[Python-Dev] Traceback problem

Christian Tismer tismer@tismer.com
Mon, 24 Feb 2003 18:34:27 +0100

Hi py-dev,

I got a problem report for Stackless today, that
it seems to leak with tracebacks.

After trying other Python versions, I found out
that this is a "feature" of Python and not related
to Stackless. The problem becomes only more visible,
since people are keeping thousands of threads alive.

Here the problem:
When an exception has been raised in a frame, and
it already is handled in an except clause, the
exception is not cleared out from tstate and also
stays alive in the frame object.
Only when the frame is left, eval_frame calls
which clear all these, breaking cycles.

Does this need to be so, and for what reason?
Would it be equivalent if I cleared error info
in the context of a finally: ?
If not, please give me advice how to solve this
problem. It exists in all long-running frames
which have seen exceptions.

Thanks a lot - chris
Christian Tismer             :^)   <mailto:tismer@tismer.com>
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