Restore dummy_threading and _dummy_thread, but deprecate them (bpo-31370) (#3648)

1 files changed, 255 insertions, 0 deletions

diff --git a/Lib/test/test_dummy_thread.py b/Lib/test/test_dummy_thread.py
new file mode 100644
index 0000000..0840be6
--- /dev/null
+++ b/Lib/test/test_dummy_thread.py
@@ -0,0 +1,255 @@
+import _dummy_thread as _thread
+import time
+import queue
+import random
+import unittest
+from test import support
+from unittest import mock
+
+DELAY = 0
+
+
+class LockTests(unittest.TestCase):
+    """Test lock objects."""
+
+    def setUp(self):
+        # Create a lock
+        self.lock = _thread.allocate_lock()
+
+    def test_initlock(self):
+        #Make sure locks start locked
+        self.assertFalse(self.lock.locked(),
+                        "Lock object is not initialized unlocked.")
+
+    def test_release(self):
+        # Test self.lock.release()
+        self.lock.acquire()
+        self.lock.release()
+        self.assertFalse(self.lock.locked(),
+                        "Lock object did not release properly.")
+
+    def test_LockType_context_manager(self):
+        with _thread.LockType():
+            pass
+        self.assertFalse(self.lock.locked(),
+                         "Acquired Lock was not released")
+
+    def test_improper_release(self):
+        #Make sure release of an unlocked thread raises RuntimeError
+        self.assertRaises(RuntimeError, self.lock.release)
+
+    def test_cond_acquire_success(self):
+        #Make sure the conditional acquiring of the lock works.
+        self.assertTrue(self.lock.acquire(0),
+                        "Conditional acquiring of the lock failed.")
+
+    def test_cond_acquire_fail(self):
+        #Test acquiring locked lock returns False
+        self.lock.acquire(0)
+        self.assertFalse(self.lock.acquire(0),
+                        "Conditional acquiring of a locked lock incorrectly "
+                         "succeeded.")
+
+    def test_uncond_acquire_success(self):
+        #Make sure unconditional acquiring of a lock works.
+        self.lock.acquire()
+        self.assertTrue(self.lock.locked(),
+                        "Uncondional locking failed.")
+
+    def test_uncond_acquire_return_val(self):
+        #Make sure that an unconditional locking returns True.
+        self.assertIs(self.lock.acquire(1), True,
+                        "Unconditional locking did not return True.")
+        self.assertIs(self.lock.acquire(), True)
+
+    def test_uncond_acquire_blocking(self):
+        #Make sure that unconditional acquiring of a locked lock blocks.
+        def delay_unlock(to_unlock, delay):
+            """Hold on to lock for a set amount of time before unlocking."""
+            time.sleep(delay)
+            to_unlock.release()
+
+        self.lock.acquire()
+        start_time = int(time.time())
+        _thread.start_new_thread(delay_unlock,(self.lock, DELAY))
+        if support.verbose:
+            print()
+            print("*** Waiting for thread to release the lock "\
+            "(approx. %s sec.) ***" % DELAY)
+        self.lock.acquire()
+        end_time = int(time.time())
+        if support.verbose:
+            print("done")
+        self.assertGreaterEqual(end_time - start_time, DELAY,
+                        "Blocking by unconditional acquiring failed.")
+
+    @mock.patch('time.sleep')
+    def test_acquire_timeout(self, mock_sleep):
+        """Test invoking acquire() with a positive timeout when the lock is
+        already acquired. Ensure that time.sleep() is invoked with the given
+        timeout and that False is returned."""
+
+        self.lock.acquire()
+        retval = self.lock.acquire(waitflag=0, timeout=1)
+        self.assertTrue(mock_sleep.called)
+        mock_sleep.assert_called_once_with(1)
+        self.assertEqual(retval, False)
+
+    def test_lock_representation(self):
+        self.lock.acquire()
+        self.assertIn("locked", repr(self.lock))
+        self.lock.release()
+        self.assertIn("unlocked", repr(self.lock))
+
+
+class MiscTests(unittest.TestCase):
+    """Miscellaneous tests."""
+
+    def test_exit(self):
+        self.assertRaises(SystemExit, _thread.exit)
+
+    def test_ident(self):
+        self.assertIsInstance(_thread.get_ident(), int,
+                              "_thread.get_ident() returned a non-integer")
+        self.assertGreater(_thread.get_ident(), 0)
+
+    def test_LockType(self):
+        self.assertIsInstance(_thread.allocate_lock(), _thread.LockType,
+                              "_thread.LockType is not an instance of what "
+                              "is returned by _thread.allocate_lock()")
+
+    def test_set_sentinel(self):
+        self.assertIsInstance(_thread._set_sentinel(), _thread.LockType,
+                              "_thread._set_sentinel() did not return a "
+                              "LockType instance.")
+
+    def test_interrupt_main(self):
+        #Calling start_new_thread with a function that executes interrupt_main
+        # should raise KeyboardInterrupt upon completion.
+        def call_interrupt():
+            _thread.interrupt_main()
+
+        self.assertRaises(KeyboardInterrupt,
+                          _thread.start_new_thread,
+                          call_interrupt,
+                          tuple())
+
+    def test_interrupt_in_main(self):
+        self.assertRaises(KeyboardInterrupt, _thread.interrupt_main)
+
+    def test_stack_size_None(self):
+        retval = _thread.stack_size(None)
+        self.assertEqual(retval, 0)
+
+    def test_stack_size_not_None(self):
+        with self.assertRaises(_thread.error) as cm:
+            _thread.stack_size("")
+        self.assertEqual(cm.exception.args[0],
+                         "setting thread stack size not supported")
+
+
+class ThreadTests(unittest.TestCase):
+    """Test thread creation."""
+
+    def test_arg_passing(self):
+        #Make sure that parameter passing works.
+        def arg_tester(queue, arg1=False, arg2=False):
+            """Use to test _thread.start_new_thread() passes args properly."""
+            queue.put((arg1, arg2))
+
+        testing_queue = queue.Queue(1)
+        _thread.start_new_thread(arg_tester, (testing_queue, True, True))
+        result = testing_queue.get()
+        self.assertTrue(result[0] and result[1],
+                        "Argument passing for thread creation "
+                        "using tuple failed")
+
+        _thread.start_new_thread(
+                arg_tester,
+                tuple(),
+                {'queue':testing_queue, 'arg1':True, 'arg2':True})
+
+        result = testing_queue.get()
+        self.assertTrue(result[0] and result[1],
+                        "Argument passing for thread creation "
+                        "using kwargs failed")
+
+        _thread.start_new_thread(
+                arg_tester,
+                (testing_queue, True),
+                {'arg2':True})
+
+        result = testing_queue.get()
+        self.assertTrue(result[0] and result[1],
+                        "Argument passing for thread creation using both tuple"
+                        " and kwargs failed")
+
+    def test_multi_thread_creation(self):
+        def queue_mark(queue, delay):
+            time.sleep(delay)
+            queue.put(_thread.get_ident())
+
+        thread_count = 5
+        testing_queue = queue.Queue(thread_count)
+
+        if support.verbose:
+            print()
+            print("*** Testing multiple thread creation "
+                  "(will take approx. %s to %s sec.) ***" % (
+                    DELAY, thread_count))
+
+        for count in range(thread_count):
+            if DELAY:
+                local_delay = round(random.random(), 1)
+            else:
+                local_delay = 0
+            _thread.start_new_thread(queue_mark,
+                                     (testing_queue, local_delay))
+        time.sleep(DELAY)
+        if support.verbose:
+            print('done')
+        self.assertEqual(testing_queue.qsize(), thread_count,
+                         "Not all %s threads executed properly "
+                         "after %s sec." % (thread_count, DELAY))
+
+    def test_args_not_tuple(self):
+        """
+        Test invoking start_new_thread() with a non-tuple value for "args".
+        Expect TypeError with a meaningful error message to be raised.
+        """
+        with self.assertRaises(TypeError) as cm:
+            _thread.start_new_thread(mock.Mock(), [])
+        self.assertEqual(cm.exception.args[0], "2nd arg must be a tuple")
+
+    def test_kwargs_not_dict(self):
+        """
+        Test invoking start_new_thread() with a non-dict value for "kwargs".
+        Expect TypeError with a meaningful error message to be raised.
+        """
+        with self.assertRaises(TypeError) as cm:
+            _thread.start_new_thread(mock.Mock(), tuple(), kwargs=[])
+        self.assertEqual(cm.exception.args[0], "3rd arg must be a dict")
+
+    def test_SystemExit(self):
+        """
+        Test invoking start_new_thread() with a function that raises
+        SystemExit.
+        The exception should be discarded.
+        """
+        func = mock.Mock(side_effect=SystemExit())
+        try:
+            _thread.start_new_thread(func, tuple())
+        except SystemExit:
+            self.fail("start_new_thread raised SystemExit.")
+
+    @mock.patch('traceback.print_exc')
+    def test_RaiseException(self, mock_print_exc):
+        """
+        Test invoking start_new_thread() with a function that raises exception.
+
+        The exception should be discarded and the traceback should be printed
+        via traceback.print_exc()
+        """
+        func = mock.Mock(side_effect=Exception)
+        _thread.start_new_thread(func, tuple())
+        self.assertTrue(mock_print_exc.called)