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Viewing changes to bzrlib/tests/test_cethread.py

  • Committer: Jelmer Vernooij
  • Date: 2012-01-24 13:14:06 UTC
  • mto: (6445.4.5 nested-trees-spec)
  • mto: This revision was merged to the branch mainline in revision 6518.
  • Revision ID: jelmer@samba.org-20120124131406-wedftkorbpv37bm0
Import nested tree doc from devnotes.

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bzrlib/tests/test_cethread.py
 
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# Copyright (C) 2010, 2011 Canonical Ltd
 
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#
 
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# This program is free software; you can redistribute it and/or modify
 
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# it under the terms of the GNU General Public License as published by
 
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# the Free Software Foundation; either version 2 of the License, or
 
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# (at your option) any later version.
 
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#
 
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# This program is distributed in the hope that it will be useful,
 
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
 
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 
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# GNU General Public License for more details.
 
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#
 
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# You should have received a copy of the GNU General Public License
 
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# along with this program; if not, write to the Free Software
 
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 
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import threading
 
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from bzrlib import (
 
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    cethread,
 
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    tests,
 
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    )
 
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class TestCatchingExceptionThread(tests.TestCase):
 
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    def test_start_and_join_smoke_test(self):
 
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        def do_nothing():
 
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            pass
 
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        tt = cethread.CatchingExceptionThread(target=do_nothing)
 
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        tt.start()
 
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        tt.join()
 
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    def test_exception_is_re_raised(self):
 
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        class MyException(Exception):
 
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            pass
 
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        def raise_my_exception():
 
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            raise MyException()
 
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        tt = cethread.CatchingExceptionThread(target=raise_my_exception)
 
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        tt.start()
 
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        self.assertRaises(MyException, tt.join)
 
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    def test_join_around_exception(self):
 
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        resume = threading.Event()
 
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        class MyException(Exception):
 
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            pass
 
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        def raise_my_exception():
 
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            # Wait for the test to tell us to resume
 
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            resume.wait()
 
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            # Now we can raise
 
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            raise MyException()
 
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        tt = cethread.CatchingExceptionThread(target=raise_my_exception)
 
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        tt.start()
 
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        tt.join(timeout=0)
 
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        self.assertIs(None, tt.exception)
 
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        resume.set()
 
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        self.assertRaises(MyException, tt.join)
 
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    def test_sync_event(self):
 
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        control = threading.Event()
 
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        in_thread = threading.Event()
 
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        class MyException(Exception):
 
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            pass
 
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        def raise_my_exception():
 
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            # Wait for the test to tell us to resume
 
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            control.wait()
 
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            # Now we can raise
 
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            raise MyException()
 
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        tt = cethread.CatchingExceptionThread(target=raise_my_exception,
 
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                                            sync_event=in_thread)
 
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        tt.start()
 
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        tt.join(timeout=0)
 
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        self.assertIs(None, tt.exception)
 
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        self.assertIs(in_thread, tt.sync_event)
 
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        control.set()
 
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        self.assertRaises(MyException, tt.join)
 
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        self.assertEquals(True, tt.sync_event.isSet())
 
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    def test_switch_and_set(self):
 
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        """Caller can precisely control a thread."""
 
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        control1 = threading.Event()
 
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        control2 = threading.Event()
 
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        control3 = threading.Event()
 
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        class TestThread(cethread.CatchingExceptionThread):
 
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            def __init__(self):
 
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                super(TestThread, self).__init__(target=self.step_by_step)
 
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                self.current_step = 'starting'
 
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                self.step1 = threading.Event()
 
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                self.set_sync_event(self.step1)
 
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                self.step2 = threading.Event()
 
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                self.final = threading.Event()
 
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            def step_by_step(self):
 
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                control1.wait()
 
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                self.current_step = 'step1'
 
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                self.switch_and_set(self.step2)
 
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                control2.wait()
 
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                self.current_step = 'step2'
 
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                self.switch_and_set(self.final)
 
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                control3.wait()
 
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                self.current_step = 'done'
 
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        tt = TestThread()
 
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        tt.start()
 
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        self.assertEquals('starting', tt.current_step)
 
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        control1.set()
 
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        tt.step1.wait()
 
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        self.assertEquals('step1', tt.current_step)
 
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        control2.set()
 
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        tt.step2.wait()
 
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        self.assertEquals('step2', tt.current_step)
 
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        control3.set()
 
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        # We don't wait on tt.final
 
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        tt.join()
 
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        self.assertEquals('done', tt.current_step)
 
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    def test_exception_while_switch_and_set(self):
 
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        control1 = threading.Event()
 
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        class MyException(Exception):
 
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            pass
 
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        class TestThread(cethread.CatchingExceptionThread):
 
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            def __init__(self, *args, **kwargs):
 
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                self.step1 = threading.Event()
 
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                self.step2 = threading.Event()
 
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                super(TestThread, self).__init__(target=self.step_by_step,
 
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                                                 sync_event=self.step1)
 
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                self.current_step = 'starting'
 
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                self.set_sync_event(self.step1)
 
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            def step_by_step(self):
 
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                control1.wait()
 
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                self.current_step = 'step1'
 
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                self.switch_and_set(self.step2)
 
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            def set_sync_event(self, event):
 
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                # We force an exception while trying to set step2
 
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                if event is self.step2:
 
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                    raise MyException()
 
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                super(TestThread, self).set_sync_event(event)
 
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        tt = TestThread()
 
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        tt.start()
 
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        self.assertEquals('starting', tt.current_step)
 
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        control1.set()
 
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        # We now wait on step1 which will be set when catching the exception
 
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        tt.step1.wait()
 
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        self.assertRaises(MyException, tt.pending_exception)
 
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        self.assertIs(tt.step1, tt.sync_event)
 
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        self.assertTrue(tt.step1.isSet())