Port asyncio to Python 2, trollius/ directory

22 files changed, 1319 insertions, 785 deletions

diff --git a/trollius/__init__.py b/trollius/__init__.py
index 011466b..a1379fb 100644
--- a/trollius/__init__.py
+++ b/trollius/__init__.py
@@ -1,4 +1,4 @@
-"""The asyncio package, tracking PEP 3156."""
+"""The trollius package, tracking PEP 3156."""
 
 import sys
 
@@ -24,6 +24,7 @@ from .events import *
 from .futures import *
 from .locks import *
 from .protocols import *
+from .py33_exceptions import *
 from .queues import *
 from .streams import *
 from .subprocess import *
@@ -33,6 +34,7 @@ from .transports import *
 __all__ = (base_events.__all__ +
            coroutines.__all__ +
            events.__all__ +
+           py33_exceptions.__all__ +
            futures.__all__ +
            locks.__all__ +
            protocols.__all__ +
@@ -48,3 +50,10 @@ if sys.platform == 'win32':  # pragma: no cover
 else:
     from .unix_events import *  # pragma: no cover
     __all__ += unix_events.__all__
+
+try:
+    from .py3_ssl import *
+    __all__ += py3_ssl.__all__
+except ImportError:
+    # SSL support is optionnal
+    pass
diff --git a/trollius/base_events.py b/trollius/base_events.py
index 5a536a2..c8541f1 100644
--- a/trollius/base_events.py
+++ b/trollius/base_events.py
@@ -15,25 +15,34 @@ to modify the meaning of the API call itself.
 
 
 import collections
-import concurrent.futures
 import heapq
 import inspect
 import logging
 import os
 import socket
 import subprocess
-import threading
-import time
-import traceback
 import sys
-import warnings
-
+import traceback
+try:
+    from collections import OrderedDict
+except ImportError:
+    # Python 2.6: use ordereddict backport
+    from ordereddict import OrderedDict
+try:
+    from threading import get_ident as _get_thread_ident
+except ImportError:
+    # Python 2
+    from threading import _get_ident as _get_thread_ident
+
+from . import compat
 from . import coroutines
 from . import events
 from . import futures
 from . import tasks
-from .coroutines import coroutine
+from .coroutines import coroutine, From, Return
+from .executor import get_default_executor
 from .log import logger
+from .time_monotonic import time_monotonic, time_monotonic_resolution
 
 
 __all__ = ['BaseEventLoop']
@@ -171,10 +180,10 @@ class Server(events.AbstractServer):
     @coroutine
     def wait_closed(self):
         if self.sockets is None or self._waiters is None:
-            return
+            raise Return()
         waiter = futures.Future(loop=self._loop)
         self._waiters.append(waiter)
-        yield from waiter
+        yield From(waiter)
 
 
 class BaseEventLoop(events.AbstractEventLoop):
@@ -191,8 +200,7 @@ class BaseEventLoop(events.AbstractEventLoop):
         self._thread_id = None
         self._clock_resolution = time.get_clock_info('monotonic').resolution
         self._exception_handler = None
-        self.set_debug((not sys.flags.ignore_environment
-                        and bool(os.environ.get('PYTHONASYNCIODEBUG'))))
+        self.set_debug(bool(os.environ.get('TROLLIUSDEBUG')))
         # In debug mode, if the execution of a callback or a step of a task
         # exceed this duration in seconds, the slow callback/task is logged.
         self.slow_callback_duration = 0.1
@@ -237,13 +245,13 @@ class BaseEventLoop(events.AbstractEventLoop):
         """Return a task factory, or None if the default one is in use."""
         return self._task_factory
 
-    def _make_socket_transport(self, sock, protocol, waiter=None, *,
+    def _make_socket_transport(self, sock, protocol, waiter=None,
                                extra=None, server=None):
         """Create socket transport."""
         raise NotImplementedError
 
     def _make_ssl_transport(self, rawsock, protocol, sslcontext, waiter=None,
-                            *, server_side=False, server_hostname=None,
+                            server_side=False, server_hostname=None,
                             extra=None, server=None):
         """Create SSL transport."""
         raise NotImplementedError
@@ -506,7 +514,7 @@ class BaseEventLoop(events.AbstractEventLoop):
         if executor is None:
             executor = self._default_executor
             if executor is None:
-                executor = concurrent.futures.ThreadPoolExecutor(_MAX_WORKERS)
+                executor = get_default_executor()
                 self._default_executor = executor
         return futures.wrap_future(executor.submit(func, *args), loop=self)
 
@@ -538,7 +546,7 @@ class BaseEventLoop(events.AbstractEventLoop):
             logger.debug(msg)
         return addrinfo
 
-    def getaddrinfo(self, host, port, *,
+    def getaddrinfo(self, host, port,
                     family=0, type=0, proto=0, flags=0):
         if self._debug:
             return self.run_in_executor(None, self._getaddrinfo_debug,
@@ -551,7 +559,7 @@ class BaseEventLoop(events.AbstractEventLoop):
         return self.run_in_executor(None, socket.getnameinfo, sockaddr, flags)
 
     @coroutine
-    def create_connection(self, protocol_factory, host=None, port=None, *,
+    def create_connection(self, protocol_factory, host=None, port=None,
                           ssl=None, family=0, proto=0, flags=0, sock=None,
                           local_addr=None, server_hostname=None):
         """Connect to a TCP server.
@@ -601,15 +609,15 @@ class BaseEventLoop(events.AbstractEventLoop):
             else:
                 f2 = None
 
-            yield from tasks.wait(fs, loop=self)
+            yield From(tasks.wait(fs, loop=self))
 
             infos = f1.result()
             if not infos:
-                raise OSError('getaddrinfo() returned empty list')
+                raise socket.error('getaddrinfo() returned empty list')
             if f2 is not None:
                 laddr_infos = f2.result()
                 if not laddr_infos:
-                    raise OSError('getaddrinfo() returned empty list')
+                    raise socket.error('getaddrinfo() returned empty list')
 
             exceptions = []
             for family, type, proto, cname, address in infos:
@@ -621,11 +629,11 @@ class BaseEventLoop(events.AbstractEventLoop):
                             try:
                                 sock.bind(laddr)
                                 break
-                            except OSError as exc:
-                                exc = OSError(
+                            except socket.error as exc:
+                                exc = socket.error(
                                     exc.errno, 'error while '
                                     'attempting to bind on address '
-                                    '{!r}: {}'.format(
+                                    '{0!r}: {1}'.format(
                                         laddr, exc.strerror.lower()))
                                 exceptions.append(exc)
                         else:
@@ -634,8 +642,8 @@ class BaseEventLoop(events.AbstractEventLoop):
                             continue
                     if self._debug:
                         logger.debug("connect %r to %r", sock, address)
-                    yield from self.sock_connect(sock, address)
-                except OSError as exc:
+                    yield From(self.sock_connect(sock, address))
+                except socket.error as exc:
                     if sock is not None:
                         sock.close()
                     exceptions.append(exc)
@@ -655,7 +663,7 @@ class BaseEventLoop(events.AbstractEventLoop):
                         raise exceptions[0]
                     # Raise a combined exception so the user can see all
                     # the various error messages.
-                    raise OSError('Multiple exceptions: {}'.format(
+                    raise socket.error('Multiple exceptions: {0}'.format(
                         ', '.join(str(exc) for exc in exceptions)))
 
         elif sock is None:
@@ -664,15 +672,15 @@ class BaseEventLoop(events.AbstractEventLoop):
 
         sock.setblocking(False)
 
-        transport, protocol = yield from self._create_connection_transport(
-            sock, protocol_factory, ssl, server_hostname)
+        transport, protocol = yield From(self._create_connection_transport(
+            sock, protocol_factory, ssl, server_hostname))
         if self._debug:
             # Get the socket from the transport because SSL transport closes
             # the old socket and creates a new SSL socket
             sock = transport.get_extra_info('socket')
             logger.debug("%r connected to %s:%r: (%r, %r)",
                          sock, host, port, transport, protocol)
-        return transport, protocol
+        raise Return(transport, protocol)
 
     @coroutine
     def _create_connection_transport(self, sock, protocol_factory, ssl,
@@ -688,12 +696,12 @@ class BaseEventLoop(events.AbstractEventLoop):
             transport = self._make_socket_transport(sock, protocol, waiter)
 
         try:
-            yield from waiter
+            yield From(waiter)
         except:
             transport.close()
             raise
 
-        return transport, protocol
+        raise Return(transport, protocol)
 
     @coroutine
     def create_datagram_endpoint(self, protocol_factory,
@@ -706,17 +714,17 @@ class BaseEventLoop(events.AbstractEventLoop):
             addr_pairs_info = (((family, proto), (None, None)),)
         else:
             # join address by (family, protocol)
-            addr_infos = collections.OrderedDict()
+            addr_infos = OrderedDict()
             for idx, addr in ((0, local_addr), (1, remote_addr)):
                 if addr is not None:
                     assert isinstance(addr, tuple) and len(addr) == 2, (
                         '2-tuple is expected')
 
-                    infos = yield from self.getaddrinfo(
+                    infos = yield From(self.getaddrinfo(
                         *addr, family=family, type=socket.SOCK_DGRAM,
-                        proto=proto, flags=flags)
+                        proto=proto, flags=flags))
                     if not infos:
-                        raise OSError('getaddrinfo() returned empty list')
+                        raise socket.error('getaddrinfo() returned empty list')
 
                     for fam, _, pro, _, address in infos:
                         key = (fam, pro)
@@ -748,9 +756,9 @@ class BaseEventLoop(events.AbstractEventLoop):
                 if local_addr:
                     sock.bind(local_address)
                 if remote_addr:
-                    yield from self.sock_connect(sock, remote_address)
+                    yield From(self.sock_connect(sock, remote_address))
                     r_addr = remote_address
-            except OSError as exc:
+            except socket.error as exc:
                 if sock is not None:
                     sock.close()
                 exceptions.append(exc)
@@ -778,16 +786,15 @@ class BaseEventLoop(events.AbstractEventLoop):
                              remote_addr, transport, protocol)
 
         try:
-            yield from waiter
+            yield From(waiter)
         except:
             transport.close()
             raise
 
-        return transport, protocol
+        raise Return(transport, protocol)
 
     @coroutine
     def create_server(self, protocol_factory, host=None, port=None,
-                      *,
                       family=socket.AF_UNSPEC,
                       flags=socket.AI_PASSIVE,
                       sock=None,
@@ -814,11 +821,11 @@ class BaseEventLoop(events.AbstractEventLoop):
             if host == '':
                 host = None
 
-            infos = yield from self.getaddrinfo(
+            infos = yield From(self.getaddrinfo(
                 host, port, family=family,
-                type=socket.SOCK_STREAM, proto=0, flags=flags)
+                type=socket.SOCK_STREAM, proto=0, flags=flags))
             if not infos:
-                raise OSError('getaddrinfo() returned empty list')
+                raise socket.error('getaddrinfo() returned empty list')
 
             completed = False
             try:
@@ -846,10 +853,11 @@ class BaseEventLoop(events.AbstractEventLoop):
                                         True)
                     try:
                         sock.bind(sa)
-                    except OSError as err:
-                        raise OSError(err.errno, 'error while attempting '
-                                      'to bind on address %r: %s'
-                                      % (sa, err.strerror.lower()))
+                    except socket.error as err:
+                        raise socket.error(err.errno,
+                                           'error while attempting '
+                                           'to bind on address %r: %s'
+                                           % (sa, err.strerror.lower()))
                 completed = True
             finally:
                 if not completed:
@@ -867,7 +875,7 @@ class BaseEventLoop(events.AbstractEventLoop):
             self._start_serving(protocol_factory, sock, ssl, server)
         if self._debug:
             logger.info("%r is serving", server)
-        return server
+        raise Return(server)
 
     @coroutine
     def connect_read_pipe(self, protocol_factory, pipe):
@@ -876,7 +884,7 @@ class BaseEventLoop(events.AbstractEventLoop):
         transport = self._make_read_pipe_transport(pipe, protocol, waiter)
 
         try:
-            yield from waiter
+            yield From(waiter)
         except:
             transport.close()
             raise
@@ -884,7 +892,7 @@ class BaseEventLoop(events.AbstractEventLoop):
         if self._debug:
             logger.debug('Read pipe %r connected: (%r, %r)',
                          pipe.fileno(), transport, protocol)
-        return transport, protocol
+        raise Return(transport, protocol)
 
     @coroutine
     def connect_write_pipe(self, protocol_factory, pipe):
@@ -893,7 +901,7 @@ class BaseEventLoop(events.AbstractEventLoop):
         transport = self._make_write_pipe_transport(pipe, protocol, waiter)
 
         try:
-            yield from waiter
+            yield From(waiter)
         except:
             transport.close()
             raise
@@ -901,7 +909,7 @@ class BaseEventLoop(events.AbstractEventLoop):
         if self._debug:
             logger.debug('Write pipe %r connected: (%r, %r)',
                          pipe.fileno(), transport, protocol)
-        return transport, protocol
+        raise Return(transport, protocol)
 
     def _log_subprocess(self, msg, stdin, stdout, stderr):
         info = [msg]
@@ -917,11 +925,11 @@ class BaseEventLoop(events.AbstractEventLoop):
         logger.debug(' '.join(info))
 
     @coroutine
-    def subprocess_shell(self, protocol_factory, cmd, *, stdin=subprocess.PIPE,
+    def subprocess_shell(self, protocol_factory, cmd, stdin=subprocess.PIPE,
                          stdout=subprocess.PIPE, stderr=subprocess.PIPE,
                          universal_newlines=False, shell=True, bufsize=0,
                          **kwargs):
-        if not isinstance(cmd, (bytes, str)):
+        if not isinstance(cmd, compat.string_types):
             raise ValueError("cmd must be a string")
         if universal_newlines:
             raise ValueError("universal_newlines must be False")
@@ -935,17 +943,20 @@ class BaseEventLoop(events.AbstractEventLoop):
             # (password) and may be too long
             debug_log = 'run shell command %r' % cmd
             self._log_subprocess(debug_log, stdin, stdout, stderr)
-        transport = yield from self._make_subprocess_transport(
-            protocol, cmd, True, stdin, stdout, stderr, bufsize, **kwargs)
+        transport = yield From(self._make_subprocess_transport(
+            protocol, cmd, True, stdin, stdout, stderr, bufsize, **kwargs))
         if self._debug:
             logger.info('%s: %r' % (debug_log, transport))
-        return transport, protocol
+        raise Return(transport, protocol)
 
     @coroutine
-    def subprocess_exec(self, protocol_factory, program, *args,
-                        stdin=subprocess.PIPE, stdout=subprocess.PIPE,
-                        stderr=subprocess.PIPE, universal_newlines=False,
-                        shell=False, bufsize=0, **kwargs):
+    def subprocess_exec(self, protocol_factory, program, *args, **kwargs):
+        stdin = kwargs.pop('stdin', subprocess.PIPE)
+        stdout = kwargs.pop('stdout', subprocess.PIPE)
+        stderr = kwargs.pop('stderr', subprocess.PIPE)
+        universal_newlines = kwargs.pop('universal_newlines', False)
+        shell = kwargs.pop('shell', False)
+        bufsize = kwargs.pop('bufsize', 0)
         if universal_newlines:
             raise ValueError("universal_newlines must be False")
         if shell:
@@ -954,7 +965,7 @@ class BaseEventLoop(events.AbstractEventLoop):
             raise ValueError("bufsize must be 0")
         popen_args = (program,) + args
         for arg in popen_args:
-            if not isinstance(arg, (str, bytes)):
+            if not isinstance(arg, compat.string_types ):
                 raise TypeError("program arguments must be "
                                 "a bytes or text string, not %s"
                                 % type(arg).__name__)
@@ -964,12 +975,12 @@ class BaseEventLoop(events.AbstractEventLoop):
             # (password) and may be too long
             debug_log = 'execute program %r' % program
             self._log_subprocess(debug_log, stdin, stdout, stderr)
-        transport = yield from self._make_subprocess_transport(
+        transport = yield From(self._make_subprocess_transport(
             protocol, popen_args, False, stdin, stdout, stderr,
-            bufsize, **kwargs)
+            bufsize, **kwargs))
         if self._debug:
             logger.info('%s: %r' % (debug_log, transport))
-        return transport, protocol
+        raise Return(transport, protocol)
 
     def set_exception_handler(self, handler):
         """Set handler as the new event loop exception handler.
@@ -985,7 +996,7 @@ class BaseEventLoop(events.AbstractEventLoop):
         """
         if handler is not None and not callable(handler):
             raise TypeError('A callable object or None is expected, '
-                            'got {!r}'.format(handler))
+                            'got {0!r}'.format(handler))
         self._exception_handler = handler
 
     def default_exception_handler(self, context):
@@ -1004,7 +1015,15 @@ class BaseEventLoop(events.AbstractEventLoop):
 
         exception = context.get('exception')
         if exception is not None:
-            exc_info = (type(exception), exception, exception.__traceback__)
+            if hasattr(exception, '__traceback__'):
+                # Python 3
+                tb = exception.__traceback__
+            else:
+                # call_exception_handler() is usually called indirectly
+                # from an except block. If it's not the case, the traceback
+                # is undefined...
+                tb = sys.exc_info()[2]
+            exc_info = (type(exception), exception, tb)
         else:
             exc_info = False
 
@@ -1015,7 +1034,7 @@ class BaseEventLoop(events.AbstractEventLoop):
 
         log_lines = [message]
         for key in sorted(context):
-            if key in {'message', 'exception'}:
+            if key in ('message', 'exception'):
                 continue
             value = context[key]
             if key == 'source_traceback':
@@ -1028,7 +1047,7 @@ class BaseEventLoop(events.AbstractEventLoop):
                 value += tb.rstrip()
             else:
                 value = repr(value)
-            log_lines.append('{}: {}'.format(key, value))
+            log_lines.append('{0}: {1}'.format(key, value))
 
         logger.error('\n'.join(log_lines), exc_info=exc_info)
 
@@ -1108,7 +1127,7 @@ class BaseEventLoop(events.AbstractEventLoop):
 
         sched_count = len(self._scheduled)
         if (sched_count > _MIN_SCHEDULED_TIMER_HANDLES and
-            self._timer_cancelled_count / sched_count >
+            float(self._timer_cancelled_count) / sched_count >
                 _MIN_CANCELLED_TIMER_HANDLES_FRACTION):
             # Remove delayed calls that were cancelled if their number
             # is too high
diff --git a/trollius/base_subprocess.py b/trollius/base_subprocess.py
index c1477b8..d3a6465 100644
--- a/trollius/base_subprocess.py
+++ b/trollius/base_subprocess.py
@@ -6,7 +6,7 @@ import warnings
 from . import futures
 from . import protocols
 from . import transports
-from .coroutines import coroutine
+from .coroutines import coroutine, From
 from .log import logger
 
 
@@ -15,7 +15,7 @@ class BaseSubprocessTransport(transports.SubprocessTransport):
     def __init__(self, loop, protocol, args, shell,
                  stdin, stdout, stderr, bufsize,
                  waiter=None, extra=None, **kwargs):
-        super().__init__(extra)
+        super(BaseSubprocessTransport, self).__init__(extra)
         self._closed = False
         self._protocol = protocol
         self._loop = loop
@@ -221,7 +221,8 @@ class BaseSubprocessTransport(transports.SubprocessTransport):
 
         waiter = futures.Future(loop=self._loop)
         self._exit_waiters.append(waiter)
-        return (yield from waiter)
+        returncode = yield From(waiter)
+        return returncode
 
     def _try_finish(self):
         assert not self._finished
diff --git a/trollius/coroutines.py b/trollius/coroutines.py
index 15475f2..b12ca3e 100644
--- a/trollius/coroutines.py
+++ b/trollius/coroutines.py
@@ -9,6 +9,7 @@ import sys
 import traceback
 import types
 
+from . import compat
 from . import events
 from . import futures
 from .log import logger
@@ -18,7 +19,7 @@ _PY35 = sys.version_info >= (3, 5)
 
 
 # Opcode of "yield from" instruction
-_YIELD_FROM = opcode.opmap['YIELD_FROM']
+_YIELD_FROM = opcode.opmap.get('YIELD_FROM', None)
 
 # If you set _DEBUG to true, @coroutine will wrap the resulting
 # generator objects in a CoroWrapper instance (defined below).  That
@@ -29,8 +30,7 @@ _YIELD_FROM = opcode.opmap['YIELD_FROM']
 # before you define your coroutines.  A downside of using this feature
 # is that tracebacks show entries for the CoroWrapper.__next__ method
 # when _DEBUG is true.
-_DEBUG = (not sys.flags.ignore_environment
-          and bool(os.environ.get('PYTHONASYNCIODEBUG')))
+_DEBUG = bool(os.environ.get('TROLLIUSDEBUG'))
 
 
 try:
@@ -74,6 +74,53 @@ _YIELD_FROM_BUG = has_yield_from_bug()
 del has_yield_from_bug
 
 
+if compat.PY33:
+    # Don't use the Return class on Python 3.3 and later to support asyncio
+    # coroutines (to avoid the warning emited in Return destructor).
+    #
+    # The problem is that Return inherits from StopIteration.  "yield from
+    # trollius_coroutine". Task._step() does not receive the Return exception,
+    # because "yield from" handles it internally. So it's not possible to set
+    # the raised attribute to True to avoid the warning in Return destructor.
+    def Return(*args):
+        if not args:
+            value = None
+        elif len(args) == 1:
+            value = args[0]
+        else:
+            value = args
+        return StopIteration(value)
+else:
+    class Return(StopIteration):
+        def __init__(self, *args):
+            StopIteration.__init__(self)
+            if not args:
+                self.value = None
+            elif len(args) == 1:
+                self.value = args[0]
+            else:
+                self.value = args
+            self.raised = False
+            if _DEBUG:
+                frame = sys._getframe(1)
+                self._source_traceback = traceback.extract_stack(frame)
+                # explicitly clear the reference to avoid reference cycles
+                frame = None
+            else:
+                self._source_traceback = None
+
+        def __del__(self):
+            if self.raised:
+                return
+
+            fmt = 'Return(%r) used without raise'
+            if self._source_traceback:
+                fmt += '\nReturn created at (most recent call last):\n'
+                tb = ''.join(traceback.format_list(self._source_traceback))
+                fmt += tb.rstrip()
+            logger.error(fmt, self.value)
+
+
 def debug_wrapper(gen):
     # This function is called from 'sys.set_coroutine_wrapper'.
     # We only wrap here coroutines defined via 'async def' syntax.
@@ -104,7 +151,8 @@ class CoroWrapper:
         return self
 
     def __next__(self):
-        return self.gen.send(None)
+        return next(self.gen)
+    next = __next__
 
     if _YIELD_FROM_BUG:
         # For for CPython issue #21209: using "yield from" and a custom
@@ -180,6 +228,56 @@ class CoroWrapper:
                 msg += tb.rstrip()
             logger.error(msg)
 
+if not compat.PY34:
+    # Backport functools.update_wrapper() from Python 3.4:
+    # - Python 2.7 fails if assigned attributes don't exist
+    # - Python 2.7 and 3.1 don't set the __wrapped__ attribute
+    # - Python 3.2 and 3.3 set __wrapped__ before updating __dict__
+    def _update_wrapper(wrapper,
+                       wrapped,
+                       assigned = functools.WRAPPER_ASSIGNMENTS,
+                       updated = functools.WRAPPER_UPDATES):
+        """Update a wrapper function to look like the wrapped function
+
+           wrapper is the function to be updated
+           wrapped is the original function
+           assigned is a tuple naming the attributes assigned directly
+           from the wrapped function to the wrapper function (defaults to
+           functools.WRAPPER_ASSIGNMENTS)
+           updated is a tuple naming the attributes of the wrapper that
+           are updated with the corresponding attribute from the wrapped
+           function (defaults to functools.WRAPPER_UPDATES)
+        """
+        for attr in assigned:
+            try:
+                value = getattr(wrapped, attr)
+            except AttributeError:
+                pass
+            else:
+                setattr(wrapper, attr, value)
+        for attr in updated:
+            getattr(wrapper, attr).update(getattr(wrapped, attr, {}))
+        # Issue #17482: set __wrapped__ last so we don't inadvertently copy it
+        # from the wrapped function when updating __dict__
+        wrapper.__wrapped__ = wrapped
+        # Return the wrapper so this can be used as a decorator via partial()
+        return wrapper
+
+    def _wraps(wrapped,
+              assigned = functools.WRAPPER_ASSIGNMENTS,
+              updated = functools.WRAPPER_UPDATES):
+        """Decorator factory to apply update_wrapper() to a wrapper function
+
+           Returns a decorator that invokes update_wrapper() with the decorated
+           function as the wrapper argument and the arguments to wraps() as the
+           remaining arguments. Default arguments are as for update_wrapper().
+           This is a convenience function to simplify applying partial() to
+           update_wrapper().
+        """
+        return functools.partial(_update_wrapper, wrapped=wrapped,
+                                 assigned=assigned, updated=updated)
+else:
+    _wraps = functools.wraps
 
 def coroutine(func):
     """Decorator to mark coroutines.
@@ -197,7 +295,7 @@ def coroutine(func):
     if inspect.isgeneratorfunction(func):
         coro = func
     else:
-        @functools.wraps(func)
+        @_wraps(func)
         def coro(*args, **kw):
             res = func(*args, **kw)
             if isinstance(res, futures.Future) or inspect.isgenerator(res):
@@ -220,7 +318,7 @@ def coroutine(func):
         else:
             wrapper = _types_coroutine(coro)
     else:
-        @functools.wraps(func)
+        @_wraps(func)
         def wrapper(*args, **kwds):
             w = CoroWrapper(coro(*args, **kwds), func=func)
             if w._source_traceback:
@@ -246,7 +344,13 @@ def iscoroutinefunction(func):
 _COROUTINE_TYPES = (types.GeneratorType, CoroWrapper)
 if _CoroutineABC is not None:
     _COROUTINE_TYPES += (_CoroutineABC,)
-
+if events.asyncio is not None:
+    # Accept also asyncio CoroWrapper for interoperability
+    if hasattr(events.asyncio, 'coroutines'):
+        _COROUTINE_TYPES += (events.asyncio.coroutines.CoroWrapper,)
+    else:
+        # old Tulip/Python versions
+        _COROUTINE_TYPES += (events.asyncio.tasks.CoroWrapper,)
 
 def iscoroutine(obj):
     """Return True if obj is a coroutine object."""
@@ -299,3 +403,19 @@ def _format_coroutine(coro):
                      % (coro_name, filename, lineno))
 
     return coro_repr
+
+
+class FromWrapper(object):
+    __slots__ = ('obj',)
+
+    def __init__(self, obj):
+        if isinstance(obj, FromWrapper):
+            obj = obj.obj
+            assert not isinstance(obj, FromWrapper)
+        self.obj = obj
+
+def From(obj):
+    if not _DEBUG:
+        return obj
+    else:
+        return FromWrapper(obj)
diff --git a/trollius/events.py b/trollius/events.py
index 496075b..3aa5b69 100644
--- a/trollius/events.py
+++ b/trollius/events.py
@@ -10,12 +10,23 @@ __all__ = ['AbstractEventLoopPolicy',
 
 import functools
 import inspect
-import reprlib
 import socket
 import subprocess
 import sys
 import threading
 import traceback
+try:
+    import reprlib   # Python 3
+except ImportError:
+    import repr as reprlib   # Python 2
+
+from trollius import compat
+try:
+    import asyncio
+except (ImportError, SyntaxError):
+    # ignore SyntaxError for convenience: ignore SyntaxError caused by "yield
+    # from" if asyncio module is in the Python path
+    asyncio = None
 
 
 _PY34 = sys.version_info >= (3, 4)
@@ -75,7 +86,7 @@ def _format_callback_source(func, args):
     return func_repr
 
 
-class Handle:
+class Handle(object):
     """Object returned by callback registration methods."""
 
     __slots__ = ('_callback', '_args', '_cancelled', '_loop',
@@ -145,14 +156,14 @@ class TimerHandle(Handle):
 
     def __init__(self, when, callback, args, loop):
         assert when is not None
-        super().__init__(callback, args, loop)
+        super(TimerHandle, self).__init__(callback, args, loop)
         if self._source_traceback:
             del self._source_traceback[-1]
         self._when = when
         self._scheduled = False
 
     def _repr_info(self):
-        info = super()._repr_info()
+        info = super(TimerHandle, self)._repr_info()
         pos = 2 if self._cancelled else 1
         info.insert(pos, 'when=%s' % self._when)
         return info
@@ -191,10 +202,10 @@ class TimerHandle(Handle):
     def cancel(self):
         if not self._cancelled:
             self._loop._timer_handle_cancelled(self)
-        super().cancel()
+        super(TimerHandle, self).cancel()
 
 
-class AbstractServer:
+class AbstractServer(object):
     """Abstract server returned by create_server()."""
 
     def close(self):
@@ -206,298 +217,303 @@ class AbstractServer:
         return NotImplemented
 
 
-class AbstractEventLoop:
-    """Abstract event loop."""
+if asyncio is not None:
+    # Reuse asyncio classes so asyncio.set_event_loop() and
+    # asyncio.set_event_loop_policy() accept Trollius event loop and trollius
+    # event loop policy
+    AbstractEventLoop = asyncio.AbstractEventLoop
+    AbstractEventLoopPolicy = asyncio.AbstractEventLoopPolicy
+else:
+    class AbstractEventLoop(object):
+        """Abstract event loop."""
 
-    # Running and stopping the event loop.
+        # Running and stopping the event loop.
 
-    def run_forever(self):
-        """Run the event loop until stop() is called."""
-        raise NotImplementedError
+        def run_forever(self):
+            """Run the event loop until stop() is called."""
+            raise NotImplementedError
 
-    def run_until_complete(self, future):
-        """Run the event loop until a Future is done.
+        def run_until_complete(self, future):
+            """Run the event loop until a Future is done.
 
-        Return the Future's result, or raise its exception.
-        """
-        raise NotImplementedError
+            Return the Future's result, or raise its exception.
+            """
+            raise NotImplementedError
 
-    def stop(self):
-        """Stop the event loop as soon as reasonable.
+        def stop(self):
+            """Stop the event loop as soon as reasonable.
 
-        Exactly how soon that is may depend on the implementation, but
-        no more I/O callbacks should be scheduled.
-        """
-        raise NotImplementedError
+            Exactly how soon that is may depend on the implementation, but
+            no more I/O callbacks should be scheduled.
+            """
+            raise NotImplementedError
 
-    def is_running(self):
-        """Return whether the event loop is currently running."""
-        raise NotImplementedError
+        def is_running(self):
+            """Return whether the event loop is currently running."""
+            raise NotImplementedError
 
-    def is_closed(self):
-        """Returns True if the event loop was closed."""
-        raise NotImplementedError
+        def is_closed(self):
+            """Returns True if the event loop was closed."""
+            raise NotImplementedError
 
-    def close(self):
-        """Close the loop.
+        def close(self):
+            """Close the loop.
 
-        The loop should not be running.
+            The loop should not be running.
 
-        This is idempotent and irreversible.
+            This is idempotent and irreversible.
 
-        No other methods should be called after this one.
-        """
-        raise NotImplementedError
+            No other methods should be called after this one.
+            """
+            raise NotImplementedError
 
-    # Methods scheduling callbacks.  All these return Handles.
+        # Methods scheduling callbacks.  All these return Handles.
 
-    def _timer_handle_cancelled(self, handle):
-        """Notification that a TimerHandle has been cancelled."""
-        raise NotImplementedError
+        def _timer_handle_cancelled(self, handle):
+            """Notification that a TimerHandle has been cancelled."""
+            raise NotImplementedError
 
-    def call_soon(self, callback, *args):
-        return self.call_later(0, callback, *args)
+        def call_soon(self, callback, *args):
+            return self.call_later(0, callback, *args)
 
-    def call_later(self, delay, callback, *args):
-        raise NotImplementedError
+        def call_later(self, delay, callback, *args):
+            raise NotImplementedError
 
-    def call_at(self, when, callback, *args):
-        raise NotImplementedError
+        def call_at(self, when, callback, *args):
+            raise NotImplementedError
 
-    def time(self):
-        raise NotImplementedError
+        def time(self):
+            raise NotImplementedError
 
-    # Method scheduling a coroutine object: create a task.
+        # Method scheduling a coroutine object: create a task.
 
-    def create_task(self, coro):
-        raise NotImplementedError
+        def create_task(self, coro):
+            raise NotImplementedError
 
-    # Methods for interacting with threads.
+        # Methods for interacting with threads.
 
-    def call_soon_threadsafe(self, callback, *args):
-        raise NotImplementedError
+        def call_soon_threadsafe(self, callback, *args):
+            raise NotImplementedError
 
-    def run_in_executor(self, executor, func, *args):
-        raise NotImplementedError
+        def run_in_executor(self, executor, func, *args):
+            raise NotImplementedError
 
-    def set_default_executor(self, executor):
-        raise NotImplementedError
+        def set_default_executor(self, executor):
+            raise NotImplementedError
 
-    # Network I/O methods returning Futures.
+        # Network I/O methods returning Futures.
 
-    def getaddrinfo(self, host, port, *, family=0, type=0, proto=0, flags=0):
-        raise NotImplementedError
+        def getaddrinfo(self, host, port, family=0, type=0, proto=0, flags=0):
+            raise NotImplementedError
 
-    def getnameinfo(self, sockaddr, flags=0):
-        raise NotImplementedError
+        def getnameinfo(self, sockaddr, flags=0):
+            raise NotImplementedError
 
-    def create_connection(self, protocol_factory, host=None, port=None, *,
-                          ssl=None, family=0, proto=0, flags=0, sock=None,
-                          local_addr=None, server_hostname=None):
-        raise NotImplementedError
+        def create_connection(self, protocol_factory, host=None, port=None,
+                              ssl=None, family=0, proto=0, flags=0, sock=None,
+                              local_addr=None, server_hostname=None):
+            raise NotImplementedError
 
-    def create_server(self, protocol_factory, host=None, port=None, *,
-                      family=socket.AF_UNSPEC, flags=socket.AI_PASSIVE,
-                      sock=None, backlog=100, ssl=None, reuse_address=None):
-        """A coroutine which creates a TCP server bound to host and port.
+        def create_server(self, protocol_factory, host=None, port=None,
+                          family=socket.AF_UNSPEC, flags=socket.AI_PASSIVE,
+                          sock=None, backlog=100, ssl=None, reuse_address=None):
+            """A coroutine which creates a TCP server bound to host and port.
 
-        The return value is a Server object which can be used to stop
-        the service.
+            The return value is a Server object which can be used to stop
+            the service.
 
-        If host is an empty string or None all interfaces are assumed
-        and a list of multiple sockets will be returned (most likely
-        one for IPv4 and another one for IPv6).
+            If host is an empty string or None all interfaces are assumed
+            and a list of multiple sockets will be returned (most likely
+            one for IPv4 and another one for IPv6).
 
-        family can be set to either AF_INET or AF_INET6 to force the
-        socket to use IPv4 or IPv6. If not set it will be determined
-        from host (defaults to AF_UNSPEC).
+            family can be set to either AF_INET or AF_INET6 to force the
+            socket to use IPv4 or IPv6. If not set it will be determined
+            from host (defaults to AF_UNSPEC).
 
-        flags is a bitmask for getaddrinfo().
+            flags is a bitmask for getaddrinfo().
 
-        sock can optionally be specified in order to use a preexisting
-        socket object.
+            sock can optionally be specified in order to use a preexisting
+            socket object.
 
-        backlog is the maximum number of queued connections passed to
-        listen() (defaults to 100).
+            backlog is the maximum number of queued connections passed to
+            listen() (defaults to 100).
 
-        ssl can be set to an SSLContext to enable SSL over the
-        accepted connections.
+            ssl can be set to an SSLContext to enable SSL over the
+            accepted connections.
 
-        reuse_address tells the kernel to reuse a local socket in
-        TIME_WAIT state, without waiting for its natural timeout to
-        expire. If not specified will automatically be set to True on
-        UNIX.
-        """
-        raise NotImplementedError
+            reuse_address tells the kernel to reuse a local socket in
+            TIME_WAIT state, without waiting for its natural timeout to
+            expire. If not specified will automatically be set to True on
+            UNIX.
+            """
+            raise NotImplementedError
 
-    def create_unix_connection(self, protocol_factory, path, *,
-                               ssl=None, sock=None,
-                               server_hostname=None):
-        raise NotImplementedError
+        def create_unix_connection(self, protocol_factory, path,
+                                   ssl=None, sock=None,
+                                   server_hostname=None):
+            raise NotImplementedError
 
-    def create_unix_server(self, protocol_factory, path, *,
-                           sock=None, backlog=100, ssl=None):
-        """A coroutine which creates a UNIX Domain Socket server.
+        def create_unix_server(self, protocol_factory, path,
+                               sock=None, backlog=100, ssl=None):
+            """A coroutine which creates a UNIX Domain Socket server.
 
-        The return value is a Server object, which can be used to stop
-        the service.
+            The return value is a Server object, which can be used to stop
+            the service.
 
-        path is a str, representing a file systsem path to bind the
-        server socket to.
+            path is a str, representing a file systsem path to bind the
+            server socket to.
 
-        sock can optionally be specified in order to use a preexisting
-        socket object.
+            sock can optionally be specified in order to use a preexisting
+            socket object.
 
-        backlog is the maximum number of queued connections passed to
-        listen() (defaults to 100).
+            backlog is the maximum number of queued connections passed to
+            listen() (defaults to 100).
 
-        ssl can be set to an SSLContext to enable SSL over the
-        accepted connections.
-        """
-        raise NotImplementedError
+            ssl can be set to an SSLContext to enable SSL over the
+            accepted connections.
+            """
+            raise NotImplementedError
 
-    def create_datagram_endpoint(self, protocol_factory,
-                                 local_addr=None, remote_addr=None, *,
-                                 family=0, proto=0, flags=0):
-        raise NotImplementedError
+        def create_datagram_endpoint(self, protocol_factory,
+                                     local_addr=None, remote_addr=None,
+                                     family=0, proto=0, flags=0):
+            raise NotImplementedError
 
-    # Pipes and subprocesses.
+        # Pipes and subprocesses.
 
-    def connect_read_pipe(self, protocol_factory, pipe):
-        """Register read pipe in event loop. Set the pipe to non-blocking mode.
+        def connect_read_pipe(self, protocol_factory, pipe):
+            """Register read pipe in event loop. Set the pipe to non-blocking mode.
 
-        protocol_factory should instantiate object with Protocol interface.
-        pipe is a file-like object.
-        Return pair (transport, protocol), where transport supports the
-        ReadTransport interface."""
-        # The reason to accept file-like object instead of just file descriptor
-        # is: we need to own pipe and close it at transport finishing
-        # Can got complicated errors if pass f.fileno(),
-        # close fd in pipe transport then close f and vise versa.
-        raise NotImplementedError
+            protocol_factory should instantiate object with Protocol interface.
+            pipe is a file-like object.
+            Return pair (transport, protocol), where transport supports the
+            ReadTransport interface."""
+            # The reason to accept file-like object instead of just file descriptor
+            # is: we need to own pipe and close it at transport finishing
+            # Can got complicated errors if pass f.fileno(),
+            # close fd in pipe transport then close f and vise versa.
+            raise NotImplementedError
 
-    def connect_write_pipe(self, protocol_factory, pipe):
-        """Register write pipe in event loop.
+        def connect_write_pipe(self, protocol_factory, pipe):
+            """Register write pipe in event loop.
 
-        protocol_factory should instantiate object with BaseProtocol interface.
-        Pipe is file-like object already switched to nonblocking.
-        Return pair (transport, protocol), where transport support
-        WriteTransport interface."""
-        # The reason to accept file-like object instead of just file descriptor
-        # is: we need to own pipe and close it at transport finishing
-        # Can got complicated errors if pass f.fileno(),
-        # close fd in pipe transport then close f and vise versa.
-        raise NotImplementedError
+            protocol_factory should instantiate object with BaseProtocol interface.
+            Pipe is file-like object already switched to nonblocking.
+            Return pair (transport, protocol), where transport support
+            WriteTransport interface."""
+            # The reason to accept file-like object instead of just file descriptor
+            # is: we need to own pipe and close it at transport finishing
+            # Can got complicated errors if pass f.fileno(),
+            # close fd in pipe transport then close f and vise versa.
+            raise NotImplementedError
 
-    def subprocess_shell(self, protocol_factory, cmd, *, stdin=subprocess.PIPE,
-                         stdout=subprocess.PIPE, stderr=subprocess.PIPE,
-                         **kwargs):
-        raise NotImplementedError
+        def subprocess_shell(self, protocol_factory, cmd, stdin=subprocess.PIPE,
+                             stdout=subprocess.PIPE, stderr=subprocess.PIPE,
+                             **kwargs):
+            raise NotImplementedError
 
-    def subprocess_exec(self, protocol_factory, *args, stdin=subprocess.PIPE,
-                        stdout=subprocess.PIPE, stderr=subprocess.PIPE,
-                        **kwargs):
-        raise NotImplementedError
+        def subprocess_exec(self, protocol_factory, *args, **kwargs):
+            raise NotImplementedError
 
-    # Ready-based callback registration methods.
-    # The add_*() methods return None.
-    # The remove_*() methods return True if something was removed,
-    # False if there was nothing to delete.
+        # Ready-based callback registration methods.
+        # The add_*() methods return None.
+        # The remove_*() methods return True if something was removed,
+        # False if there was nothing to delete.
 
-    def add_reader(self, fd, callback, *args):
-        raise NotImplementedError
+        def add_reader(self, fd, callback, *args):
+            raise NotImplementedError
 
-    def remove_reader(self, fd):
-        raise NotImplementedError
+        def remove_reader(self, fd):
+            raise NotImplementedError
 
-    def add_writer(self, fd, callback, *args):
-        raise NotImplementedError
+        def add_writer(self, fd, callback, *args):
+            raise NotImplementedError
 
-    def remove_writer(self, fd):
-        raise NotImplementedError
+        def remove_writer(self, fd):
+            raise NotImplementedError
 
-    # Completion based I/O methods returning Futures.
+        # Completion based I/O methods returning Futures.
 
-    def sock_recv(self, sock, nbytes):
-        raise NotImplementedError
+        def sock_recv(self, sock, nbytes):
+            raise NotImplementedError
 
-    def sock_sendall(self, sock, data):
-        raise NotImplementedError
+        def sock_sendall(self, sock, data):
+            raise NotImplementedError
 
-    def sock_connect(self, sock, address):
-        raise NotImplementedError
+        def sock_connect(self, sock, address):
+            raise NotImplementedError
 
-    def sock_accept(self, sock):
-        raise NotImplementedError
+        def sock_accept(self, sock):
+            raise NotImplementedError
 
-    # Signal handling.
+        # Signal handling.
 
-    def add_signal_handler(self, sig, callback, *args):
-        raise NotImplementedError
+        def add_signal_handler(self, sig, callback, *args):
+            raise NotImplementedError
 
-    def remove_signal_handler(self, sig):
-        raise NotImplementedError
+        def remove_signal_handler(self, sig):
+            raise NotImplementedError
 
-    # Task factory.
+        # Task factory.
 
-    def set_task_factory(self, factory):
-        raise NotImplementedError
+        def set_task_factory(self, factory):
+            raise NotImplementedError
 
-    def get_task_factory(self):
-        raise NotImplementedError
+        def get_task_factory(self):
+            raise NotImplementedError
 
-    # Error handlers.
+        # Error handlers.
 
-    def set_exception_handler(self, handler):
-        raise NotImplementedError
+        def set_exception_handler(self, handler):
+            raise NotImplementedError
 
-    def default_exception_handler(self, context):
-        raise NotImplementedError
+        def default_exception_handler(self, context):
+            raise NotImplementedError
 
-    def call_exception_handler(self, context):
-        raise NotImplementedError
+        def call_exception_handler(self, context):
+            raise NotImplementedError
 
-    # Debug flag management.
+        # Debug flag management.
 
-    def get_debug(self):
-        raise NotImplementedError
+        def get_debug(self):
+            raise NotImplementedError
 
-    def set_debug(self, enabled):
-        raise NotImplementedError
+        def set_debug(self, enabled):
+            raise NotImplementedError
 
 
-class AbstractEventLoopPolicy:
-    """Abstract policy for accessing the event loop."""
+    class AbstractEventLoopPolicy(object):
+        """Abstract policy for accessing the event loop."""
 
-    def get_event_loop(self):
-        """Get the event loop for the current context.
+        def get_event_loop(self):
+            """Get the event loop for the current context.
 
-        Returns an event loop object implementing the BaseEventLoop interface,
-        or raises an exception in case no event loop has been set for the
-        current context and the current policy does not specify to create one.
+            Returns an event loop object implementing the BaseEventLoop interface,
+            or raises an exception in case no event loop has been set for the
+            current context and the current policy does not specify to create one.
 
-        It should never return None."""
-        raise NotImplementedError
+            It should never return None."""
+            raise NotImplementedError
 
-    def set_event_loop(self, loop):
-        """Set the event loop for the current context to loop."""
-        raise NotImplementedError
+        def set_event_loop(self, loop):
+            """Set the event loop for the current context to loop."""
+            raise NotImplementedError
 
-    def new_event_loop(self):
-        """Create and return a new event loop object according to this
-        policy's rules. If there's need to set this loop as the event loop for
-        the current context, set_event_loop must be called explicitly."""
-        raise NotImplementedError
+        def new_event_loop(self):
+            """Create and return a new event loop object according to this
+            policy's rules. If there's need to set this loop as the event loop for
+            the current context, set_event_loop must be called explicitly."""
+            raise NotImplementedError
 
-    # Child processes handling (Unix only).
+        # Child processes handling (Unix only).
 
-    def get_child_watcher(self):
-        "Get the watcher for child processes."
-        raise NotImplementedError
+        def get_child_watcher(self):
+            "Get the watcher for child processes."
+            raise NotImplementedError
 
-    def set_child_watcher(self, watcher):
-        """Set the watcher for child processes."""
-        raise NotImplementedError
+        def set_child_watcher(self, watcher):
+            """Set the watcher for child processes."""
+            raise NotImplementedError
 
 
 class BaseDefaultEventLoopPolicy(AbstractEventLoopPolicy):
diff --git a/trollius/futures.py b/trollius/futures.py
index d06828a..80f6d11 100644
--- a/trollius/futures.py
+++ b/trollius/futures.py
@@ -5,13 +5,17 @@ __all__ = ['CancelledError', 'TimeoutError',
            'Future', 'wrap_future',
            ]
 
-import concurrent.futures._base
 import logging
-import reprlib
 import sys
 import traceback
+try:
+    import reprlib   # Python 3
+except ImportError:
+    import repr as reprlib   # Python 2
 
+from . import compat
 from . import events
+from . import executor
 
 # States for Future.
 _PENDING = 'PENDING'
@@ -21,9 +25,9 @@ _FINISHED = 'FINISHED'
 _PY34 = sys.version_info >= (3, 4)
 _PY35 = sys.version_info >= (3, 5)
 
-Error = concurrent.futures._base.Error
-CancelledError = concurrent.futures.CancelledError
-TimeoutError = concurrent.futures.TimeoutError
+Error = executor.Error
+CancelledError = executor.CancelledError
+TimeoutError = executor.TimeoutError
 
 STACK_DEBUG = logging.DEBUG - 1  # heavy-duty debugging
 
@@ -32,7 +36,7 @@ class InvalidStateError(Error):
     """The operation is not allowed in this state."""
 
 
-class _TracebackLogger:
+class _TracebackLogger(object):
     """Helper to log a traceback upon destruction if not cleared.
 
     This solves a nasty problem with Futures and Tasks that have an
@@ -112,7 +116,7 @@ class _TracebackLogger:
             self.loop.call_exception_handler({'message': msg})
 
 
-class Future:
+class Future(object):
     """This class is *almost* compatible with concurrent.futures.Future.
 
     Differences:
@@ -138,10 +142,14 @@ class Future:
 
     _blocking = False  # proper use of future (yield vs yield from)
 
+    # Used by Python 2 to raise the exception with the original traceback
+    # in the exception() method in debug mode
+    _exception_tb = None
+
     _log_traceback = False   # Used for Python 3.4 and later
     _tb_logger = None        # Used for Python 3.3 only
 
-    def __init__(self, *, loop=None):
+    def __init__(self, loop=None):
         """Initialize the future.
 
         The optional event_loop argument allows to explicitly set the event
@@ -168,23 +176,23 @@ class Future:
         if size == 1:
             cb = format_cb(cb[0])
         elif size == 2:
-            cb = '{}, {}'.format(format_cb(cb[0]), format_cb(cb[1]))
+            cb = '{0}, {1}'.format(format_cb(cb[0]), format_cb(cb[1]))
         elif size > 2:
-            cb = '{}, <{} more>, {}'.format(format_cb(cb[0]),
-                                            size-2,
-                                            format_cb(cb[-1]))
+            cb = '{0}, <{1} more>, {2}'.format(format_cb(cb[0]),
+                                               size-2,
+                                               format_cb(cb[-1]))
         return 'cb=[%s]' % cb
 
     def _repr_info(self):
         info = [self._state.lower()]
         if self._state == _FINISHED:
             if self._exception is not None:
-                info.append('exception={!r}'.format(self._exception))
+                info.append('exception={0!r}'.format(self._exception))
             else:
                 # use reprlib to limit the length of the output, especially
                 # for very long strings
                 result = reprlib.repr(self._result)
-                info.append('result={}'.format(result))
+                info.append('result={0}'.format(result))
         if self._callbacks:
             info.append(self._format_callbacks())
         if self._source_traceback:
@@ -272,8 +280,13 @@ class Future:
         if self._tb_logger is not None:
             self._tb_logger.clear()
             self._tb_logger = None
+        exc_tb = self._exception_tb
+        self._exception_tb = None
         if self._exception is not None:
-            raise self._exception
+            if exc_tb is not None:
+                compat.reraise(type(self._exception), self._exception, exc_tb)
+            else:
+                raise self._exception
         return self._result
 
     def exception(self):
@@ -292,6 +305,7 @@ class Future:
         if self._tb_logger is not None:
             self._tb_logger.clear()
             self._tb_logger = None
+        self._exception_tb = None
         return self._exception
 
     def add_done_callback(self, fn):
@@ -334,31 +348,61 @@ class Future:
         InvalidStateError.
         """
         if self._state != _PENDING:
-            raise InvalidStateError('{}: {!r}'.format(self._state, self))
+            raise InvalidStateError('{0}: {1!r}'.format(self._state, self))
         self._result = result
         self._state = _FINISHED
         self._schedule_callbacks()
 
+    def _get_exception_tb(self):
+        return self._exception_tb
+
     def set_exception(self, exception):
+        self._set_exception_with_tb(exception, None)
+
+    def _set_exception_with_tb(self, exception, exc_tb):
         """Mark the future done and set an exception.
 
         If the future is already done when this method is called, raises
         InvalidStateError.
         """
         if self._state != _PENDING:
-            raise InvalidStateError('{}: {!r}'.format(self._state, self))
+            raise InvalidStateError('{0}: {1!r}'.format(self._state, self))
         if isinstance(exception, type):
             exception = exception()
         self._exception = exception
+        if exc_tb is not None:
+            self._exception_tb = exc_tb
+            exc_tb = None
+        elif self._loop.get_debug() and not compat.PY3:
+            self._exception_tb = sys.exc_info()[2]
         self._state = _FINISHED
         self._schedule_callbacks()
         if _PY34:
             self._log_traceback = True
         else:
             self._tb_logger = _TracebackLogger(self, exception)
-            # Arrange for the logger to be activated after all callbacks
-            # have had a chance to call result() or exception().
-            self._loop.call_soon(self._tb_logger.activate)
+            if hasattr(exception, '__traceback__'):
+                # Python 3: exception contains a link to the traceback
+
+                # Arrange for the logger to be activated after all callbacks
+                # have had a chance to call result() or exception().
+                self._loop.call_soon(self._tb_logger.activate)
+            else:
+                if self._loop.get_debug():
+                    frame = sys._getframe(1)
+                    tb = ['Traceback (most recent call last):\n']
+                    if self._exception_tb is not None:
+                        tb += traceback.format_tb(self._exception_tb)
+                    else:
+                        tb += traceback.format_stack(frame)
+                    tb += traceback.format_exception_only(type(exception), exception)
+                    self._tb_logger.tb = tb
+                else:
+                    self._tb_logger.tb = traceback.format_exception_only(
+                                                        type(exception),
+                                                        exception)
+
+                self._tb_logger.exc = None
 
     # Truly internal methods.
 
@@ -392,12 +436,18 @@ class Future:
         __await__ = __iter__ # make compatible with 'await' expression
 
 
-def wrap_future(fut, *, loop=None):
+if events.asyncio is not None:
+    # Accept also asyncio Future objects for interoperability
+    _FUTURE_CLASSES = (Future, events.asyncio.Future)
+else:
+    _FUTURE_CLASSES = Future
+
+def wrap_future(fut, loop=None):
     """Wrap concurrent.futures.Future object."""
-    if isinstance(fut, Future):
+    if isinstance(fut, _FUTURE_CLASSES):
         return fut
-    assert isinstance(fut, concurrent.futures.Future), \
-        'concurrent.futures.Future is expected, got {!r}'.format(fut)
+    assert isinstance(fut, executor.Future), \
+        'concurrent.futures.Future is expected, got {0!r}'.format(fut)
     if loop is None:
         loop = events.get_event_loop()
     new_future = Future(loop=loop)
diff --git a/trollius/locks.py b/trollius/locks.py
index b2e516b..ecbe3b3 100644
--- a/trollius/locks.py
+++ b/trollius/locks.py
@@ -7,7 +7,7 @@ import sys
 
 from . import events
 from . import futures
-from .coroutines import coroutine
+from .coroutines import coroutine, From, Return
 
 
 _PY35 = sys.version_info >= (3, 5)
@@ -19,7 +19,7 @@ class _ContextManager:
     This enables the following idiom for acquiring and releasing a
     lock around a block:
 
-        with (yield from lock):
+        with (yield From(lock)):
             <block>
 
     while failing loudly when accidentally using:
@@ -43,7 +43,7 @@ class _ContextManager:
             self._lock = None  # Crudely prevent reuse.
 
 
-class _ContextManagerMixin:
+class _ContextManagerMixin(object):
     def __enter__(self):
         raise RuntimeError(
             '"yield from" should be used as context manager expression')
@@ -111,16 +111,16 @@ class Lock(_ContextManagerMixin):
     release() call resets the state to unlocked; first coroutine which
     is blocked in acquire() is being processed.
 
-    acquire() is a coroutine and should be called with 'yield from'.
+    acquire() is a coroutine and should be called with 'yield From'.
 
-    Locks also support the context management protocol.  '(yield from lock)'
+    Locks also support the context management protocol.  '(yield From(lock))'
     should be used as context manager expression.
 
     Usage:
 
         lock = Lock()
         ...
-        yield from lock
+        yield From(lock)
         try:
             ...
         finally:
@@ -130,20 +130,20 @@ class Lock(_ContextManagerMixin):
 
         lock = Lock()
         ...
-        with (yield from lock):
+        with (yield From(lock)):
              ...
 
     Lock objects can be tested for locking state:
 
         if not lock.locked():
-           yield from lock
+           yield From(lock)
         else:
            # lock is acquired
            ...
 
     """
 
-    def __init__(self, *, loop=None):
+    def __init__(self, loop=None):
         self._waiters = collections.deque()
         self._locked = False
         if loop is not None:
@@ -152,11 +152,11 @@ class Lock(_ContextManagerMixin):
             self._loop = events.get_event_loop()
 
     def __repr__(self):
-        res = super().__repr__()
+        res = super(Lock, self).__repr__()
         extra = 'locked' if self._locked else 'unlocked'
         if self._waiters:
-            extra = '{},waiters:{}'.format(extra, len(self._waiters))
-        return '<{} [{}]>'.format(res[1:-1], extra)
+            extra = '{0},waiters:{1}'.format(extra, len(self._waiters))
+        return '<{0} [{1}]>'.format(res[1:-1], extra)
 
     def locked(self):
         """Return True if lock is acquired."""
@@ -171,14 +171,14 @@ class Lock(_ContextManagerMixin):
         """
         if not self._waiters and not self._locked:
             self._locked = True
-            return True
+            raise Return(True)
 
         fut = futures.Future(loop=self._loop)
         self._waiters.append(fut)
         try:
-            yield from fut
+            yield From(fut)
             self._locked = True
-            return True
+            raise Return(True)
         finally:
             self._waiters.remove(fut)
 
@@ -204,7 +204,7 @@ class Lock(_ContextManagerMixin):
             raise RuntimeError('Lock is not acquired.')
 
 
-class Event:
+class Event(object):
     """Asynchronous equivalent to threading.Event.
 
     Class implementing event objects. An event manages a flag that can be set
@@ -213,7 +213,7 @@ class Event:
     false.
     """
 
-    def __init__(self, *, loop=None):
+    def __init__(self, loop=None):
         self._waiters = collections.deque()
         self._value = False
         if loop is not None:
@@ -222,11 +222,11 @@ class Event:
             self._loop = events.get_event_loop()
 
     def __repr__(self):
-        res = super().__repr__()
+        res = super(Event, self).__repr__()
         extra = 'set' if self._value else 'unset'
         if self._waiters:
-            extra = '{},waiters:{}'.format(extra, len(self._waiters))
-        return '<{} [{}]>'.format(res[1:-1], extra)
+            extra = '{0},waiters:{1}'.format(extra, len(self._waiters))
+        return '<{0} [{1}]>'.format(res[1:-1], extra)
 
     def is_set(self):
         """Return True if and only if the internal flag is true."""
@@ -259,13 +259,13 @@ class Event:
         set() to set the flag to true, then return True.
         """
         if self._value:
-            return True
+            raise Return(True)
 
         fut = futures.Future(loop=self._loop)
         self._waiters.append(fut)
         try:
-            yield from fut
-            return True
+            yield From(fut)
+            raise Return(True)
         finally:
             self._waiters.remove(fut)
 
@@ -280,7 +280,7 @@ class Condition(_ContextManagerMixin):
     A new Lock object is created and used as the underlying lock.
     """
 
-    def __init__(self, lock=None, *, loop=None):
+    def __init__(self, lock=None, loop=None):
         if loop is not None:
             self._loop = loop
         else:
@@ -300,11 +300,11 @@ class Condition(_ContextManagerMixin):
         self._waiters = collections.deque()
 
     def __repr__(self):
-        res = super().__repr__()
+        res = super(Condition, self).__repr__()
         extra = 'locked' if self.locked() else 'unlocked'
         if self._waiters:
-            extra = '{},waiters:{}'.format(extra, len(self._waiters))
-        return '<{} [{}]>'.format(res[1:-1], extra)
+            extra = '{0},waiters:{1}'.format(extra, len(self._waiters))
+        return '<{0} [{1}]>'.format(res[1:-1], extra)
 
     @coroutine
     def wait(self):
@@ -326,13 +326,13 @@ class Condition(_ContextManagerMixin):
             fut = futures.Future(loop=self._loop)
             self._waiters.append(fut)
             try:
-                yield from fut
-                return True
+                yield From(fut)
+                raise Return(True)
             finally:
                 self._waiters.remove(fut)
 
         finally:
-            yield from self.acquire()
+            yield From(self.acquire())
 
     @coroutine
     def wait_for(self, predicate):
@@ -344,9 +344,9 @@ class Condition(_ContextManagerMixin):
         """
         result = predicate()
         while not result:
-            yield from self.wait()
+            yield From(self.wait())
             result = predicate()
-        return result
+        raise Return(result)
 
     def notify(self, n=1):
         """By default, wake up one coroutine waiting on this condition, if any.
@@ -396,7 +396,7 @@ class Semaphore(_ContextManagerMixin):
     ValueError is raised.
     """
 
-    def __init__(self, value=1, *, loop=None):
+    def __init__(self, value=1, loop=None):
         if value < 0:
             raise ValueError("Semaphore initial value must be >= 0")
         self._value = value
@@ -407,12 +407,12 @@ class Semaphore(_ContextManagerMixin):
             self._loop = events.get_event_loop()
 
     def __repr__(self):
-        res = super().__repr__()
-        extra = 'locked' if self.locked() else 'unlocked,value:{}'.format(
+        res = super(Semaphore, self).__repr__()
+        extra = 'locked' if self.locked() else 'unlocked,value:{0}'.format(
             self._value)
         if self._waiters:
-            extra = '{},waiters:{}'.format(extra, len(self._waiters))
-        return '<{} [{}]>'.format(res[1:-1], extra)
+            extra = '{0},waiters:{1}'.format(extra, len(self._waiters))
+        return '<{0} [{1}]>'.format(res[1:-1], extra)
 
     def locked(self):
         """Returns True if semaphore can not be acquired immediately."""
@@ -430,14 +430,14 @@ class Semaphore(_ContextManagerMixin):
         """
         if not self._waiters and self._value > 0:
             self._value -= 1
-            return True
+            raise Return(True)
 
         fut = futures.Future(loop=self._loop)
         self._waiters.append(fut)
         try:
-            yield from fut
+            yield From(fut)
             self._value -= 1
-            return True
+            raise Return(True)
         finally:
             self._waiters.remove(fut)
 
@@ -460,11 +460,11 @@ class BoundedSemaphore(Semaphore):
     above the initial value.
     """
 
-    def __init__(self, value=1, *, loop=None):
+    def __init__(self, value=1, loop=None):
         self._bound_value = value
-        super().__init__(value, loop=loop)
+        super(BoundedSemaphore, self).__init__(value, loop=loop)
 
     def release(self):
         if self._value >= self._bound_value:
             raise ValueError('BoundedSemaphore released too many times')
-        super().release()
+        super(BoundedSemaphore, self).release()
diff --git a/trollius/proactor_events.py b/trollius/proactor_events.py
index 9c2b8f1..49d8bc3 100644
--- a/trollius/proactor_events.py
+++ b/trollius/proactor_events.py
@@ -16,6 +16,9 @@ from . import futures
 from . import sslproto
 from . import transports
 from .log import logger
+from .compat import flatten_bytes
+from .py33_exceptions import (BrokenPipeError,
+    ConnectionAbortedError, ConnectionResetError)
 
 
 class _ProactorBasePipeTransport(transports._FlowControlMixin,
@@ -24,7 +27,7 @@ class _ProactorBasePipeTransport(transports._FlowControlMixin,
 
     def __init__(self, loop, sock, protocol, waiter=None,
                  extra=None, server=None):
-        super().__init__(extra, loop)
+        super(_ProactorBasePipeTransport, self).__init__(extra, loop)
         self._set_extra(sock)
         self._sock = sock
         self._protocol = protocol
@@ -143,7 +146,8 @@ class _ProactorReadPipeTransport(_ProactorBasePipeTransport,
 
     def __init__(self, loop, sock, protocol, waiter=None,
                  extra=None, server=None):
-        super().__init__(loop, sock, protocol, waiter, extra, server)
+        super(_ProactorReadPipeTransport, self).__init__(loop, sock, protocol,
+                                                         waiter, extra, server)
         self._paused = False
         self._loop.call_soon(self._loop_reading)
 
@@ -220,9 +224,7 @@ class _ProactorBaseWritePipeTransport(_ProactorBasePipeTransport,
     """Transport for write pipes."""
 
     def write(self, data):
-        if not isinstance(data, (bytes, bytearray, memoryview)):
-            raise TypeError('data argument must be byte-ish (%r)',
-                            type(data))
+        data = flatten_bytes(data)
         if self._eof_written:
             raise RuntimeError('write_eof() already called')
 
@@ -301,7 +303,7 @@ class _ProactorBaseWritePipeTransport(_ProactorBasePipeTransport,
 
 class _ProactorWritePipeTransport(_ProactorBaseWritePipeTransport):
     def __init__(self, *args, **kw):
-        super().__init__(*args, **kw)
+        super(_ProactorWritePipeTransport, self).__init__(*args, **kw)
         self._read_fut = self._loop._proactor.recv(self._sock, 16)
         self._read_fut.add_done_callback(self._pipe_closed)
 
@@ -368,7 +370,7 @@ class _ProactorSocketTransport(_ProactorReadPipeTransport,
 class BaseProactorEventLoop(base_events.BaseEventLoop):
 
     def __init__(self, proactor):
-        super().__init__()
+        super(BaseProactorEventLoop, self).__init__()
         logger.debug('Using proactor: %s', proactor.__class__.__name__)
         self._proactor = proactor
         self._selector = proactor   # convenient alias
@@ -383,7 +385,7 @@ class BaseProactorEventLoop(base_events.BaseEventLoop):
                                         extra, server)
 
     def _make_ssl_transport(self, rawsock, protocol, sslcontext, waiter=None,
-                            *, server_side=False, server_hostname=None,
+                            server_side=False, server_hostname=None,
                             extra=None, server=None):
         if not sslproto._is_sslproto_available():
             raise NotImplementedError("Proactor event loop requires Python 3.5"
@@ -427,7 +429,7 @@ class BaseProactorEventLoop(base_events.BaseEventLoop):
         self._selector = None
 
         # Close the event loop
-        super().close()
+        super(BaseProactorEventLoop, self).close()
 
     def sock_recv(self, sock, n):
         return self._proactor.recv(sock, n)
diff --git a/trollius/protocols.py b/trollius/protocols.py
index 80fcac9..2c18287 100644
--- a/trollius/protocols.py
+++ b/trollius/protocols.py
@@ -4,7 +4,7 @@ __all__ = ['BaseProtocol', 'Protocol', 'DatagramProtocol',
            'SubprocessProtocol']
 
 
-class BaseProtocol:
+class BaseProtocol(object):
     """Common base class for protocol interfaces.
 
     Usually user implements protocols that derived from BaseProtocol
diff --git a/trollius/queues.py b/trollius/queues.py
index ed11662..d856305 100644
--- a/trollius/queues.py
+++ b/trollius/queues.py
@@ -9,6 +9,7 @@ import heapq
 from . import events
 from . import futures
 from . import locks
+from .coroutines import From, Return
 from .tasks import coroutine
 
 
@@ -26,7 +27,7 @@ class QueueFull(Exception):
     pass
 
 
-class Queue:
+class Queue(object):
     """A queue, useful for coordinating producer and consumer coroutines.
 
     If maxsize is less than or equal to zero, the queue size is infinite. If it
@@ -38,7 +39,7 @@ class Queue:
     interrupted between calling qsize() and doing an operation on the Queue.
     """
 
-    def __init__(self, maxsize=0, *, loop=None):
+    def __init__(self, maxsize=0, loop=None):
         if loop is None:
             self._loop = events.get_event_loop()
         else:
@@ -73,22 +74,22 @@ class Queue:
         self._finished.clear()
 
     def __repr__(self):
-        return '<{} at {:#x} {}>'.format(
+        return '<{0} at {1:#x} {2}>'.format(
             type(self).__name__, id(self), self._format())
 
     def __str__(self):
-        return '<{} {}>'.format(type(self).__name__, self._format())
+        return '<{0} {1}>'.format(type(self).__name__, self._format())
 
     def _format(self):
-        result = 'maxsize={!r}'.format(self._maxsize)
+        result = 'maxsize={0!r}'.format(self._maxsize)
         if getattr(self, '_queue', None):
-            result += ' _queue={!r}'.format(list(self._queue))
+            result += ' _queue={0!r}'.format(list(self._queue))
         if self._getters:
-            result += ' _getters[{}]'.format(len(self._getters))
+            result += ' _getters[{0}]'.format(len(self._getters))
         if self._putters:
-            result += ' _putters[{}]'.format(len(self._putters))
+            result += ' _putters[{0}]'.format(len(self._putters))
         if self._unfinished_tasks:
-            result += ' tasks={}'.format(self._unfinished_tasks)
+            result += ' tasks={0}'.format(self._unfinished_tasks)
         return result
 
     def _consume_done_getters(self):
@@ -149,7 +150,7 @@ class Queue:
             waiter = futures.Future(loop=self._loop)
 
             self._putters.append((item, waiter))
-            yield from waiter
+            yield From(waiter)
 
         else:
             self.__put_internal(item)
@@ -195,15 +196,16 @@ class Queue:
             # ChannelTest.test_wait.
             self._loop.call_soon(putter._set_result_unless_cancelled, None)
 
-            return self._get()
+            raise Return(self._get())
 
         elif self.qsize():
-            return self._get()
+            raise Return(self._get())
         else:
             waiter = futures.Future(loop=self._loop)
 
             self._getters.append(waiter)
-            return (yield from waiter)
+            result = yield From(waiter)
+            raise Return(result)
 
     def get_nowait(self):
         """Remove and return an item from the queue.
@@ -257,7 +259,7 @@ class Queue:
         When the count of unfinished tasks drops to zero, join() unblocks.
         """
         if self._unfinished_tasks > 0:
-            yield from self._finished.wait()
+            yield From(self._finished.wait())
 
 
 class PriorityQueue(Queue):
diff --git a/trollius/selector_events.py b/trollius/selector_events.py
index 7c5b9b5..ec14974 100644
--- a/trollius/selector_events.py
+++ b/trollius/selector_events.py
@@ -14,6 +14,8 @@ import sys
 import warnings
 try:
     import ssl
+    from .py3_ssl import (wrap_ssl_error, SSLContext, SSLWantReadError,
+                          SSLWantWriteError)
 except ImportError:  # pragma: no cover
     ssl = None
 
@@ -24,8 +26,26 @@ from . import futures
 from . import selectors
 from . import transports
 from . import sslproto
+from .compat import flatten_bytes
 from .coroutines import coroutine
 from .log import logger
+from .py33_exceptions import (wrap_error,
+    BlockingIOError, InterruptedError, ConnectionAbortedError, BrokenPipeError,
+    ConnectionResetError)
+
+# On Mac OS 10.6 with Python 2.6.1 or OpenIndiana 148 with Python 2.6.4,
+# _SelectorSslTransport._read_ready() hangs if the socket has no data.
+# Example: test_events.test_create_server_ssl()
+_SSL_REQUIRES_SELECT = (sys.version_info < (2, 6, 6))
+if _SSL_REQUIRES_SELECT:
+    import select
+
+
+def _get_socket_error(sock, address):
+    err = sock.getsockopt(socket.SOL_SOCKET, socket.SO_ERROR)
+    if err != 0:
+        # Jump to the except clause below.
+        raise OSError(err, 'Connect call failed %s' % (address,))
 
 
 def _test_selector_event(selector, fd, event):
@@ -46,7 +66,7 @@ class BaseSelectorEventLoop(base_events.BaseEventLoop):
     """
 
     def __init__(self, selector=None):
-        super().__init__()
+        super(BaseSelectorEventLoop, self).__init__()
 
         if selector is None:
             selector = selectors.DefaultSelector()
@@ -54,13 +74,13 @@ class BaseSelectorEventLoop(base_events.BaseEventLoop):
         self._selector = selector
         self._make_self_pipe()
 
-    def _make_socket_transport(self, sock, protocol, waiter=None, *,
+    def _make_socket_transport(self, sock, protocol, waiter=None,
                                extra=None, server=None):
         return _SelectorSocketTransport(self, sock, protocol, waiter,
                                         extra, server)
 
     def _make_ssl_transport(self, rawsock, protocol, sslcontext, waiter=None,
-                            *, server_side=False, server_hostname=None,
+                            server_side=False, server_hostname=None,
                             extra=None, server=None):
         if not sslproto._is_sslproto_available():
             return self._make_legacy_ssl_transport(
@@ -75,7 +95,7 @@ class BaseSelectorEventLoop(base_events.BaseEventLoop):
         return ssl_protocol._app_transport
 
     def _make_legacy_ssl_transport(self, rawsock, protocol, sslcontext,
-                                   waiter, *,
+                                   waiter,
                                    server_side=False, server_hostname=None,
                                    extra=None, server=None):
         # Use the legacy API: SSL_write, SSL_read, etc. The legacy API is used
@@ -95,7 +115,7 @@ class BaseSelectorEventLoop(base_events.BaseEventLoop):
         if self.is_closed():
             return
         self._close_self_pipe()
-        super().close()
+        super(BaseSelectorEventLoop, self).close()
         if self._selector is not None:
             self._selector.close()
             self._selector = None
@@ -125,7 +145,7 @@ class BaseSelectorEventLoop(base_events.BaseEventLoop):
     def _read_from_self(self):
         while True:
             try:
-                data = self._ssock.recv(4096)
+                data = wrap_error(self._ssock.recv, 4096)
                 if not data:
                     break
                 self._process_self_data(data)
@@ -143,7 +163,7 @@ class BaseSelectorEventLoop(base_events.BaseEventLoop):
         csock = self._csock
         if csock is not None:
             try:
-                csock.send(b'\0')
+                wrap_error(csock.send, b'\0')
             except OSError:
                 if self._debug:
                     logger.debug("Fail to write a null byte into the "
@@ -158,14 +178,14 @@ class BaseSelectorEventLoop(base_events.BaseEventLoop):
     def _accept_connection(self, protocol_factory, sock,
                            sslcontext=None, server=None):
         try:
-            conn, addr = sock.accept()
+            conn, addr = wrap_error(sock.accept)
             if self._debug:
                 logger.debug("%r got a new connection from %r: %r",
                              server, addr, conn)
             conn.setblocking(False)
         except (BlockingIOError, InterruptedError, ConnectionAbortedError):
             pass  # False alarm.
-        except OSError as exc:
+        except socket.error as exc:
             # There's nowhere to send the error, so just log it.
             if exc.errno in (errno.EMFILE, errno.ENFILE,
                              errno.ENOBUFS, errno.ENOMEM):
@@ -331,7 +351,7 @@ class BaseSelectorEventLoop(base_events.BaseEventLoop):
         if fut.cancelled():
             return
         try:
-            data = sock.recv(n)
+            data = wrap_error(sock.recv, n)
         except (BlockingIOError, InterruptedError):
             self.add_reader(fd, self._sock_recv, fut, True, sock, n)
         except Exception as exc:
@@ -368,7 +388,7 @@ class BaseSelectorEventLoop(base_events.BaseEventLoop):
             return
 
         try:
-            n = sock.send(data)
+            n = wrap_error(sock.send, data)
         except (BlockingIOError, InterruptedError):
             n = 0
         except Exception as exc:
@@ -408,7 +428,7 @@ class BaseSelectorEventLoop(base_events.BaseEventLoop):
     def _sock_connect(self, fut, sock, address):
         fd = sock.fileno()
         try:
-            sock.connect(address)
+            wrap_error(sock.connect, address)
         except (BlockingIOError, InterruptedError):
             # Issue #23618: When the C function connect() fails with EINTR, the
             # connection runs in background. We have to wait until the socket
@@ -430,10 +450,7 @@ class BaseSelectorEventLoop(base_events.BaseEventLoop):
             return
 
         try:
-            err = sock.getsockopt(socket.SOL_SOCKET, socket.SO_ERROR)
-            if err != 0:
-                # Jump to any except clause below.
-                raise OSError(err, 'Connect call failed %s' % (address,))
+            wrap_error(_get_socket_error, sock, address)
         except (BlockingIOError, InterruptedError):
             # socket is still registered, the callback will be retried later
             pass
@@ -465,7 +482,7 @@ class BaseSelectorEventLoop(base_events.BaseEventLoop):
         if fut.cancelled():
             return
         try:
-            conn, address = sock.accept()
+            conn, address = wrap_error(sock.accept)
             conn.setblocking(False)
         except (BlockingIOError, InterruptedError):
             self.add_reader(fd, self._sock_accept, fut, True, sock)
@@ -506,7 +523,7 @@ class _SelectorTransport(transports._FlowControlMixin,
     _sock = None
 
     def __init__(self, loop, sock, protocol, extra=None, server=None):
-        super().__init__(extra, loop)
+        super(_SelectorTransport, self).__init__(extra, loop)
         self._extra['socket'] = sock
         self._extra['sockname'] = sock.getsockname()
         if 'peername' not in self._extra:
@@ -593,7 +610,7 @@ class _SelectorTransport(transports._FlowControlMixin,
         if self._conn_lost:
             return
         if self._buffer:
-            self._buffer.clear()
+            del self._buffer[:]
             self._loop.remove_writer(self._sock_fd)
         if not self._closing:
             self._closing = True
@@ -623,7 +640,7 @@ class _SelectorSocketTransport(_SelectorTransport):
 
     def __init__(self, loop, sock, protocol, waiter=None,
                  extra=None, server=None):
-        super().__init__(loop, sock, protocol, extra, server)
+        super(_SelectorSocketTransport, self).__init__(loop, sock, protocol, extra, server)
         self._eof = False
         self._paused = False
 
@@ -657,7 +674,7 @@ class _SelectorSocketTransport(_SelectorTransport):
 
     def _read_ready(self):
         try:
-            data = self._sock.recv(self.max_size)
+            data = wrap_error(self._sock.recv, self.max_size)
         except (BlockingIOError, InterruptedError):
             pass
         except Exception as exc:
@@ -678,9 +695,7 @@ class _SelectorSocketTransport(_SelectorTransport):
                     self.close()
 
     def write(self, data):
-        if not isinstance(data, (bytes, bytearray, memoryview)):
-            raise TypeError('data argument must be byte-ish (%r)',
-                            type(data))
+        data = flatten_bytes(data)
         if self._eof:
             raise RuntimeError('Cannot call write() after write_eof()')
         if not data:
@@ -695,7 +710,7 @@ class _SelectorSocketTransport(_SelectorTransport):
         if not self._buffer:
             # Optimization: try to send now.
             try:
-                n = self._sock.send(data)
+                n = wrap_error(self._sock.send, data)
             except (BlockingIOError, InterruptedError):
                 pass
             except Exception as exc:
@@ -715,13 +730,14 @@ class _SelectorSocketTransport(_SelectorTransport):
     def _write_ready(self):
         assert self._buffer, 'Data should not be empty'
 
+        data = flatten_bytes(self._buffer)
         try:
-            n = self._sock.send(self._buffer)
+            n = wrap_error(self._sock.send, data)
         except (BlockingIOError, InterruptedError):
             pass
         except Exception as exc:
             self._loop.remove_writer(self._sock_fd)
-            self._buffer.clear()
+            del self._buffer[:]
             self._fatal_error(exc, 'Fatal write error on socket transport')
         else:
             if n:
@@ -766,7 +782,7 @@ class _SelectorSslTransport(_SelectorTransport):
             wrap_kwargs['server_hostname'] = server_hostname
         sslsock = sslcontext.wrap_socket(rawsock, **wrap_kwargs)
 
-        super().__init__(loop, sslsock, protocol, extra, server)
+        super(_SelectorSslTransport, self).__init__(loop, sslsock, protocol, extra, server)
         # the protocol connection is only made after the SSL handshake
         self._protocol_connected = False
 
@@ -797,12 +813,12 @@ class _SelectorSslTransport(_SelectorTransport):
 
     def _on_handshake(self, start_time):
         try:
-            self._sock.do_handshake()
-        except ssl.SSLWantReadError:
+            wrap_ssl_error(self._sock.do_handshake)
+        except SSLWantReadError:
             self._loop.add_reader(self._sock_fd,
                                   self._on_handshake, start_time)
             return
-        except ssl.SSLWantWriteError:
+        except SSLWantWriteError:
             self._loop.add_writer(self._sock_fd,
                                   self._on_handshake, start_time)
             return
@@ -842,8 +858,9 @@ class _SelectorSslTransport(_SelectorTransport):
         # Add extra info that becomes available after handshake.
         self._extra.update(peercert=peercert,
                            cipher=self._sock.cipher(),
-                           compression=self._sock.compression(),
                            )
+        if hasattr(self._sock, 'compression'):
+            self._extra['compression'] = self._sock.compression()
 
         self._read_wants_write = False
         self._write_wants_read = False
@@ -883,6 +900,9 @@ class _SelectorSslTransport(_SelectorTransport):
         if self._loop.get_debug():
             logger.debug("%r resumes reading", self)
 
+    def _sock_recv(self):
+        return wrap_ssl_error(self._sock.recv, self.max_size)
+
     def _read_ready(self):
         if self._write_wants_read:
             self._write_wants_read = False
@@ -892,10 +912,16 @@ class _SelectorSslTransport(_SelectorTransport):
                 self._loop.add_writer(self._sock_fd, self._write_ready)
 
         try:
-            data = self._sock.recv(self.max_size)
-        except (BlockingIOError, InterruptedError, ssl.SSLWantReadError):
+            if _SSL_REQUIRES_SELECT:
+                rfds = (self._sock.fileno(),)
+                rfds = select.select(rfds, (), (), 0.0)[0]
+                if not rfds:
+                    # False alarm.
+                    return
+            data = wrap_error(self._sock_recv)
+        except (BlockingIOError, InterruptedError, SSLWantReadError):
             pass
-        except ssl.SSLWantWriteError:
+        except SSLWantWriteError:
             self._read_wants_write = True
             self._loop.remove_reader(self._sock_fd)
             self._loop.add_writer(self._sock_fd, self._write_ready)
@@ -924,17 +950,18 @@ class _SelectorSslTransport(_SelectorTransport):
                 self._loop.add_reader(self._sock_fd, self._read_ready)
 
         if self._buffer:
+            data = flatten_bytes(self._buffer)
             try:
-                n = self._sock.send(self._buffer)
-            except (BlockingIOError, InterruptedError, ssl.SSLWantWriteError):
+                n = wrap_error(self._sock.send, data)
+            except (BlockingIOError, InterruptedError, SSLWantWriteError):
                 n = 0
-            except ssl.SSLWantReadError:
+            except SSLWantReadError:
                 n = 0
                 self._loop.remove_writer(self._sock_fd)
                 self._write_wants_read = True
             except Exception as exc:
                 self._loop.remove_writer(self._sock_fd)
-                self._buffer.clear()
+                del self._buffer[:]
                 self._fatal_error(exc, 'Fatal write error on SSL transport')
                 return
 
@@ -949,9 +976,7 @@ class _SelectorSslTransport(_SelectorTransport):
                 self._call_connection_lost(None)
 
     def write(self, data):
-        if not isinstance(data, (bytes, bytearray, memoryview)):
-            raise TypeError('data argument must be byte-ish (%r)',
-                            type(data))
+        data = flatten_bytes(data)
         if not data:
             return
 
@@ -978,7 +1003,8 @@ class _SelectorDatagramTransport(_SelectorTransport):
 
     def __init__(self, loop, sock, protocol, address=None,
                  waiter=None, extra=None):
-        super().__init__(loop, sock, protocol, extra)
+        super(_SelectorDatagramTransport, self).__init__(loop, sock,
+                                                         protocol, extra)
         self._address = address
         self._loop.call_soon(self._protocol.connection_made, self)
         # only start reading when connection_made() has been called
@@ -993,7 +1019,7 @@ class _SelectorDatagramTransport(_SelectorTransport):
 
     def _read_ready(self):
         try:
-            data, addr = self._sock.recvfrom(self.max_size)
+            data, addr = wrap_error(self._sock.recvfrom, self.max_size)
         except (BlockingIOError, InterruptedError):
             pass
         except OSError as exc:
@@ -1004,9 +1030,7 @@ class _SelectorDatagramTransport(_SelectorTransport):
             self._protocol.datagram_received(data, addr)
 
     def sendto(self, data, addr=None):
-        if not isinstance(data, (bytes, bytearray, memoryview)):
-            raise TypeError('data argument must be byte-ish (%r)',
-                            type(data))
+        data = flatten_bytes(data)
         if not data:
             return
 
@@ -1024,9 +1048,9 @@ class _SelectorDatagramTransport(_SelectorTransport):
             # Attempt to send it right away first.
             try:
                 if self._address:
-                    self._sock.send(data)
+                    wrap_error(self._sock.send, data)
                 else:
-                    self._sock.sendto(data, addr)
+                    wrap_error(self._sock.sendto, data, addr)
                 return
             except (BlockingIOError, InterruptedError):
                 self._loop.add_writer(self._sock_fd, self._sendto_ready)
@@ -1047,9 +1071,9 @@ class _SelectorDatagramTransport(_SelectorTransport):
             data, addr = self._buffer.popleft()
             try:
                 if self._address:
-                    self._sock.send(data)
+                    wrap_error(self._sock.send, data)
                 else:
-                    self._sock.sendto(data, addr)
+                    wrap_error(self._sock.sendto, data, addr)
             except (BlockingIOError, InterruptedError):
                 self._buffer.appendleft((data, addr))  # Try again later.
                 break
diff --git a/trollius/selectors.py b/trollius/selectors.py
index 6d569c3..d2f822c 100644
--- a/trollius/selectors.py
+++ b/trollius/selectors.py
@@ -11,6 +11,9 @@ import math
 import select
 import sys
 
+from .py33_exceptions import wrap_error, InterruptedError
+from .compat import integer_types
+
 
 # generic events, that must be mapped to implementation-specific ones
 EVENT_READ = (1 << 0)
@@ -29,16 +32,16 @@ def _fileobj_to_fd(fileobj):
     Raises:
     ValueError if the object is invalid
     """
-    if isinstance(fileobj, int):
+    if isinstance(fileobj, integer_types):
         fd = fileobj
     else:
         try:
             fd = int(fileobj.fileno())
         except (AttributeError, TypeError, ValueError):
             raise ValueError("Invalid file object: "
-                             "{!r}".format(fileobj)) from None
+                             "{0!r}".format(fileobj))
     if fd < 0:
-        raise ValueError("Invalid file descriptor: {}".format(fd))
+        raise ValueError("Invalid file descriptor: {0}".format(fd))
     return fd
 
 
@@ -61,13 +64,13 @@ class _SelectorMapping(Mapping):
             fd = self._selector._fileobj_lookup(fileobj)
             return self._selector._fd_to_key[fd]
         except KeyError:
-            raise KeyError("{!r} is not registered".format(fileobj)) from None
+            raise KeyError("{0!r} is not registered".format(fileobj))
 
     def __iter__(self):
         return iter(self._selector._fd_to_key)
 
 
-class BaseSelector(metaclass=ABCMeta):
+class BaseSelector(object):
     """Selector abstract base class.
 
     A selector supports registering file objects to be monitored for specific
@@ -81,6 +84,7 @@ class BaseSelector(metaclass=ABCMeta):
     depending on the platform. The default `Selector` class uses the most
     efficient implementation on the current platform.
     """
+    __metaclass__ = ABCMeta
 
     @abstractmethod
     def register(self, fileobj, events, data=None):
@@ -179,7 +183,7 @@ class BaseSelector(metaclass=ABCMeta):
         try:
             return mapping[fileobj]
         except KeyError:
-            raise KeyError("{!r} is not registered".format(fileobj)) from None
+            raise KeyError("{0!r} is not registered".format(fileobj))
 
     @abstractmethod
     def get_map(self):
@@ -223,12 +227,12 @@ class _BaseSelectorImpl(BaseSelector):
 
     def register(self, fileobj, events, data=None):
         if (not events) or (events & ~(EVENT_READ | EVENT_WRITE)):
-            raise ValueError("Invalid events: {!r}".format(events))
+            raise ValueError("Invalid events: {0!r}".format(events))
 
         key = SelectorKey(fileobj, self._fileobj_lookup(fileobj), events, data)
 
         if key.fd in self._fd_to_key:
-            raise KeyError("{!r} (FD {}) is already registered"
+            raise KeyError("{0!r} (FD {1}) is already registered"
                            .format(fileobj, key.fd))
 
         self._fd_to_key[key.fd] = key
@@ -238,7 +242,7 @@ class _BaseSelectorImpl(BaseSelector):
         try:
             key = self._fd_to_key.pop(self._fileobj_lookup(fileobj))
         except KeyError:
-            raise KeyError("{!r} is not registered".format(fileobj)) from None
+            raise KeyError("{0!r} is not registered".format(fileobj))
         return key
 
     def modify(self, fileobj, events, data=None):
@@ -246,7 +250,7 @@ class _BaseSelectorImpl(BaseSelector):
         try:
             key = self._fd_to_key[self._fileobj_lookup(fileobj)]
         except KeyError:
-            raise KeyError("{!r} is not registered".format(fileobj)) from None
+            raise KeyError("{0!r} is not registered".format(fileobj))
         if events != key.events:
             self.unregister(fileobj)
             key = self.register(fileobj, events, data)
@@ -282,12 +286,12 @@ class SelectSelector(_BaseSelectorImpl):
     """Select-based selector."""
 
     def __init__(self):
-        super().__init__()
+        super(SelectSelector, self).__init__()
         self._readers = set()
         self._writers = set()
 
     def register(self, fileobj, events, data=None):
-        key = super().register(fileobj, events, data)
+        key = super(SelectSelector, self).register(fileobj, events, data)
         if events & EVENT_READ:
             self._readers.add(key.fd)
         if events & EVENT_WRITE:
@@ -295,7 +299,7 @@ class SelectSelector(_BaseSelectorImpl):
         return key
 
     def unregister(self, fileobj):
-        key = super().unregister(fileobj)
+        key = super(SelectSelector, self).unregister(fileobj)
         self._readers.discard(key.fd)
         self._writers.discard(key.fd)
         return key
@@ -311,7 +315,8 @@ class SelectSelector(_BaseSelectorImpl):
         timeout = None if timeout is None else max(timeout, 0)
         ready = []
         try:
-            r, w, _ = self._select(self._readers, self._writers, [], timeout)
+            r, w, _ = wrap_error(self._select,
+                                 self._readers, self._writers, [], timeout)
         except InterruptedError:
             return ready
         r = set(r)
@@ -335,11 +340,11 @@ if hasattr(select, 'poll'):
         """Poll-based selector."""
 
         def __init__(self):
-            super().__init__()
+            super(PollSelector, self).__init__()
             self._poll = select.poll()
 
         def register(self, fileobj, events, data=None):
-            key = super().register(fileobj, events, data)
+            key = super(PollSelector, self).register(fileobj, events, data)
             poll_events = 0
             if events & EVENT_READ:
                 poll_events |= select.POLLIN
@@ -349,7 +354,7 @@ if hasattr(select, 'poll'):
             return key
 
         def unregister(self, fileobj):
-            key = super().unregister(fileobj)
+            key = super(PollSelector, self).unregister(fileobj)
             self._poll.unregister(key.fd)
             return key
 
@@ -361,10 +366,10 @@ if hasattr(select, 'poll'):
             else:
                 # poll() has a resolution of 1 millisecond, round away from
                 # zero to wait *at least* timeout seconds.
-                timeout = math.ceil(timeout * 1e3)
+                timeout = int(math.ceil(timeout * 1e3))
             ready = []
             try:
-                fd_event_list = self._poll.poll(timeout)
+                fd_event_list = wrap_error(self._poll.poll, timeout)
             except InterruptedError:
                 return ready
             for fd, event in fd_event_list:
@@ -386,14 +391,14 @@ if hasattr(select, 'epoll'):
         """Epoll-based selector."""
 
         def __init__(self):
-            super().__init__()
+            super(EpollSelector, self).__init__()
             self._epoll = select.epoll()
 
         def fileno(self):
             return self._epoll.fileno()
 
         def register(self, fileobj, events, data=None):
-            key = super().register(fileobj, events, data)
+            key = super(EpollSelector, self).register(fileobj, events, data)
             epoll_events = 0
             if events & EVENT_READ:
                 epoll_events |= select.EPOLLIN
@@ -403,7 +408,7 @@ if hasattr(select, 'epoll'):
             return key
 
         def unregister(self, fileobj):
-            key = super().unregister(fileobj)
+            key = super(EpollSelector, self).unregister(fileobj)
             try:
                 self._epoll.unregister(key.fd)
             except OSError:
@@ -429,7 +434,7 @@ if hasattr(select, 'epoll'):
 
             ready = []
             try:
-                fd_event_list = self._epoll.poll(timeout, max_ev)
+                fd_event_list = wrap_error(self._epoll.poll, timeout, max_ev)
             except InterruptedError:
                 return ready
             for fd, event in fd_event_list:
@@ -446,7 +451,7 @@ if hasattr(select, 'epoll'):
 
         def close(self):
             self._epoll.close()
-            super().close()
+            super(EpollSelector, self).close()
 
 
 if hasattr(select, 'devpoll'):
@@ -455,14 +460,14 @@ if hasattr(select, 'devpoll'):
         """Solaris /dev/poll selector."""
 
         def __init__(self):
-            super().__init__()
+            super(DevpollSelector, self).__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)
+            key = super(DevpollSelector, self).register(fileobj, events, data)
             poll_events = 0
             if events & EVENT_READ:
                 poll_events |= select.POLLIN
@@ -472,7 +477,7 @@ if hasattr(select, 'devpoll'):
             return key
 
         def unregister(self, fileobj):
-            key = super().unregister(fileobj)
+            key = super(DevpollSelector, self).unregister(fileobj)
             self._devpoll.unregister(key.fd)
             return key
 
@@ -504,7 +509,7 @@ if hasattr(select, 'devpoll'):
 
         def close(self):
             self._devpoll.close()
-            super().close()
+            super(DevpollSelector, self).close()
 
 
 if hasattr(select, 'kqueue'):
@@ -513,14 +518,14 @@ if hasattr(select, 'kqueue'):
         """Kqueue-based selector."""
 
         def __init__(self):
-            super().__init__()
+            super(KqueueSelector, self).__init__()
             self._kqueue = select.kqueue()
 
         def fileno(self):
             return self._kqueue.fileno()
 
         def register(self, fileobj, events, data=None):
-            key = super().register(fileobj, events, data)
+            key = super(KqueueSelector, self).register(fileobj, events, data)
             if events & EVENT_READ:
                 kev = select.kevent(key.fd, select.KQ_FILTER_READ,
                                     select.KQ_EV_ADD)
@@ -532,7 +537,7 @@ if hasattr(select, 'kqueue'):
             return key
 
         def unregister(self, fileobj):
-            key = super().unregister(fileobj)
+            key = super(KqueueSelector, self).unregister(fileobj)
             if key.events & EVENT_READ:
                 kev = select.kevent(key.fd, select.KQ_FILTER_READ,
                                     select.KQ_EV_DELETE)
@@ -557,7 +562,8 @@ if hasattr(select, 'kqueue'):
             max_ev = len(self._fd_to_key)
             ready = []
             try:
-                kev_list = self._kqueue.control(None, max_ev, timeout)
+                kev_list = wrap_error(self._kqueue.control,
+                                      None, max_ev, timeout)
             except InterruptedError:
                 return ready
             for kev in kev_list:
@@ -576,7 +582,7 @@ if hasattr(select, 'kqueue'):
 
         def close(self):
             self._kqueue.close()
-            super().close()
+            super(KqueueSelector, self).close()
 
 
 # Choose the best implementation, roughly:
diff --git a/trollius/sslproto.py b/trollius/sslproto.py
index 235855e..5f4920a 100644
--- a/trollius/sslproto.py
+++ b/trollius/sslproto.py
@@ -9,6 +9,7 @@ except ImportError:  # pragma: no cover
 from . import protocols
 from . import transports
 from .log import logger
+from .py3_ssl import BACKPORT_SSL_CONTEXT
 
 
 def _create_transport_context(server_side, server_hostname):
@@ -26,10 +27,11 @@ def _create_transport_context(server_side, server_hostname):
     else:
         # Fallback for Python 3.3.
         sslcontext = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
-        sslcontext.options |= ssl.OP_NO_SSLv2
-        sslcontext.options |= ssl.OP_NO_SSLv3
-        sslcontext.set_default_verify_paths()
-        sslcontext.verify_mode = ssl.CERT_REQUIRED
+        if not BACKPORT_SSL_CONTEXT:
+            sslcontext.options |= ssl.OP_NO_SSLv2
+            sslcontext.options |= ssl.OP_NO_SSLv3
+            sslcontext.set_default_verify_paths()
+            sslcontext.verify_mode = ssl.CERT_REQUIRED
     return sslcontext
 
 
@@ -43,6 +45,11 @@ _DO_HANDSHAKE = "DO_HANDSHAKE"
 _WRAPPED = "WRAPPED"
 _SHUTDOWN = "SHUTDOWN"
 
+if hasattr(ssl, 'CertificateError'):
+    _SSL_ERRORS = (ssl.SSLError, ssl.CertificateError)
+else:
+    _SSL_ERRORS = ssl.SSLError
+
 
 class _SSLPipe(object):
     """An SSL "Pipe".
@@ -224,7 +231,7 @@ class _SSLPipe(object):
             elif self._state == _UNWRAPPED:
                 # Drain possible plaintext data after close_notify.
                 appdata.append(self._incoming.read())
-        except (ssl.SSLError, ssl.CertificateError) as exc:
+        except _SSL_ERRORS as exc:
             if getattr(exc, 'errno', None) not in (
                     ssl.SSL_ERROR_WANT_READ, ssl.SSL_ERROR_WANT_WRITE,
                     ssl.SSL_ERROR_SYSCALL):
@@ -569,7 +576,8 @@ class SSLProtocol(protocols.Protocol):
                     ssl.match_hostname(peercert, self._server_hostname)
         except BaseException as exc:
             if self._loop.get_debug():
-                if isinstance(exc, ssl.CertificateError):
+                if (hasattr(ssl, 'CertificateError')
+                and isinstance(exc, ssl.CertificateError)):
                     logger.warning("%r: SSL handshake failed "
                                    "on verifying the certificate",
                                    self, exc_info=True)
diff --git a/trollius/streams.py b/trollius/streams.py
index 176c65e..c235c5a 100644
--- a/trollius/streams.py
+++ b/trollius/streams.py
@@ -15,7 +15,8 @@ from . import coroutines
 from . import events
 from . import futures
 from . import protocols
-from .coroutines import coroutine
+from .coroutines import coroutine, From, Return
+from .py33_exceptions import ConnectionResetError
 from .log import logger
 
 
@@ -38,7 +39,7 @@ class IncompleteReadError(EOFError):
 
 
 @coroutine
-def open_connection(host=None, port=None, *,
+def open_connection(host=None, port=None,
                     loop=None, limit=_DEFAULT_LIMIT, **kwds):
     """A wrapper for create_connection() returning a (reader, writer) pair.
 
@@ -61,14 +62,14 @@ def open_connection(host=None, port=None, *,
         loop = events.get_event_loop()
     reader = StreamReader(limit=limit, loop=loop)
     protocol = StreamReaderProtocol(reader, loop=loop)
-    transport, _ = yield from loop.create_connection(
-        lambda: protocol, host, port, **kwds)
+    transport, _ = yield From(loop.create_connection(
+        lambda: protocol, host, port, **kwds))
     writer = StreamWriter(transport, protocol, reader, loop)
-    return reader, writer
+    raise Return(reader, writer)
 
 
 @coroutine
-def start_server(client_connected_cb, host=None, port=None, *,
+def start_server(client_connected_cb, host=None, port=None,
                  loop=None, limit=_DEFAULT_LIMIT, **kwds):
     """Start a socket server, call back for each client connected.
 
@@ -100,28 +101,29 @@ def start_server(client_connected_cb, host=None, port=None, *,
                                         loop=loop)
         return protocol
 
-    return (yield from loop.create_server(factory, host, port, **kwds))
+    server = yield From(loop.create_server(factory, host, port, **kwds))
+    raise Return(server)
 
 
 if hasattr(socket, 'AF_UNIX'):
     # UNIX Domain Sockets are supported on this platform
 
     @coroutine
-    def open_unix_connection(path=None, *,
+    def open_unix_connection(path=None,
                              loop=None, limit=_DEFAULT_LIMIT, **kwds):
         """Similar to `open_connection` but works with UNIX Domain Sockets."""
         if loop is None:
             loop = events.get_event_loop()
         reader = StreamReader(limit=limit, loop=loop)
         protocol = StreamReaderProtocol(reader, loop=loop)
-        transport, _ = yield from loop.create_unix_connection(
-            lambda: protocol, path, **kwds)
+        transport, _ = yield From(loop.create_unix_connection(
+            lambda: protocol, path, **kwds))
         writer = StreamWriter(transport, protocol, reader, loop)
-        return reader, writer
+        raise Return(reader, writer)
 
 
     @coroutine
-    def start_unix_server(client_connected_cb, path=None, *,
+    def start_unix_server(client_connected_cb, path=None,
                           loop=None, limit=_DEFAULT_LIMIT, **kwds):
         """Similar to `start_server` but works with UNIX Domain Sockets."""
         if loop is None:
@@ -133,7 +135,8 @@ if hasattr(socket, 'AF_UNIX'):
                                             loop=loop)
             return protocol
 
-        return (yield from loop.create_unix_server(factory, path, **kwds))
+        server = (yield From(loop.create_unix_server(factory, path, **kwds)))
+        raise Return(server)
 
 
 class FlowControlMixin(protocols.Protocol):
@@ -199,7 +202,7 @@ class FlowControlMixin(protocols.Protocol):
         assert waiter is None or waiter.cancelled()
         waiter = futures.Future(loop=self._loop)
         self._drain_waiter = waiter
-        yield from waiter
+        yield From(waiter)
 
 
 class StreamReaderProtocol(FlowControlMixin, protocols.Protocol):
@@ -212,7 +215,7 @@ class StreamReaderProtocol(FlowControlMixin, protocols.Protocol):
     """
 
     def __init__(self, stream_reader, client_connected_cb=None, loop=None):
-        super().__init__(loop=loop)
+        super(StreamReaderProtocol, self).__init__(loop=loop)
         self._stream_reader = stream_reader
         self._stream_writer = None
         self._client_connected_cb = client_connected_cb
@@ -233,7 +236,7 @@ class StreamReaderProtocol(FlowControlMixin, protocols.Protocol):
             self._stream_reader.feed_eof()
         else:
             self._stream_reader.set_exception(exc)
-        super().connection_lost(exc)
+        super(StreamReaderProtocol, self).connection_lost(exc)
 
     def data_received(self, data):
         self._stream_reader.feed_data(data)
@@ -242,7 +245,7 @@ class StreamReaderProtocol(FlowControlMixin, protocols.Protocol):
         self._stream_reader.feed_eof()
 
 
-class StreamWriter:
+class StreamWriter(object):
     """Wraps a Transport.
 
     This exposes write(), writelines(), [can_]write_eof(),
@@ -295,16 +298,16 @@ class StreamWriter:
         The intended use is to write
 
           w.write(data)
-          yield from w.drain()
+          yield From(w.drain())
         """
         if self._reader is not None:
             exc = self._reader.exception()
             if exc is not None:
                 raise exc
-        yield from self._protocol._drain_helper()
+        yield From(self._protocol._drain_helper())
 
 
-class StreamReader:
+class StreamReader(object):
 
     def __init__(self, limit=_DEFAULT_LIMIT, loop=None):
         # The line length limit is  a security feature;
@@ -391,9 +394,16 @@ class StreamReader:
             raise RuntimeError('%s() called while another coroutine is '
                                'already waiting for incoming data' % func_name)
 
+        # In asyncio, there is no need to recheck if we got data or EOF thanks
+        # to "yield from". In trollius, a StreamReader method can be called
+        # after the _wait_for_data() coroutine is scheduled and before it is
+        # really executed.
+        if self._buffer or self._eof:
+            return
+
         self._waiter = futures.Future(loop=self._loop)
         try:
-            yield from self._waiter
+            yield From(self._waiter)
         finally:
             self._waiter = None
 
@@ -410,7 +420,7 @@ class StreamReader:
                 ichar = self._buffer.find(b'\n')
                 if ichar < 0:
                     line.extend(self._buffer)
-                    self._buffer.clear()
+                    del self._buffer[:]
                 else:
                     ichar += 1
                     line.extend(self._buffer[:ichar])
@@ -425,10 +435,10 @@ class StreamReader:
                 break
 
             if not_enough:
-                yield from self._wait_for_data('readline')
+                yield From(self._wait_for_data('readline'))
 
         self._maybe_resume_transport()
-        return bytes(line)
+        raise Return(bytes(line))
 
     @coroutine
     def read(self, n=-1):
@@ -436,7 +446,7 @@ class StreamReader:
             raise self._exception
 
         if not n:
-            return b''
+            raise Return(b'')
 
         if n < 0:
             # This used to just loop creating a new waiter hoping to
@@ -445,25 +455,25 @@ class StreamReader:
             # bytes.  So just call self.read(self._limit) until EOF.
             blocks = []
             while True:
-                block = yield from self.read(self._limit)
+                block = yield From(self.read(self._limit))
                 if not block:
                     break
                 blocks.append(block)
-            return b''.join(blocks)
+            raise Return(b''.join(blocks))
         else:
             if not self._buffer and not self._eof:
-                yield from self._wait_for_data('read')
+                yield From(self._wait_for_data('read'))
 
         if n < 0 or len(self._buffer) <= n:
             data = bytes(self._buffer)
-            self._buffer.clear()
+            del self._buffer[:]
         else:
             # n > 0 and len(self._buffer) > n
             data = bytes(self._buffer[:n])
             del self._buffer[:n]
 
         self._maybe_resume_transport()
-        return data
+        raise Return(data)
 
     @coroutine
     def readexactly(self, n):
@@ -479,14 +489,14 @@ class StreamReader:
 
         blocks = []
         while n > 0:
-            block = yield from self.read(n)
+            block = yield From(self.read(n))
             if not block:
                 partial = b''.join(blocks)
                 raise IncompleteReadError(partial, len(partial) + n)
             blocks.append(block)
             n -= len(block)
 
-        return b''.join(blocks)
+        raise Return(b''.join(blocks))
 
     if _PY35:
         @coroutine
diff --git a/trollius/subprocess.py b/trollius/subprocess.py
index 4600a9f..2f1becf 100644
--- a/trollius/subprocess.py
+++ b/trollius/subprocess.py
@@ -8,13 +8,16 @@ from . import futures
 from . import protocols
 from . import streams
 from . import tasks
-from .coroutines import coroutine
+from .coroutines import coroutine, From, Return
+from .py33_exceptions import (BrokenPipeError, ConnectionResetError,
+                              ProcessLookupError)
 from .log import logger
 
 
 PIPE = subprocess.PIPE
 STDOUT = subprocess.STDOUT
-DEVNULL = subprocess.DEVNULL
+if hasattr(subprocess, 'DEVNULL'):
+    DEVNULL = subprocess.DEVNULL
 
 
 class SubprocessStreamProtocol(streams.FlowControlMixin,
@@ -22,7 +25,7 @@ class SubprocessStreamProtocol(streams.FlowControlMixin,
     """Like StreamReaderProtocol, but for a subprocess."""
 
     def __init__(self, limit, loop):
-        super().__init__(loop=loop)
+        super(SubprocessStreamProtocol, self).__init__(loop=loop)
         self._limit = limit
         self.stdin = self.stdout = self.stderr = None
         self._transport = None
@@ -115,7 +118,8 @@ class Process:
         """Wait until the process exit and return the process return code.
 
         This method is a coroutine."""
-        return (yield from self._transport._wait())
+        return_code = yield From(self._transport._wait())
+        raise Return(return_code)
 
     def send_signal(self, signal):
         self._transport.send_signal(signal)
@@ -134,7 +138,7 @@ class Process:
             logger.debug('%r communicate: feed stdin (%s bytes)',
                         self, len(input))
         try:
-            yield from self.stdin.drain()
+            yield From(self.stdin.drain())
         except (BrokenPipeError, ConnectionResetError) as exc:
             # communicate() ignores BrokenPipeError and ConnectionResetError
             if debug:
@@ -159,12 +163,12 @@ class Process:
         if self._loop.get_debug():
             name = 'stdout' if fd == 1 else 'stderr'
             logger.debug('%r communicate: read %s', self, name)
-        output = yield from stream.read()
+        output = yield From(stream.read())
         if self._loop.get_debug():
             name = 'stdout' if fd == 1 else 'stderr'
             logger.debug('%r communicate: close %s', self, name)
         transport.close()
-        return output
+        raise Return(output)
 
     @coroutine
     def communicate(self, input=None):
@@ -180,36 +184,43 @@ class Process:
             stderr = self._read_stream(2)
         else:
             stderr = self._noop()
-        stdin, stdout, stderr = yield from tasks.gather(stdin, stdout, stderr,
-                                                        loop=self._loop)
-        yield from self.wait()
-        return (stdout, stderr)
+        stdin, stdout, stderr = yield From(tasks.gather(stdin, stdout, stderr,
+                                                        loop=self._loop))
+        yield From(self.wait())
+        raise Return(stdout, stderr)
 
 
 @coroutine
-def create_subprocess_shell(cmd, stdin=None, stdout=None, stderr=None,
-                            loop=None, limit=streams._DEFAULT_LIMIT, **kwds):
+def create_subprocess_shell(cmd, **kwds):
+    stdin = kwds.pop('stdin', None)
+    stdout = kwds.pop('stdout', None)
+    stderr = kwds.pop('stderr', None)
+    loop = kwds.pop('loop', None)
+    limit = kwds.pop('limit', streams._DEFAULT_LIMIT)
     if loop is None:
         loop = events.get_event_loop()
     protocol_factory = lambda: SubprocessStreamProtocol(limit=limit,
                                                         loop=loop)
-    transport, protocol = yield from loop.subprocess_shell(
+    transport, protocol = yield From(loop.subprocess_shell(
                                             protocol_factory,
                                             cmd, stdin=stdin, stdout=stdout,
-                                            stderr=stderr, **kwds)
-    return Process(transport, protocol, loop)
+                                            stderr=stderr, **kwds))
+    raise Return(Process(transport, protocol, loop))
 
 @coroutine
-def create_subprocess_exec(program, *args, stdin=None, stdout=None,
-                           stderr=None, loop=None,
-                           limit=streams._DEFAULT_LIMIT, **kwds):
+def create_subprocess_exec(program, *args, **kwds):
+    stdin = kwds.pop('stdin', None)
+    stdout = kwds.pop('stdout', None)
+    stderr = kwds.pop('stderr', None)
+    loop = kwds.pop('loop', None)
+    limit = kwds.pop('limit', streams._DEFAULT_LIMIT)
     if loop is None:
         loop = events.get_event_loop()
     protocol_factory = lambda: SubprocessStreamProtocol(limit=limit,
                                                         loop=loop)
-    transport, protocol = yield from loop.subprocess_exec(
+    transport, protocol = yield From(loop.subprocess_exec(
                                             protocol_factory,
                                             program, *args,
                                             stdin=stdin, stdout=stdout,
-                                            stderr=stderr, **kwds)
-    return Process(transport, protocol, loop)
+                                            stderr=stderr, **kwds))
+    raise Return(Process(transport, protocol, loop))
diff --git a/trollius/tasks.py b/trollius/tasks.py
index d8193ba..1fb23cd 100644
--- a/trollius/tasks.py
+++ b/trollius/tasks.py
@@ -14,16 +14,30 @@ import sys
 import types
 import traceback
 import warnings
-import weakref
+try:
+    from weakref import WeakSet
+except ImportError:
+    # Python 2.6
+    from .py27_weakrefset import WeakSet
 
+from . import compat
 from . import coroutines
 from . import events
+from . import executor
 from . import futures
-from .coroutines import coroutine
+from .locks import Lock, Condition, Semaphore, _ContextManager
+from .coroutines import coroutine, From, Return
+
 
 _PY34 = (sys.version_info >= (3, 4))
 
 
+@coroutine
+def _lock_coroutine(lock):
+    yield From(lock.acquire())
+    raise Return(_ContextManager(lock))
+
+
 class Task(futures.Future):
     """A coroutine wrapped in a Future."""
 
@@ -37,7 +51,7 @@ class Task(futures.Future):
     # must be _wakeup().
 
     # Weak set containing all tasks alive.
-    _all_tasks = weakref.WeakSet()
+    _all_tasks = WeakSet()
 
     # Dictionary containing tasks that are currently active in
     # all running event loops.  {EventLoop: Task}
@@ -67,11 +81,11 @@ class Task(futures.Future):
         """
         if loop is None:
             loop = events.get_event_loop()
-        return {t for t in cls._all_tasks if t._loop is loop}
+        return set(t for t in cls._all_tasks if t._loop is loop)
 
-    def __init__(self, coro, *, loop=None):
+    def __init__(self, coro, loop=None):
         assert coroutines.iscoroutine(coro), repr(coro)
-        super().__init__(loop=loop)
+        super(Task, self).__init__(loop=loop)
         if self._source_traceback:
             del self._source_traceback[-1]
         self._coro = coro
@@ -96,7 +110,7 @@ class Task(futures.Future):
             futures.Future.__del__(self)
 
     def _repr_info(self):
-        info = super()._repr_info()
+        info = super(Task, self)._repr_info()
 
         if self._must_cancel:
             # replace status
@@ -109,7 +123,7 @@ class Task(futures.Future):
             info.insert(2, 'wait_for=%r' % self._fut_waiter)
         return info
 
-    def get_stack(self, *, limit=None):
+    def get_stack(self, limit=None):
         """Return the list of stack frames for this task's coroutine.
 
         If the coroutine is not done, this returns the stack where it is
@@ -152,7 +166,7 @@ class Task(futures.Future):
                 tb = tb.tb_next
         return frames
 
-    def print_stack(self, *, limit=None, file=None):
+    def print_stack(self, limit=None, file=None):
         """Print the stack or traceback for this task's coroutine.
 
         This produces output similar to that of the traceback module,
@@ -219,9 +233,9 @@ class Task(futures.Future):
         self._must_cancel = True
         return True
 
-    def _step(self, value=None, exc=None):
+    def _step(self, value=None, exc=None, exc_tb=None):
         assert not self.done(), \
-            '_step(): already done: {!r}, {!r}, {!r}'.format(self, value, exc)
+            '_step(): already done: {0!r}, {1!r}, {2!r}'.format(self, value, exc)
         if self._must_cancel:
             if not isinstance(exc, futures.CancelledError):
                 exc = futures.CancelledError()
@@ -229,6 +243,10 @@ class Task(futures.Future):
         coro = self._coro
         self._fut_waiter = None
 
+        if exc_tb is not None:
+            init_exc = exc
+        else:
+            init_exc = None
         self.__class__._current_tasks[self._loop] = self
         # Call either coro.throw(exc) or coro.send(value).
         try:
@@ -237,71 +255,104 @@ class Task(futures.Future):
             else:
                 result = coro.send(value)
         except StopIteration as exc:
-            self.set_result(exc.value)
+            if compat.PY33:
+                # asyncio Task object? get the result of the coroutine
+                result = exc.value
+            else:
+                if isinstance(exc, Return):
+                    exc.raised = True
+                    result = exc.value
+                else:
+                    result = None
+            self.set_result(result)
         except futures.CancelledError as exc:
-            super().cancel()  # I.e., Future.cancel(self).
-        except Exception as exc:
-            self.set_exception(exc)
+            super(Task, self).cancel()  # I.e., Future.cancel(self).
         except BaseException as exc:
-            self.set_exception(exc)
-            raise
+            if exc is init_exc:
+                self._set_exception_with_tb(exc, exc_tb)
+                exc_tb = None
+            else:
+                self.set_exception(exc)
+
+            if not isinstance(exc, Exception):
+                # reraise BaseException
+                raise
         else:
-            if isinstance(result, futures.Future):
-                # Yielded Future must come from Future.__iter__().
-                if result._blocking:
-                    result._blocking = False
-                    result.add_done_callback(self._wakeup)
-                    self._fut_waiter = result
-                    if self._must_cancel:
-                        if self._fut_waiter.cancel():
-                            self._must_cancel = False
+            if coroutines._DEBUG:
+                if not coroutines._coroutine_at_yield_from(self._coro):
+                    # trollius coroutine must "yield From(...)"
+                    if not isinstance(result, coroutines.FromWrapper):
+                        self._loop.call_soon(
+                            self._step, None,
+                            RuntimeError("yield used without From"))
+                        return
+                    result = result.obj
                 else:
-                    self._loop.call_soon(
-                        self._step, None,
-                        RuntimeError(
-                            'yield was used instead of yield from '
-                            'in task {!r} with {!r}'.format(self, result)))
+                    # asyncio coroutine using "yield from ..."
+                    if isinstance(result, coroutines.FromWrapper):
+                        result = result.obj
+            elif isinstance(result, coroutines.FromWrapper):
+                result = result.obj
+
+            if coroutines.iscoroutine(result):
+                # "yield coroutine" creates a task, the current task
+                # will wait until the new task is done
+                result = self._loop.create_task(result)
+            # FIXME: faster check. common base class? hasattr?
+            elif isinstance(result, (Lock, Condition, Semaphore)):
+                coro = _lock_coroutine(result)
+                result = self._loop.create_task(coro)
+
+            if isinstance(result, futures._FUTURE_CLASSES):
+                # Yielded Future must come from Future.__iter__().
+                result.add_done_callback(self._wakeup)
+                self._fut_waiter = result
+                if self._must_cancel:
+                    if self._fut_waiter.cancel():
+                        self._must_cancel = False
             elif result is None:
                 # Bare yield relinquishes control for one event loop iteration.
                 self._loop.call_soon(self._step)
-            elif inspect.isgenerator(result):
-                # Yielding a generator is just wrong.
-                self._loop.call_soon(
-                    self._step, None,
-                    RuntimeError(
-                        'yield was used instead of yield from for '
-                        'generator in task {!r} with {}'.format(
-                            self, result)))
             else:
                 # Yielding something else is an error.
                 self._loop.call_soon(
                     self._step, None,
                     RuntimeError(
-                        'Task got bad yield: {!r}'.format(result)))
+                        'Task got bad yield: {0!r}'.format(result)))
         finally:
             self.__class__._current_tasks.pop(self._loop)
             self = None  # Needed to break cycles when an exception occurs.
 
     def _wakeup(self, future):
-        try:
-            value = future.result()
-        except Exception as exc:
-            # This may also be a cancellation.
-            self._step(None, exc)
+        if (future._state == futures._FINISHED
+        and future._exception is not None):
+            # Get the traceback before calling exception(), because calling
+            # the exception() method clears the traceback
+            exc_tb = future._get_exception_tb()
+            exc = future.exception()
+            self._step(None, exc, exc_tb)
+            exc_tb = None
         else:
-            self._step(value, None)
+            try:
+                value = future.result()
+            except Exception as exc:
+                # This may also be a cancellation.
+                self._step(None, exc)
+            else:
+                self._step(value, None)
         self = None  # Needed to break cycles when an exception occurs.
 
 
 # wait() and as_completed() similar to those in PEP 3148.
 
-FIRST_COMPLETED = concurrent.futures.FIRST_COMPLETED
-FIRST_EXCEPTION = concurrent.futures.FIRST_EXCEPTION
-ALL_COMPLETED = concurrent.futures.ALL_COMPLETED
+# Export symbols in trollius.tasks for compatibility with asyncio
+FIRST_COMPLETED = executor.FIRST_COMPLETED
+FIRST_EXCEPTION = executor.FIRST_EXCEPTION
+ALL_COMPLETED = executor.ALL_COMPLETED
 
 
 @coroutine
-def wait(fs, *, loop=None, timeout=None, return_when=ALL_COMPLETED):
+def wait(fs, loop=None, timeout=None, return_when=ALL_COMPLETED):
     """Wait for the Futures and coroutines given by fs to complete.
 
     The sequence futures must not be empty.
@@ -312,24 +363,25 @@ def wait(fs, *, loop=None, timeout=None, return_when=ALL_COMPLETED):
 
     Usage:
 
-        done, pending = yield from asyncio.wait(fs)
+        done, pending = yield From(asyncio.wait(fs))
 
     Note: This does not raise TimeoutError! Futures that aren't done
     when the timeout occurs are returned in the second set.
     """
-    if isinstance(fs, futures.Future) or coroutines.iscoroutine(fs):
+    if isinstance(fs, futures._FUTURE_CLASSES) or coroutines.iscoroutine(fs):
         raise TypeError("expect a list of futures, not %s" % type(fs).__name__)
     if not fs:
         raise ValueError('Set of coroutines/Futures is empty.')
     if return_when not in (FIRST_COMPLETED, FIRST_EXCEPTION, ALL_COMPLETED):
-        raise ValueError('Invalid return_when value: {}'.format(return_when))
+        raise ValueError('Invalid return_when value: {0}'.format(return_when))
 
     if loop is None:
         loop = events.get_event_loop()
 
-    fs = {ensure_future(f, loop=loop) for f in set(fs)}
+    fs = set(ensure_future(f, loop=loop) for f in set(fs))
 
-    return (yield from _wait(fs, timeout, return_when, loop))
+    result = yield From(_wait(fs, timeout, return_when, loop))
+    raise Return(result)
 
 
 def _release_waiter(waiter, *args):
@@ -338,7 +390,7 @@ def _release_waiter(waiter, *args):
 
 
 @coroutine
-def wait_for(fut, timeout, *, loop=None):
+def wait_for(fut, timeout, loop=None):
     """Wait for the single Future or coroutine to complete, with timeout.
 
     Coroutine will be wrapped in Task.
@@ -355,7 +407,8 @@ def wait_for(fut, timeout, *, loop=None):
         loop = events.get_event_loop()
 
     if timeout is None:
-        return (yield from fut)
+	result = yield From(fut)
+        raise Return(result)
 
     waiter = futures.Future(loop=loop)
     timeout_handle = loop.call_later(timeout, _release_waiter, waiter)
@@ -367,14 +420,14 @@ def wait_for(fut, timeout, *, loop=None):
     try:
         # wait until the future completes or the timeout
         try:
-            yield from waiter
+            yield From(waiter)
         except futures.CancelledError:
             fut.remove_done_callback(cb)
             fut.cancel()
             raise
 
         if fut.done():
-            return fut.result()
+            raise Return(fut.result())
         else:
             fut.remove_done_callback(cb)
             fut.cancel()
@@ -394,12 +447,11 @@ def _wait(fs, timeout, return_when, loop):
     timeout_handle = None
     if timeout is not None:
         timeout_handle = loop.call_later(timeout, _release_waiter, waiter)
-    counter = len(fs)
+    non_local = {'counter': len(fs)}
 
     def _on_completion(f):
-        nonlocal counter
-        counter -= 1
-        if (counter <= 0 or
+        non_local['counter'] -= 1
+        if (non_local['counter'] <= 0 or
             return_when == FIRST_COMPLETED or
             return_when == FIRST_EXCEPTION and (not f.cancelled() and
                                                 f.exception() is not None)):
@@ -412,7 +464,7 @@ def _wait(fs, timeout, return_when, loop):
         f.add_done_callback(_on_completion)
 
     try:
-        yield from waiter
+        yield From(waiter)
     finally:
         if timeout_handle is not None:
             timeout_handle.cancel()
@@ -424,11 +476,11 @@ def _wait(fs, timeout, return_when, loop):
             done.add(f)
         else:
             pending.add(f)
-    return done, pending
+    raise Return(done, pending)
 
 
 # This is *not* a @coroutine!  It is just an iterator (yielding Futures).
-def as_completed(fs, *, loop=None, timeout=None):
+def as_completed(fs, loop=None, timeout=None):
     """Return an iterator whose values are coroutines.
 
     When waiting for the yielded coroutines you'll get the results (or
@@ -438,18 +490,18 @@ def as_completed(fs, *, loop=None, timeout=None):
     This differs from PEP 3148; the proper way to use this is:
 
         for f in as_completed(fs):
-            result = yield from f  # The 'yield from' may raise.
+            result = yield From(f)  # The 'yield' may raise.
             # Use result.
 
-    If a timeout is specified, the 'yield from' will raise
+    If a timeout is specified, the 'yield' will raise
     TimeoutError when the timeout occurs before all Futures are done.
 
     Note: The futures 'f' are not necessarily members of fs.
     """
-    if isinstance(fs, futures.Future) or coroutines.iscoroutine(fs):
+    if isinstance(fs, futures._FUTURE_CLASSES) or coroutines.iscoroutine(fs):
         raise TypeError("expect a list of futures, not %s" % type(fs).__name__)
     loop = loop if loop is not None else events.get_event_loop()
-    todo = {ensure_future(f, loop=loop) for f in set(fs)}
+    todo = set(ensure_future(f, loop=loop) for f in set(fs))
     from .queues import Queue  # Import here to avoid circular import problem.
     done = Queue(loop=loop)
     timeout_handle = None
@@ -470,11 +522,11 @@ def as_completed(fs, *, loop=None, timeout=None):
 
     @coroutine
     def _wait_for_one():
-        f = yield from done.get()
+        f = yield From(done.get())
         if f is None:
             # Dummy value from _on_timeout().
             raise futures.TimeoutError
-        return f.result()  # May raise f.exception().
+        raise Return(f.result())   # May raise f.exception().
 
     for f in todo:
         f.add_done_callback(_on_completion)
@@ -485,18 +537,19 @@ def as_completed(fs, *, loop=None, timeout=None):
 
 
 @coroutine
-def sleep(delay, result=None, *, loop=None):
+def sleep(delay, result=None, loop=None):
     """Coroutine that completes after a given time (in seconds)."""
     future = futures.Future(loop=loop)
     h = future._loop.call_later(delay,
                                 future._set_result_unless_cancelled, result)
     try:
-        return (yield from future)
+        result = yield From(future)
+        raise Return(result)
     finally:
         h.cancel()
 
 
-def async(coro_or_future, *, loop=None):
+def async(coro_or_future, loop=None):
     """Wrap a coroutine in a future.
 
     If the argument is a Future, it is returned directly.
@@ -515,7 +568,10 @@ def ensure_future(coro_or_future, *, loop=None):
 
     If the argument is a Future, it is returned directly.
     """
-    if isinstance(coro_or_future, futures.Future):
+    # FIXME: only check if coroutines._DEBUG is True?
+    if isinstance(coro_or_future, coroutines.FromWrapper):
+        coro_or_future = coro_or_future.obj
+    if isinstance(coro_or_future, futures._FUTURE_CLASSES):
         if loop is not None and loop is not coro_or_future._loop:
             raise ValueError('loop argument must agree with Future')
         return coro_or_future
@@ -538,8 +594,8 @@ class _GatheringFuture(futures.Future):
     cancelled.
     """
 
-    def __init__(self, children, *, loop=None):
-        super().__init__(loop=loop)
+    def __init__(self, children, loop=None):
+        super(_GatheringFuture, self).__init__(loop=loop)
         self._children = children
 
     def cancel(self):
@@ -550,7 +606,7 @@ class _GatheringFuture(futures.Future):
         return True
 
 
-def gather(*coros_or_futures, loop=None, return_exceptions=False):
+def gather(*coros_or_futures, **kw):
     """Return a future aggregating results from the given coroutines
     or futures.
 
@@ -570,6 +626,11 @@ def gather(*coros_or_futures, loop=None, return_exceptions=False):
     prevent the cancellation of one child to cause other children to
     be cancelled.)
     """
+    loop = kw.pop('loop', None)
+    return_exceptions = kw.pop('return_exceptions', False)
+    if kw:
+        raise TypeError("unexpected keyword")
+
     if not coros_or_futures:
         outer = futures.Future(loop=loop)
         outer.set_result([])
@@ -577,7 +638,7 @@ def gather(*coros_or_futures, loop=None, return_exceptions=False):
 
     arg_to_fut = {}
     for arg in set(coros_or_futures):
-        if not isinstance(arg, futures.Future):
+        if not isinstance(arg, futures._FUTURE_CLASSES):
             fut = ensure_future(arg, loop=loop)
             if loop is None:
                 loop = fut._loop
@@ -595,11 +656,10 @@ def gather(*coros_or_futures, loop=None, return_exceptions=False):
     children = [arg_to_fut[arg] for arg in coros_or_futures]
     nchildren = len(children)
     outer = _GatheringFuture(children, loop=loop)
-    nfinished = 0
+    non_local = {'nfinished': 0}
     results = [None] * nchildren
 
     def _done_callback(i, fut):
-        nonlocal nfinished
         if outer.done():
             if not fut.cancelled():
                 # Mark exception retrieved.
@@ -619,8 +679,8 @@ def gather(*coros_or_futures, loop=None, return_exceptions=False):
         else:
             res = fut._result
         results[i] = res
-        nfinished += 1
-        if nfinished == nchildren:
+        non_local['nfinished'] += 1
+        if non_local['nfinished'] == nchildren:
             outer.set_result(results)
 
     for i, fut in enumerate(children):
@@ -628,16 +688,16 @@ def gather(*coros_or_futures, loop=None, return_exceptions=False):
     return outer
 
 
-def shield(arg, *, loop=None):
+def shield(arg, loop=None):
     """Wait for a future, shielding it from cancellation.
 
     The statement
 
-        res = yield from shield(something())
+        res = yield From(shield(something()))
 
     is exactly equivalent to the statement
 
-        res = yield from something()
+        res = yield From(something())
 
     *except* that if the coroutine containing it is cancelled, the
     task running in something() is not cancelled.  From the POV of
@@ -650,7 +710,7 @@ def shield(arg, *, loop=None):
     you can combine shield() with a try/except clause, as follows:
 
         try:
-            res = yield from shield(something())
+            res = yield From(shield(something()))
         except CancelledError:
             res = None
     """
diff --git a/trollius/test_support.py b/trollius/test_support.py
index 0fadfad..b40576a 100644
--- a/trollius/test_support.py
+++ b/trollius/test_support.py
@@ -4,6 +4,7 @@
 
 # Ignore symbol TEST_HOME_DIR: test_events works without it
 
+from __future__ import absolute_import
 import functools
 import gc
 import os
@@ -14,6 +15,7 @@ import subprocess
 import sys
 import time
 
+from trollius import test_utils
 
 # A constant likely larger than the underlying OS pipe buffer size, to
 # make writes blocking.
@@ -39,7 +41,9 @@ def _assert_python(expected_success, *args, **env_vars):
         isolated = env_vars.pop('__isolated')
     else:
         isolated = not env_vars
-    cmd_line = [sys.executable, '-X', 'faulthandler']
+    cmd_line = [sys.executable]
+    if sys.version_info >= (3, 3):
+        cmd_line.extend(('-X', 'faulthandler'))
     if isolated and sys.version_info >= (3, 4):
         # isolated mode: ignore Python environment variables, ignore user
         # site-packages, and don't add the current directory to sys.path
@@ -248,7 +252,7 @@ def requires_mac_ver(*min_version):
                 else:
                     if version < min_version:
                         min_version_txt = '.'.join(map(str, min_version))
-                        raise unittest.SkipTest(
+                        raise test_utils.SkipTest(
                             "Mac OS X %s or higher required, not %s"
                             % (min_version_txt, version_txt))
             return func(*args, **kw)
@@ -275,7 +279,7 @@ def _requires_unix_version(sysname, min_version):
                 else:
                     if version < min_version:
                         min_version_txt = '.'.join(map(str, min_version))
-                        raise unittest.SkipTest(
+                        raise test_utils.SkipTest(
                             "%s version %s or higher required, not %s"
                             % (sysname, min_version_txt, version_txt))
             return func(*args, **kw)
@@ -300,9 +304,6 @@ except ImportError:
 
 # Use test.script_helper if available
 try:
-    from test.support.script_helper import assert_python_ok
+    from test.script_helper import assert_python_ok
 except ImportError:
-    try:
-        from test.script_helper import assert_python_ok
-    except ImportError:
-        pass
+    pass
diff --git a/trollius/test_utils.py b/trollius/test_utils.py
index af7f5bc..caa98f7 100644
--- a/trollius/test_utils.py
+++ b/trollius/test_utils.py
@@ -7,20 +7,32 @@ import logging
 import os
 import re
 import socket
-import socketserver
 import sys
 import tempfile
 import threading
 import time
-import unittest
-from unittest import mock
 
-from http.server import HTTPServer
 from wsgiref.simple_server import WSGIRequestHandler, WSGIServer
 
 try:
+    import socketserver
+    from http.server import HTTPServer
+except ImportError:
+    # Python 2
+    import SocketServer as socketserver
+    from BaseHTTPServer import HTTPServer
+
+try:
+    from unittest import mock
+except ImportError:
+    # Python < 3.3
+    import mock
+
+try:
     import ssl
+    from .py3_ssl import SSLContext, wrap_socket
 except ImportError:  # pragma: no cover
+    # SSL support disabled in Python
     ssl = None
 
 from . import base_events
@@ -37,27 +49,116 @@ if sys.platform == 'win32':  # pragma: no cover
 else:
     from socket import socketpair  # pragma: no cover
 
+try:
+    import unittest
+    skipIf = unittest.skipIf
+    skipUnless = unittest.skipUnless
+    SkipTest = unittest.SkipTest
+    _TestCase = unittest.TestCase
+except AttributeError:
+    # Python 2.6: use the backported unittest module called "unittest2"
+    import unittest2
+    skipIf = unittest2.skipIf
+    skipUnless = unittest2.skipUnless
+    SkipTest = unittest2.SkipTest
+    _TestCase = unittest2.TestCase
+
+
+if not hasattr(_TestCase, 'assertRaisesRegex'):
+    class _BaseTestCaseContext:
+
+        def __init__(self, test_case):
+            self.test_case = test_case
+
+        def _raiseFailure(self, standardMsg):
+            msg = self.test_case._formatMessage(self.msg, standardMsg)
+            raise self.test_case.failureException(msg)
+
+
+    class _AssertRaisesBaseContext(_BaseTestCaseContext):
+
+        def __init__(self, expected, test_case, callable_obj=None,
+                     expected_regex=None):
+            _BaseTestCaseContext.__init__(self, test_case)
+            self.expected = expected
+            self.test_case = test_case
+            if callable_obj is not None:
+                try:
+                    self.obj_name = callable_obj.__name__
+                except AttributeError:
+                    self.obj_name = str(callable_obj)
+            else:
+                self.obj_name = None
+            if isinstance(expected_regex, (bytes, str)):
+                expected_regex = re.compile(expected_regex)
+            self.expected_regex = expected_regex
+            self.msg = None
+
+        def handle(self, name, callable_obj, args, kwargs):
+            """
+            If callable_obj is None, assertRaises/Warns is being used as a
+            context manager, so check for a 'msg' kwarg and return self.
+            If callable_obj is not None, call it passing args and kwargs.
+            """
+            if callable_obj is None:
+                self.msg = kwargs.pop('msg', None)
+                return self
+            with self:
+                callable_obj(*args, **kwargs)
+
+
+    class _AssertRaisesContext(_AssertRaisesBaseContext):
+        """A context manager used to implement TestCase.assertRaises* methods."""
+
+        def __enter__(self):
+            return self
+
+        def __exit__(self, exc_type, exc_value, tb):
+            if exc_type is None:
+                try:
+                    exc_name = self.expected.__name__
+                except AttributeError:
+                    exc_name = str(self.expected)
+                if self.obj_name:
+                    self._raiseFailure("{0} not raised by {1}".format(exc_name,
+                                                                    self.obj_name))
+                else:
+                    self._raiseFailure("{0} not raised".format(exc_name))
+            if not issubclass(exc_type, self.expected):
+                # let unexpected exceptions pass through
+                return False
+            self.exception = exc_value
+            if self.expected_regex is None:
+                return True
+
+            expected_regex = self.expected_regex
+            if not expected_regex.search(str(exc_value)):
+                self._raiseFailure('"{0}" does not match "{1}"'.format(
+                         expected_regex.pattern, str(exc_value)))
+            return True
+
 
 def dummy_ssl_context():
     if ssl is None:
         return None
     else:
-        return ssl.SSLContext(ssl.PROTOCOL_SSLv23)
+        return SSLContext(ssl.PROTOCOL_SSLv23)
 
 
-def run_briefly(loop):
+def run_briefly(loop, steps=1):
     @coroutine
     def once():
         pass
-    gen = once()
-    t = loop.create_task(gen)
-    # Don't log a warning if the task is not done after run_until_complete().
-    # It occurs if the loop is stopped or if a task raises a BaseException.
-    t._log_destroy_pending = False
-    try:
-        loop.run_until_complete(t)
-    finally:
-        gen.close()
+    for step in range(steps):
+        gen = once()
+        t = loop.create_task(gen)
+        # Don't log a warning if the task is not done after run_until_complete().
+        # It occurs if the loop is stopped or if a task raises a BaseException.
+        t._log_destroy_pending = False
+        try:
+            loop.run_until_complete(t)
+        finally:
+            gen.close()
 
 
 def run_until(loop, pred, timeout=30):
@@ -89,12 +190,12 @@ class SilentWSGIRequestHandler(WSGIRequestHandler):
         pass
 
 
-class SilentWSGIServer(WSGIServer):
+class SilentWSGIServer(WSGIServer, object):
 
     request_timeout = 2
 
     def get_request(self):
-        request, client_addr = super().get_request()
+        request, client_addr = super(SilentWSGIServer, self).get_request()
         request.settimeout(self.request_timeout)
         return request, client_addr
 
@@ -115,10 +216,10 @@ class SSLWSGIServerMixin:
                                 'test', 'test_asyncio')
         keyfile = os.path.join(here, 'ssl_key.pem')
         certfile = os.path.join(here, 'ssl_cert.pem')
-        ssock = ssl.wrap_socket(request,
-                                keyfile=keyfile,
-                                certfile=certfile,
-                                server_side=True)
+        ssock = wrap_socket(request,
+                            keyfile=keyfile,
+                            certfile=certfile,
+                            server_side=True)
         try:
             self.RequestHandlerClass(ssock, client_address, self)
             ssock.close()
@@ -131,7 +232,7 @@ class SSLWSGIServer(SSLWSGIServerMixin, SilentWSGIServer):
     pass
 
 
-def _run_test_server(*, address, use_ssl=False, server_cls, server_ssl_cls):
+def _run_test_server(address, use_ssl, server_cls, server_ssl_cls):
 
     def app(environ, start_response):
         status = '200 OK'
@@ -158,7 +259,7 @@ def _run_test_server(*, address, use_ssl=False, server_cls, server_ssl_cls):
 
 if hasattr(socket, 'AF_UNIX'):
 
-    class UnixHTTPServer(socketserver.UnixStreamServer, HTTPServer):
+    class UnixHTTPServer(socketserver.UnixStreamServer, HTTPServer, object):
 
         def server_bind(self):
             socketserver.UnixStreamServer.server_bind(self)
@@ -166,7 +267,7 @@ if hasattr(socket, 'AF_UNIX'):
             self.server_port = 80
 
 
-    class UnixWSGIServer(UnixHTTPServer, WSGIServer):
+    class UnixWSGIServer(UnixHTTPServer, WSGIServer, object):
 
         request_timeout = 2
 
@@ -175,7 +276,7 @@ if hasattr(socket, 'AF_UNIX'):
             self.setup_environ()
 
         def get_request(self):
-            request, client_addr = super().get_request()
+            request, client_addr = super(UnixWSGIServer, self).get_request()
             request.settimeout(self.request_timeout)
             # Code in the stdlib expects that get_request
             # will return a socket and a tuple (host, port).
@@ -214,18 +315,20 @@ if hasattr(socket, 'AF_UNIX'):
 
 
     @contextlib.contextmanager
-    def run_test_unix_server(*, use_ssl=False):
+    def run_test_unix_server(use_ssl=False):
         with unix_socket_path() as path:
-            yield from _run_test_server(address=path, use_ssl=use_ssl,
-                                        server_cls=SilentUnixWSGIServer,
-                                        server_ssl_cls=UnixSSLWSGIServer)
+            for item in _run_test_server(address=path, use_ssl=use_ssl,
+                                         server_cls=SilentUnixWSGIServer,
+                                         server_ssl_cls=UnixSSLWSGIServer):
+                yield item
 
 
 @contextlib.contextmanager
-def run_test_server(*, host='127.0.0.1', port=0, use_ssl=False):
-    yield from _run_test_server(address=(host, port), use_ssl=use_ssl,
-                                server_cls=SilentWSGIServer,
-                                server_ssl_cls=SSLWSGIServer)
+def run_test_server(host='127.0.0.1', port=0, use_ssl=False):
+    for item in _run_test_server(address=(host, port), use_ssl=use_ssl,
+                                 server_cls=SilentWSGIServer,
+                                 server_ssl_cls=SSLWSGIServer):
+        yield item
 
 
 def make_test_protocol(base):
@@ -278,7 +381,7 @@ class TestLoop(base_events.BaseEventLoop):
     """
 
     def __init__(self, gen=None):
-        super().__init__()
+        super(TestLoop, self).__init__()
 
         if gen is None:
             def gen():
@@ -307,7 +410,7 @@ class TestLoop(base_events.BaseEventLoop):
             self._time += advance
 
     def close(self):
-        super().close()
+        super(TestLoop, self).close()
         if self._check_on_close:
             try:
                 self._gen.send(0)
@@ -328,11 +431,11 @@ class TestLoop(base_events.BaseEventLoop):
             return False
 
     def assert_reader(self, fd, callback, *args):
-        assert fd in self.readers, 'fd {} is not registered'.format(fd)
+        assert fd in self.readers, 'fd {0} is not registered'.format(fd)
         handle = self.readers[fd]
-        assert handle._callback == callback, '{!r} != {!r}'.format(
+        assert handle._callback == callback, '{0!r} != {1!r}'.format(
             handle._callback, callback)
-        assert handle._args == args, '{!r} != {!r}'.format(
+        assert handle._args == args, '{0!r} != {1!r}'.format(
             handle._args, args)
 
     def add_writer(self, fd, callback, *args):
@@ -347,11 +450,11 @@ class TestLoop(base_events.BaseEventLoop):
             return False
 
     def assert_writer(self, fd, callback, *args):
-        assert fd in self.writers, 'fd {} is not registered'.format(fd)
+        assert fd in self.writers, 'fd {0} is not registered'.format(fd)
         handle = self.writers[fd]
-        assert handle._callback == callback, '{!r} != {!r}'.format(
+        assert handle._callback == callback, '{0!r} != {1!r}'.format(
             handle._callback, callback)
-        assert handle._args == args, '{!r} != {!r}'.format(
+        assert handle._args == args, '{0!r} != {1!r}'.format(
             handle._args, args)
 
     def reset_counters(self):
@@ -359,7 +462,7 @@ class TestLoop(base_events.BaseEventLoop):
         self.remove_writer_count = collections.defaultdict(int)
 
     def _run_once(self):
-        super()._run_once()
+        super(TestLoop, self)._run_once()
         for when in self._timers:
             advance = self._gen.send(when)
             self.advance_time(advance)
@@ -367,7 +470,7 @@ class TestLoop(base_events.BaseEventLoop):
 
     def call_at(self, when, callback, *args):
         self._timers.append(when)
-        return super().call_at(when, callback, *args)
+        return super(TestLoop, self).call_at(when, callback, *args)
 
     def _process_events(self, event_list):
         return
@@ -400,8 +503,8 @@ def get_function_source(func):
     return source
 
 
-class TestCase(unittest.TestCase):
-    def set_event_loop(self, loop, *, cleanup=True):
+class TestCase(_TestCase):
+    def set_event_loop(self, loop, cleanup=True):
         assert loop is not None
         # ensure that the event loop is passed explicitly in asyncio
         events.set_event_loop(None)
@@ -420,6 +523,48 @@ class TestCase(unittest.TestCase):
         # in an except block of a generator
         self.assertEqual(sys.exc_info(), (None, None, None))
 
+    if not hasattr(_TestCase, 'assertRaisesRegex'):
+        def assertRaisesRegex(self, expected_exception, expected_regex,
+                              callable_obj=None, *args, **kwargs):
+            """Asserts that the message in a raised exception matches a regex.
+
+            Args:
+                expected_exception: Exception class expected to be raised.
+                expected_regex: Regex (re pattern object or string) expected
+                        to be found in error message.
+                callable_obj: Function to be called.
+                msg: Optional message used in case of failure. Can only be used
+                        when assertRaisesRegex is used as a context manager.
+                args: Extra args.
+                kwargs: Extra kwargs.
+            """
+            context = _AssertRaisesContext(expected_exception, self, callable_obj,
+                                           expected_regex)
+
+            return context.handle('assertRaisesRegex', callable_obj, args, kwargs)
+
+    if not hasattr(_TestCase, 'assertRegex'):
+        def assertRegex(self, text, expected_regex, msg=None):
+            """Fail the test unless the text matches the regular expression."""
+            if isinstance(expected_regex, (str, bytes)):
+                assert expected_regex, "expected_regex must not be empty."
+                expected_regex = re.compile(expected_regex)
+            if not expected_regex.search(text):
+                msg = msg or "Regex didn't match"
+                msg = '%s: %r not found in %r' % (msg, expected_regex.pattern, text)
+                raise self.failureException(msg)
+
+    def check_soure_traceback(self, source_traceback, lineno_delta):
+        frame = sys._getframe(1)
+        filename = frame.f_code.co_filename
+        lineno = frame.f_lineno + lineno_delta
+        name = frame.f_code.co_name
+        self.assertIsInstance(source_traceback, list)
+        self.assertEqual(source_traceback[-1][:3],
+                         (filename,
+                          lineno,
+                          name))
+
 
 @contextlib.contextmanager
 def disable_logger():
diff --git a/trollius/transports.py b/trollius/transports.py
index 22df3c7..5bdbdaf 100644
--- a/trollius/transports.py
+++ b/trollius/transports.py
@@ -1,6 +1,7 @@
 """Abstract Transport class."""
 
 import sys
+from .compat import flatten_bytes
 
 _PY34 = sys.version_info >= (3, 4)
 
@@ -9,7 +10,7 @@ __all__ = ['BaseTransport', 'ReadTransport', 'WriteTransport',
            ]
 
 
-class BaseTransport:
+class BaseTransport(object):
     """Base class for transports."""
 
     def __init__(self, extra=None):
@@ -94,12 +95,8 @@ class WriteTransport(BaseTransport):
         The default implementation concatenates the arguments and
         calls write() on the result.
         """
-        if not _PY34:
-            # In Python 3.3, bytes.join() doesn't handle memoryview.
-            list_of_data = (
-                bytes(data) if isinstance(data, memoryview) else data
-                for data in list_of_data)
-        self.write(b''.join(list_of_data))
+        data = map(flatten_bytes, list_of_data)
+        self.write(b''.join(data))
 
     def write_eof(self):
         """Close the write end after flushing buffered data.
@@ -230,7 +227,7 @@ class _FlowControlMixin(Transport):
     override set_write_buffer_limits() (e.g. to specify different
     defaults).
 
-    The subclass constructor must call super().__init__(extra).  This
+    The subclass constructor must call super(Class, self).__init__(extra).  This
     will call set_write_buffer_limits().
 
     The user may call set_write_buffer_limits() and
@@ -239,7 +236,7 @@ class _FlowControlMixin(Transport):
     """
 
     def __init__(self, extra=None, loop=None):
-        super().__init__(extra)
+        super(_FlowControlMixin, self).__init__(extra)
         assert loop is not None
         self._loop = loop
         self._protocol_paused = False
diff --git a/trollius/unix_events.py b/trollius/unix_events.py
index 75e7c9c..fcccaaa 100644
--- a/trollius/unix_events.py
+++ b/trollius/unix_events.py
@@ -1,4 +1,5 @@
 """Selector event loop for Unix with signal handling."""
+from __future__ import absolute_import
 
 import errno
 import os
@@ -13,6 +14,7 @@ import warnings
 
 from . import base_events
 from . import base_subprocess
+from . import compat
 from . import constants
 from . import coroutines
 from . import events
@@ -20,8 +22,13 @@ from . import futures
 from . import selector_events
 from . import selectors
 from . import transports
-from .coroutines import coroutine
+from .compat import flatten_bytes
+from .coroutines import coroutine, From, Return
 from .log import logger
+from .py33_exceptions import (
+    reraise, wrap_error,
+    BlockingIOError, BrokenPipeError, ConnectionResetError,
+    InterruptedError, ChildProcessError)
 
 
 __all__ = ['SelectorEventLoop',
@@ -33,9 +40,10 @@ if sys.platform == 'win32':  # pragma: no cover
     raise ImportError('Signals are not really supported on Windows')
 
 
-def _sighandler_noop(signum, frame):
-    """Dummy signal handler."""
-    pass
+if compat.PY33:
+    def _sighandler_noop(signum, frame):
+        """Dummy signal handler."""
+        pass
 
 
 class _UnixSelectorEventLoop(selector_events.BaseSelectorEventLoop):
@@ -45,23 +53,27 @@ class _UnixSelectorEventLoop(selector_events.BaseSelectorEventLoop):
     """
 
     def __init__(self, selector=None):
-        super().__init__(selector)
+        super(_UnixSelectorEventLoop, self).__init__(selector)
         self._signal_handlers = {}
 
     def _socketpair(self):
         return socket.socketpair()
 
     def close(self):
-        super().close()
+        super(_UnixSelectorEventLoop, self).close()
         for sig in list(self._signal_handlers):
             self.remove_signal_handler(sig)
 
-    def _process_self_data(self, data):
-        for signum in data:
-            if not signum:
-                # ignore null bytes written by _write_to_self()
-                continue
-            self._handle_signal(signum)
+    # On Python <= 3.2, the C signal handler of Python writes a null byte into
+    # the wakeup file descriptor. We cannot retrieve the signal numbers from
+    # the file descriptor.
+    if compat.PY33:
+        def _process_self_data(self, data):
+            for signum in data:
+                if not signum:
+                    # ignore null bytes written by _write_to_self()
+                    continue
+                self._handle_signal(signum)
 
     def add_signal_handler(self, sig, callback, *args):
         """Add a handler for a signal.  UNIX only.
@@ -88,14 +100,30 @@ class _UnixSelectorEventLoop(selector_events.BaseSelectorEventLoop):
         self._signal_handlers[sig] = handle
 
         try:
-            # Register a dummy signal handler to ask Python to write the signal
-            # number in the wakup file descriptor. _process_self_data() will
-            # read signal numbers from this file descriptor to handle signals.
-            signal.signal(sig, _sighandler_noop)
+            if compat.PY33:
+                # On Python 3.3 and newer, the C signal handler writes the
+                # signal number into the wakeup file descriptor and then calls
+                # Py_AddPendingCall() to schedule the Python signal handler.
+                #
+                # Register a dummy signal handler to ask Python to write the
+                # signal number into the wakup file descriptor.
+                # _process_self_data() will read signal numbers from this file
+                # descriptor to handle signals.
+                signal.signal(sig, _sighandler_noop)
+            else:
+                # On Python 3.2 and older, the C signal handler first calls
+                # Py_AddPendingCall() to schedule the Python signal handler,
+                # and then write a null byte into the wakeup file descriptor.
+                signal.signal(sig, self._handle_signal)
 
             # Set SA_RESTART to limit EINTR occurrences.
             signal.siginterrupt(sig, False)
-        except OSError as exc:
+        except (RuntimeError, OSError) as exc:
+            # On Python 2, signal.signal(signal.SIGKILL, signal.SIG_IGN) raises
+            # RuntimeError(22, 'Invalid argument'). On Python 3,
+            # OSError(22, 'Invalid argument') is raised instead.
+            exc_type, exc_value, tb = sys.exc_info()
+
             del self._signal_handlers[sig]
             if not self._signal_handlers:
                 try:
@@ -103,12 +131,12 @@ class _UnixSelectorEventLoop(selector_events.BaseSelectorEventLoop):
                 except (ValueError, OSError) as nexc:
                     logger.info('set_wakeup_fd(-1) failed: %s', nexc)
 
-            if exc.errno == errno.EINVAL:
-                raise RuntimeError('sig {} cannot be caught'.format(sig))
+            if isinstance(exc, RuntimeError) or exc.errno == errno.EINVAL:
+                raise RuntimeError('sig {0} cannot be caught'.format(sig))
             else:
-                raise
+                reraise(exc_type, exc_value, tb)
 
-    def _handle_signal(self, sig):
+    def _handle_signal(self, sig, frame=None):
         """Internal helper that is the actual signal handler."""
         handle = self._signal_handlers.get(sig)
         if handle is None:
@@ -138,7 +166,7 @@ class _UnixSelectorEventLoop(selector_events.BaseSelectorEventLoop):
             signal.signal(sig, handler)
         except OSError as exc:
             if exc.errno == errno.EINVAL:
-                raise RuntimeError('sig {} cannot be caught'.format(sig))
+                raise RuntimeError('sig {0} cannot be caught'.format(sig))
             else:
                 raise
 
@@ -157,11 +185,11 @@ class _UnixSelectorEventLoop(selector_events.BaseSelectorEventLoop):
         Raise RuntimeError if there is a problem setting up the handler.
         """
         if not isinstance(sig, int):
-            raise TypeError('sig must be an int, not {!r}'.format(sig))
+            raise TypeError('sig must be an int, not {0!r}'.format(sig))
 
         if not (1 <= sig < signal.NSIG):
             raise ValueError(
-                'sig {} out of range(1, {})'.format(sig, signal.NSIG))
+                'sig {0} out of range(1, {1})'.format(sig, signal.NSIG))
 
     def _make_read_pipe_transport(self, pipe, protocol, waiter=None,
                                   extra=None):
@@ -185,7 +213,7 @@ class _UnixSelectorEventLoop(selector_events.BaseSelectorEventLoop):
             watcher.add_child_handler(transp.get_pid(),
                                       self._child_watcher_callback, transp)
             try:
-                yield from waiter
+                yield From(waiter)
             except Exception as exc:
                 # Workaround CPython bug #23353: using yield/yield-from in an
                 # except block of a generator doesn't clear properly
@@ -196,16 +224,16 @@ class _UnixSelectorEventLoop(selector_events.BaseSelectorEventLoop):
 
             if err is not None:
                 transp.close()
-                yield from transp._wait()
+                yield From(transp._wait())
                 raise err
 
-        return transp
+        raise Return(transp)
 
     def _child_watcher_callback(self, pid, returncode, transp):
         self.call_soon_threadsafe(transp._process_exited, returncode)
 
     @coroutine
-    def create_unix_connection(self, protocol_factory, path, *,
+    def create_unix_connection(self, protocol_factory, path,
                                ssl=None, sock=None,
                                server_hostname=None):
         assert server_hostname is None or isinstance(server_hostname, str)
@@ -225,7 +253,7 @@ class _UnixSelectorEventLoop(selector_events.BaseSelectorEventLoop):
             sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM, 0)
             try:
                 sock.setblocking(False)
-                yield from self.sock_connect(sock, path)
+                yield From(self.sock_connect(sock, path))
             except:
                 sock.close()
                 raise
@@ -235,12 +263,12 @@ class _UnixSelectorEventLoop(selector_events.BaseSelectorEventLoop):
                 raise ValueError('no path and sock were specified')
             sock.setblocking(False)
 
-        transport, protocol = yield from self._create_connection_transport(
-            sock, protocol_factory, ssl, server_hostname)
-        return transport, protocol
+        transport, protocol = yield From(self._create_connection_transport(
+            sock, protocol_factory, ssl, server_hostname))
+        raise Return(transport, protocol)
 
     @coroutine
-    def create_unix_server(self, protocol_factory, path=None, *,
+    def create_unix_server(self, protocol_factory, path=None,
                            sock=None, backlog=100, ssl=None):
         if isinstance(ssl, bool):
             raise TypeError('ssl argument must be an SSLContext or None')
@@ -254,13 +282,13 @@ class _UnixSelectorEventLoop(selector_events.BaseSelectorEventLoop):
 
             try:
                 sock.bind(path)
-            except OSError as exc:
+            except socket.error as exc:
                 sock.close()
                 if exc.errno == errno.EADDRINUSE:
                     # Let's improve the error message by adding
                     # with what exact address it occurs.
-                    msg = 'Address {!r} is already in use'.format(path)
-                    raise OSError(errno.EADDRINUSE, msg) from None
+                    msg = 'Address {0!r} is already in use'.format(path)
+                    raise OSError(errno.EADDRINUSE, msg)
                 else:
                     raise
             except:
@@ -273,7 +301,7 @@ class _UnixSelectorEventLoop(selector_events.BaseSelectorEventLoop):
 
             if sock.family != socket.AF_UNIX:
                 raise ValueError(
-                    'A UNIX Domain Socket was expected, got {!r}'.format(sock))
+                    'A UNIX Domain Socket was expected, got {0!r}'.format(sock))
 
         server = base_events.Server(self, [sock])
         sock.listen(backlog)
@@ -283,6 +311,7 @@ class _UnixSelectorEventLoop(selector_events.BaseSelectorEventLoop):
 
 
 if hasattr(os, 'set_blocking'):
+    # Python 3.5 and newer
     def _set_nonblocking(fd):
         os.set_blocking(fd, False)
 else:
@@ -299,7 +328,7 @@ class _UnixReadPipeTransport(transports.ReadTransport):
     max_size = 256 * 1024  # max bytes we read in one event loop iteration
 
     def __init__(self, loop, pipe, protocol, waiter=None, extra=None):
-        super().__init__(extra)
+        super(_UnixReadPipeTransport, self).__init__(extra)
         self._extra['pipe'] = pipe
         self._loop = loop
         self._pipe = pipe
@@ -341,7 +370,7 @@ class _UnixReadPipeTransport(transports.ReadTransport):
 
     def _read_ready(self):
         try:
-            data = os.read(self._fileno, self.max_size)
+            data = wrap_error(os.read, self._fileno, self.max_size)
         except (BlockingIOError, InterruptedError):
             pass
         except OSError as exc:
@@ -409,7 +438,7 @@ class _UnixWritePipeTransport(transports._FlowControlMixin,
                               transports.WriteTransport):
 
     def __init__(self, loop, pipe, protocol, waiter=None, extra=None):
-        super().__init__(extra, loop)
+        super(_UnixWritePipeTransport, self).__init__(extra, loop)
         self._extra['pipe'] = pipe
         self._pipe = pipe
         self._fileno = pipe.fileno()
@@ -475,9 +504,7 @@ class _UnixWritePipeTransport(transports._FlowControlMixin,
             self._close()
 
     def write(self, data):
-        assert isinstance(data, (bytes, bytearray, memoryview)), repr(data)
-        if isinstance(data, bytearray):
-            data = memoryview(data)
+        data = flatten_bytes(data)
         if not data:
             return
 
@@ -491,7 +518,7 @@ class _UnixWritePipeTransport(transports._FlowControlMixin,
         if not self._buffer:
             # Attempt to send it right away first.
             try:
-                n = os.write(self._fileno, data)
+                n = wrap_error(os.write, self._fileno, data)
             except (BlockingIOError, InterruptedError):
                 n = 0
             except Exception as exc:
@@ -511,9 +538,9 @@ class _UnixWritePipeTransport(transports._FlowControlMixin,
         data = b''.join(self._buffer)
         assert data, 'Data should not be empty'
 
-        self._buffer.clear()
+        del self._buffer[:]
         try:
-            n = os.write(self._fileno, data)
+            n = wrap_error(os.write, self._fileno, data)
         except (BlockingIOError, InterruptedError):
             self._buffer.append(data)
         except Exception as exc:
@@ -582,7 +609,7 @@ class _UnixWritePipeTransport(transports._FlowControlMixin,
         self._closing = True
         if self._buffer:
             self._loop.remove_writer(self._fileno)
-        self._buffer.clear()
+        del self._buffer[:]
         self._loop.remove_reader(self._fileno)
         self._loop.call_soon(self._call_connection_lost, exc)
 
@@ -633,11 +660,20 @@ class _UnixSubprocessTransport(base_subprocess.BaseSubprocessTransport):
             args, shell=shell, stdin=stdin, stdout=stdout, stderr=stderr,
             universal_newlines=False, bufsize=bufsize, **kwargs)
         if stdin_w is not None:
+            # Retrieve the file descriptor from stdin_w, stdin_w should not
+            # "own" the file descriptor anymore: closing stdin_fd file
+            # descriptor must close immediatly the file
             stdin.close()
-            self._proc.stdin = open(stdin_w.detach(), 'wb', buffering=bufsize)
+            if hasattr(stdin_w, 'detach'):
+                stdin_fd = stdin_w.detach()
+                self._proc.stdin = os.fdopen(stdin_fd, 'wb', bufsize)
+            else:
+                stdin_dup = os.dup(stdin_w.fileno())
+                stdin_w.close()
+                self._proc.stdin = os.fdopen(stdin_dup, 'wb', bufsize)
 
 
-class AbstractChildWatcher:
+class AbstractChildWatcher(object):
     """Abstract base class for monitoring child processes.
 
     Objects derived from this class monitor a collection of subprocesses and
@@ -773,12 +809,12 @@ class SafeChildWatcher(BaseChildWatcher):
     """
 
     def __init__(self):
-        super().__init__()
+        super(SafeChildWatcher, self).__init__()
         self._callbacks = {}
 
     def close(self):
         self._callbacks.clear()
-        super().close()
+        super(SafeChildWatcher, self).close()
 
     def __enter__(self):
         return self
@@ -850,7 +886,7 @@ class FastChildWatcher(BaseChildWatcher):
     (O(1) each time a child terminates).
     """
     def __init__(self):
-        super().__init__()
+        super(FastChildWatcher, self).__init__()
         self._callbacks = {}
         self._lock = threading.Lock()
         self._zombies = {}
@@ -859,7 +895,7 @@ class FastChildWatcher(BaseChildWatcher):
     def close(self):
         self._callbacks.clear()
         self._zombies.clear()
-        super().close()
+        super(FastChildWatcher, self).close()
 
     def __enter__(self):
         with self._lock:
@@ -906,7 +942,7 @@ class FastChildWatcher(BaseChildWatcher):
         # long as we're able to reap a child.
         while True:
             try:
-                pid, status = os.waitpid(-1, os.WNOHANG)
+                pid, status = wrap_error(os.waitpid, -1, os.WNOHANG)
             except ChildProcessError:
                 # No more child processes exist.
                 return
@@ -949,7 +985,7 @@ class _UnixDefaultEventLoopPolicy(events.BaseDefaultEventLoopPolicy):
     _loop_factory = _UnixSelectorEventLoop
 
     def __init__(self):
-        super().__init__()
+        super(_UnixDefaultEventLoopPolicy, self).__init__()
         self._watcher = None
 
     def _init_watcher(self):
@@ -968,7 +1004,7 @@ class _UnixDefaultEventLoopPolicy(events.BaseDefaultEventLoopPolicy):
         the child watcher.
         """
 
-        super().set_event_loop(loop)
+        super(_UnixDefaultEventLoopPolicy, self).set_event_loop(loop)
 
         if self._watcher is not None and \
             isinstance(threading.current_thread(), threading._MainThread):
diff --git a/trollius/windows_events.py b/trollius/windows_events.py
index 922594f..7f7764e 100644
--- a/trollius/windows_events.py
+++ b/trollius/windows_events.py
@@ -11,12 +11,15 @@ from . import events
 from . import base_subprocess
 from . import futures
 from . import proactor_events
+from . import py33_winapi as _winapi
 from . import selector_events
 from . import tasks
 from . import windows_utils
 from . import _overlapped
-from .coroutines import coroutine
+from .coroutines import coroutine, From, Return
 from .log import logger
+from .py33_exceptions import (wrap_error, get_error_class,
+    ConnectionRefusedError, BrokenPipeError)
 
 
 __all__ = ['SelectorEventLoop', 'ProactorEventLoop', 'IocpProactor',
@@ -42,14 +45,14 @@ class _OverlappedFuture(futures.Future):
     Cancelling it will immediately cancel the overlapped operation.
     """
 
-    def __init__(self, ov, *, loop=None):
-        super().__init__(loop=loop)
+    def __init__(self, ov, loop=None):
+        super(_OverlappedFuture, self).__init__(loop=loop)
         if self._source_traceback:
             del self._source_traceback[-1]
         self._ov = ov
 
     def _repr_info(self):
-        info = super()._repr_info()
+        info = super(_OverlappedFuture, self)._repr_info()
         if self._ov is not None:
             state = 'pending' if self._ov.pending else 'completed'
             info.insert(1, 'overlapped=<%s, %#x>' % (state, self._ov.address))
@@ -73,22 +76,22 @@ class _OverlappedFuture(futures.Future):
 
     def cancel(self):
         self._cancel_overlapped()
-        return super().cancel()
+        return super(_OverlappedFuture, self).cancel()
 
     def set_exception(self, exception):
-        super().set_exception(exception)
+        super(_OverlappedFuture, self).set_exception(exception)
         self._cancel_overlapped()
 
     def set_result(self, result):
-        super().set_result(result)
+        super(_OverlappedFuture, self).set_result(result)
         self._ov = None
 
 
 class _BaseWaitHandleFuture(futures.Future):
     """Subclass of Future which represents a wait handle."""
 
-    def __init__(self, ov, handle, wait_handle, *, loop=None):
-        super().__init__(loop=loop)
+    def __init__(self, ov, handle, wait_handle, loop=None):
+        super(_BaseWaitHandleFuture, self).__init__(loop=loop)
         if self._source_traceback:
             del self._source_traceback[-1]
         # Keep a reference to the Overlapped object to keep it alive until the
@@ -107,7 +110,7 @@ class _BaseWaitHandleFuture(futures.Future):
                 _winapi.WAIT_OBJECT_0)
 
     def _repr_info(self):
-        info = super()._repr_info()
+        info = super(_BaseWaitHandleFuture, self)._repr_info()
         info.append('handle=%#x' % self._handle)
         if self._handle is not None:
             state = 'signaled' if self._poll() else 'waiting'
@@ -147,15 +150,15 @@ class _BaseWaitHandleFuture(futures.Future):
 
     def cancel(self):
         self._unregister_wait()
-        return super().cancel()
+        return super(_BaseWaitHandleFuture, self).cancel()
 
     def set_exception(self, exception):
         self._unregister_wait()
-        super().set_exception(exception)
+        super(_BaseWaitHandleFuture, self).set_exception(exception)
 
     def set_result(self, result):
         self._unregister_wait()
-        super().set_result(result)
+        super(_BaseWaitHandleFuture, self).set_result(result)
 
 
 class _WaitCancelFuture(_BaseWaitHandleFuture):
@@ -163,8 +166,9 @@ class _WaitCancelFuture(_BaseWaitHandleFuture):
     _WaitHandleFuture using an event.
     """
 
-    def __init__(self, ov, event, wait_handle, *, loop=None):
-        super().__init__(ov, event, wait_handle, loop=loop)
+    def __init__(self, ov, event, wait_handle, loop=None):
+        super(_WaitCancelFuture, self).__init__(ov, event, wait_handle,
+                                                loop=loop)
 
         self._done_callback = None
 
@@ -178,8 +182,9 @@ class _WaitCancelFuture(_BaseWaitHandleFuture):
 
 
 class _WaitHandleFuture(_BaseWaitHandleFuture):
-    def __init__(self, ov, handle, wait_handle, proactor, *, loop=None):
-        super().__init__(ov, handle, wait_handle, loop=loop)
+    def __init__(self, ov, handle, wait_handle, proactor, loop=None):
+        super(_WaitHandleFuture, self).__init__(ov, handle, wait_handle,
+                                                loop=loop)
         self._proactor = proactor
         self._unregister_proactor = True
         self._event = _overlapped.CreateEvent(None, True, False, None)
@@ -201,7 +206,7 @@ class _WaitHandleFuture(_BaseWaitHandleFuture):
         self._proactor._unregister(self._ov)
         self._proactor = None
 
-        super()._unregister_wait_cb(fut)
+        super(_WaitHandleFuture, self)._unregister_wait_cb(fut)
 
     def _unregister_wait(self):
         if not self._registered:
@@ -259,7 +264,7 @@ class PipeServer(object):
         flags = _winapi.PIPE_ACCESS_DUPLEX | _winapi.FILE_FLAG_OVERLAPPED
         if first:
             flags |= _winapi.FILE_FLAG_FIRST_PIPE_INSTANCE
-        h = _winapi.CreateNamedPipe(
+        h = wrap_error(_winapi.CreateNamedPipe,
             self._address, flags,
             _winapi.PIPE_TYPE_MESSAGE | _winapi.PIPE_READMODE_MESSAGE |
             _winapi.PIPE_WAIT,
@@ -301,7 +306,7 @@ class ProactorEventLoop(proactor_events.BaseProactorEventLoop):
     def __init__(self, proactor=None):
         if proactor is None:
             proactor = IocpProactor()
-        super().__init__(proactor)
+        super(ProactorEventLoop, self).__init__(proactor)
 
     def _socketpair(self):
         return windows_utils.socketpair()
@@ -309,11 +314,11 @@ class ProactorEventLoop(proactor_events.BaseProactorEventLoop):
     @coroutine
     def create_pipe_connection(self, protocol_factory, address):
         f = self._proactor.connect_pipe(address)
-        pipe = yield from f
+        pipe = yield From(f)
         protocol = protocol_factory()
         trans = self._make_duplex_pipe_transport(pipe, protocol,
                                                  extra={'addr': address})
-        return trans, protocol
+        raise Return(trans, protocol)
 
     @coroutine
     def start_serving_pipe(self, protocol_factory, address):
@@ -372,7 +377,7 @@ class ProactorEventLoop(proactor_events.BaseProactorEventLoop):
                                              waiter=waiter, extra=extra,
                                              **kwargs)
         try:
-            yield from waiter
+            yield From(waiter)
         except Exception as exc:
             # Workaround CPython bug #23353: using yield/yield-from in an
             # except block of a generator doesn't clear properly sys.exc_info()
@@ -382,13 +387,13 @@ class ProactorEventLoop(proactor_events.BaseProactorEventLoop):
 
         if err is not None:
             transp.close()
-            yield from transp._wait()
+            yield From(transp._wait())
             raise err
 
-        return transp
+        raise Return(transp)
 
 
-class IocpProactor:
+class IocpProactor(object):
     """Proactor implementation using IOCP."""
 
     def __init__(self, concurrency=0xffffffff):
@@ -426,16 +431,16 @@ class IocpProactor:
         ov = _overlapped.Overlapped(NULL)
         try:
             if isinstance(conn, socket.socket):
-                ov.WSARecv(conn.fileno(), nbytes, flags)
+                wrap_error(ov.WSARecv, conn.fileno(), nbytes, flags)
             else:
-                ov.ReadFile(conn.fileno(), nbytes)
+                wrap_error(ov.ReadFile, conn.fileno(), nbytes)
         except BrokenPipeError:
             return self._result(b'')
 
         def finish_recv(trans, key, ov):
             try:
-                return ov.getresult()
-            except OSError as exc:
+                return wrap_error(ov.getresult)
+            except WindowsError as exc:
                 if exc.winerror == _overlapped.ERROR_NETNAME_DELETED:
                     raise ConnectionResetError(*exc.args)
                 else:
@@ -453,8 +458,8 @@ class IocpProactor:
 
         def finish_send(trans, key, ov):
             try:
-                return ov.getresult()
-            except OSError as exc:
+                return wrap_error(ov.getresult)
+            except WindowsError as exc:
                 if exc.winerror == _overlapped.ERROR_NETNAME_DELETED:
                     raise ConnectionResetError(*exc.args)
                 else:
@@ -469,7 +474,7 @@ class IocpProactor:
         ov.AcceptEx(listener.fileno(), conn.fileno())
 
         def finish_accept(trans, key, ov):
-            ov.getresult()
+            wrap_error(ov.getresult)
             # Use SO_UPDATE_ACCEPT_CONTEXT so getsockname() etc work.
             buf = struct.pack('@P', listener.fileno())
             conn.setsockopt(socket.SOL_SOCKET,
@@ -481,7 +486,7 @@ class IocpProactor:
         def accept_coro(future, conn):
             # Coroutine closing the accept socket if the future is cancelled
             try:
-                yield from future
+                yield From(future)
             except futures.CancelledError:
                 conn.close()
                 raise
@@ -496,7 +501,7 @@ class IocpProactor:
         # The socket needs to be locally bound before we call ConnectEx().
         try:
             _overlapped.BindLocal(conn.fileno(), conn.family)
-        except OSError as e:
+        except WindowsError as e:
             if e.winerror != errno.WSAEINVAL:
                 raise
             # Probably already locally bound; check using getsockname().
@@ -506,7 +511,7 @@ class IocpProactor:
         ov.ConnectEx(conn.fileno(), address)
 
         def finish_connect(trans, key, ov):
-            ov.getresult()
+            wrap_error(ov.getresult)
             # Use SO_UPDATE_CONNECT_CONTEXT so getsockname() etc work.
             conn.setsockopt(socket.SOL_SOCKET,
                             _overlapped.SO_UPDATE_CONNECT_CONTEXT, 0)
@@ -526,7 +531,7 @@ class IocpProactor:
             return self._result(pipe)
 
         def finish_accept_pipe(trans, key, ov):
-            ov.getresult()
+            wrap_error(ov.getresult)
             return pipe
 
         return self._register(ov, pipe, finish_accept_pipe)
@@ -539,17 +544,17 @@ class IocpProactor:
             # Call CreateFile() in a loop until it doesn't fail with
             # ERROR_PIPE_BUSY
             try:
-                handle = _overlapped.ConnectPipe(address)
+                handle = wrap_error(_overlapped.ConnectPipe, address)
                 break
-            except OSError as exc:
+            except WindowsError as exc:
                 if exc.winerror != _overlapped.ERROR_PIPE_BUSY:
                     raise
 
             # ConnectPipe() failed with ERROR_PIPE_BUSY: retry later
             delay = min(delay * 2, CONNECT_PIPE_MAX_DELAY)
-            yield from tasks.sleep(delay, loop=self._loop)
+            yield From(tasks.sleep(delay, loop=self._loop))
 
-        return windows_utils.PipeHandle(handle)
+        raise Return(windows_utils.PipeHandle(handle))
 
     def wait_for_handle(self, handle, timeout=None):
         """Wait for a handle.
@@ -572,7 +577,7 @@ class IocpProactor:
         else:
             # RegisterWaitForSingleObject() has a resolution of 1 millisecond,
             # round away from zero to wait *at least* timeout seconds.
-            ms = math.ceil(timeout * 1e3)
+            ms = int(math.ceil(timeout * 1e3))
 
         # We only create ov so we can use ov.address as a key for the cache.
         ov = _overlapped.Overlapped(NULL)
@@ -660,7 +665,7 @@ class IocpProactor:
         else:
             # GetQueuedCompletionStatus() has a resolution of 1 millisecond,
             # round away from zero to wait *at least* timeout seconds.
-            ms = math.ceil(timeout * 1e3)
+            ms = int(math.ceil(timeout * 1e3))
             if ms >= INFINITE:
                 raise ValueError("timeout too big")
 
@@ -705,7 +710,7 @@ class IocpProactor:
         # Remove unregisted futures
         for ov in self._unregistered:
             self._cache.pop(ov.address, None)
-        self._unregistered.clear()
+        del self._unregistered[:]
 
     def _stop_serving(self, obj):
         # obj is a socket or pipe handle.  It will be closed in
diff --git a/trollius/windows_utils.py b/trollius/windows_utils.py
index 870cd13..b2b9617 100644
--- a/trollius/windows_utils.py
+++ b/trollius/windows_utils.py
@@ -1,6 +1,7 @@
 """
 Various Windows specific bits and pieces
 """
+from __future__ import absolute_import
 
 import sys
 
@@ -16,6 +17,9 @@ import subprocess
 import tempfile
 import warnings
 
+from . import py33_winapi as _winapi
+from .py33_exceptions import wrap_error, BlockingIOError, InterruptedError
+
 
 __all__ = ['socketpair', 'pipe', 'Popen', 'PIPE', 'PipeHandle']
 
@@ -64,7 +68,7 @@ else:
             try:
                 csock.setblocking(False)
                 try:
-                    csock.connect((addr, port))
+                    wrap_error(csock.connect, (addr, port))
                 except (BlockingIOError, InterruptedError):
                     pass
                 csock.setblocking(True)
@@ -80,7 +84,7 @@ else:
 # Replacement for os.pipe() using handles instead of fds
 
 
-def pipe(*, duplex=False, overlapped=(True, True), bufsize=BUFSIZE):
+def pipe(duplex=False, overlapped=(True, True), bufsize=BUFSIZE):
     """Like os.pipe() but with overlapped support and using handles not fds."""
     address = tempfile.mktemp(prefix=r'\\.\pipe\python-pipe-%d-%d-' %
                               (os.getpid(), next(_mmap_counter)))
@@ -115,7 +119,12 @@ def pipe(*, duplex=False, overlapped=(True, True), bufsize=BUFSIZE):
             flags_and_attribs, _winapi.NULL)
 
         ov = _winapi.ConnectNamedPipe(h1, overlapped=True)
-        ov.GetOverlappedResult(True)
+        if hasattr(ov, 'GetOverlappedResult'):
+            # _winapi module of Python 3.3
+            ov.GetOverlappedResult(True)
+        else:
+            # _overlapped module
+            wrap_error(ov.getresult, True)
         return h1, h2
     except:
         if h1 is not None:
@@ -128,7 +137,7 @@ def pipe(*, duplex=False, overlapped=(True, True), bufsize=BUFSIZE):
 # Wrapper for a pipe handle
 
 
-class PipeHandle:
+class PipeHandle(object):
     """Wrapper for an overlapped pipe handle which is vaguely file-object like.
 
     The IOCP event loop can use these instead of socket objects.
@@ -152,7 +161,7 @@ class PipeHandle:
             raise ValueError("I/O operatioon on closed pipe")
         return self._handle
 
-    def close(self, *, CloseHandle=_winapi.CloseHandle):
+    def close(self, CloseHandle=_winapi.CloseHandle):
         if self._handle is not None:
             CloseHandle(self._handle)
             self._handle = None
@@ -200,8 +209,11 @@ class Popen(subprocess.Popen):
         else:
             stderr_wfd = stderr
         try:
-            super().__init__(args, stdin=stdin_rfd, stdout=stdout_wfd,
-                             stderr=stderr_wfd, **kwds)
+            super(Popen, self).__init__(args,
+                                        stdin=stdin_rfd,
+                                        stdout=stdout_wfd,
+                                        stderr=stderr_wfd,
+                                        **kwds)
         except:
             for h in (stdin_wh, stdout_rh, stderr_rh):
                 if h is not None: