GH-120804: Remove SafeChildWatcher, FastChildWatcher and MultiLoopChildWatcher from asyncio (#120805)

Remove SafeChildWatcher, FastChildWatcher and MultiLoopChildWatcher from asyncio. These child watchers have been deprecated since Python 3.12. The tests are also removed and some more tests will be added after the rewrite of child watchers.

1 files changed, 0 insertions, 636 deletions

diff --git a/Lib/test/test_asyncio/test_unix_events.py b/Lib/test/test_asyncio/test_unix_events.py
index 9452213c685..42fb54a4c3a 100644
--- a/Lib/test/test_asyncio/test_unix_events.py
+++ b/Lib/test/test_asyncio/test_unix_events.py
@@ -1138,578 +1138,6 @@ class AbstractChildWatcherTests(unittest.TestCase):
             NotImplementedError, watcher.__exit__, f, f, f)
 
 
-class BaseChildWatcherTests(unittest.TestCase):
-
-    def test_not_implemented(self):
-        f = mock.Mock()
-        watcher = unix_events.BaseChildWatcher()
-        self.assertRaises(
-            NotImplementedError, watcher._do_waitpid, f)
-
-
-class ChildWatcherTestsMixin:
-
-    ignore_warnings = mock.patch.object(log.logger, "warning")
-
-    def setUp(self):
-        super().setUp()
-        self.loop = self.new_test_loop()
-        self.running = False
-        self.zombies = {}
-
-        with mock.patch.object(
-                self.loop, "add_signal_handler") as self.m_add_signal_handler:
-            self.watcher = self.create_watcher()
-            self.watcher.attach_loop(self.loop)
-
-    def waitpid(self, pid, flags):
-        if isinstance(self.watcher, asyncio.SafeChildWatcher) or pid != -1:
-            self.assertGreater(pid, 0)
-        try:
-            if pid < 0:
-                return self.zombies.popitem()
-            else:
-                return pid, self.zombies.pop(pid)
-        except KeyError:
-            pass
-        if self.running:
-            return 0, 0
-        else:
-            raise ChildProcessError()
-
-    def add_zombie(self, pid, status):
-        self.zombies[pid] = status
-
-    def waitstatus_to_exitcode(self, status):
-        if status > 32768:
-            return status - 32768
-        elif 32700 < status < 32768:
-            return status - 32768
-        else:
-            return status
-
-    def test_create_watcher(self):
-        self.m_add_signal_handler.assert_called_once_with(
-            signal.SIGCHLD, self.watcher._sig_chld)
-
-    def waitpid_mocks(func):
-        def wrapped_func(self):
-            def patch(target, wrapper):
-                return mock.patch(target, wraps=wrapper,
-                                  new_callable=mock.Mock)
-
-            with patch('asyncio.unix_events.waitstatus_to_exitcode', self.waitstatus_to_exitcode), \
-                 patch('os.waitpid', self.waitpid) as m_waitpid:
-                func(self, m_waitpid)
-        return wrapped_func
-
-    @waitpid_mocks
-    def test_sigchld(self, m_waitpid):
-        # register a child
-        callback = mock.Mock()
-
-        with self.watcher:
-            self.running = True
-            self.watcher.add_child_handler(42, callback, 9, 10, 14)
-
-        self.assertFalse(callback.called)
-
-        # child is running
-        self.watcher._sig_chld()
-
-        self.assertFalse(callback.called)
-
-        # child terminates (returncode 12)
-        self.running = False
-        self.add_zombie(42, EXITCODE(12))
-        self.watcher._sig_chld()
-
-        callback.assert_called_once_with(42, 12, 9, 10, 14)
-
-        callback.reset_mock()
-
-        # ensure that the child is effectively reaped
-        self.add_zombie(42, EXITCODE(13))
-        with self.ignore_warnings:
-            self.watcher._sig_chld()
-
-        self.assertFalse(callback.called)
-
-        # sigchld called again
-        self.zombies.clear()
-        self.watcher._sig_chld()
-
-        self.assertFalse(callback.called)
-
-    @waitpid_mocks
-    def test_sigchld_two_children(self, m_waitpid):
-        callback1 = mock.Mock()
-        callback2 = mock.Mock()
-
-        # register child 1
-        with self.watcher:
-            self.running = True
-            self.watcher.add_child_handler(43, callback1, 7, 8)
-
-        self.assertFalse(callback1.called)
-        self.assertFalse(callback2.called)
-
-        # register child 2
-        with self.watcher:
-            self.watcher.add_child_handler(44, callback2, 147, 18)
-
-        self.assertFalse(callback1.called)
-        self.assertFalse(callback2.called)
-
-        # children are running
-        self.watcher._sig_chld()
-
-        self.assertFalse(callback1.called)
-        self.assertFalse(callback2.called)
-
-        # child 1 terminates (signal 3)
-        self.add_zombie(43, SIGNAL(3))
-        self.watcher._sig_chld()
-
-        callback1.assert_called_once_with(43, -3, 7, 8)
-        self.assertFalse(callback2.called)
-
-        callback1.reset_mock()
-
-        # child 2 still running
-        self.watcher._sig_chld()
-
-        self.assertFalse(callback1.called)
-        self.assertFalse(callback2.called)
-
-        # child 2 terminates (code 108)
-        self.add_zombie(44, EXITCODE(108))
-        self.running = False
-        self.watcher._sig_chld()
-
-        callback2.assert_called_once_with(44, 108, 147, 18)
-        self.assertFalse(callback1.called)
-
-        callback2.reset_mock()
-
-        # ensure that the children are effectively reaped
-        self.add_zombie(43, EXITCODE(14))
-        self.add_zombie(44, EXITCODE(15))
-        with self.ignore_warnings:
-            self.watcher._sig_chld()
-
-        self.assertFalse(callback1.called)
-        self.assertFalse(callback2.called)
-
-        # sigchld called again
-        self.zombies.clear()
-        self.watcher._sig_chld()
-
-        self.assertFalse(callback1.called)
-        self.assertFalse(callback2.called)
-
-    @waitpid_mocks
-    def test_sigchld_two_children_terminating_together(self, m_waitpid):
-        callback1 = mock.Mock()
-        callback2 = mock.Mock()
-
-        # register child 1
-        with self.watcher:
-            self.running = True
-            self.watcher.add_child_handler(45, callback1, 17, 8)
-
-        self.assertFalse(callback1.called)
-        self.assertFalse(callback2.called)
-
-        # register child 2
-        with self.watcher:
-            self.watcher.add_child_handler(46, callback2, 1147, 18)
-
-        self.assertFalse(callback1.called)
-        self.assertFalse(callback2.called)
-
-        # children are running
-        self.watcher._sig_chld()
-
-        self.assertFalse(callback1.called)
-        self.assertFalse(callback2.called)
-
-        # child 1 terminates (code 78)
-        # child 2 terminates (signal 5)
-        self.add_zombie(45, EXITCODE(78))
-        self.add_zombie(46, SIGNAL(5))
-        self.running = False
-        self.watcher._sig_chld()
-
-        callback1.assert_called_once_with(45, 78, 17, 8)
-        callback2.assert_called_once_with(46, -5, 1147, 18)
-
-        callback1.reset_mock()
-        callback2.reset_mock()
-
-        # ensure that the children are effectively reaped
-        self.add_zombie(45, EXITCODE(14))
-        self.add_zombie(46, EXITCODE(15))
-        with self.ignore_warnings:
-            self.watcher._sig_chld()
-
-        self.assertFalse(callback1.called)
-        self.assertFalse(callback2.called)
-
-    @waitpid_mocks
-    def test_sigchld_race_condition(self, m_waitpid):
-        # register a child
-        callback = mock.Mock()
-
-        with self.watcher:
-            # child terminates before being registered
-            self.add_zombie(50, EXITCODE(4))
-            self.watcher._sig_chld()
-
-            self.watcher.add_child_handler(50, callback, 1, 12)
-
-        callback.assert_called_once_with(50, 4, 1, 12)
-        callback.reset_mock()
-
-        # ensure that the child is effectively reaped
-        self.add_zombie(50, SIGNAL(1))
-        with self.ignore_warnings:
-            self.watcher._sig_chld()
-
-        self.assertFalse(callback.called)
-
-    @waitpid_mocks
-    def test_sigchld_replace_handler(self, m_waitpid):
-        callback1 = mock.Mock()
-        callback2 = mock.Mock()
-
-        # register a child
-        with self.watcher:
-            self.running = True
-            self.watcher.add_child_handler(51, callback1, 19)
-
-        self.assertFalse(callback1.called)
-        self.assertFalse(callback2.called)
-
-        # register the same child again
-        with self.watcher:
-            self.watcher.add_child_handler(51, callback2, 21)
-
-        self.assertFalse(callback1.called)
-        self.assertFalse(callback2.called)
-
-        # child terminates (signal 8)
-        self.running = False
-        self.add_zombie(51, SIGNAL(8))
-        self.watcher._sig_chld()
-
-        callback2.assert_called_once_with(51, -8, 21)
-        self.assertFalse(callback1.called)
-
-        callback2.reset_mock()
-
-        # ensure that the child is effectively reaped
-        self.add_zombie(51, EXITCODE(13))
-        with self.ignore_warnings:
-            self.watcher._sig_chld()
-
-        self.assertFalse(callback1.called)
-        self.assertFalse(callback2.called)
-
-    @waitpid_mocks
-    def test_sigchld_remove_handler(self, m_waitpid):
-        callback = mock.Mock()
-
-        # register a child
-        with self.watcher:
-            self.running = True
-            self.watcher.add_child_handler(52, callback, 1984)
-
-        self.assertFalse(callback.called)
-
-        # unregister the child
-        self.watcher.remove_child_handler(52)
-
-        self.assertFalse(callback.called)
-
-        # child terminates (code 99)
-        self.running = False
-        self.add_zombie(52, EXITCODE(99))
-        with self.ignore_warnings:
-            self.watcher._sig_chld()
-
-        self.assertFalse(callback.called)
-
-    @waitpid_mocks
-    def test_sigchld_unknown_status(self, m_waitpid):
-        callback = mock.Mock()
-
-        # register a child
-        with self.watcher:
-            self.running = True
-            self.watcher.add_child_handler(53, callback, -19)
-
-        self.assertFalse(callback.called)
-
-        # terminate with unknown status
-        self.zombies[53] = 1178
-        self.running = False
-        self.watcher._sig_chld()
-
-        callback.assert_called_once_with(53, 1178, -19)
-
-        callback.reset_mock()
-
-        # ensure that the child is effectively reaped
-        self.add_zombie(53, EXITCODE(101))
-        with self.ignore_warnings:
-            self.watcher._sig_chld()
-
-        self.assertFalse(callback.called)
-
-    @waitpid_mocks
-    def test_remove_child_handler(self, m_waitpid):
-        callback1 = mock.Mock()
-        callback2 = mock.Mock()
-        callback3 = mock.Mock()
-
-        # register children
-        with self.watcher:
-            self.running = True
-            self.watcher.add_child_handler(54, callback1, 1)
-            self.watcher.add_child_handler(55, callback2, 2)
-            self.watcher.add_child_handler(56, callback3, 3)
-
-        # remove child handler 1
-        self.assertTrue(self.watcher.remove_child_handler(54))
-
-        # remove child handler 2 multiple times
-        self.assertTrue(self.watcher.remove_child_handler(55))
-        self.assertFalse(self.watcher.remove_child_handler(55))
-        self.assertFalse(self.watcher.remove_child_handler(55))
-
-        # all children terminate
-        self.add_zombie(54, EXITCODE(0))
-        self.add_zombie(55, EXITCODE(1))
-        self.add_zombie(56, EXITCODE(2))
-        self.running = False
-        with self.ignore_warnings:
-            self.watcher._sig_chld()
-
-        self.assertFalse(callback1.called)
-        self.assertFalse(callback2.called)
-        callback3.assert_called_once_with(56, 2, 3)
-
-    @waitpid_mocks
-    def test_sigchld_unhandled_exception(self, m_waitpid):
-        callback = mock.Mock()
-
-        # register a child
-        with self.watcher:
-            self.running = True
-            self.watcher.add_child_handler(57, callback)
-
-        # raise an exception
-        m_waitpid.side_effect = ValueError
-
-        with mock.patch.object(log.logger,
-                               'error') as m_error:
-
-            self.assertEqual(self.watcher._sig_chld(), None)
-            self.assertTrue(m_error.called)
-
-    @waitpid_mocks
-    def test_sigchld_child_reaped_elsewhere(self, m_waitpid):
-        # register a child
-        callback = mock.Mock()
-
-        with self.watcher:
-            self.running = True
-            self.watcher.add_child_handler(58, callback)
-
-        self.assertFalse(callback.called)
-
-        # child terminates
-        self.running = False
-        self.add_zombie(58, EXITCODE(4))
-
-        # waitpid is called elsewhere
-        os.waitpid(58, os.WNOHANG)
-
-        m_waitpid.reset_mock()
-
-        # sigchld
-        with self.ignore_warnings:
-            self.watcher._sig_chld()
-
-        if isinstance(self.watcher, asyncio.FastChildWatcher):
-            # here the FastChildWatcher enters a deadlock
-            # (there is no way to prevent it)
-            self.assertFalse(callback.called)
-        else:
-            callback.assert_called_once_with(58, 255)
-
-    @waitpid_mocks
-    def test_sigchld_unknown_pid_during_registration(self, m_waitpid):
-        # register two children
-        callback1 = mock.Mock()
-        callback2 = mock.Mock()
-
-        with self.ignore_warnings, self.watcher:
-            self.running = True
-            # child 1 terminates
-            self.add_zombie(591, EXITCODE(7))
-            # an unknown child terminates
-            self.add_zombie(593, EXITCODE(17))
-
-            self.watcher._sig_chld()
-
-            self.watcher.add_child_handler(591, callback1)
-            self.watcher.add_child_handler(592, callback2)
-
-        callback1.assert_called_once_with(591, 7)
-        self.assertFalse(callback2.called)
-
-    @waitpid_mocks
-    def test_set_loop(self, m_waitpid):
-        # register a child
-        callback = mock.Mock()
-
-        with self.watcher:
-            self.running = True
-            self.watcher.add_child_handler(60, callback)
-
-        # attach a new loop
-        old_loop = self.loop
-        self.loop = self.new_test_loop()
-        patch = mock.patch.object
-
-        with patch(old_loop, "remove_signal_handler") as m_old_remove, \
-             patch(self.loop, "add_signal_handler") as m_new_add:
-
-            self.watcher.attach_loop(self.loop)
-
-            m_old_remove.assert_called_once_with(
-                signal.SIGCHLD)
-            m_new_add.assert_called_once_with(
-                signal.SIGCHLD, self.watcher._sig_chld)
-
-        # child terminates
-        self.running = False
-        self.add_zombie(60, EXITCODE(9))
-        self.watcher._sig_chld()
-
-        callback.assert_called_once_with(60, 9)
-
-    @waitpid_mocks
-    def test_set_loop_race_condition(self, m_waitpid):
-        # register 3 children
-        callback1 = mock.Mock()
-        callback2 = mock.Mock()
-        callback3 = mock.Mock()
-
-        with self.watcher:
-            self.running = True
-            self.watcher.add_child_handler(61, callback1)
-            self.watcher.add_child_handler(62, callback2)
-            self.watcher.add_child_handler(622, callback3)
-
-        # detach the loop
-        old_loop = self.loop
-        self.loop = None
-
-        with mock.patch.object(
-                old_loop, "remove_signal_handler") as m_remove_signal_handler:
-
-            with self.assertWarnsRegex(
-                    RuntimeWarning, 'A loop is being detached'):
-                self.watcher.attach_loop(None)
-
-            m_remove_signal_handler.assert_called_once_with(
-                signal.SIGCHLD)
-
-        # child 1 & 2 terminate
-        self.add_zombie(61, EXITCODE(11))
-        self.add_zombie(62, SIGNAL(5))
-
-        # SIGCHLD was not caught
-        self.assertFalse(callback1.called)
-        self.assertFalse(callback2.called)
-        self.assertFalse(callback3.called)
-
-        # attach a new loop
-        self.loop = self.new_test_loop()
-
-        with mock.patch.object(
-                self.loop, "add_signal_handler") as m_add_signal_handler:
-
-            self.watcher.attach_loop(self.loop)
-
-            m_add_signal_handler.assert_called_once_with(
-                signal.SIGCHLD, self.watcher._sig_chld)
-            callback1.assert_called_once_with(61, 11)  # race condition!
-            callback2.assert_called_once_with(62, -5)  # race condition!
-            self.assertFalse(callback3.called)
-
-        callback1.reset_mock()
-        callback2.reset_mock()
-
-        # child 3 terminates
-        self.running = False
-        self.add_zombie(622, EXITCODE(19))
-        self.watcher._sig_chld()
-
-        self.assertFalse(callback1.called)
-        self.assertFalse(callback2.called)
-        callback3.assert_called_once_with(622, 19)
-
-    @waitpid_mocks
-    def test_close(self, m_waitpid):
-        # register two children
-        callback1 = mock.Mock()
-
-        with self.watcher:
-            self.running = True
-            # child 1 terminates
-            self.add_zombie(63, EXITCODE(9))
-            # other child terminates
-            self.add_zombie(65, EXITCODE(18))
-            self.watcher._sig_chld()
-
-            self.watcher.add_child_handler(63, callback1)
-            self.watcher.add_child_handler(64, callback1)
-
-            self.assertEqual(len(self.watcher._callbacks), 1)
-            if isinstance(self.watcher, asyncio.FastChildWatcher):
-                self.assertEqual(len(self.watcher._zombies), 1)
-
-            with mock.patch.object(
-                    self.loop,
-                    "remove_signal_handler") as m_remove_signal_handler:
-
-                self.watcher.close()
-
-                m_remove_signal_handler.assert_called_once_with(
-                    signal.SIGCHLD)
-                self.assertFalse(self.watcher._callbacks)
-                if isinstance(self.watcher, asyncio.FastChildWatcher):
-                    self.assertFalse(self.watcher._zombies)
-
-
-class SafeChildWatcherTests (ChildWatcherTestsMixin, test_utils.TestCase):
-    def create_watcher(self):
-        with warnings.catch_warnings():
-            warnings.simplefilter("ignore", DeprecationWarning)
-            return asyncio.SafeChildWatcher()
-
-
-class FastChildWatcherTests (ChildWatcherTestsMixin, test_utils.TestCase):
-    def create_watcher(self):
-        with warnings.catch_warnings():
-            warnings.simplefilter("ignore", DeprecationWarning)
-            return asyncio.FastChildWatcher()
-
-
 class PolicyTests(unittest.TestCase):
 
     def create_policy(self):
@@ -1739,70 +1167,6 @@ class PolicyTests(unittest.TestCase):
         with self.assertWarns(DeprecationWarning):
             self.assertIs(watcher, policy.get_child_watcher())
 
-    def test_get_child_watcher_after_set(self):
-        policy = self.create_policy()
-        with warnings.catch_warnings():
-            warnings.simplefilter("ignore", DeprecationWarning)
-            watcher = asyncio.FastChildWatcher()
-            policy.set_child_watcher(watcher)
-
-        self.assertIs(policy._watcher, watcher)
-        with self.assertWarns(DeprecationWarning):
-            self.assertIs(watcher, policy.get_child_watcher())
-
-    def test_get_child_watcher_thread(self):
-
-        def f():
-            policy.set_event_loop(policy.new_event_loop())
-
-            self.assertIsInstance(policy.get_event_loop(),
-                                  asyncio.AbstractEventLoop)
-            with warnings.catch_warnings():
-                warnings.simplefilter("ignore", DeprecationWarning)
-                watcher = policy.get_child_watcher()
-
-            self.assertIsInstance(watcher, asyncio.SafeChildWatcher)
-            self.assertIsNone(watcher._loop)
-
-            policy.get_event_loop().close()
-
-        policy = self.create_policy()
-        with warnings.catch_warnings():
-            warnings.simplefilter("ignore", DeprecationWarning)
-            policy.set_child_watcher(asyncio.SafeChildWatcher())
-
-        th = threading.Thread(target=f)
-        th.start()
-        th.join()
-
-    def test_child_watcher_replace_mainloop_existing(self):
-        policy = self.create_policy()
-        loop = policy.new_event_loop()
-        policy.set_event_loop(loop)
-
-        # Explicitly setup SafeChildWatcher,
-        # default ThreadedChildWatcher has no _loop property
-        with warnings.catch_warnings():
-            warnings.simplefilter("ignore", DeprecationWarning)
-            watcher = asyncio.SafeChildWatcher()
-            policy.set_child_watcher(watcher)
-        watcher.attach_loop(loop)
-
-        self.assertIs(watcher._loop, loop)
-
-        new_loop = policy.new_event_loop()
-        policy.set_event_loop(new_loop)
-
-        self.assertIs(watcher._loop, new_loop)
-
-        policy.set_event_loop(None)
-
-        self.assertIs(watcher._loop, None)
-
-        loop.close()
-        new_loop.close()
-
-
 class TestFunctional(unittest.TestCase):
 
     def setUp(self):