Bugs item #1565525, was opened at 2006-09-26 06:58 Message generated for change (Tracker Item Submitted) made by Item Submitter You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1565525&group_id=5470
Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Python Interpreter Core Group: Python 2.5 Status: Open Resolution: None Priority: 5 Submitted By: Greg Hazel (ghazel) Assigned to: Nobody/Anonymous (nobody) Summary: gc allowing tracebacks to eat up memory Initial Comment: Attached is a file which demonstrates an oddity about traceback objects and the gc. The observed behaviour is that when the tuple from sys.exc_info() is stored on an object which is inside the local scope, the object, thus exc_info tuple, are not collected even when both leave scope. If you run the test with "s.e = sys.exc_info()" commented out, the observed memory footprint of the process quickly approaches and sits at 5,677,056 bytes. Totally reasonable. If you uncomment that line, the memory footprint climbs to 283,316,224 bytes quite rapidly. That's a two order of magnitude difference! If you uncomment the "gc.collect()" line, the process still hits 148,910,080 bytes. This was observed in production code, where exc_info tuples are saved for re-raising later to get the stack- appending behaviour tracebacks and 'raise' perform. The example includes a large array to simulate application state. I assume this is bad behaviour occurring because the traceback object holds frames, and those frames hold a reference to the local objects, thus the exc_info tuple itself, thus causing a circular reference which involves the entire stack. Either the gc needs to be improved to prevent this from growing so wildly, or the traceback objects need to (optionally?) hold frames which do not have references or have weak references instead. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1565525&group_id=5470 _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
