[Python-Dev] cProfile with generator throwing (original) (raw)

Georg Brandl g.brandl at gmx.net
Sat Jun 9 09:42:08 CEST 2007

Eyal Lotem schrieb:

Hi. It seems that cProfile does not support throwing exceptions into generators properly, when an external timer routine is used.

The problem is that lsprof.c: ptraceentercall assumes that there are no exceptions set when it is called, which is not true when the generator frame is being gensendex'd to send an exception into it (Maybe you could say that only CallExternalTimer assumes this, but I am not sure). This assumption causes its eventual call to CallExternalTimer to discover that an error is set and assume that it was caused by its own work (which it wasn't). I am not sure what the right way to fix this is, so I cannot send a patch. Here is a minimalist example to reproduce the bug:

import cProfile import time p=cProfile.Profile(time.clock) def f(): ... yield 1 ... p.run("f().throw(Exception())") Exception exceptions.Exception: Exception() in <cProfile.Profile_ _object at 0xb7f5a304> ignored Traceback (most recent call last): File "", line 1, in File "/usr/lib/python2.5/cProfile.py", line 135, in run return self.runctx(cmd, dict, dict) File "/usr/lib/python2.5/cProfile.py", line 140, in runctx exec cmd in globals, locals File "", line 1, in File "", line 1, in f SystemError: error return without exception set

There might be a similar problem with trace functions, see bug #1733757 which is quite obscure too.

Georg

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