Initial checkin of asyncio package (== Tulip, == PEP 3156).

Lib/test/test_asyncio/test_unix_events.py

@@ -0,0 +1,767 @@
+"""Tests for unix_events.py."""
+
+import gc
+import errno
+import io
+import pprint
+import signal
+import stat
+import sys
+import unittest
+import unittest.mock
+
+
+from asyncio import events
+from asyncio import futures
+from asyncio import protocols
+from asyncio import test_utils
+from asyncio import unix_events
+
+
+@unittest.skipUnless(signal, 'Signals are not supported')
+class SelectorEventLoopTests(unittest.TestCase):
+
+    def setUp(self):
+        self.loop = unix_events.SelectorEventLoop()
+        events.set_event_loop(None)
+
+    def tearDown(self):
+        self.loop.close()
+
+    def test_check_signal(self):
+        self.assertRaises(
+            TypeError, self.loop._check_signal, '1')
+        self.assertRaises(
+            ValueError, self.loop._check_signal, signal.NSIG + 1)
+
+    def test_handle_signal_no_handler(self):
+        self.loop._handle_signal(signal.NSIG + 1, ())
+
+    def test_handle_signal_cancelled_handler(self):
+        h = events.Handle(unittest.mock.Mock(), ())
+        h.cancel()
+        self.loop._signal_handlers[signal.NSIG + 1] = h
+        self.loop.remove_signal_handler = unittest.mock.Mock()
+        self.loop._handle_signal(signal.NSIG + 1, ())
+        self.loop.remove_signal_handler.assert_called_with(signal.NSIG + 1)
+
+    @unittest.mock.patch('asyncio.unix_events.signal')
+    def test_add_signal_handler_setup_error(self, m_signal):
+        m_signal.NSIG = signal.NSIG
+        m_signal.set_wakeup_fd.side_effect = ValueError
+
+        self.assertRaises(
+            RuntimeError,
+            self.loop.add_signal_handler,
+            signal.SIGINT, lambda: True)
+
+    @unittest.mock.patch('asyncio.unix_events.signal')
+    def test_add_signal_handler(self, m_signal):
+        m_signal.NSIG = signal.NSIG
+
+        cb = lambda: True
+        self.loop.add_signal_handler(signal.SIGHUP, cb)
+        h = self.loop._signal_handlers.get(signal.SIGHUP)
+        self.assertTrue(isinstance(h, events.Handle))
+        self.assertEqual(h._callback, cb)
+
+    @unittest.mock.patch('asyncio.unix_events.signal')
+    def test_add_signal_handler_install_error(self, m_signal):
+        m_signal.NSIG = signal.NSIG
+
+        def set_wakeup_fd(fd):
+            if fd == -1:
+                raise ValueError()
+        m_signal.set_wakeup_fd = set_wakeup_fd
+
+        class Err(OSError):
+            errno = errno.EFAULT
+        m_signal.signal.side_effect = Err
+
+        self.assertRaises(
+            Err,
+            self.loop.add_signal_handler,
+            signal.SIGINT, lambda: True)
+
+    @unittest.mock.patch('asyncio.unix_events.signal')
+    @unittest.mock.patch('asyncio.unix_events.asyncio_log')
+    def test_add_signal_handler_install_error2(self, m_logging, m_signal):
+        m_signal.NSIG = signal.NSIG
+
+        class Err(OSError):
+            errno = errno.EINVAL
+        m_signal.signal.side_effect = Err
+
+        self.loop._signal_handlers[signal.SIGHUP] = lambda: True
+        self.assertRaises(
+            RuntimeError,
+            self.loop.add_signal_handler,
+            signal.SIGINT, lambda: True)
+        self.assertFalse(m_logging.info.called)
+        self.assertEqual(1, m_signal.set_wakeup_fd.call_count)
+
+    @unittest.mock.patch('asyncio.unix_events.signal')
+    @unittest.mock.patch('asyncio.unix_events.asyncio_log')
+    def test_add_signal_handler_install_error3(self, m_logging, m_signal):
+        class Err(OSError):
+            errno = errno.EINVAL
+        m_signal.signal.side_effect = Err
+        m_signal.NSIG = signal.NSIG
+
+        self.assertRaises(
+            RuntimeError,
+            self.loop.add_signal_handler,
+            signal.SIGINT, lambda: True)
+        self.assertFalse(m_logging.info.called)
+        self.assertEqual(2, m_signal.set_wakeup_fd.call_count)
+
+    @unittest.mock.patch('asyncio.unix_events.signal')
+    def test_remove_signal_handler(self, m_signal):
+        m_signal.NSIG = signal.NSIG
+
+        self.loop.add_signal_handler(signal.SIGHUP, lambda: True)
+
+        self.assertTrue(
+            self.loop.remove_signal_handler(signal.SIGHUP))
+        self.assertTrue(m_signal.set_wakeup_fd.called)
+        self.assertTrue(m_signal.signal.called)
+        self.assertEqual(
+            (signal.SIGHUP, m_signal.SIG_DFL), m_signal.signal.call_args[0])
+
+    @unittest.mock.patch('asyncio.unix_events.signal')
+    def test_remove_signal_handler_2(self, m_signal):
+        m_signal.NSIG = signal.NSIG
+        m_signal.SIGINT = signal.SIGINT
+
+        self.loop.add_signal_handler(signal.SIGINT, lambda: True)
+        self.loop._signal_handlers[signal.SIGHUP] = object()
+        m_signal.set_wakeup_fd.reset_mock()
+
+        self.assertTrue(
+            self.loop.remove_signal_handler(signal.SIGINT))
+        self.assertFalse(m_signal.set_wakeup_fd.called)
+        self.assertTrue(m_signal.signal.called)
+        self.assertEqual(
+            (signal.SIGINT, m_signal.default_int_handler),
+            m_signal.signal.call_args[0])
+
+    @unittest.mock.patch('asyncio.unix_events.signal')
+    @unittest.mock.patch('asyncio.unix_events.asyncio_log')
+    def test_remove_signal_handler_cleanup_error(self, m_logging, m_signal):
+        m_signal.NSIG = signal.NSIG
+        self.loop.add_signal_handler(signal.SIGHUP, lambda: True)
+
+        m_signal.set_wakeup_fd.side_effect = ValueError
+
+        self.loop.remove_signal_handler(signal.SIGHUP)
+        self.assertTrue(m_logging.info)
+
+    @unittest.mock.patch('asyncio.unix_events.signal')
+    def test_remove_signal_handler_error(self, m_signal):
+        m_signal.NSIG = signal.NSIG
+        self.loop.add_signal_handler(signal.SIGHUP, lambda: True)
+
+        m_signal.signal.side_effect = OSError
+
+        self.assertRaises(
+            OSError, self.loop.remove_signal_handler, signal.SIGHUP)
+
+    @unittest.mock.patch('asyncio.unix_events.signal')
+    def test_remove_signal_handler_error2(self, m_signal):
+        m_signal.NSIG = signal.NSIG
+        self.loop.add_signal_handler(signal.SIGHUP, lambda: True)
+
+        class Err(OSError):
+            errno = errno.EINVAL
+        m_signal.signal.side_effect = Err
+
+        self.assertRaises(
+            RuntimeError, self.loop.remove_signal_handler, signal.SIGHUP)
+
+    @unittest.mock.patch('os.WTERMSIG')
+    @unittest.mock.patch('os.WEXITSTATUS')
+    @unittest.mock.patch('os.WIFSIGNALED')
+    @unittest.mock.patch('os.WIFEXITED')
+    @unittest.mock.patch('os.waitpid')
+    def test__sig_chld(self, m_waitpid, m_WIFEXITED, m_WIFSIGNALED,
+                       m_WEXITSTATUS, m_WTERMSIG):
+        m_waitpid.side_effect = [(7, object()), ChildProcessError]
+        m_WIFEXITED.return_value = True
+        m_WIFSIGNALED.return_value = False
+        m_WEXITSTATUS.return_value = 3
+        transp = unittest.mock.Mock()
+        self.loop._subprocesses[7] = transp
+
+        self.loop._sig_chld()
+        transp._process_exited.assert_called_with(3)
+        self.assertFalse(m_WTERMSIG.called)
+
+    @unittest.mock.patch('os.WTERMSIG')
+    @unittest.mock.patch('os.WEXITSTATUS')
+    @unittest.mock.patch('os.WIFSIGNALED')
+    @unittest.mock.patch('os.WIFEXITED')
+    @unittest.mock.patch('os.waitpid')
+    def test__sig_chld_signal(self, m_waitpid, m_WIFEXITED, m_WIFSIGNALED,
+                              m_WEXITSTATUS, m_WTERMSIG):
+        m_waitpid.side_effect = [(7, object()), ChildProcessError]
+        m_WIFEXITED.return_value = False
+        m_WIFSIGNALED.return_value = True
+        m_WTERMSIG.return_value = 1
+        transp = unittest.mock.Mock()
+        self.loop._subprocesses[7] = transp
+
+        self.loop._sig_chld()
+        transp._process_exited.assert_called_with(-1)
+        self.assertFalse(m_WEXITSTATUS.called)
+
+    @unittest.mock.patch('os.WTERMSIG')
+    @unittest.mock.patch('os.WEXITSTATUS')
+    @unittest.mock.patch('os.WIFSIGNALED')
+    @unittest.mock.patch('os.WIFEXITED')
+    @unittest.mock.patch('os.waitpid')
+    def test__sig_chld_zero_pid(self, m_waitpid, m_WIFEXITED, m_WIFSIGNALED,
+                                m_WEXITSTATUS, m_WTERMSIG):
+        m_waitpid.side_effect = [(0, object()), ChildProcessError]
+        transp = unittest.mock.Mock()
+        self.loop._subprocesses[7] = transp
+
+        self.loop._sig_chld()
+        self.assertFalse(transp._process_exited.called)
+        self.assertFalse(m_WIFSIGNALED.called)
+        self.assertFalse(m_WIFEXITED.called)
+        self.assertFalse(m_WTERMSIG.called)
+        self.assertFalse(m_WEXITSTATUS.called)
+
+    @unittest.mock.patch('os.WTERMSIG')
+    @unittest.mock.patch('os.WEXITSTATUS')
+    @unittest.mock.patch('os.WIFSIGNALED')
+    @unittest.mock.patch('os.WIFEXITED')
+    @unittest.mock.patch('os.waitpid')
+    def test__sig_chld_not_registered_subprocess(self, m_waitpid,
+                                                 m_WIFEXITED, m_WIFSIGNALED,
+                                                 m_WEXITSTATUS, m_WTERMSIG):
+        m_waitpid.side_effect = [(7, object()), ChildProcessError]
+        m_WIFEXITED.return_value = True
+        m_WIFSIGNALED.return_value = False
+        m_WEXITSTATUS.return_value = 3
+
+        self.loop._sig_chld()
+        self.assertFalse(m_WTERMSIG.called)
+
+    @unittest.mock.patch('os.WTERMSIG')
+    @unittest.mock.patch('os.WEXITSTATUS')
+    @unittest.mock.patch('os.WIFSIGNALED')
+    @unittest.mock.patch('os.WIFEXITED')
+    @unittest.mock.patch('os.waitpid')
+    def test__sig_chld_unknown_status(self, m_waitpid,
+                                      m_WIFEXITED, m_WIFSIGNALED,
+                                      m_WEXITSTATUS, m_WTERMSIG):
+        m_waitpid.side_effect = [(7, object()), ChildProcessError]
+        m_WIFEXITED.return_value = False
+        m_WIFSIGNALED.return_value = False
+        transp = unittest.mock.Mock()
+        self.loop._subprocesses[7] = transp
+
+        self.loop._sig_chld()
+        self.assertFalse(transp._process_exited.called)
+        self.assertFalse(m_WEXITSTATUS.called)
+        self.assertFalse(m_WTERMSIG.called)
+
+    @unittest.mock.patch('asyncio.unix_events.asyncio_log')
+    @unittest.mock.patch('os.WTERMSIG')
+    @unittest.mock.patch('os.WEXITSTATUS')
+    @unittest.mock.patch('os.WIFSIGNALED')
+    @unittest.mock.patch('os.WIFEXITED')
+    @unittest.mock.patch('os.waitpid')
+    def test__sig_chld_unknown_status_in_handler(self, m_waitpid,
+                                                 m_WIFEXITED, m_WIFSIGNALED,
+                                                 m_WEXITSTATUS, m_WTERMSIG,
+                                                 m_log):
+        m_waitpid.side_effect = Exception
+        transp = unittest.mock.Mock()
+        self.loop._subprocesses[7] = transp
+
+        self.loop._sig_chld()
+        self.assertFalse(transp._process_exited.called)
+        self.assertFalse(m_WIFSIGNALED.called)
+        self.assertFalse(m_WIFEXITED.called)
+        self.assertFalse(m_WTERMSIG.called)
+        self.assertFalse(m_WEXITSTATUS.called)
+        m_log.exception.assert_called_with(
+            'Unknown exception in SIGCHLD handler')
+
+    @unittest.mock.patch('os.waitpid')
+    def test__sig_chld_process_error(self, m_waitpid):
+        m_waitpid.side_effect = ChildProcessError
+        self.loop._sig_chld()
+        self.assertTrue(m_waitpid.called)
+
+
+class UnixReadPipeTransportTests(unittest.TestCase):
+
+    def setUp(self):
+        self.loop = test_utils.TestLoop()
+        self.protocol = test_utils.make_test_protocol(protocols.Protocol)
+        self.pipe = unittest.mock.Mock(spec_set=io.RawIOBase)
+        self.pipe.fileno.return_value = 5
+
+        fcntl_patcher = unittest.mock.patch('fcntl.fcntl')
+        fcntl_patcher.start()
+        self.addCleanup(fcntl_patcher.stop)
+
+    def test_ctor(self):
+        tr = unix_events._UnixReadPipeTransport(
+            self.loop, self.pipe, self.protocol)
+        self.loop.assert_reader(5, tr._read_ready)
+        test_utils.run_briefly(self.loop)
+        self.protocol.connection_made.assert_called_with(tr)
+
+    def test_ctor_with_waiter(self):
+        fut = futures.Future(loop=self.loop)
+        unix_events._UnixReadPipeTransport(
+            self.loop, self.pipe, self.protocol, fut)
+        test_utils.run_briefly(self.loop)
+        self.assertIsNone(fut.result())
+
+    @unittest.mock.patch('os.read')
+    def test__read_ready(self, m_read):
+        tr = unix_events._UnixReadPipeTransport(
+            self.loop, self.pipe, self.protocol)
+        m_read.return_value = b'data'
+        tr._read_ready()
+
+        m_read.assert_called_with(5, tr.max_size)
+        self.protocol.data_received.assert_called_with(b'data')
+
+    @unittest.mock.patch('os.read')
+    def test__read_ready_eof(self, m_read):
+        tr = unix_events._UnixReadPipeTransport(
+            self.loop, self.pipe, self.protocol)
+        m_read.return_value = b''
+        tr._read_ready()
+
+        m_read.assert_called_with(5, tr.max_size)
+        self.assertFalse(self.loop.readers)
+        test_utils.run_briefly(self.loop)
+        self.protocol.eof_received.assert_called_with()
+        self.protocol.connection_lost.assert_called_with(None)
+
+    @unittest.mock.patch('os.read')
+    def test__read_ready_blocked(self, m_read):
+        tr = unix_events._UnixReadPipeTransport(
+            self.loop, self.pipe, self.protocol)
+        m_read.side_effect = BlockingIOError
+        tr._read_ready()
+
+        m_read.assert_called_with(5, tr.max_size)
+        test_utils.run_briefly(self.loop)
+        self.assertFalse(self.protocol.data_received.called)
+
+    @unittest.mock.patch('asyncio.log.asyncio_log.exception')
+    @unittest.mock.patch('os.read')
+    def test__read_ready_error(self, m_read, m_logexc):
+        tr = unix_events._UnixReadPipeTransport(
+            self.loop, self.pipe, self.protocol)
+        err = OSError()
+        m_read.side_effect = err
+        tr._close = unittest.mock.Mock()
+        tr._read_ready()
+
+        m_read.assert_called_with(5, tr.max_size)
+        tr._close.assert_called_with(err)
+        m_logexc.assert_called_with('Fatal error for %s', tr)
+
+    @unittest.mock.patch('os.read')
+    def test_pause(self, m_read):
+        tr = unix_events._UnixReadPipeTransport(
+            self.loop, self.pipe, self.protocol)
+
+        m = unittest.mock.Mock()
+        self.loop.add_reader(5, m)
+        tr.pause()
+        self.assertFalse(self.loop.readers)
+
+    @unittest.mock.patch('os.read')
+    def test_resume(self, m_read):
+        tr = unix_events._UnixReadPipeTransport(
+            self.loop, self.pipe, self.protocol)
+
+        tr.resume()
+        self.loop.assert_reader(5, tr._read_ready)
+
+    @unittest.mock.patch('os.read')
+    def test_close(self, m_read):
+        tr = unix_events._UnixReadPipeTransport(
+            self.loop, self.pipe, self.protocol)
+
+        tr._close = unittest.mock.Mock()
+        tr.close()
+        tr._close.assert_called_with(None)
+
+    @unittest.mock.patch('os.read')
+    def test_close_already_closing(self, m_read):
+        tr = unix_events._UnixReadPipeTransport(
+            self.loop, self.pipe, self.protocol)
+
+        tr._closing = True
+        tr._close = unittest.mock.Mock()
+        tr.close()
+        self.assertFalse(tr._close.called)
+
+    @unittest.mock.patch('os.read')
+    def test__close(self, m_read):
+        tr = unix_events._UnixReadPipeTransport(
+            self.loop, self.pipe, self.protocol)
+
+        err = object()
+        tr._close(err)
+        self.assertTrue(tr._closing)
+        self.assertFalse(self.loop.readers)
+        test_utils.run_briefly(self.loop)
+        self.protocol.connection_lost.assert_called_with(err)
+
+    def test__call_connection_lost(self):
+        tr = unix_events._UnixReadPipeTransport(
+            self.loop, self.pipe, self.protocol)
+
+        err = None
+        tr._call_connection_lost(err)
+        self.protocol.connection_lost.assert_called_with(err)
+        self.pipe.close.assert_called_with()
+
+        self.assertIsNone(tr._protocol)
+        self.assertEqual(2, sys.getrefcount(self.protocol),
+                         pprint.pformat(gc.get_referrers(self.protocol)))
+        self.assertIsNone(tr._loop)
+        self.assertEqual(2, sys.getrefcount(self.loop),
+                         pprint.pformat(gc.get_referrers(self.loop)))
+
+    def test__call_connection_lost_with_err(self):
+        tr = unix_events._UnixReadPipeTransport(
+            self.loop, self.pipe, self.protocol)
+
+        err = OSError()
+        tr._call_connection_lost(err)
+        self.protocol.connection_lost.assert_called_with(err)
+        self.pipe.close.assert_called_with()
+
+        self.assertIsNone(tr._protocol)
+        self.assertEqual(2, sys.getrefcount(self.protocol),
+                         pprint.pformat(gc.get_referrers(self.protocol)))
+        self.assertIsNone(tr._loop)
+        self.assertEqual(2, sys.getrefcount(self.loop),
+                         pprint.pformat(gc.get_referrers(self.loop)))
+
+
+class UnixWritePipeTransportTests(unittest.TestCase):
+
+    def setUp(self):
+        self.loop = test_utils.TestLoop()
+        self.protocol = test_utils.make_test_protocol(protocols.BaseProtocol)
+        self.pipe = unittest.mock.Mock(spec_set=io.RawIOBase)
+        self.pipe.fileno.return_value = 5
+
+        fcntl_patcher = unittest.mock.patch('fcntl.fcntl')
+        fcntl_patcher.start()
+        self.addCleanup(fcntl_patcher.stop)
+
+        fstat_patcher = unittest.mock.patch('os.fstat')
+        m_fstat = fstat_patcher.start()
+        st = unittest.mock.Mock()
+        st.st_mode = stat.S_IFIFO
+        m_fstat.return_value = st
+        self.addCleanup(fstat_patcher.stop)
+
+    def test_ctor(self):
+        tr = unix_events._UnixWritePipeTransport(
+            self.loop, self.pipe, self.protocol)
+        self.loop.assert_reader(5, tr._read_ready)
+        test_utils.run_briefly(self.loop)
+        self.protocol.connection_made.assert_called_with(tr)
+
+    def test_ctor_with_waiter(self):
+        fut = futures.Future(loop=self.loop)
+        tr = unix_events._UnixWritePipeTransport(
+            self.loop, self.pipe, self.protocol, fut)
+        self.loop.assert_reader(5, tr._read_ready)
+        test_utils.run_briefly(self.loop)
+        self.assertEqual(None, fut.result())
+
+    def test_can_write_eof(self):
+        tr = unix_events._UnixWritePipeTransport(
+            self.loop, self.pipe, self.protocol)
+        self.assertTrue(tr.can_write_eof())
+
+    @unittest.mock.patch('os.write')
+    def test_write(self, m_write):
+        tr = unix_events._UnixWritePipeTransport(
+            self.loop, self.pipe, self.protocol)
+
+        m_write.return_value = 4
+        tr.write(b'data')
+        m_write.assert_called_with(5, b'data')
+        self.assertFalse(self.loop.writers)
+        self.assertEqual([], tr._buffer)
+
+    @unittest.mock.patch('os.write')
+    def test_write_no_data(self, m_write):
+        tr = unix_events._UnixWritePipeTransport(
+            self.loop, self.pipe, self.protocol)
+
+        tr.write(b'')
+        self.assertFalse(m_write.called)
+        self.assertFalse(self.loop.writers)
+        self.assertEqual([], tr._buffer)
+
+    @unittest.mock.patch('os.write')
+    def test_write_partial(self, m_write):
+        tr = unix_events._UnixWritePipeTransport(
+            self.loop, self.pipe, self.protocol)
+
+        m_write.return_value = 2
+        tr.write(b'data')
+        m_write.assert_called_with(5, b'data')
+        self.loop.assert_writer(5, tr._write_ready)
+        self.assertEqual([b'ta'], tr._buffer)
+
+    @unittest.mock.patch('os.write')
+    def test_write_buffer(self, m_write):
+        tr = unix_events._UnixWritePipeTransport(
+            self.loop, self.pipe, self.protocol)
+
+        self.loop.add_writer(5, tr._write_ready)
+        tr._buffer = [b'previous']
+        tr.write(b'data')
+        self.assertFalse(m_write.called)
+        self.loop.assert_writer(5, tr._write_ready)
+        self.assertEqual([b'previous', b'data'], tr._buffer)
+
+    @unittest.mock.patch('os.write')
+    def test_write_again(self, m_write):
+        tr = unix_events._UnixWritePipeTransport(
+            self.loop, self.pipe, self.protocol)
+
+        m_write.side_effect = BlockingIOError()
+        tr.write(b'data')
+        m_write.assert_called_with(5, b'data')
+        self.loop.assert_writer(5, tr._write_ready)
+        self.assertEqual([b'data'], tr._buffer)
+
+    @unittest.mock.patch('asyncio.unix_events.asyncio_log')
+    @unittest.mock.patch('os.write')
+    def test_write_err(self, m_write, m_log):
+        tr = unix_events._UnixWritePipeTransport(
+            self.loop, self.pipe, self.protocol)
+
+        err = OSError()
+        m_write.side_effect = err
+        tr._fatal_error = unittest.mock.Mock()
+        tr.write(b'data')
+        m_write.assert_called_with(5, b'data')
+        self.assertFalse(self.loop.writers)
+        self.assertEqual([], tr._buffer)
+        tr._fatal_error.assert_called_with(err)
+        self.assertEqual(1, tr._conn_lost)
+
+        tr.write(b'data')
+        self.assertEqual(2, tr._conn_lost)
+        tr.write(b'data')
+        tr.write(b'data')
+        tr.write(b'data')
+        tr.write(b'data')
+        # This is a bit overspecified. :-(
+        m_log.warning.assert_called_with(
+            'pipe closed by peer or os.write(pipe, data) raised exception.')
+
+    @unittest.mock.patch('os.write')
+    def test_write_close(self, m_write):
+        tr = unix_events._UnixWritePipeTransport(
+            self.loop, self.pipe, self.protocol)
+        tr._read_ready()  # pipe was closed by peer
+
+        tr.write(b'data')
+        self.assertEqual(tr._conn_lost, 1)
+        tr.write(b'data')
+        self.assertEqual(tr._conn_lost, 2)
+
+    def test__read_ready(self):
+        tr = unix_events._UnixWritePipeTransport(self.loop, self.pipe,
+                                                 self.protocol)
+        tr._read_ready()
+        self.assertFalse(self.loop.readers)
+        self.assertFalse(self.loop.writers)
+        self.assertTrue(tr._closing)
+        test_utils.run_briefly(self.loop)
+        self.protocol.connection_lost.assert_called_with(None)
+
+    @unittest.mock.patch('os.write')
+    def test__write_ready(self, m_write):
+        tr = unix_events._UnixWritePipeTransport(
+            self.loop, self.pipe, self.protocol)
+        self.loop.add_writer(5, tr._write_ready)
+        tr._buffer = [b'da', b'ta']
+        m_write.return_value = 4
+        tr._write_ready()
+        m_write.assert_called_with(5, b'data')
+        self.assertFalse(self.loop.writers)
+        self.assertEqual([], tr._buffer)
+
+    @unittest.mock.patch('os.write')
+    def test__write_ready_partial(self, m_write):
+        tr = unix_events._UnixWritePipeTransport(
+            self.loop, self.pipe, self.protocol)
+
+        self.loop.add_writer(5, tr._write_ready)
+        tr._buffer = [b'da', b'ta']
+        m_write.return_value = 3
+        tr._write_ready()
+        m_write.assert_called_with(5, b'data')
+        self.loop.assert_writer(5, tr._write_ready)
+        self.assertEqual([b'a'], tr._buffer)
+
+    @unittest.mock.patch('os.write')
+    def test__write_ready_again(self, m_write):
+        tr = unix_events._UnixWritePipeTransport(
+            self.loop, self.pipe, self.protocol)
+
+        self.loop.add_writer(5, tr._write_ready)
+        tr._buffer = [b'da', b'ta']
+        m_write.side_effect = BlockingIOError()
+        tr._write_ready()
+        m_write.assert_called_with(5, b'data')
+        self.loop.assert_writer(5, tr._write_ready)
+        self.assertEqual([b'data'], tr._buffer)
+
+    @unittest.mock.patch('os.write')
+    def test__write_ready_empty(self, m_write):
+        tr = unix_events._UnixWritePipeTransport(
+            self.loop, self.pipe, self.protocol)
+
+        self.loop.add_writer(5, tr._write_ready)
+        tr._buffer = [b'da', b'ta']
+        m_write.return_value = 0
+        tr._write_ready()
+        m_write.assert_called_with(5, b'data')
+        self.loop.assert_writer(5, tr._write_ready)
+        self.assertEqual([b'data'], tr._buffer)
+
+    @unittest.mock.patch('asyncio.log.asyncio_log.exception')
+    @unittest.mock.patch('os.write')
+    def test__write_ready_err(self, m_write, m_logexc):
+        tr = unix_events._UnixWritePipeTransport(
+            self.loop, self.pipe, self.protocol)
+
+        self.loop.add_writer(5, tr._write_ready)
+        tr._buffer = [b'da', b'ta']
+        m_write.side_effect = err = OSError()
+        tr._write_ready()
+        m_write.assert_called_with(5, b'data')
+        self.assertFalse(self.loop.writers)
+        self.assertFalse(self.loop.readers)
+        self.assertEqual([], tr._buffer)
+        self.assertTrue(tr._closing)
+        m_logexc.assert_called_with('Fatal error for %s', tr)
+        self.assertEqual(1, tr._conn_lost)
+        test_utils.run_briefly(self.loop)
+        self.protocol.connection_lost.assert_called_with(err)
+
+    @unittest.mock.patch('os.write')
+    def test__write_ready_closing(self, m_write):
+        tr = unix_events._UnixWritePipeTransport(
+            self.loop, self.pipe, self.protocol)
+
+        self.loop.add_writer(5, tr._write_ready)
+        tr._closing = True
+        tr._buffer = [b'da', b'ta']
+        m_write.return_value = 4
+        tr._write_ready()
+        m_write.assert_called_with(5, b'data')
+        self.assertFalse(self.loop.writers)
+        self.assertFalse(self.loop.readers)
+        self.assertEqual([], tr._buffer)
+        self.protocol.connection_lost.assert_called_with(None)
+        self.pipe.close.assert_called_with()
+
+    @unittest.mock.patch('os.write')
+    def test_abort(self, m_write):
+        tr = unix_events._UnixWritePipeTransport(
+            self.loop, self.pipe, self.protocol)
+
+        self.loop.add_writer(5, tr._write_ready)
+        self.loop.add_reader(5, tr._read_ready)
+        tr._buffer = [b'da', b'ta']
+        tr.abort()
+        self.assertFalse(m_write.called)
+        self.assertFalse(self.loop.readers)
+        self.assertFalse(self.loop.writers)
+        self.assertEqual([], tr._buffer)
+        self.assertTrue(tr._closing)
+        test_utils.run_briefly(self.loop)
+        self.protocol.connection_lost.assert_called_with(None)
+
+    def test__call_connection_lost(self):
+        tr = unix_events._UnixWritePipeTransport(
+            self.loop, self.pipe, self.protocol)
+
+        err = None
+        tr._call_connection_lost(err)
+        self.protocol.connection_lost.assert_called_with(err)
+        self.pipe.close.assert_called_with()
+
+        self.assertIsNone(tr._protocol)
+        self.assertEqual(2, sys.getrefcount(self.protocol),
+                         pprint.pformat(gc.get_referrers(self.protocol)))
+        self.assertIsNone(tr._loop)
+        self.assertEqual(2, sys.getrefcount(self.loop),
+                         pprint.pformat(gc.get_referrers(self.loop)))
+
+    def test__call_connection_lost_with_err(self):
+        tr = unix_events._UnixWritePipeTransport(
+            self.loop, self.pipe, self.protocol)
+
+        err = OSError()
+        tr._call_connection_lost(err)
+        self.protocol.connection_lost.assert_called_with(err)
+        self.pipe.close.assert_called_with()
+
+        self.assertIsNone(tr._protocol)
+        self.assertEqual(2, sys.getrefcount(self.protocol),
+                         pprint.pformat(gc.get_referrers(self.protocol)))
+        self.assertIsNone(tr._loop)
+        self.assertEqual(2, sys.getrefcount(self.loop),
+                         pprint.pformat(gc.get_referrers(self.loop)))
+
+    def test_close(self):
+        tr = unix_events._UnixWritePipeTransport(
+            self.loop, self.pipe, self.protocol)
+
+        tr.write_eof = unittest.mock.Mock()
+        tr.close()
+        tr.write_eof.assert_called_with()
+
+    def test_close_closing(self):
+        tr = unix_events._UnixWritePipeTransport(
+            self.loop, self.pipe, self.protocol)
+
+        tr.write_eof = unittest.mock.Mock()
+        tr._closing = True
+        tr.close()
+        self.assertFalse(tr.write_eof.called)
+
+    def test_write_eof(self):
+        tr = unix_events._UnixWritePipeTransport(
+            self.loop, self.pipe, self.protocol)
+
+        tr.write_eof()
+        self.assertTrue(tr._closing)
+        self.assertFalse(self.loop.readers)
+        test_utils.run_briefly(self.loop)
+        self.protocol.connection_lost.assert_called_with(None)
+
+    def test_write_eof_pending(self):
+        tr = unix_events._UnixWritePipeTransport(
+            self.loop, self.pipe, self.protocol)
+        tr._buffer = [b'data']
+        tr.write_eof()
+        self.assertTrue(tr._closing)
+        self.assertFalse(self.protocol.connection_lost.called)