Merge Tulip into Trollius

21 files changed, 406 insertions, 41 deletions

diff --git a/Makefile b/Makefile
index 85ab9c8..768298b 100644
--- a/Makefile
+++ b/Makefile
@@ -44,9 +44,19 @@ clean:
 	rm -rf .tox
 
 
+# For distribution builders only!
 # Push a source distribution for Python 3.3 to PyPI.
 # You must update the version in setup.py first.
-# The corresponding action on Windows is pypi.bat.
-# A PyPI user configuration in ~/.pypirc is required.
+# A PyPI user configuration in ~/.pypirc is required;
+# you can create a suitable confifuration using
+#   python setup.py register
 pypi: clean
 	python3.3 setup.py sdist upload
+
+# The corresponding action on Windows is pypi.bat.  For that to work,
+# you need to install wheel and setuptools.  The easiest way is to get
+# pip using the get-pip.py script found here:
+# https://pip.pypa.io/en/latest/installing.html#install-pip 
+# That will install setuptools and pip; then you can just do
+#   \Python33\python.exe -m pip install wheel 
+# after which the pypi.bat script should work.
diff --git a/asyncio/base_events.py b/asyncio/base_events.py
index edbf598..4d5d831 100644
--- a/asyncio/base_events.py
+++ b/asyncio/base_events.py
@@ -262,6 +262,8 @@ class BaseEventLoop(events.AbstractEventLoop):
         """Like call_later(), but uses an absolute time."""
         if tasks.iscoroutinefunction(callback):
             raise TypeError("coroutines cannot be used with call_at()")
+        if self._debug:
+            self._assert_is_current_event_loop()
         timer = events.TimerHandle(when, callback, args, self)
         heapq.heappush(self._scheduled, timer)
         return timer
@@ -276,15 +278,34 @@ class BaseEventLoop(events.AbstractEventLoop):
         Any positional arguments after the callback will be passed to
         the callback when it is called.
         """
+        return self._call_soon(callback, args, check_loop=True)
+
+    def _call_soon(self, callback, args, check_loop):
         if tasks.iscoroutinefunction(callback):
             raise TypeError("coroutines cannot be used with call_soon()")
+        if self._debug and check_loop:
+            self._assert_is_current_event_loop()
         handle = events.Handle(callback, args, self)
         self._ready.append(handle)
         return handle
 
+    def _assert_is_current_event_loop(self):
+        """Asserts that this event loop is the current event loop.
+
+        Non-threadsafe methods of this class make this assumption and will
+        likely behave incorrectly when the assumption is violated.
+
+        Should only be called when (self._debug == True). The caller is
+        responsible for checking this condition for performance reasons.
+        """
+        if events.get_event_loop() is not self:
+            raise RuntimeError(
+                "non-threadsafe operation invoked on an event loop other "
+                "than the current one")
+
     def call_soon_threadsafe(self, callback, *args):
         """XXX"""
-        handle = self.call_soon(callback, *args)
+        handle = self._call_soon(callback, args, check_loop=False)
         self._write_to_self()
         return handle
 
@@ -768,11 +789,7 @@ class BaseEventLoop(events.AbstractEventLoop):
         elif self._scheduled:
             # Compute the desired timeout.
             when = self._scheduled[0]._when
-            deadline = max(0, when - self.time())
-            if timeout is None:
-                timeout = deadline
-            else:
-                timeout = min(timeout, deadline)
+            timeout = max(0, when - self.time())
 
         # TODO: Instrumentation only in debug mode?
         if logger.isEnabledFor(logging.INFO):
diff --git a/asyncio/coroutines.py b/asyncio/coroutines.py
index 307db56..a13f6b7 100644
--- a/asyncio/coroutines.py
+++ b/asyncio/coroutines.py
@@ -38,7 +38,7 @@ class Return(StopIteration):
 class CoroWrapper(object):
     # Wrapper for coroutine in _DEBUG mode.
 
-    __slots__ = ['gen', 'func', '__name__', '__doc__']
+    __slots__ = ['gen', 'func', '__name__', '__doc__', '__weakref__']
 
     def __init__(self, gen, func):
         assert inspect.isgenerator(gen), gen
@@ -52,7 +52,12 @@ class CoroWrapper(object):
         return next(self.gen)
     next = __next__
 
-    def send(self, value):
+    def send(self, *value):
+        # We use `*value` because of a bug in CPythons prior
+        # to 3.4.1. See issue #21209 and test_yield_from_corowrapper
+        # for details.  This workaround should be removed in 3.5.0.
+        if len(value) == 1:
+            value = value[0]
         return self.gen.send(value)
 
     def throw(self, exc):
@@ -61,8 +66,22 @@ class CoroWrapper(object):
     def close(self):
         return self.gen.close()
 
+    @property
+    def gi_frame(self):
+        return self.gen.gi_frame
+
+    @property
+    def gi_running(self):
+        return self.gen.gi_running
+
+    @property
+    def gi_code(self):
+        return self.gen.gi_code
+
     def __del__(self):
-        frame = self.gen.gi_frame
+        # Be careful accessing self.gen.frame -- self.gen might not exist.
+        gen = getattr(self, 'gen', None)
+        frame = getattr(gen, 'gi_frame', None)
         if frame is not None and frame.f_lasti == -1:
             func = self.func
             code = func.__code__
diff --git a/asyncio/events.py b/asyncio/events.py
index 6eb48dc..37a8647 100644
--- a/asyncio/events.py
+++ b/asyncio/events.py
@@ -17,7 +17,7 @@ import socket
 class Handle(object):
     """Object returned by callback registration methods."""
 
-    __slots__ = ['_callback', '_args', '_cancelled', '_loop']
+    __slots__ = ['_callback', '_args', '_cancelled', '_loop', '__weakref__']
 
     def __init__(self, callback, args, loop):
         assert not isinstance(callback, Handle), 'A Handle is not a callback'
diff --git a/asyncio/selector_events.py b/asyncio/selector_events.py
index e5e58f2..39e8ab8 100644
--- a/asyncio/selector_events.py
+++ b/asyncio/selector_events.py
@@ -109,10 +109,17 @@ class BaseSelectorEventLoop(base_events.BaseEventLoop):
             pass
 
     def _write_to_self(self):
-        try:
-            wrap_error(self._csock.send, b'x')
-        except (BlockingIOError, InterruptedError):
-            pass
+        # This may be called from a different thread, possibly after
+        # _close_self_pipe() has been called or even while it is
+        # running.  Guard for self._csock being None or closed.  When
+        # a socket is closed, send() raises OSError (with errno set to
+        # EBADF, but let's not rely on the exact error code).
+        csock = self._csock
+        if csock is not None:
+            try:
+                wrap_error(csock.send, b'x')
+            except OSError:
+                pass
 
     def _start_serving(self, protocol_factory, sock,
                        sslcontext=None, server=None):
diff --git a/asyncio/selectors.py b/asyncio/selectors.py
index 30f3c2e..ffd7555 100644
--- a/asyncio/selectors.py
+++ b/asyncio/selectors.py
@@ -446,6 +446,64 @@ if hasattr(select, 'epoll'):
             super(EpollSelector, self).close()
 
 
+if hasattr(select, 'devpoll'):
+
+    class DevpollSelector(_BaseSelectorImpl):
+        """Solaris /dev/poll selector."""
+
+        def __init__(self):
+            super().__init__()
+            self._devpoll = select.devpoll()
+
+        def fileno(self):
+            return self._devpoll.fileno()
+
+        def register(self, fileobj, events, data=None):
+            key = super().register(fileobj, events, data)
+            poll_events = 0
+            if events & EVENT_READ:
+                poll_events |= select.POLLIN
+            if events & EVENT_WRITE:
+                poll_events |= select.POLLOUT
+            self._devpoll.register(key.fd, poll_events)
+            return key
+
+        def unregister(self, fileobj):
+            key = super().unregister(fileobj)
+            self._devpoll.unregister(key.fd)
+            return key
+
+        def select(self, timeout=None):
+            if timeout is None:
+                timeout = None
+            elif timeout <= 0:
+                timeout = 0
+            else:
+                # devpoll() has a resolution of 1 millisecond, round away from
+                # zero to wait *at least* timeout seconds.
+                timeout = math.ceil(timeout * 1e3)
+            ready = []
+            try:
+                fd_event_list = self._devpoll.poll(timeout)
+            except InterruptedError:
+                return ready
+            for fd, event in fd_event_list:
+                events = 0
+                if event & ~select.POLLIN:
+                    events |= EVENT_WRITE
+                if event & ~select.POLLOUT:
+                    events |= EVENT_READ
+
+                key = self._key_from_fd(fd)
+                if key:
+                    ready.append((key, events & key.events))
+            return ready
+
+        def close(self):
+            self._devpoll.close()
+            super().close()
+
+
 if hasattr(select, 'kqueue'):
 
     class KqueueSelector(_BaseSelectorImpl):
@@ -519,12 +577,14 @@ if hasattr(select, 'kqueue'):
             super(KqueueSelector, self).close()
 
 
-# Choose the best implementation: roughly, epoll|kqueue > poll > select.
+# Choose the best implementation: roughly, epoll|kqueue|devpoll > poll > select.
 # select() also can't accept a FD > FD_SETSIZE (usually around 1024)
 if 'KqueueSelector' in globals():
     DefaultSelector = KqueueSelector
 elif 'EpollSelector' in globals():
     DefaultSelector = EpollSelector
+elif 'DevpollSelector' in globals():
+    DefaultSelector = DevpollSelector
 elif 'PollSelector' in globals():
     DefaultSelector = PollSelector
 else:
diff --git a/asyncio/streams.py b/asyncio/streams.py
index 85bdbd4..0860700 100644
--- a/asyncio/streams.py
+++ b/asyncio/streams.py
@@ -423,12 +423,17 @@ class StreamReader(object):
             raise Return(b'')
 
         if n < 0:
-            while not self._eof:
-                self._waiter = self._create_waiter('read')
-                try:
-                    yield From(self._waiter)
-                finally:
-                    self._waiter = None
+            # This used to just loop creating a new waiter hoping to
+            # collect everything in self._buffer, but that would
+            # deadlock if the subprocess sends more than self.limit
+            # bytes.  So just call self.read(self._limit) until EOF.
+            blocks = []
+            while True:
+                block = yield From(self.read(self._limit))
+                if not block:
+                    break
+                blocks.append(block)
+            raise Return(b''.join(blocks))
         else:
             if not self._buffer and not self._eof:
                 self._waiter = self._create_waiter('read')
diff --git a/asyncio/tasks.py b/asyncio/tasks.py
index aee7404..411182d 100644
--- a/asyncio/tasks.py
+++ b/asyncio/tasks.py
@@ -171,6 +171,25 @@ class Task(futures.Future):
                 print(line, file=file, end='')
 
     def cancel(self):
+        """Request that a task to cancel itself.
+
+        This arranges for a CancellationError to be thrown into the
+        wrapped coroutine on the next cycle through the event loop.
+        The coroutine then has a chance to clean up or even deny
+        the request using try/except/finally.
+
+        Contrary to Future.cancel(), this does not guarantee that the
+        task will be cancelled: the exception might be caught and
+        acted upon, delaying cancellation of the task or preventing it
+        completely.  The task may also return a value or raise a
+        different exception.
+
+        Immediately after this method is called, Task.cancelled() will
+        not return True (unless the task was already cancelled).  A
+        task will be marked as cancelled when the wrapped coroutine
+        terminates with a CancelledError exception (even if cancel()
+        was not called).
+        """
         if self.done():
             return False
         if self._fut_waiter is not None:
diff --git a/asyncio/unix_events.py b/asyncio/unix_events.py
index d87adef..758c7d5 100644
--- a/asyncio/unix_events.py
+++ b/asyncio/unix_events.py
@@ -218,6 +218,10 @@ class _UnixSelectorEventLoop(selector_events.BaseSelectorEventLoop):
             raise TypeError('ssl argument must be an SSLContext or None')
 
         if path is not None:
+            if sock is not None:
+                raise ValueError(
+                    'path and sock can not be specified at the same time')
+
             sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
 
             try:
diff --git a/examples/echo_client_tulip.py b/examples/echo_client_tulip.py
new file mode 100644
index 0000000..7d91e43
--- /dev/null
+++ b/examples/echo_client_tulip.py
@@ -0,0 +1,20 @@
+import asyncio
+from asyncio import From
+
+END = b'Bye-bye!\n'
+
+@asyncio.coroutine
+def echo_client():
+    reader, writer = yield From(asyncio.open_connection('localhost', 8000))
+    writer.write(b'Hello, world\n')
+    writer.write(b'What a fine day it is.\n')
+    writer.write(END)
+    while True:
+        line = yield From(reader.readline())
+        print('received:', line)
+        if line == END or not line:
+            break
+    writer.close()
+
+loop = asyncio.get_event_loop()
+loop.run_until_complete(echo_client())
diff --git a/examples/echo_server_tulip.py b/examples/echo_server_tulip.py
new file mode 100644
index 0000000..7b024de
--- /dev/null
+++ b/examples/echo_server_tulip.py
@@ -0,0 +1,18 @@
+import asyncio
+from asyncio import From
+
+@asyncio.coroutine
+def echo_server():
+    yield From(asyncio.start_server(handle_connection, 'localhost', 8000))
+
+@asyncio.coroutine
+def handle_connection(reader, writer):
+    while True:
+        data = yield From(reader.read(8192))
+        if not data:
+            break
+        writer.write(data)
+
+loop = asyncio.get_event_loop()
+loop.run_until_complete(echo_server())
+loop.run_forever()
diff --git a/examples/subprocess_attach_read_pipe.py b/examples/subprocess_attach_read_pipe.py
index 7df95aa..eeccfde 100644
--- a/examples/subprocess_attach_read_pipe.py
+++ b/examples/subprocess_attach_read_pipe.py
@@ -7,7 +7,7 @@ from asyncio import From
 code = """
 import os, sys
 fd = int(sys.argv[1])
-data = os.write(fd, b'data')
+os.write(fd, b'data')
 os.close(fd)
 """
 
diff --git a/runtests.py b/runtests.py
index 48ff215..66448ad 100644..100755
--- a/runtests.py
+++ b/runtests.py
@@ -25,6 +25,7 @@ import optparse
 import gc
 import logging
 import os
+import random
 import re
 import sys
 import textwrap
@@ -66,6 +67,12 @@ ARGS.add_option(
     '--findleaks', action='store_true', dest='findleaks',
     help='detect tests that leak memory')
 ARGS.add_option(
+    '-r', '--randomize', action='store_true',
+    help='randomize test execution order.')
+ARGS.add_option(
+    '--seed', type=int,
+    help='random seed to reproduce a previous random run')
+ARGS.add_option(
     '-q', action="store_true", dest='quiet', help='quiet')
 ARGS.add_option(
     '--tests', action="store", dest='testsdir', default='tests',
@@ -126,6 +133,14 @@ def load_modules(basedir, suffix='.py'):
     return mods
 
 
+def randomize_tests(tests, seed):
+    if seed is None:
+        seed = random.randrange(10000000)
+    random.seed(seed)
+    print("Using random seed", seed)
+    random.shuffle(tests._tests)
+
+
 class TestsFinder:
 
     def __init__(self, testsdir, includes=(), excludes=()):
@@ -267,12 +282,16 @@ def runtests():
         if args.forever:
             while True:
                 tests = finder.load_tests()
+                if args.randomize:
+                    randomize_tests(tests, args.seed)
                 result = runner_factory(verbosity=v,
                                         failfast=failfast).run(tests)
                 if not result.wasSuccessful():
                     sys.exit(1)
         else:
             tests = finder.load_tests()
+            if args.randomize:
+                randomize_tests(tests, args.seed)
             result = runner_factory(verbosity=v,
                                     failfast=failfast).run(tests)
             sys.exit(not result.wasSuccessful())
diff --git a/setup.cfg b/setup.cfg
deleted file mode 100644
index da2a775..0000000
--- a/setup.cfg
+++ /dev/null
@@ -1,2 +0,0 @@
-[build_ext]
-inplace = 1
diff --git a/tests/test_base_events.py b/tests/test_base_events.py
index 3c5adfe..b659199 100644
--- a/tests/test_base_events.py
+++ b/tests/test_base_events.py
@@ -138,6 +138,29 @@ class BaseEventLoopTests(test_utils.TestCase):
         # are really slow
         self.assertLessEqual(dt, 0.9, dt)
 
+    def test_assert_is_current_event_loop(self):
+        def cb():
+            pass
+
+        other_loop = base_events.BaseEventLoop()
+        other_loop._selector = mock.Mock()
+        asyncio.set_event_loop(other_loop)
+
+        # raise RuntimeError if the event loop is different in debug mode
+        self.loop.set_debug(True)
+        with self.assertRaises(RuntimeError):
+            self.loop.call_soon(cb)
+        with self.assertRaises(RuntimeError):
+            self.loop.call_later(60, cb)
+        with self.assertRaises(RuntimeError):
+            self.loop.call_at(self.loop.time() + 60, cb)
+
+        # check disabled if debug mode is disabled
+        self.loop.set_debug(False)
+        self.loop.call_soon(cb)
+        self.loop.call_later(60, cb)
+        self.loop.call_at(self.loop.time() + 60, cb)
+
     def test_run_once_in_executor_handle(self):
         def cb():
             pass
@@ -333,6 +356,7 @@ class BaseEventLoopTests(test_utils.TestCase):
     def test_default_exc_handler_coro(self):
         self.loop._process_events = mock.Mock()
         self.loop.set_debug(True)
+        asyncio.set_event_loop(self.loop)
 
         @asyncio.coroutine
         def zero_error_coro():
diff --git a/tests/test_events.py b/tests/test_events.py
index b882658..f1e57b3 100644
--- a/tests/test_events.py
+++ b/tests/test_events.py
@@ -13,6 +13,7 @@ import sys
 import threading
 import errno
 import unittest
+import weakref
 
 try:
     import ssl
@@ -714,6 +715,19 @@ class EventLoopTestsMixin(object):
         # close server
         server.close()
 
+    @unittest.skipUnless(hasattr(socket, 'AF_UNIX'), 'No UNIX Sockets')
+    def test_create_unix_server_path_socket_error(self):
+        proto = MyProto(loop=self.loop)
+        sock = socket.socket()
+        try:
+            f = self.loop.create_unix_server(lambda: proto, '/test', sock=sock)
+            with self.assertRaisesRegex(ValueError,
+                                        'path and sock can not be specified '
+                                        'at the same time'):
+                server = self.loop.run_until_complete(f)
+        finally:
+            sock.close()
+
     def _create_ssl_context(self, certfile, keyfile=None):
         sslcontext = asyncio.SSLContext(ssl.PROTOCOL_SSLv23)
         if not asyncio.BACKPORT_SSL_CONTEXT:
@@ -1797,6 +1811,11 @@ class HandleTests(test_utils.TestCase):
             'handle': h
         })
 
+    def test_handle_weakref(self):
+        wd = weakref.WeakValueDictionary()
+        h = asyncio.Handle(lambda: None, (), object())
+        wd['h'] = h  # Would fail without __weakref__ slot.
+
 
 class TimerTests(test_utils.TestCase):
 
diff --git a/tests/test_futures.py b/tests/test_futures.py
index fa23334..66ffc57 100644
--- a/tests/test_futures.py
+++ b/tests/test_futures.py
@@ -170,6 +170,7 @@ class FutureTests(test_utils.TestCase):
     @mock.patch('asyncio.base_events.logger')
     def test_tb_logger_exception_unretrieved(self, m_log):
         self.loop.set_debug(True)
+        asyncio.set_event_loop(self.loop)
         fut = asyncio.Future(loop=self.loop)
         fut.set_exception(RuntimeError('boom'))
         del fut
diff --git a/tests/test_selector_events.py b/tests/test_selector_events.py
index 52901d8..5df0d67 100644
--- a/tests/test_selector_events.py
+++ b/tests/test_selector_events.py
@@ -137,8 +137,9 @@ class BaseSelectorEventLoopTests(test_utils.TestCase):
         self.assertIsNone(self.loop._write_to_self())
 
     def test_write_to_self_exception(self):
-        self.loop._csock.send.side_effect = OSError()
-        self.assertRaises(OSError, self.loop._write_to_self)
+        # _write_to_self() swallows OSError
+        self.loop._csock.send.side_effect = RuntimeError()
+        self.assertRaises(RuntimeError, self.loop._write_to_self)
 
     def test_sock_recv(self):
         sock = mock.Mock()
diff --git a/tests/test_streams.py b/tests/test_streams.py
index 76f71e2..15a4303 100644
--- a/tests/test_streams.py
+++ b/tests/test_streams.py
@@ -1,7 +1,10 @@
 """Tests for streams.py."""
 
 import gc
+import io
+import os
 import socket
+import sys
 import unittest
 try:
     import ssl
@@ -10,6 +13,7 @@ except ImportError:
 
 import asyncio
 from asyncio import Return, From
+from asyncio import compat
 from asyncio import test_utils
 from asyncio.test_utils import mock
 
@@ -584,6 +588,46 @@ class StreamReaderTests(test_utils.TestCase):
             server.stop()
             self.assertEqual(msg, b"hello world!\n")
 
+    @unittest.skipIf(sys.platform == 'win32', "Don't have pipes")
+    def test_read_all_from_pipe_reader(self):
+        # See Tulip issue 168.  This test is derived from the example
+        # subprocess_attach_read_pipe.py, but we configure the
+        # StreamReader's limit so that twice it is less than the size
+        # of the data writter.  Also we must explicitly attach a child
+        # watcher to the event loop.
+
+        code = """\
+import os, sys
+fd = int(sys.argv[1])
+os.write(fd, b'data')
+os.close(fd)
+"""
+        rfd, wfd = os.pipe()
+        args = [sys.executable, '-c', code, str(wfd)]
+
+        pipe = io.open(rfd, 'rb', 0)
+        reader = asyncio.StreamReader(loop=self.loop, limit=1)
+        protocol = asyncio.StreamReaderProtocol(reader, loop=self.loop)
+        transport, _ = self.loop.run_until_complete(
+            self.loop.connect_read_pipe(lambda: protocol, pipe))
+
+        watcher = asyncio.SafeChildWatcher()
+        watcher.attach_loop(self.loop)
+        try:
+            asyncio.set_child_watcher(watcher)
+            kw = {'loop': self.loop}
+            if compat.PY3:
+                kw['pass_fds'] = set((wfd,))
+            proc = self.loop.run_until_complete(
+                asyncio.create_subprocess_exec(*args, **kw))
+            self.loop.run_until_complete(proc.wait())
+        finally:
+            asyncio.set_child_watcher(None)
+
+        os.close(wfd)
+        data = self.loop.run_until_complete(reader.read(-1))
+        self.assertEqual(data, b'data')
+
 
 if __name__ == '__main__':
     unittest.main()
diff --git a/tests/test_tasks.py b/tests/test_tasks.py
index 75fc71c..b4afabf 100644
--- a/tests/test_tasks.py
+++ b/tests/test_tasks.py
@@ -2,7 +2,9 @@
 
 import gc
 import os.path
+import types
 import unittest
+import weakref
 
 import asyncio
 from asyncio import From, Return
@@ -1367,23 +1369,102 @@ class TaskTests(test_utils.TestCase):
         self.assertRaises(ValueError, self.loop.run_until_complete,
             asyncio.wait([], loop=self.loop))
 
-    def test_yield_without_from(self):
-        old_debug = coroutines._DEBUG
+    def test_corowrapper_mocks_generator(self):
+
+        def check():
+            # A function that asserts various things.
+            # Called twice, with different debug flag values.
+
+            @asyncio.coroutine
+            def coro():
+                # The actual coroutine.
+                self.assertTrue(gen.gi_running)
+                yield From(fut)
+
+            # A completed Future used to run the coroutine.
+            fut = asyncio.Future(loop=self.loop)
+            fut.set_result(None)
+
+            # Call the coroutine.
+            gen = coro()
+
+            # Check some properties.
+            self.assertTrue(asyncio.iscoroutine(gen))
+            self.assertIsInstance(gen.gi_frame, types.FrameType)
+            self.assertFalse(gen.gi_running)
+            self.assertIsInstance(gen.gi_code, types.CodeType)
+
+            # Run it.
+            self.loop.run_until_complete(gen)
+
+            # The frame should have changed.
+            self.assertIsNone(gen.gi_frame)
+
+        # Save debug flag.
+        old_debug = asyncio.coroutines._DEBUG
+        try:
+            # Test with debug flag cleared.
+            asyncio.coroutines._DEBUG = False
+            check()
+
+            # Test with debug flag set.
+            asyncio.coroutines._DEBUG = True
+            check()
+
+        finally:
+            # Restore original debug flag.
+            asyncio.coroutines._DEBUG = old_debug
+
+    def test_yield_from_corowrapper(self):
+        old_debug = asyncio.coroutines._DEBUG
+        asyncio.coroutines._DEBUG = True
         try:
             @asyncio.coroutine
-            def task():
-                yield None
-                raise Return("done")
+            def t1():
+                res = yield From(t2())
+                raise Return(res)
+
+            @asyncio.coroutine
+            def t2():
+                f = asyncio.Future(loop=self.loop)
+                asyncio.Task(t3(f), loop=self.loop)
+                res = yield From(f)
+                raise Return(res)
 
-            coroutines._DEBUG = False
-            value = self.loop.run_until_complete(task())
-            self.assertEqual(value, "done")
+            @asyncio.coroutine
+            def t3(f):
+                f.set_result((1, 2, 3))
 
-            coroutines._DEBUG = True
-            self.assertRaises(RuntimeError,
-                              self.loop.run_until_complete, task())
+            task = asyncio.Task(t1(), loop=self.loop)
+            val = self.loop.run_until_complete(task)
+            self.assertEqual(val, (1, 2, 3))
         finally:
-            coroutines._DEBUG = old_debug
+            asyncio.coroutines._DEBUG = old_debug
+
+    def test_yield_from_corowrapper_send(self):
+        def foo():
+            a = yield
+            raise Return(a)
+
+        def call(arg):
+            cw = asyncio.coroutines.CoroWrapper(foo(), foo)
+            cw.send(None)
+            try:
+                cw.send(arg)
+            except Return as ex:
+                return ex.value
+            else:
+                raise AssertionError('StopIteration was expected')
+
+        self.assertEqual(call((1, 2)), (1, 2))
+        self.assertEqual(call('spam'), 'spam')
+
+    def test_corowrapper_weakref(self):
+        wd = weakref.WeakValueDictionary()
+        def foo(): yield From([])
+        cw = asyncio.coroutines.CoroWrapper(foo(), foo)
+        wd['cw'] = cw  # Would fail without __weakref__ slot.
+        cw.gen = None  # Suppress warning from __del__.
 
 
 class GatherTestsBase:
diff --git a/tests/test_unix_events.py b/tests/test_unix_events.py
index 4f0e6ce..86f7992 100644
--- a/tests/test_unix_events.py
+++ b/tests/test_unix_events.py
@@ -1345,7 +1345,6 @@ class ChildWatcherTestsMixin:
         with self.ignore_warnings:
             self.watcher._sig_chld()
 
-        callback.assert_called(m.waitpid)
         if isinstance(self.watcher, asyncio.FastChildWatcher):
             # here the FastChildWatche enters a deadlock
             # (there is no way to prevent it)