From f137f75ab82019b7b4db6d45bd69e2c0b155b2eb Mon Sep 17 00:00:00 2001 From: Guido van Rossum Date: Thu, 4 Oct 2001 00:58:24 +0000 Subject: [PATCH] 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. --- Lib/profile.py | 49 +++++++++++++------- Lib/test/output/test_profile | 17 +++++++ Lib/test/test_profile.py | 86 ++++++++++++++++++++++++++++++++++++ 3 files changed, 135 insertions(+), 17 deletions(-) create mode 100644 Lib/test/output/test_profile create mode 100644 Lib/test/test_profile.py diff --git a/Lib/profile.py b/Lib/profile.py index 91679052b23..73aeff9fe86 100755 --- a/Lib/profile.py +++ b/Lib/profile.py @@ -109,18 +109,18 @@ class Profile: avoid contaminating the program that we are profiling. (old profiler used to write into the frames local dictionary!!) Derived classes can change the definition of some entries, as long as they leave - [-2:] intact. + [3:] intact. - [ 0] = Time that needs to be charged to the parent frame's function. - It is used so that a function call will not have to access the - timing data for the parent frame. - [ 1] = Total time spent in this frame's function, excluding time in - subfunctions - [ 2] = Cumulative time spent in this frame's function, including time in - all subfunctions to this frame. - [-3] = Name of the function that corresponds to this frame. - [-2] = Actual frame that we correspond to (used to sync exception handling) - [-1] = Our parent 6-tuple (corresponds to frame.f_back) + [0] = Time that needs to be charged to the parent frame's function. + It is used so that a function call will not have to access the + timing data for the parent frame. + [1] = Total time spent in this frame's function, excluding time in + subfunctions + [2] = Cumulative time spent in this frame's function, including time in + all subfunctions to this frame (but excluding this frame!). + [3] = Name of the function that corresponds to this frame. + [4] = Actual frame that we correspond to (used to sync exception handling) + [5] = Our parent 6-tuple (corresponds to frame.f_back) Timing data for each function is stored as a 5-tuple in the dictionary self.timings[]. The index is always the name stored in self.cur[4]. @@ -243,10 +243,21 @@ def trace_dispatch_exception(self, frame, t): rt, rtt, rct, rfn, rframe, rcur = self.cur if (rframe is not frame) and rcur: return self.trace_dispatch_return(rframe, t) - return 0 + self.cur = rt, rtt+t, rct, rfn, rframe, rcur + return 1 def trace_dispatch_call(self, frame, t): + if self.cur and frame.f_back is not self.cur[4]: + rt, rtt, rct, rfn, rframe, rcur = self.cur + if not isinstance(rframe, Profile.fake_frame): + if rframe.f_back is not frame.f_back: + print rframe, rframe.f_back + print frame, frame.f_back + raise "Bad call", self.cur[3] + self.trace_dispatch_return(rframe, 0) + if self.cur and frame.f_back is not self.cur[4]: + raise "Bad call[2]", self.cur[3] fcode = frame.f_code fn = (fcode.co_filename, fcode.co_firstlineno, fcode.co_name) self.cur = (t, 0, 0, fn, frame, self.cur) @@ -259,7 +270,11 @@ def trace_dispatch_call(self, frame, t): return 1 def trace_dispatch_return(self, frame, t): - # if not frame is self.cur[-2]: raise "Bad return", self.cur[3] + if frame is not self.cur[4]: + if frame is self.cur[4].f_back: + self.trace_dispatch_return(self.cur[4], 0) + else: + raise "Bad return", self.cur[3] # Prefix "r" means part of the Returning or exiting frame # Prefix "p" means part of the Previous or older frame @@ -302,7 +317,7 @@ def trace_dispatch_return(self, frame, t): # very nice :-). def set_cmd(self, cmd): - if self.cur[-1]: return # already set + if self.cur[5]: return # already set self.cmd = cmd self.simulate_call(cmd) @@ -324,7 +339,7 @@ def __init__(self, code, prior): def simulate_call(self, name): code = self.fake_code('profile', 0, name) if self.cur: - pframe = self.cur[-2] + pframe = self.cur[4] else: pframe = None frame = self.fake_frame(code, pframe) @@ -337,10 +352,10 @@ def simulate_call(self, name): def simulate_cmd_complete(self): get_time = self.get_time t = get_time() - self.t - while self.cur[-1]: + while self.cur[5]: # We *can* cause assertion errors here if # dispatch_trace_return checks for a frame match! - a = self.dispatch['return'](self, self.cur[-2], t) + a = self.dispatch['return'](self, self.cur[4], t) t = 0 self.t = get_time() - t diff --git a/Lib/test/output/test_profile b/Lib/test/output/test_profile new file mode 100644 index 00000000000..b36a016aef6 --- /dev/null +++ b/Lib/test/output/test_profile @@ -0,0 +1,17 @@ +test_profile + 53 function calls in 1.000 CPU seconds + + Ordered by: standard name + + ncalls tottime percall cumtime percall filename:lineno(function) + 1 0.000 0.000 1.000 1.000 :1(?) + 0 0.000 0.000 profile:0(profiler) + 1 0.000 0.000 1.000 1.000 profile:0(testfunc()) + 1 0.400 0.400 1.000 1.000 test_profile.py:21(testfunc) + 2 0.080 0.040 0.600 0.300 test_profile.py:30(helper) + 4 0.116 0.029 0.120 0.030 test_profile.py:48(helper1) + 8 0.312 0.039 0.400 0.050 test_profile.py:56(helper2) + 8 0.064 0.008 0.080 0.010 test_profile.py:66(subhelper) + 28 0.028 0.001 0.028 0.001 test_profile.py:78(__getattr__) + + diff --git a/Lib/test/test_profile.py b/Lib/test/test_profile.py new file mode 100644 index 00000000000..460d56fdfab --- /dev/null +++ b/Lib/test/test_profile.py @@ -0,0 +1,86 @@ +"""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()