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Viewing changes to bzrlib/tests/test_lsprof.py

  • Committer: Robert Collins
  • Date: 2010-07-04 06:22:11 UTC
  • mto: This revision was merged to the branch mainline in revision 5332.
  • Revision ID: robertc@robertcollins.net-20100704062211-tk9hw6bnsn5x47fm
``bzrlib.lsprof.profile`` will no longer silently generate bad threaded
profiles when concurrent profile requests are made. Instead the profile
requests will be serialised. Reentrant requests will now deadlock.
(Robert Collins)

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bzrlib/tests/test_lsprof.py
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import cPickle
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import os
 
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import threading
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import bzrlib
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from bzrlib import tests
 
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from bzrlib import errors, tests
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class _LSProfFeature(tests.Feature):
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        lines = [str(data) for data in stats.data]
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        lines = [line for line in lines if 'a_function' in line]
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        self.assertLength(1, lines)
 
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    def test_block_0(self):
 
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        # When profiler_block is 0, reentrant profile requests fail.
 
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        self.overrideAttr(bzrlib.lsprof.BzrProfiler, 'profiler_block', 0)
 
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        inner_calls = []
 
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        def inner():
 
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            profiler = bzrlib.lsprof.BzrProfiler()
 
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            self.assertRaises(errors.BzrError, profiler.start)
 
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            inner_calls.append(True)
 
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        bzrlib.lsprof.profile(inner)
 
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        self.assertLength(1, inner_calls)
 
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    def test_block_1(self):
 
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        # When profiler_block is 1, concurrent profiles serialise.
 
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        # This is tested by manually acquiring the profiler lock, then
 
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        # starting a thread that tries to profile, and releasing the lock. 
 
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        # We know due to test_block_0 that two profiles at once hit the lock,
 
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        # so while this isn't perfect (we'd want a callback on the lock being
 
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        # entered to allow lockstep evaluation of the actions), its good enough
 
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        # to be confident regressions would be caught. Alternatively, if this
 
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        # is flakey, a fake Lock object can be used to trace the calls made.
 
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        calls = []
 
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        def profiled():
 
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            calls.append('profiled')
 
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        def do_profile():
 
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            bzrlib.lsprof.profile(profiled)
 
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            calls.append('after_profiled')
 
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        thread = threading.Thread(target=do_profile)
 
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        bzrlib.lsprof.BzrProfiler.profiler_lock.acquire()
 
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        try:
 
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            try:
 
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                thread.start()
 
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            finally:
 
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                bzrlib.lsprof.BzrProfiler.profiler_lock.release()
 
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        finally:
 
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            thread.join()
 
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        self.assertLength(2, calls)