Based on lsprof (patch #1212837) by Brett Rosen and Ted Czotter.
With further editing by Michael Hudson and myself.
History in svn repo: http://codespeak.net/svn/user/arigo/hack/misc/lsprof
* Module/_lsprof.c is the internal C module, Lib/cProfile.py a wrapper.
* pstats.py updated to display cProfile's caller/callee timings if available.
* setup.py and NEWS updated.
* documentation updates in the profiler section:
- explain the differences between the three profilers that we have now
- profile and cProfile can use a unified documentation, like (c)Pickle
- mention that hotshot is "for specialized usage" now
- removed references to the "old profiler" that no longer exists
* test updates:
- extended test_profile to cover delicate cases like recursion
- added tests for the caller/callee displays
- added test_cProfile, performing the same tests for cProfile
* TO-DO:
- cProfile gives a nicer name to built-in, particularly built-in methods,
which could be backported to profile.
- not tested on Windows recently!
it deals correctly with some anomalous cases; according to this test
suite I've fixed it right.
The anomalous cases had to do with 'exception' events: these aren't
generated when they would be most helpful, and the profiler has to
work hard to recover the right information. The problems occur when C
code (such as hasattr(), which is used as the example here) calls back
into Python code and clears an exception raised by that Python code.
Consider this example:
def foo():
hasattr(obj, "bar")
Where obj is an instance from a class like this:
class C:
def __getattr__(self, name):
raise AttributeError
The profiler sees the following sequence of events:
call (foo)
call (__getattr__)
exception (in __getattr__)
return (from foo)
Previously, the profiler would assume the return event returned from
__getattr__. An if statement checking for this condition and raising
an exception was commented out... This version does the right thing.
Armin Rigo
Tim Peters
Nicholas Bastin
Guido van Rossum