New submission from Mark Dickinson <[EMAIL PROTECTED]>: As of revision 65077 of the trunk, I'm getting errors in test_multiprocessing that seem to point to memory corruption in object allocation/deallocation. The failures are intermittent, and of a similar nature to the errors I was seeing previously, outlined in issue 3088.
The platform is OS X 10.5.4 (not a fresh install---it was an upgrade from OS X 10.4, in case this makes any difference), running on a MacBook Pro. I'm running a freshly checked out debug build of the trunk. Here's what I did: (1) make a fresh svn+ssh checkout of the trunk (2) ./configure --with-pydebug && make (3) ./python.exe Lib/test/test_multiprocessing.py (4) repeat step (3) until something nasty happens. The results vary from run to run, and 80-90% of the runs of test_multiprocessing pass. Here are 3 of the failures I've seen, occurring on three separate runs of test_multiprocessing. Failure 1: test_notify_all (__main__.WithManagerTestCondition) ... Assertion failed: (pool->ref.count > 0), function PyObject_Free, file Objects/obmalloc.c, line 1100. Failure 2: test_imap_unordered (__main__.WithManagerTestPool) ... python.exe(32381,0xb0513000) malloc: *** error for object 0xdbdbdbdb: pointer being reallocated was not allocated *** set a breakpoint in malloc_error_break to debug python.exe(32381,0xb0513000) malloc: *** error for object 0xdbdbdbdb: Non-aligned pointer being freed *** set a breakpoint in malloc_error_break to debug Fatal Python error: UNREF invalid object ERROR Failure 3: test_imap_unordered (__main__.WithManagerTestPool) ... Fatal Python error: UNREF invalid object ERROR I have very little (i.e. no) experience of debugging this kind of failure, and little understanding of how the multiprocessing module works. But I can and will follow instructions and suggestions about how to debug this. Stupid question: it appears from reading the comments in that file that obmalloc.c is (intentionally) not thread-safe. Could this have anything to do with the failures above? ---------- assignee: jnoller components: Extension Modules messages: 69917 nosy: jnoller, marketdickinson severity: normal status: open title: Memory corruption in multiprocessing module, OS X 10.5.4 type: crash versions: Python 2.6 _______________________________________ Python tracker <[EMAIL PROTECTED]> <http://bugs.python.org/issue3399> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
