diff options
Diffstat (limited to 'tests/test_statemachine.py')
| -rw-r--r-- | tests/test_statemachine.py | 163 |
1 files changed, 154 insertions, 9 deletions
diff --git a/tests/test_statemachine.py b/tests/test_statemachine.py index 6749c8de..e44b8e48 100644 --- a/tests/test_statemachine.py +++ b/tests/test_statemachine.py @@ -1,5 +1,5 @@ import unittest -import time, threading +import time, threading, random, functools if __name__ == '__main__': import sys, os @@ -15,25 +15,23 @@ class testStateMachine(unittest.TestCase): def testDefaults(self): "Test ensure transitions occur correctly in a single thread" s = sm.StateMachine(('one','two','three')) -# self.assertTrue(s.one) self.assertTrue(s['one']) -# self.failIf(s.two) self.failIf(s['two']) try: - s.booga + s['booga'] self.fail('s.booga is an invalid state and should throw an exception!') except: pass #expected exception - + # just make sure __str__ works, no reason to test its exact value: + print str(s) + + def testTransitions(self): "Test ensure transitions occur correctly in a single thread" s = sm.StateMachine(('one','two','three')) -# self.assertTrue(s.one) self.assertTrue( s.transition('one', 'two') ) -# self.assertTrue( s.two ) self.assertTrue( s['two'] ) -# self.failIf( s.one ) self.failIf( s['one'] ) self.assertTrue( s.transition('two', 'three') ) @@ -83,12 +81,12 @@ class testStateMachine(unittest.TestCase): thread_state = {'ready': False, 'transitioned': False} def t1(): - # this will block until the main thread transitions to 'two' if s['two']: print 'thread has already transitioned!' self.fail() thread_state['ready'] = True print 'Thread is ready' + # this will block until the main thread transitions to 'two' self.assertTrue( s.transition('two','three', wait=20) ) print 'transitioned to three!' thread_state['transitioned'] = True @@ -109,6 +107,153 @@ class testStateMachine(unittest.TestCase): self.assertTrue( thread_state['transitioned'] ) + def testForRaceCondition(self): + """Attempt to allow two threads to perform the same transition; + only one should ever make it.""" + + s = sm.StateMachine(('one','two','three')) + + def t1(num): + while True: + if not trigger['go'] or thread_state[num] in (True,False): + time.sleep( random.random()/100 ) # < .01s + if thread_state[num] == 'quit': break + continue + + thread_state[num] = s.transition('one','two' ) +# print '-', + + thread_count = 20 + threads = [] + thread_state = {} + def reset(): + for c in range(thread_count): thread_state[c] = "reset" + trigger = {'go':False} # use of a plain boolean seems to be non-volatile between threads. + + for c in range(thread_count): + thread_state[c] = "reset" + thread = threading.Thread( target= functools.partial(t1,c) ) + threads.append( thread ) + thread.daemon = True + thread.start() + + for x in range(100): # this will take 10s to execute +# print "+", + trigger['go'] = True + time.sleep(.1) + trigger['go'] = False + winners = 0 + for (num, state) in thread_state.items(): + if state == True: winners = winners +1 + elif state != False: raise Exception( "!%d!%s!" % (num,state) ) + + self.assertEqual( 1, winners, "Expected one winner! %d" % winners ) + self.assertTrue( s.ensure('two') ) + self.assertTrue( s.transition('two','one') ) # return to the first state. + reset() + + # now let the threads quit gracefully: + for c in range(thread_count): thread_state[c] = 'quit' + time.sleep(2) + + + def testTransitionFunctions(self): + "test that a `func` argument allows or blocks the transition correctly." + + s = sm.StateMachine(('one','two','three')) + + def alwaysFalse(): return False + def alwaysTrue(): return True + + self.failIf( s.transition('one','two', func=alwaysFalse) ) + self.assertTrue(s['one']) + self.failIf(s['two']) + + self.assertTrue( s.transition('one','two', func=alwaysTrue) ) + self.failIf(s['one']) + self.assertTrue(s['two']) + + + def testTransitionFuncException(self): + "if a transition function throws an exeption, ensure we're in a sane state" + + s = sm.StateMachine(('one','two','three')) + + def alwaysException(): raise Exception('whups!') + + try: + self.failIf( s.transition('one','two', func=alwaysException) ) + self.fail("exception should have been thrown") + except: pass #expected exception + + self.assertTrue(s['one']) + self.failIf(s['two']) + + # ensure a subsequent attempt completes normally: + self.assertTrue( s.transition('one','two') ) + self.failIf(s['one']) + self.assertTrue(s['two']) + + + def testContextManager(self): + + s = sm.StateMachine(('one','two','three')) + + with s.transition_ctx('one','two'): + self.assertTrue( s['one'] ) + self.failIf( s['two'] ) + + #successful transition b/c no exception was thrown + self.assertTrue( s['two'] ) + self.failIf( s['one'] ) + + # failed transition because exception is thrown: + try: + with s.transition_ctx('two','three'): + raise Exception("boom!") + self.fail('exception expected') + except: pass + + self.failIf( s.current_state() in ('one','three') ) + self.assertTrue( s['two'] ) + + def testCtxManagerTransitionFailure(self): + + s = sm.StateMachine(('one','two','three')) + + with s.transition_ctx('two','three') as result: + self.failIf( result ) + self.assertTrue( s['one'] ) + self.failIf( s.current_state in ('two','three') ) + + self.assertTrue( s['one'] ) + + def r1(): + print 'thread 1 started' + self.assertTrue( s.transition('one','two') ) + print 'thread 1 transitioned' + + def r2(): + print 'thread 2 started' + self.failIf( s['two'] ) + with s.transition_ctx('two','three', 10) as result: + self.assertTrue( result ) + self.assertTrue( s['two'] ) + print 'thread 2 will transition on exit from the context manager...' + self.assertTrue( s['three'] ) + print 'transitioned to %s' % s.current_state() + + t1 = threading.Thread(target=r1) + t2 = threading.Thread(target=r2) + + t2.start() # this should block until r1 goes + time.sleep(1) + t1.start() + + t1.join() + t2.join() + + self.assertTrue( s['three'] ) suite = unittest.TestLoader().loadTestsFromTestCase(testStateMachine) |