add hg and python

sys/lib/python/test/test_queue.py

@@ -0,0 +1,281 @@
+# Some simple Queue module tests, plus some failure conditions
+# to ensure the Queue locks remain stable.
+import Queue
+import sys
+import threading
+import time
+
+from test.test_support import verify, TestFailed, verbose
+
+QUEUE_SIZE = 5
+
+# A thread to run a function that unclogs a blocked Queue.
+class _TriggerThread(threading.Thread):
+    def __init__(self, fn, args):
+        self.fn = fn
+        self.args = args
+        self.startedEvent = threading.Event()
+        threading.Thread.__init__(self)
+
+    def run(self):
+        # The sleep isn't necessary, but is intended to give the blocking
+        # function in the main thread a chance at actually blocking before
+        # we unclog it.  But if the sleep is longer than the timeout-based
+        # tests wait in their blocking functions, those tests will fail.
+        # So we give them much longer timeout values compared to the
+        # sleep here (I aimed at 10 seconds for blocking functions --
+        # they should never actually wait that long - they should make
+        # progress as soon as we call self.fn()).
+        time.sleep(0.1)
+        self.startedEvent.set()
+        self.fn(*self.args)
+
+# Execute a function that blocks, and in a separate thread, a function that
+# triggers the release.  Returns the result of the blocking function.
+# Caution:  block_func must guarantee to block until trigger_func is
+# called, and trigger_func must guarantee to change queue state so that
+# block_func can make enough progress to return.  In particular, a
+# block_func that just raises an exception regardless of whether trigger_func
+# is called will lead to timing-dependent sporadic failures, and one of
+# those went rarely seen but undiagnosed for years.  Now block_func
+# must be unexceptional.  If block_func is supposed to raise an exception,
+# call _doExceptionalBlockingTest() instead.
+def _doBlockingTest(block_func, block_args, trigger_func, trigger_args):
+    t = _TriggerThread(trigger_func, trigger_args)
+    t.start()
+    result = block_func(*block_args)
+    # If block_func returned before our thread made the call, we failed!
+    if not t.startedEvent.isSet():
+        raise TestFailed("blocking function '%r' appeared not to block" %
+                         block_func)
+    t.join(10) # make sure the thread terminates
+    if t.isAlive():
+        raise TestFailed("trigger function '%r' appeared to not return" %
+                         trigger_func)
+    return result
+
+# Call this instead if block_func is supposed to raise an exception.
+def _doExceptionalBlockingTest(block_func, block_args, trigger_func,
+                               trigger_args, expected_exception_class):
+    t = _TriggerThread(trigger_func, trigger_args)
+    t.start()
+    try:
+        try:
+            block_func(*block_args)
+        except expected_exception_class:
+            raise
+        else:
+            raise TestFailed("expected exception of kind %r" %
+                             expected_exception_class)
+    finally:
+        t.join(10) # make sure the thread terminates
+        if t.isAlive():
+            raise TestFailed("trigger function '%r' appeared to not return" %
+                             trigger_func)
+        if not t.startedEvent.isSet():
+            raise TestFailed("trigger thread ended but event never set")
+
+# A Queue subclass that can provoke failure at a moment's notice :)
+class FailingQueueException(Exception):
+    pass
+
+class FailingQueue(Queue.Queue):
+    def __init__(self, *args):
+        self.fail_next_put = False
+        self.fail_next_get = False
+        Queue.Queue.__init__(self, *args)
+    def _put(self, item):
+        if self.fail_next_put:
+            self.fail_next_put = False
+            raise FailingQueueException, "You Lose"
+        return Queue.Queue._put(self, item)
+    def _get(self):
+        if self.fail_next_get:
+            self.fail_next_get = False
+            raise FailingQueueException, "You Lose"
+        return Queue.Queue._get(self)
+
+def FailingQueueTest(q):
+    if not q.empty():
+        raise RuntimeError, "Call this function with an empty queue"
+    for i in range(QUEUE_SIZE-1):
+        q.put(i)
+    # Test a failing non-blocking put.
+    q.fail_next_put = True
+    try:
+        q.put("oops", block=0)
+        raise TestFailed("The queue didn't fail when it should have")
+    except FailingQueueException:
+        pass
+    q.fail_next_put = True
+    try:
+        q.put("oops", timeout=0.1)
+        raise TestFailed("The queue didn't fail when it should have")
+    except FailingQueueException:
+        pass
+    q.put("last")
+    verify(q.full(), "Queue should be full")
+    # Test a failing blocking put
+    q.fail_next_put = True
+    try:
+        _doBlockingTest(q.put, ("full",), q.get, ())
+        raise TestFailed("The queue didn't fail when it should have")
+    except FailingQueueException:
+        pass
+    # Check the Queue isn't damaged.
+    # put failed, but get succeeded - re-add
+    q.put("last")
+    # Test a failing timeout put
+    q.fail_next_put = True
+    try:
+        _doExceptionalBlockingTest(q.put, ("full", True, 10), q.get, (),
+                                   FailingQueueException)
+        raise TestFailed("The queue didn't fail when it should have")
+    except FailingQueueException:
+        pass
+    # Check the Queue isn't damaged.
+    # put failed, but get succeeded - re-add
+    q.put("last")
+    verify(q.full(), "Queue should be full")
+    q.get()
+    verify(not q.full(), "Queue should not be full")
+    q.put("last")
+    verify(q.full(), "Queue should be full")
+    # Test a blocking put
+    _doBlockingTest( q.put, ("full",), q.get, ())
+    # Empty it
+    for i in range(QUEUE_SIZE):
+        q.get()
+    verify(q.empty(), "Queue should be empty")
+    q.put("first")
+    q.fail_next_get = True
+    try:
+        q.get()
+        raise TestFailed("The queue didn't fail when it should have")
+    except FailingQueueException:
+        pass
+    verify(not q.empty(), "Queue should not be empty")
+    q.fail_next_get = True
+    try:
+        q.get(timeout=0.1)
+        raise TestFailed("The queue didn't fail when it should have")
+    except FailingQueueException:
+        pass
+    verify(not q.empty(), "Queue should not be empty")
+    q.get()
+    verify(q.empty(), "Queue should be empty")
+    q.fail_next_get = True
+    try:
+        _doExceptionalBlockingTest(q.get, (), q.put, ('empty',),
+                                   FailingQueueException)
+        raise TestFailed("The queue didn't fail when it should have")
+    except FailingQueueException:
+        pass
+    # put succeeded, but get failed.
+    verify(not q.empty(), "Queue should not be empty")
+    q.get()
+    verify(q.empty(), "Queue should be empty")
+
+def SimpleQueueTest(q):
+    if not q.empty():
+        raise RuntimeError, "Call this function with an empty queue"
+    # I guess we better check things actually queue correctly a little :)
+    q.put(111)
+    q.put(222)
+    verify(q.get() == 111 and q.get() == 222,
+           "Didn't seem to queue the correct data!")
+    for i in range(QUEUE_SIZE-1):
+        q.put(i)
+        verify(not q.empty(), "Queue should not be empty")
+    verify(not q.full(), "Queue should not be full")
+    q.put("last")
+    verify(q.full(), "Queue should be full")
+    try:
+        q.put("full", block=0)
+        raise TestFailed("Didn't appear to block with a full queue")
+    except Queue.Full:
+        pass
+    try:
+        q.put("full", timeout=0.01)
+        raise TestFailed("Didn't appear to time-out with a full queue")
+    except Queue.Full:
+        pass
+    # Test a blocking put
+    _doBlockingTest(q.put, ("full",), q.get, ())
+    _doBlockingTest(q.put, ("full", True, 10), q.get, ())
+    # Empty it
+    for i in range(QUEUE_SIZE):
+        q.get()
+    verify(q.empty(), "Queue should be empty")
+    try:
+        q.get(block=0)
+        raise TestFailed("Didn't appear to block with an empty queue")
+    except Queue.Empty:
+        pass
+    try:
+        q.get(timeout=0.01)
+        raise TestFailed("Didn't appear to time-out with an empty queue")
+    except Queue.Empty:
+        pass
+    # Test a blocking get
+    _doBlockingTest(q.get, (), q.put, ('empty',))
+    _doBlockingTest(q.get, (True, 10), q.put, ('empty',))
+
+cum = 0
+cumlock = threading.Lock()
+
+def worker(q):
+    global cum
+    while True:
+        x = q.get()
+        if x is None:
+            q.task_done()
+            return
+        cumlock.acquire()
+        try:
+            cum += x
+        finally:
+            cumlock.release()
+        q.task_done()
+
+def QueueJoinTest(q):
+    global cum
+    cum = 0
+    for i in (0,1):
+        threading.Thread(target=worker, args=(q,)).start()
+    for i in xrange(100):
+        q.put(i)
+    q.join()
+    verify(cum==sum(range(100)), "q.join() did not block until all tasks were done")
+    for i in (0,1):
+        q.put(None)         # instruct the threads to close
+    q.join()                # verify that you can join twice
+
+def QueueTaskDoneTest(q):
+    try:
+        q.task_done()
+    except ValueError:
+        pass
+    else:
+        raise TestFailed("Did not detect task count going negative")
+
+def test():
+    q = Queue.Queue()
+    QueueTaskDoneTest(q)
+    QueueJoinTest(q)
+    QueueJoinTest(q)
+    QueueTaskDoneTest(q)
+
+    q = Queue.Queue(QUEUE_SIZE)
+    # Do it a couple of times on the same queue
+    SimpleQueueTest(q)
+    SimpleQueueTest(q)
+    if verbose:
+        print "Simple Queue tests seemed to work"
+    q = FailingQueue(QUEUE_SIZE)
+    FailingQueueTest(q)
+    FailingQueueTest(q)
+    if verbose:
+        print "Failing Queue tests seemed to work"
+
+test()