python-3.6.zip added from Github

README.cosmo contains the necessary links.

third_party/python/Lib/test/test_concurrent_futures.py

@@ -0,0 +1,836 @@
+import test.support
+
+# Skip tests if _multiprocessing wasn't built.
+test.support.import_module('_multiprocessing')
+# Skip tests if sem_open implementation is broken.
+test.support.import_module('multiprocessing.synchronize')
+# import threading after _multiprocessing to raise a more relevant error
+# message: "No module named _multiprocessing". _multiprocessing is not compiled
+# without thread support.
+test.support.import_module('threading')
+
+from test.support.script_helper import assert_python_ok
+
+import itertools
+import os
+import sys
+import threading
+import time
+import unittest
+import weakref
+
+from concurrent import futures
+from concurrent.futures._base import (
+    PENDING, RUNNING, CANCELLED, CANCELLED_AND_NOTIFIED, FINISHED, Future)
+from concurrent.futures.process import BrokenProcessPool
+
+
+def create_future(state=PENDING, exception=None, result=None):
+    f = Future()
+    f._state = state
+    f._exception = exception
+    f._result = result
+    return f
+
+
+PENDING_FUTURE = create_future(state=PENDING)
+RUNNING_FUTURE = create_future(state=RUNNING)
+CANCELLED_FUTURE = create_future(state=CANCELLED)
+CANCELLED_AND_NOTIFIED_FUTURE = create_future(state=CANCELLED_AND_NOTIFIED)
+EXCEPTION_FUTURE = create_future(state=FINISHED, exception=OSError())
+SUCCESSFUL_FUTURE = create_future(state=FINISHED, result=42)
+
+
+def mul(x, y):
+    return x * y
+
+
+def sleep_and_raise(t):
+    time.sleep(t)
+    raise Exception('this is an exception')
+
+def sleep_and_print(t, msg):
+    time.sleep(t)
+    print(msg)
+    sys.stdout.flush()
+
+
+class MyObject(object):
+    def my_method(self):
+        pass
+
+
+def make_dummy_object(_):
+    return MyObject()
+
+
+class BaseTestCase(unittest.TestCase):
+    def setUp(self):
+        self._thread_key = test.support.threading_setup()
+
+    def tearDown(self):
+        test.support.reap_children()
+        test.support.threading_cleanup(*self._thread_key)
+
+
+class ExecutorMixin:
+    worker_count = 5
+
+    def setUp(self):
+        super().setUp()
+
+        self.t1 = time.monotonic()
+        try:
+            self.executor = self.executor_type(max_workers=self.worker_count)
+        except NotImplementedError as e:
+            self.skipTest(str(e))
+        self._prime_executor()
+
+    def tearDown(self):
+        self.executor.shutdown(wait=True)
+        self.executor = None
+
+        dt = time.monotonic() - self.t1
+        if test.support.verbose:
+            print("%.2fs" % dt, end=' ')
+        self.assertLess(dt, 300, "synchronization issue: test lasted too long")
+
+        super().tearDown()
+
+    def _prime_executor(self):
+        # Make sure that the executor is ready to do work before running the
+        # tests. This should reduce the probability of timeouts in the tests.
+        futures = [self.executor.submit(time.sleep, 0.1)
+                   for _ in range(self.worker_count)]
+
+        for f in futures:
+            f.result()
+
+
+class ThreadPoolMixin(ExecutorMixin):
+    executor_type = futures.ThreadPoolExecutor
+
+
+class ProcessPoolMixin(ExecutorMixin):
+    executor_type = futures.ProcessPoolExecutor
+
+
+class ExecutorShutdownTest:
+    def test_run_after_shutdown(self):
+        self.executor.shutdown()
+        self.assertRaises(RuntimeError,
+                          self.executor.submit,
+                          pow, 2, 5)
+
+    def test_interpreter_shutdown(self):
+        # Test the atexit hook for shutdown of worker threads and processes
+        rc, out, err = assert_python_ok('-c', """if 1:
+            from concurrent.futures import {executor_type}
+            from time import sleep
+            from test.test_concurrent_futures import sleep_and_print
+            t = {executor_type}(5)
+            t.submit(sleep_and_print, 1.0, "apple")
+            """.format(executor_type=self.executor_type.__name__))
+        # Errors in atexit hooks don't change the process exit code, check
+        # stderr manually.
+        self.assertFalse(err)
+        self.assertEqual(out.strip(), b"apple")
+
+    def test_hang_issue12364(self):
+        fs = [self.executor.submit(time.sleep, 0.1) for _ in range(50)]
+        self.executor.shutdown()
+        for f in fs:
+            f.result()
+
+
+class ThreadPoolShutdownTest(ThreadPoolMixin, ExecutorShutdownTest, BaseTestCase):
+    def _prime_executor(self):
+        pass
+
+    def test_threads_terminate(self):
+        self.executor.submit(mul, 21, 2)
+        self.executor.submit(mul, 6, 7)
+        self.executor.submit(mul, 3, 14)
+        self.assertEqual(len(self.executor._threads), 3)
+        self.executor.shutdown()
+        for t in self.executor._threads:
+            t.join()
+
+    def test_context_manager_shutdown(self):
+        with futures.ThreadPoolExecutor(max_workers=5) as e:
+            executor = e
+            self.assertEqual(list(e.map(abs, range(-5, 5))),
+                             [5, 4, 3, 2, 1, 0, 1, 2, 3, 4])
+
+        for t in executor._threads:
+            t.join()
+
+    def test_del_shutdown(self):
+        executor = futures.ThreadPoolExecutor(max_workers=5)
+        executor.map(abs, range(-5, 5))
+        threads = executor._threads
+        del executor
+
+        for t in threads:
+            t.join()
+
+    def test_thread_names_assigned(self):
+        executor = futures.ThreadPoolExecutor(
+            max_workers=5, thread_name_prefix='SpecialPool')
+        executor.map(abs, range(-5, 5))
+        threads = executor._threads
+        del executor
+
+        for t in threads:
+            self.assertRegex(t.name, r'^SpecialPool_[0-4]$')
+            t.join()
+
+    def test_thread_names_default(self):
+        executor = futures.ThreadPoolExecutor(max_workers=5)
+        executor.map(abs, range(-5, 5))
+        threads = executor._threads
+        del executor
+
+        for t in threads:
+            # Ensure that our default name is reasonably sane and unique when
+            # no thread_name_prefix was supplied.
+            self.assertRegex(t.name, r'ThreadPoolExecutor-\d+_[0-4]$')
+            t.join()
+
+
+class ProcessPoolShutdownTest(ProcessPoolMixin, ExecutorShutdownTest, BaseTestCase):
+    def _prime_executor(self):
+        pass
+
+    def test_processes_terminate(self):
+        self.executor.submit(mul, 21, 2)
+        self.executor.submit(mul, 6, 7)
+        self.executor.submit(mul, 3, 14)
+        self.assertEqual(len(self.executor._processes), 5)
+        processes = self.executor._processes
+        self.executor.shutdown()
+
+        for p in processes.values():
+            p.join()
+
+    def test_context_manager_shutdown(self):
+        with futures.ProcessPoolExecutor(max_workers=5) as e:
+            processes = e._processes
+            self.assertEqual(list(e.map(abs, range(-5, 5))),
+                             [5, 4, 3, 2, 1, 0, 1, 2, 3, 4])
+
+        for p in processes.values():
+            p.join()
+
+    def test_del_shutdown(self):
+        executor = futures.ProcessPoolExecutor(max_workers=5)
+        list(executor.map(abs, range(-5, 5)))
+        queue_management_thread = executor._queue_management_thread
+        processes = executor._processes
+        call_queue = executor._call_queue
+        del executor
+
+        queue_management_thread.join()
+        for p in processes.values():
+            p.join()
+        call_queue.close()
+        call_queue.join_thread()
+
+
+class WaitTests:
+
+    def test_first_completed(self):
+        future1 = self.executor.submit(mul, 21, 2)
+        future2 = self.executor.submit(time.sleep, 1.5)
+
+        done, not_done = futures.wait(
+                [CANCELLED_FUTURE, future1, future2],
+                 return_when=futures.FIRST_COMPLETED)
+
+        self.assertEqual(set([future1]), done)
+        self.assertEqual(set([CANCELLED_FUTURE, future2]), not_done)
+
+    def test_first_completed_some_already_completed(self):
+        future1 = self.executor.submit(time.sleep, 1.5)
+
+        finished, pending = futures.wait(
+                 [CANCELLED_AND_NOTIFIED_FUTURE, SUCCESSFUL_FUTURE, future1],
+                 return_when=futures.FIRST_COMPLETED)
+
+        self.assertEqual(
+                set([CANCELLED_AND_NOTIFIED_FUTURE, SUCCESSFUL_FUTURE]),
+                finished)
+        self.assertEqual(set([future1]), pending)
+
+    def test_first_exception(self):
+        future1 = self.executor.submit(mul, 2, 21)
+        future2 = self.executor.submit(sleep_and_raise, 1.5)
+        future3 = self.executor.submit(time.sleep, 3)
+
+        finished, pending = futures.wait(
+                [future1, future2, future3],
+                return_when=futures.FIRST_EXCEPTION)
+
+        self.assertEqual(set([future1, future2]), finished)
+        self.assertEqual(set([future3]), pending)
+
+    def test_first_exception_some_already_complete(self):
+        future1 = self.executor.submit(divmod, 21, 0)
+        future2 = self.executor.submit(time.sleep, 1.5)
+
+        finished, pending = futures.wait(
+                [SUCCESSFUL_FUTURE,
+                 CANCELLED_FUTURE,
+                 CANCELLED_AND_NOTIFIED_FUTURE,
+                 future1, future2],
+                return_when=futures.FIRST_EXCEPTION)
+
+        self.assertEqual(set([SUCCESSFUL_FUTURE,
+                              CANCELLED_AND_NOTIFIED_FUTURE,
+                              future1]), finished)
+        self.assertEqual(set([CANCELLED_FUTURE, future2]), pending)
+
+    def test_first_exception_one_already_failed(self):
+        future1 = self.executor.submit(time.sleep, 2)
+
+        finished, pending = futures.wait(
+                 [EXCEPTION_FUTURE, future1],
+                 return_when=futures.FIRST_EXCEPTION)
+
+        self.assertEqual(set([EXCEPTION_FUTURE]), finished)
+        self.assertEqual(set([future1]), pending)
+
+    def test_all_completed(self):
+        future1 = self.executor.submit(divmod, 2, 0)
+        future2 = self.executor.submit(mul, 2, 21)
+
+        finished, pending = futures.wait(
+                [SUCCESSFUL_FUTURE,
+                 CANCELLED_AND_NOTIFIED_FUTURE,
+                 EXCEPTION_FUTURE,
+                 future1,
+                 future2],
+                return_when=futures.ALL_COMPLETED)
+
+        self.assertEqual(set([SUCCESSFUL_FUTURE,
+                              CANCELLED_AND_NOTIFIED_FUTURE,
+                              EXCEPTION_FUTURE,
+                              future1,
+                              future2]), finished)
+        self.assertEqual(set(), pending)
+
+    def test_timeout(self):
+        future1 = self.executor.submit(mul, 6, 7)
+        future2 = self.executor.submit(time.sleep, 6)
+
+        finished, pending = futures.wait(
+                [CANCELLED_AND_NOTIFIED_FUTURE,
+                 EXCEPTION_FUTURE,
+                 SUCCESSFUL_FUTURE,
+                 future1, future2],
+                timeout=5,
+                return_when=futures.ALL_COMPLETED)
+
+        self.assertEqual(set([CANCELLED_AND_NOTIFIED_FUTURE,
+                              EXCEPTION_FUTURE,
+                              SUCCESSFUL_FUTURE,
+                              future1]), finished)
+        self.assertEqual(set([future2]), pending)
+
+
+class ThreadPoolWaitTests(ThreadPoolMixin, WaitTests, BaseTestCase):
+
+    def test_pending_calls_race(self):
+        # Issue #14406: multi-threaded race condition when waiting on all
+        # futures.
+        event = threading.Event()
+        def future_func():
+            event.wait()
+        oldswitchinterval = sys.getswitchinterval()
+        sys.setswitchinterval(1e-6)
+        try:
+            fs = {self.executor.submit(future_func) for i in range(100)}
+            event.set()
+            futures.wait(fs, return_when=futures.ALL_COMPLETED)
+        finally:
+            sys.setswitchinterval(oldswitchinterval)
+
+
+class ProcessPoolWaitTests(ProcessPoolMixin, WaitTests, BaseTestCase):
+    pass
+
+
+class AsCompletedTests:
+    # TODO(brian@sweetapp.com): Should have a test with a non-zero timeout.
+    def test_no_timeout(self):
+        future1 = self.executor.submit(mul, 2, 21)
+        future2 = self.executor.submit(mul, 7, 6)
+
+        completed = set(futures.as_completed(
+                [CANCELLED_AND_NOTIFIED_FUTURE,
+                 EXCEPTION_FUTURE,
+                 SUCCESSFUL_FUTURE,
+                 future1, future2]))
+        self.assertEqual(set(
+                [CANCELLED_AND_NOTIFIED_FUTURE,
+                 EXCEPTION_FUTURE,
+                 SUCCESSFUL_FUTURE,
+                 future1, future2]),
+                completed)
+
+    def test_zero_timeout(self):
+        future1 = self.executor.submit(time.sleep, 2)
+        completed_futures = set()
+        try:
+            for future in futures.as_completed(
+                    [CANCELLED_AND_NOTIFIED_FUTURE,
+                     EXCEPTION_FUTURE,
+                     SUCCESSFUL_FUTURE,
+                     future1],
+                    timeout=0):
+                completed_futures.add(future)
+        except futures.TimeoutError:
+            pass
+
+        self.assertEqual(set([CANCELLED_AND_NOTIFIED_FUTURE,
+                              EXCEPTION_FUTURE,
+                              SUCCESSFUL_FUTURE]),
+                         completed_futures)
+
+    def test_duplicate_futures(self):
+        # Issue 20367. Duplicate futures should not raise exceptions or give
+        # duplicate responses.
+        # Issue #31641: accept arbitrary iterables.
+        future1 = self.executor.submit(time.sleep, 2)
+        completed = [
+            f for f in futures.as_completed(itertools.repeat(future1, 3))
+        ]
+        self.assertEqual(len(completed), 1)
+
+    def test_free_reference_yielded_future(self):
+        # Issue #14406: Generator should not keep references
+        # to finished futures.
+        futures_list = [Future() for _ in range(8)]
+        futures_list.append(create_future(state=CANCELLED_AND_NOTIFIED))
+        futures_list.append(create_future(state=FINISHED, result=42))
+
+        with self.assertRaises(futures.TimeoutError):
+            for future in futures.as_completed(futures_list, timeout=0):
+                futures_list.remove(future)
+                wr = weakref.ref(future)
+                del future
+                self.assertIsNone(wr())
+
+        futures_list[0].set_result("test")
+        for future in futures.as_completed(futures_list):
+            futures_list.remove(future)
+            wr = weakref.ref(future)
+            del future
+            self.assertIsNone(wr())
+            if futures_list:
+                futures_list[0].set_result("test")
+
+    def test_correct_timeout_exception_msg(self):
+        futures_list = [CANCELLED_AND_NOTIFIED_FUTURE, PENDING_FUTURE,
+                        RUNNING_FUTURE, SUCCESSFUL_FUTURE]
+
+        with self.assertRaises(futures.TimeoutError) as cm:
+            list(futures.as_completed(futures_list, timeout=0))
+
+        self.assertEqual(str(cm.exception), '2 (of 4) futures unfinished')
+
+
+class ThreadPoolAsCompletedTests(ThreadPoolMixin, AsCompletedTests, BaseTestCase):
+    pass
+
+
+class ProcessPoolAsCompletedTests(ProcessPoolMixin, AsCompletedTests, BaseTestCase):
+    pass
+
+
+class ExecutorTest:
+    # Executor.shutdown() and context manager usage is tested by
+    # ExecutorShutdownTest.
+    def test_submit(self):
+        future = self.executor.submit(pow, 2, 8)
+        self.assertEqual(256, future.result())
+
+    def test_submit_keyword(self):
+        future = self.executor.submit(mul, 2, y=8)
+        self.assertEqual(16, future.result())
+
+    def test_map(self):
+        self.assertEqual(
+                list(self.executor.map(pow, range(10), range(10))),
+                list(map(pow, range(10), range(10))))
+
+        self.assertEqual(
+                list(self.executor.map(pow, range(10), range(10), chunksize=3)),
+                list(map(pow, range(10), range(10))))
+
+    def test_map_exception(self):
+        i = self.executor.map(divmod, [1, 1, 1, 1], [2, 3, 0, 5])
+        self.assertEqual(i.__next__(), (0, 1))
+        self.assertEqual(i.__next__(), (0, 1))
+        self.assertRaises(ZeroDivisionError, i.__next__)
+
+    def test_map_timeout(self):
+        results = []
+        try:
+            for i in self.executor.map(time.sleep,
+                                       [0, 0, 6],
+                                       timeout=5):
+                results.append(i)
+        except futures.TimeoutError:
+            pass
+        else:
+            self.fail('expected TimeoutError')
+
+        self.assertEqual([None, None], results)
+
+    def test_shutdown_race_issue12456(self):
+        # Issue #12456: race condition at shutdown where trying to post a
+        # sentinel in the call queue blocks (the queue is full while processes
+        # have exited).
+        self.executor.map(str, [2] * (self.worker_count + 1))
+        self.executor.shutdown()
+
+    @test.support.cpython_only
+    def test_no_stale_references(self):
+        # Issue #16284: check that the executors don't unnecessarily hang onto
+        # references.
+        my_object = MyObject()
+        my_object_collected = threading.Event()
+        my_object_callback = weakref.ref(
+            my_object, lambda obj: my_object_collected.set())
+        # Deliberately discarding the future.
+        self.executor.submit(my_object.my_method)
+        del my_object
+
+        collected = my_object_collected.wait(timeout=5.0)
+        self.assertTrue(collected,
+                        "Stale reference not collected within timeout.")
+
+    def test_max_workers_negative(self):
+        for number in (0, -1):
+            with self.assertRaisesRegex(ValueError,
+                                        "max_workers must be greater "
+                                        "than 0"):
+                self.executor_type(max_workers=number)
+
+    def test_free_reference(self):
+        # Issue #14406: Result iterator should not keep an internal
+        # reference to result objects.
+        for obj in self.executor.map(make_dummy_object, range(10)):
+            wr = weakref.ref(obj)
+            del obj
+            self.assertIsNone(wr())
+
+
+class ThreadPoolExecutorTest(ThreadPoolMixin, ExecutorTest, BaseTestCase):
+    def test_map_submits_without_iteration(self):
+        """Tests verifying issue 11777."""
+        finished = []
+        def record_finished(n):
+            finished.append(n)
+
+        self.executor.map(record_finished, range(10))
+        self.executor.shutdown(wait=True)
+        self.assertCountEqual(finished, range(10))
+
+    def test_default_workers(self):
+        executor = self.executor_type()
+        self.assertEqual(executor._max_workers,
+                         (os.cpu_count() or 1) * 5)
+
+
+class ProcessPoolExecutorTest(ProcessPoolMixin, ExecutorTest, BaseTestCase):
+    def test_killed_child(self):
+        # When a child process is abruptly terminated, the whole pool gets
+        # "broken".
+        futures = [self.executor.submit(time.sleep, 3)]
+        # Get one of the processes, and terminate (kill) it
+        p = next(iter(self.executor._processes.values()))
+        p.terminate()
+        for fut in futures:
+            self.assertRaises(BrokenProcessPool, fut.result)
+        # Submitting other jobs fails as well.
+        self.assertRaises(BrokenProcessPool, self.executor.submit, pow, 2, 8)
+
+    def test_map_chunksize(self):
+        def bad_map():
+            list(self.executor.map(pow, range(40), range(40), chunksize=-1))
+
+        ref = list(map(pow, range(40), range(40)))
+        self.assertEqual(
+            list(self.executor.map(pow, range(40), range(40), chunksize=6)),
+            ref)
+        self.assertEqual(
+            list(self.executor.map(pow, range(40), range(40), chunksize=50)),
+            ref)
+        self.assertEqual(
+            list(self.executor.map(pow, range(40), range(40), chunksize=40)),
+            ref)
+        self.assertRaises(ValueError, bad_map)
+
+    @classmethod
+    def _test_traceback(cls):
+        raise RuntimeError(123) # some comment
+
+    def test_traceback(self):
+        # We want ensure that the traceback from the child process is
+        # contained in the traceback raised in the main process.
+        future = self.executor.submit(self._test_traceback)
+        with self.assertRaises(Exception) as cm:
+            future.result()
+
+        exc = cm.exception
+        self.assertIs(type(exc), RuntimeError)
+        self.assertEqual(exc.args, (123,))
+        cause = exc.__cause__
+        self.assertIs(type(cause), futures.process._RemoteTraceback)
+        self.assertIn('raise RuntimeError(123) # some comment', cause.tb)
+
+        with test.support.captured_stderr() as f1:
+            try:
+                raise exc
+            except RuntimeError:
+                sys.excepthook(*sys.exc_info())
+        self.assertIn('raise RuntimeError(123) # some comment',
+                      f1.getvalue())
+
+
+class FutureTests(BaseTestCase):
+    def test_done_callback_with_result(self):
+        callback_result = None
+        def fn(callback_future):
+            nonlocal callback_result
+            callback_result = callback_future.result()
+
+        f = Future()
+        f.add_done_callback(fn)
+        f.set_result(5)
+        self.assertEqual(5, callback_result)
+
+    def test_done_callback_with_exception(self):
+        callback_exception = None
+        def fn(callback_future):
+            nonlocal callback_exception
+            callback_exception = callback_future.exception()
+
+        f = Future()
+        f.add_done_callback(fn)
+        f.set_exception(Exception('test'))
+        self.assertEqual(('test',), callback_exception.args)
+
+    def test_done_callback_with_cancel(self):
+        was_cancelled = None
+        def fn(callback_future):
+            nonlocal was_cancelled
+            was_cancelled = callback_future.cancelled()
+
+        f = Future()
+        f.add_done_callback(fn)
+        self.assertTrue(f.cancel())
+        self.assertTrue(was_cancelled)
+
+    def test_done_callback_raises(self):
+        with test.support.captured_stderr() as stderr:
+            raising_was_called = False
+            fn_was_called = False
+
+            def raising_fn(callback_future):
+                nonlocal raising_was_called
+                raising_was_called = True
+                raise Exception('doh!')
+
+            def fn(callback_future):
+                nonlocal fn_was_called
+                fn_was_called = True
+
+            f = Future()
+            f.add_done_callback(raising_fn)
+            f.add_done_callback(fn)
+            f.set_result(5)
+            self.assertTrue(raising_was_called)
+            self.assertTrue(fn_was_called)
+            self.assertIn('Exception: doh!', stderr.getvalue())
+
+    def test_done_callback_already_successful(self):
+        callback_result = None
+        def fn(callback_future):
+            nonlocal callback_result
+            callback_result = callback_future.result()
+
+        f = Future()
+        f.set_result(5)
+        f.add_done_callback(fn)
+        self.assertEqual(5, callback_result)
+
+    def test_done_callback_already_failed(self):
+        callback_exception = None
+        def fn(callback_future):
+            nonlocal callback_exception
+            callback_exception = callback_future.exception()
+
+        f = Future()
+        f.set_exception(Exception('test'))
+        f.add_done_callback(fn)
+        self.assertEqual(('test',), callback_exception.args)
+
+    def test_done_callback_already_cancelled(self):
+        was_cancelled = None
+        def fn(callback_future):
+            nonlocal was_cancelled
+            was_cancelled = callback_future.cancelled()
+
+        f = Future()
+        self.assertTrue(f.cancel())
+        f.add_done_callback(fn)
+        self.assertTrue(was_cancelled)
+
+    def test_repr(self):
+        self.assertRegex(repr(PENDING_FUTURE),
+                         '<Future at 0x[0-9a-f]+ state=pending>')
+        self.assertRegex(repr(RUNNING_FUTURE),
+                         '<Future at 0x[0-9a-f]+ state=running>')
+        self.assertRegex(repr(CANCELLED_FUTURE),
+                         '<Future at 0x[0-9a-f]+ state=cancelled>')
+        self.assertRegex(repr(CANCELLED_AND_NOTIFIED_FUTURE),
+                         '<Future at 0x[0-9a-f]+ state=cancelled>')
+        self.assertRegex(
+                repr(EXCEPTION_FUTURE),
+                '<Future at 0x[0-9a-f]+ state=finished raised OSError>')
+        self.assertRegex(
+                repr(SUCCESSFUL_FUTURE),
+                '<Future at 0x[0-9a-f]+ state=finished returned int>')
+
+
+    def test_cancel(self):
+        f1 = create_future(state=PENDING)
+        f2 = create_future(state=RUNNING)
+        f3 = create_future(state=CANCELLED)
+        f4 = create_future(state=CANCELLED_AND_NOTIFIED)
+        f5 = create_future(state=FINISHED, exception=OSError())
+        f6 = create_future(state=FINISHED, result=5)
+
+        self.assertTrue(f1.cancel())
+        self.assertEqual(f1._state, CANCELLED)
+
+        self.assertFalse(f2.cancel())
+        self.assertEqual(f2._state, RUNNING)
+
+        self.assertTrue(f3.cancel())
+        self.assertEqual(f3._state, CANCELLED)
+
+        self.assertTrue(f4.cancel())
+        self.assertEqual(f4._state, CANCELLED_AND_NOTIFIED)
+
+        self.assertFalse(f5.cancel())
+        self.assertEqual(f5._state, FINISHED)
+
+        self.assertFalse(f6.cancel())
+        self.assertEqual(f6._state, FINISHED)
+
+    def test_cancelled(self):
+        self.assertFalse(PENDING_FUTURE.cancelled())
+        self.assertFalse(RUNNING_FUTURE.cancelled())
+        self.assertTrue(CANCELLED_FUTURE.cancelled())
+        self.assertTrue(CANCELLED_AND_NOTIFIED_FUTURE.cancelled())
+        self.assertFalse(EXCEPTION_FUTURE.cancelled())
+        self.assertFalse(SUCCESSFUL_FUTURE.cancelled())
+
+    def test_done(self):
+        self.assertFalse(PENDING_FUTURE.done())
+        self.assertFalse(RUNNING_FUTURE.done())
+        self.assertTrue(CANCELLED_FUTURE.done())
+        self.assertTrue(CANCELLED_AND_NOTIFIED_FUTURE.done())
+        self.assertTrue(EXCEPTION_FUTURE.done())
+        self.assertTrue(SUCCESSFUL_FUTURE.done())
+
+    def test_running(self):
+        self.assertFalse(PENDING_FUTURE.running())
+        self.assertTrue(RUNNING_FUTURE.running())
+        self.assertFalse(CANCELLED_FUTURE.running())
+        self.assertFalse(CANCELLED_AND_NOTIFIED_FUTURE.running())
+        self.assertFalse(EXCEPTION_FUTURE.running())
+        self.assertFalse(SUCCESSFUL_FUTURE.running())
+
+    def test_result_with_timeout(self):
+        self.assertRaises(futures.TimeoutError,
+                          PENDING_FUTURE.result, timeout=0)
+        self.assertRaises(futures.TimeoutError,
+                          RUNNING_FUTURE.result, timeout=0)
+        self.assertRaises(futures.CancelledError,
+                          CANCELLED_FUTURE.result, timeout=0)
+        self.assertRaises(futures.CancelledError,
+                          CANCELLED_AND_NOTIFIED_FUTURE.result, timeout=0)
+        self.assertRaises(OSError, EXCEPTION_FUTURE.result, timeout=0)
+        self.assertEqual(SUCCESSFUL_FUTURE.result(timeout=0), 42)
+
+    def test_result_with_success(self):
+        # TODO(brian@sweetapp.com): This test is timing dependent.
+        def notification():
+            # Wait until the main thread is waiting for the result.
+            time.sleep(1)
+            f1.set_result(42)
+
+        f1 = create_future(state=PENDING)
+        t = threading.Thread(target=notification)
+        t.start()
+
+        self.assertEqual(f1.result(timeout=5), 42)
+        t.join()
+
+    def test_result_with_cancel(self):
+        # TODO(brian@sweetapp.com): This test is timing dependent.
+        def notification():
+            # Wait until the main thread is waiting for the result.
+            time.sleep(1)
+            f1.cancel()
+
+        f1 = create_future(state=PENDING)
+        t = threading.Thread(target=notification)
+        t.start()
+
+        self.assertRaises(futures.CancelledError, f1.result, timeout=5)
+        t.join()
+
+    def test_exception_with_timeout(self):
+        self.assertRaises(futures.TimeoutError,
+                          PENDING_FUTURE.exception, timeout=0)
+        self.assertRaises(futures.TimeoutError,
+                          RUNNING_FUTURE.exception, timeout=0)
+        self.assertRaises(futures.CancelledError,
+                          CANCELLED_FUTURE.exception, timeout=0)
+        self.assertRaises(futures.CancelledError,
+                          CANCELLED_AND_NOTIFIED_FUTURE.exception, timeout=0)
+        self.assertTrue(isinstance(EXCEPTION_FUTURE.exception(timeout=0),
+                                   OSError))
+        self.assertEqual(SUCCESSFUL_FUTURE.exception(timeout=0), None)
+
+    def test_exception_with_success(self):
+        def notification():
+            # Wait until the main thread is waiting for the exception.
+            time.sleep(1)
+            with f1._condition:
+                f1._state = FINISHED
+                f1._exception = OSError()
+                f1._condition.notify_all()
+
+        f1 = create_future(state=PENDING)
+        t = threading.Thread(target=notification)
+        t.start()
+
+        self.assertTrue(isinstance(f1.exception(timeout=5), OSError))
+        t.join()
+
+@test.support.reap_threads
+def test_main():
+    try:
+        test.support.run_unittest(__name__)
+    finally:
+        test.support.reap_children()
+
+if __name__ == "__main__":
+    test_main()