[Python-Dev] cProfile with generator throwing
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: ptrace_enter_call assumes that there
> are no exceptions set when it is called, which is not true when the
> generator frame is being gen_send_ex'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
>>>> def f():
> ... yield 1
> Exception exceptions.Exception: Exception() in <cProfile.Profile
> object at 0xb7f5a304> ignored
> Traceback (most recent call last):
> File "<stdin>", line 1, in <module>
> 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 "<string>", line 1, in <module>
> File "<stdin>", 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.
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