[Python-checkins] CVS: python/dist/src/Lib/test test_profile.py,NONE,1.1

2001年10月03日 17:58:26 -0700

Update of /cvsroot/python/python/dist/src/Lib/test
In directory usw-pr-cvs1:/tmp/cvs-serv14852/test
Added Files:
	test_profile.py 
Log Message:
Hopefully fix the profiler right. Add a test suite that checks that
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.
--- NEW FILE: test_profile.py ---
"""Test suite for the profile module."""
import profile
# In order to have reproducible time, we simulate a timer in the global
# variable 'ticks', which represents simulated time in milliseconds.
# (We can't use a helper function increment the timer since it would be
# included in the profile and would appear to consume all the time.)
ticks = 0
 
def test_main():
 global ticks
 ticks = 0
 prof = profile.Profile(timer)
 prof.runctx("testfunc()", globals(), globals())
 prof.print_stats()
def timer():
 return ticks*0.001
def testfunc():
 # 1 call
 # 1000 ticks total: 400 ticks local, 600 ticks in subfunctions
 global ticks
 ticks += 199
 helper() # 300
 helper() # 300
 ticks += 201
def helper():
 # 2 calls
 # 300 ticks total: 40 ticks local, 260 ticks in subfunctions
 global ticks
 ticks += 1
 helper1() # 30
 ticks += 3
 helper1() # 30
 ticks += 6
 helper2() # 50
 ticks += 5
 helper2() # 50
 ticks += 4
 helper2() # 50
 ticks += 7
 helper2() # 50
 ticks += 14
def helper1():
 # 4 calls
 # 30 ticks total: 29 ticks local, 1 tick in subfunctions
 global ticks
 ticks += 10
 hasattr(C(), "foo")
 ticks += 19
def helper2():
 # 8 calls
 # 50 ticks local: 39 ticks local, 11 ticks in subfunctions
 global ticks
 ticks += 11
 hasattr(C(), "bar") # 1
 ticks += 13
 subhelper() # 10
 ticks += 15
def subhelper():
 # 8 calls
 # 10 ticks total: 8 ticks local, 2 ticks in subfunctions
 global ticks
 ticks += 2
 for i in range(2):
 try:
 C().foo # 1 x 2
 except AttributeError:
 ticks += 3 # 3 x 2
class C:
 def __getattr__(self, name):
 # 28 calls
 # 1 tick, local
 global ticks
 ticks += 1
 raise AttributeError
if __name__ == "__main__":
 test_main()