/guido/cpython/Lib/traceback.py", line 153, in _format_exception_iter File "/Users/guido/cpython/Lib/traceback.py", line 18, in _format_list_iter File "/Users/guido/cpython/Lib/traceback.py", line 65, in _extract_tb_or_stack_iter File "/Users/guido/cpython/Lib/linecache.py", line 15, in getline File "/Users/guido/cpython/Lib/linecache.py", line 41, in getlines File "/Users/guido/cpython/Lib/linecache.py", line 126, in updatecache File "/Users/guido/cpython/Lib/tokenize.py", line 431, in open TypeError: bad argument type for built-in operation This suggests the problem is triggered by some I/O due to the exception logging in the __del__ method. The gdb traceback (too big to post here) tells me that this PyModule_GetState() call is in the IO_STATE macro in textiowrapper_init(). The whole thing seems to be in a GC run called from Py_Finalize(). Check out the attached @bt.txt. Any ideas? (The TypeError is simply what PyModule_GetState() returns for a non-module argument -- I made it take the same exit path for NULL.) ---------- files: @bt.txt messages: 206721 nosy: gvanrossum, haypo, pitrou priority: normal severity: normal status: open title: Crash due to I/O in __del__ type: crash versions: Python 3.4 Added file: http://bugs.python.org/file33241/@bt.txt _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue20038> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
