Uploaded Test files

venv/Lib/site-packages/zmq/eventloop/minitornado/__init__.py

@@ -0,0 +1,11 @@
+import warnings
+class VisibleDeprecationWarning(UserWarning):
+    """A DeprecationWarning that users should see."""
+    pass
+
+warnings.warn("""zmq.eventloop.minitornado is deprecated in pyzmq 14.0 and will be removed.
+    Install tornado itself to use zmq with the tornado IOLoop.
+    """,
+    VisibleDeprecationWarning,
+    stacklevel=4,
+)

venv/Lib/site-packages/zmq/eventloop/minitornado/concurrent.py

@@ -0,0 +1,14 @@
+"""pyzmq does not ship tornado's futures,
+this just raises informative NotImplementedErrors to avoid having to change too much code.
+"""
+
+class NotImplementedFuture(object):
+    def __init__(self, *args, **kwargs):
+        raise NotImplementedError("pyzmq does not ship tornado's Futures, "
+            "install tornado >= 3.0 for future support."
+        )
+
+Future = TracebackFuture = NotImplementedFuture
+
+def is_future(x):
+    return isinstance(x, Future)

venv/Lib/site-packages/zmq/eventloop/minitornado/log.py

@@ -0,0 +1,6 @@
+"""minimal subset of tornado.log for zmq.eventloop.minitornado"""
+
+import logging
+
+app_log = logging.getLogger("tornado.application")
+gen_log = logging.getLogger("tornado.general")

venv/Lib/site-packages/zmq/eventloop/minitornado/platform/auto.py

@@ -0,0 +1,45 @@
+#!/usr/bin/env python
+#
+# Copyright 2011 Facebook
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+"""Implementation of platform-specific functionality.
+
+For each function or class described in `tornado.platform.interface`,
+the appropriate platform-specific implementation exists in this module.
+Most code that needs access to this functionality should do e.g.::
+
+    from tornado.platform.auto import set_close_exec
+"""
+
+from __future__ import absolute_import, division, print_function, with_statement
+
+import os
+
+if os.name == 'nt':
+    from .common import Waker
+    from .windows import set_close_exec
+else:
+    from .posix import set_close_exec, Waker
+
+try:
+    # monotime monkey-patches the time module to have a monotonic function
+    # in versions of python before 3.3.
+    import monotime
+except ImportError:
+    pass
+try:
+    from time import monotonic as monotonic_time
+except ImportError:
+    monotonic_time = None

venv/Lib/site-packages/zmq/eventloop/minitornado/platform/common.py

@@ -0,0 +1,91 @@
+"""Lowest-common-denominator implementations of platform functionality."""
+from __future__ import absolute_import, division, print_function, with_statement
+
+import errno
+import socket
+
+from . import interface
+
+
+class Waker(interface.Waker):
+    """Create an OS independent asynchronous pipe.
+
+    For use on platforms that don't have os.pipe() (or where pipes cannot
+    be passed to select()), but do have sockets.  This includes Windows
+    and Jython.
+    """
+    def __init__(self):
+        # Based on Zope async.py: http://svn.zope.org/zc.ngi/trunk/src/zc/ngi/async.py
+
+        self.writer = socket.socket()
+        # Disable buffering -- pulling the trigger sends 1 byte,
+        # and we want that sent immediately, to wake up ASAP.
+        self.writer.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
+
+        count = 0
+        while 1:
+            count += 1
+            # Bind to a local port; for efficiency, let the OS pick
+            # a free port for us.
+            # Unfortunately, stress tests showed that we may not
+            # be able to connect to that port ("Address already in
+            # use") despite that the OS picked it.  This appears
+            # to be a race bug in the Windows socket implementation.
+            # So we loop until a connect() succeeds (almost always
+            # on the first try).  See the long thread at
+            # http://mail.zope.org/pipermail/zope/2005-July/160433.html
+            # for hideous details.
+            a = socket.socket()
+            a.bind(("127.0.0.1", 0))
+            a.listen(1)
+            connect_address = a.getsockname()  # assigned (host, port) pair
+            try:
+                self.writer.connect(connect_address)
+                break    # success
+            except socket.error as detail:
+                if (not hasattr(errno, 'WSAEADDRINUSE') or
+                        detail[0] != errno.WSAEADDRINUSE):
+                    # "Address already in use" is the only error
+                    # I've seen on two WinXP Pro SP2 boxes, under
+                    # Pythons 2.3.5 and 2.4.1.
+                    raise
+                # (10048, 'Address already in use')
+                # assert count <= 2 # never triggered in Tim's tests
+                if count >= 10:  # I've never seen it go above 2
+                    a.close()
+                    self.writer.close()
+                    raise socket.error("Cannot bind trigger!")
+                # Close `a` and try again.  Note:  I originally put a short
+                # sleep() here, but it didn't appear to help or hurt.
+                a.close()
+
+        self.reader, addr = a.accept()
+        self.reader.setblocking(0)
+        self.writer.setblocking(0)
+        a.close()
+        self.reader_fd = self.reader.fileno()
+
+    def fileno(self):
+        return self.reader.fileno()
+
+    def write_fileno(self):
+        return self.writer.fileno()
+
+    def wake(self):
+        try:
+            self.writer.send(b"x")
+        except (IOError, socket.error):
+            pass
+
+    def consume(self):
+        try:
+            while True:
+                result = self.reader.recv(1024)
+                if not result:
+                    break
+        except (IOError, socket.error):
+            pass
+
+    def close(self):
+        self.reader.close()
+        self.writer.close()

venv/Lib/site-packages/zmq/eventloop/minitornado/platform/interface.py

@@ -0,0 +1,63 @@
+#!/usr/bin/env python
+#
+# Copyright 2011 Facebook
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+"""Interfaces for platform-specific functionality.
+
+This module exists primarily for documentation purposes and as base classes
+for other tornado.platform modules.  Most code should import the appropriate
+implementation from `tornado.platform.auto`.
+"""
+
+from __future__ import absolute_import, division, print_function, with_statement
+
+
+def set_close_exec(fd):
+    """Sets the close-on-exec bit (``FD_CLOEXEC``)for a file descriptor."""
+    raise NotImplementedError()
+
+
+class Waker(object):
+    """A socket-like object that can wake another thread from ``select()``.
+
+    The `~tornado.ioloop.IOLoop` will add the Waker's `fileno()` to
+    its ``select`` (or ``epoll`` or ``kqueue``) calls.  When another
+    thread wants to wake up the loop, it calls `wake`.  Once it has woken
+    up, it will call `consume` to do any necessary per-wake cleanup.  When
+    the ``IOLoop`` is closed, it closes its waker too.
+    """
+    def fileno(self):
+        """Returns the read file descriptor for this waker.
+
+        Must be suitable for use with ``select()`` or equivalent on the
+        local platform.
+        """
+        raise NotImplementedError()
+
+    def write_fileno(self):
+        """Returns the write file descriptor for this waker."""
+        raise NotImplementedError()
+
+    def wake(self):
+        """Triggers activity on the waker's file descriptor."""
+        raise NotImplementedError()
+
+    def consume(self):
+        """Called after the listen has woken up to do any necessary cleanup."""
+        raise NotImplementedError()
+
+    def close(self):
+        """Closes the waker's file descriptor(s)."""
+        raise NotImplementedError()

venv/Lib/site-packages/zmq/eventloop/minitornado/platform/posix.py

@@ -0,0 +1,70 @@
+#!/usr/bin/env python
+#
+# Copyright 2011 Facebook
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+"""Posix implementations of platform-specific functionality."""
+
+from __future__ import absolute_import, division, print_function, with_statement
+
+import fcntl
+import os
+
+from . import interface
+
+
+def set_close_exec(fd):
+    flags = fcntl.fcntl(fd, fcntl.F_GETFD)
+    fcntl.fcntl(fd, fcntl.F_SETFD, flags | fcntl.FD_CLOEXEC)
+
+
+def _set_nonblocking(fd):
+    flags = fcntl.fcntl(fd, fcntl.F_GETFL)
+    fcntl.fcntl(fd, fcntl.F_SETFL, flags | os.O_NONBLOCK)
+
+
+class Waker(interface.Waker):
+    def __init__(self):
+        r, w = os.pipe()
+        _set_nonblocking(r)
+        _set_nonblocking(w)
+        set_close_exec(r)
+        set_close_exec(w)
+        self.reader = os.fdopen(r, "rb", 0)
+        self.writer = os.fdopen(w, "wb", 0)
+
+    def fileno(self):
+        return self.reader.fileno()
+
+    def write_fileno(self):
+        return self.writer.fileno()
+
+    def wake(self):
+        try:
+            self.writer.write(b"x")
+        except IOError:
+            pass
+
+    def consume(self):
+        try:
+            while True:
+                result = self.reader.read()
+                if not result:
+                    break
+        except IOError:
+            pass
+
+    def close(self):
+        self.reader.close()
+        self.writer.close()

venv/Lib/site-packages/zmq/eventloop/minitornado/platform/windows.py

@@ -0,0 +1,20 @@
+# NOTE: win32 support is currently experimental, and not recommended
+# for production use.
+
+
+from __future__ import absolute_import, division, print_function, with_statement
+import ctypes
+import ctypes.wintypes
+
+# See: http://msdn.microsoft.com/en-us/library/ms724935(VS.85).aspx
+SetHandleInformation = ctypes.windll.kernel32.SetHandleInformation
+SetHandleInformation.argtypes = (ctypes.wintypes.HANDLE, ctypes.wintypes.DWORD, ctypes.wintypes.DWORD)
+SetHandleInformation.restype = ctypes.wintypes.BOOL
+
+HANDLE_FLAG_INHERIT = 0x00000001
+
+
+def set_close_exec(fd):
+    success = SetHandleInformation(fd, HANDLE_FLAG_INHERIT, 0)
+    if not success:
+        raise ctypes.GetLastError()

venv/Lib/site-packages/zmq/eventloop/minitornado/stack_context.py

@@ -0,0 +1,388 @@
+#!/usr/bin/env python
+#
+# Copyright 2010 Facebook
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+"""`StackContext` allows applications to maintain threadlocal-like state
+that follows execution as it moves to other execution contexts.
+
+The motivating examples are to eliminate the need for explicit
+``async_callback`` wrappers (as in `tornado.web.RequestHandler`), and to
+allow some additional context to be kept for logging.
+
+This is slightly magic, but it's an extension of the idea that an
+exception handler is a kind of stack-local state and when that stack
+is suspended and resumed in a new context that state needs to be
+preserved.  `StackContext` shifts the burden of restoring that state
+from each call site (e.g.  wrapping each `.AsyncHTTPClient` callback
+in ``async_callback``) to the mechanisms that transfer control from
+one context to another (e.g. `.AsyncHTTPClient` itself, `.IOLoop`,
+thread pools, etc).
+
+Example usage::
+
+    @contextlib.contextmanager
+    def die_on_error():
+        try:
+            yield
+        except Exception:
+            logging.error("exception in asynchronous operation",exc_info=True)
+            sys.exit(1)
+
+    with StackContext(die_on_error):
+        # Any exception thrown here *or in callback and its descendants*
+        # will cause the process to exit instead of spinning endlessly
+        # in the ioloop.
+        http_client.fetch(url, callback)
+    ioloop.start()
+
+Most applications shouldn't have to work with `StackContext` directly.
+Here are a few rules of thumb for when it's necessary:
+
+* If you're writing an asynchronous library that doesn't rely on a
+  stack_context-aware library like `tornado.ioloop` or `tornado.iostream`
+  (for example, if you're writing a thread pool), use
+  `.stack_context.wrap()` before any asynchronous operations to capture the
+  stack context from where the operation was started.
+
+* If you're writing an asynchronous library that has some shared
+  resources (such as a connection pool), create those shared resources
+  within a ``with stack_context.NullContext():`` block.  This will prevent
+  ``StackContexts`` from leaking from one request to another.
+
+* If you want to write something like an exception handler that will
+  persist across asynchronous calls, create a new `StackContext` (or
+  `ExceptionStackContext`), and make your asynchronous calls in a ``with``
+  block that references your `StackContext`.
+"""
+
+from __future__ import absolute_import, division, print_function, with_statement
+
+import sys
+import threading
+
+from .util import raise_exc_info
+
+
+class StackContextInconsistentError(Exception):
+    pass
+
+
+class _State(threading.local):
+    def __init__(self):
+        self.contexts = (tuple(), None)
+_state = _State()
+
+
+class StackContext(object):
+    """Establishes the given context as a StackContext that will be transferred.
+
+    Note that the parameter is a callable that returns a context
+    manager, not the context itself.  That is, where for a
+    non-transferable context manager you would say::
+
+      with my_context():
+
+    StackContext takes the function itself rather than its result::
+
+      with StackContext(my_context):
+
+    The result of ``with StackContext() as cb:`` is a deactivation
+    callback.  Run this callback when the StackContext is no longer
+    needed to ensure that it is not propagated any further (note that
+    deactivating a context does not affect any instances of that
+    context that are currently pending).  This is an advanced feature
+    and not necessary in most applications.
+    """
+    def __init__(self, context_factory):
+        self.context_factory = context_factory
+        self.contexts = []
+        self.active = True
+
+    def _deactivate(self):
+        self.active = False
+
+    # StackContext protocol
+    def enter(self):
+        context = self.context_factory()
+        self.contexts.append(context)
+        context.__enter__()
+
+    def exit(self, type, value, traceback):
+        context = self.contexts.pop()
+        context.__exit__(type, value, traceback)
+
+    # Note that some of this code is duplicated in ExceptionStackContext
+    # below.  ExceptionStackContext is more common and doesn't need
+    # the full generality of this class.
+    def __enter__(self):
+        self.old_contexts = _state.contexts
+        self.new_contexts = (self.old_contexts[0] + (self,), self)
+        _state.contexts = self.new_contexts
+
+        try:
+            self.enter()
+        except:
+            _state.contexts = self.old_contexts
+            raise
+
+        return self._deactivate
+
+    def __exit__(self, type, value, traceback):
+        try:
+            self.exit(type, value, traceback)
+        finally:
+            final_contexts = _state.contexts
+            _state.contexts = self.old_contexts
+
+            # Generator coroutines and with-statements with non-local
+            # effects interact badly.  Check here for signs of
+            # the stack getting out of sync.
+            # Note that this check comes after restoring _state.context
+            # so that if it fails things are left in a (relatively)
+            # consistent state.
+            if final_contexts is not self.new_contexts:
+                raise StackContextInconsistentError(
+                    'stack_context inconsistency (may be caused by yield '
+                    'within a "with StackContext" block)')
+
+            # Break up a reference to itself to allow for faster GC on CPython.
+            self.new_contexts = None
+
+
+class ExceptionStackContext(object):
+    """Specialization of StackContext for exception handling.
+
+    The supplied ``exception_handler`` function will be called in the
+    event of an uncaught exception in this context.  The semantics are
+    similar to a try/finally clause, and intended use cases are to log
+    an error, close a socket, or similar cleanup actions.  The
+    ``exc_info`` triple ``(type, value, traceback)`` will be passed to the
+    exception_handler function.
+
+    If the exception handler returns true, the exception will be
+    consumed and will not be propagated to other exception handlers.
+    """
+    def __init__(self, exception_handler):
+        self.exception_handler = exception_handler
+        self.active = True
+
+    def _deactivate(self):
+        self.active = False
+
+    def exit(self, type, value, traceback):
+        if type is not None:
+            return self.exception_handler(type, value, traceback)
+
+    def __enter__(self):
+        self.old_contexts = _state.contexts
+        self.new_contexts = (self.old_contexts[0], self)
+        _state.contexts = self.new_contexts
+
+        return self._deactivate
+
+    def __exit__(self, type, value, traceback):
+        try:
+            if type is not None:
+                return self.exception_handler(type, value, traceback)
+        finally:
+            final_contexts = _state.contexts
+            _state.contexts = self.old_contexts
+
+            if final_contexts is not self.new_contexts:
+                raise StackContextInconsistentError(
+                    'stack_context inconsistency (may be caused by yield '
+                    'within a "with StackContext" block)')
+
+            # Break up a reference to itself to allow for faster GC on CPython.
+            self.new_contexts = None
+
+
+class NullContext(object):
+    """Resets the `StackContext`.
+
+    Useful when creating a shared resource on demand (e.g. an
+    `.AsyncHTTPClient`) where the stack that caused the creating is
+    not relevant to future operations.
+    """
+    def __enter__(self):
+        self.old_contexts = _state.contexts
+        _state.contexts = (tuple(), None)
+
+    def __exit__(self, type, value, traceback):
+        _state.contexts = self.old_contexts
+
+
+def _remove_deactivated(contexts):
+    """Remove deactivated handlers from the chain"""
+    # Clean ctx handlers
+    stack_contexts = tuple([h for h in contexts[0] if h.active])
+
+    # Find new head
+    head = contexts[1]
+    while head is not None and not head.active:
+        head = head.old_contexts[1]
+
+    # Process chain
+    ctx = head
+    while ctx is not None:
+        parent = ctx.old_contexts[1]
+
+        while parent is not None:
+            if parent.active:
+                break
+            ctx.old_contexts = parent.old_contexts
+            parent = parent.old_contexts[1]
+
+        ctx = parent
+
+    return (stack_contexts, head)
+
+
+def wrap(fn):
+    """Returns a callable object that will restore the current `StackContext`
+    when executed.
+
+    Use this whenever saving a callback to be executed later in a
+    different execution context (either in a different thread or
+    asynchronously in the same thread).
+    """
+    # Check if function is already wrapped
+    if fn is None or hasattr(fn, '_wrapped'):
+        return fn
+
+    # Capture current stack head
+    # TODO: Any other better way to store contexts and update them in wrapped function?
+    cap_contexts = [_state.contexts]
+
+    if not cap_contexts[0][0] and not cap_contexts[0][1]:
+        # Fast path when there are no active contexts.
+        def null_wrapper(*args, **kwargs):
+            try:
+                current_state = _state.contexts
+                _state.contexts = cap_contexts[0]
+                return fn(*args, **kwargs)
+            finally:
+                _state.contexts = current_state
+        null_wrapper._wrapped = True
+        return null_wrapper
+
+    def wrapped(*args, **kwargs):
+        ret = None
+        try:
+            # Capture old state
+            current_state = _state.contexts
+
+            # Remove deactivated items
+            cap_contexts[0] = contexts = _remove_deactivated(cap_contexts[0])
+
+            # Force new state
+            _state.contexts = contexts
+
+            # Current exception
+            exc = (None, None, None)
+            top = None
+
+            # Apply stack contexts
+            last_ctx = 0
+            stack = contexts[0]
+
+            # Apply state
+            for n in stack:
+                try:
+                    n.enter()
+                    last_ctx += 1
+                except:
+                    # Exception happened. Record exception info and store top-most handler
+                    exc = sys.exc_info()
+                    top = n.old_contexts[1]
+
+            # Execute callback if no exception happened while restoring state
+            if top is None:
+                try:
+                    ret = fn(*args, **kwargs)
+                except:
+                    exc = sys.exc_info()
+                    top = contexts[1]
+
+            # If there was exception, try to handle it by going through the exception chain
+            if top is not None:
+                exc = _handle_exception(top, exc)
+            else:
+                # Otherwise take shorter path and run stack contexts in reverse order
+                while last_ctx > 0:
+                    last_ctx -= 1
+                    c = stack[last_ctx]
+
+                    try:
+                        c.exit(*exc)
+                    except:
+                        exc = sys.exc_info()
+                        top = c.old_contexts[1]
+                        break
+                else:
+                    top = None
+
+                # If if exception happened while unrolling, take longer exception handler path
+                if top is not None:
+                    exc = _handle_exception(top, exc)
+
+            # If exception was not handled, raise it
+            if exc != (None, None, None):
+                raise_exc_info(exc)
+        finally:
+            _state.contexts = current_state
+        return ret
+
+    wrapped._wrapped = True
+    return wrapped
+
+
+def _handle_exception(tail, exc):
+    while tail is not None:
+        try:
+            if tail.exit(*exc):
+                exc = (None, None, None)
+        except:
+            exc = sys.exc_info()
+
+        tail = tail.old_contexts[1]
+
+    return exc
+
+
+def run_with_stack_context(context, func):
+    """Run a coroutine ``func`` in the given `StackContext`.
+
+    It is not safe to have a ``yield`` statement within a ``with StackContext``
+    block, so it is difficult to use stack context with `.gen.coroutine`.
+    This helper function runs the function in the correct context while
+    keeping the ``yield`` and ``with`` statements syntactically separate.
+
+    Example::
+
+        @gen.coroutine
+        def incorrect():
+            with StackContext(ctx):
+                # ERROR: this will raise StackContextInconsistentError
+                yield other_coroutine()
+
+        @gen.coroutine
+        def correct():
+            yield run_with_stack_context(StackContext(ctx), other_coroutine)
+
+    .. versionadded:: 3.1
+    """
+    with context:
+        return func()

venv/Lib/site-packages/zmq/eventloop/minitornado/util.py

@@ -0,0 +1,216 @@
+"""Miscellaneous utility functions and classes.
+
+This module is used internally by Tornado.  It is not necessarily expected
+that the functions and classes defined here will be useful to other
+applications, but they are documented here in case they are.
+
+The one public-facing part of this module is the `Configurable` class
+and its `~Configurable.configure` method, which becomes a part of the
+interface of its subclasses, including `.AsyncHTTPClient`, `.IOLoop`,
+and `.Resolver`.
+"""
+
+from __future__ import absolute_import, division, print_function, with_statement
+
+import sys
+
+
+# Fake unicode literal support:  Python 3.2 doesn't have the u'' marker for
+# literal strings, and alternative solutions like "from __future__ import
+# unicode_literals" have other problems (see PEP 414).  u() can be applied
+# to ascii strings that include \u escapes (but they must not contain
+# literal non-ascii characters).
+if not isinstance(b'', type('')):
+    def u(s):
+        return s
+    unicode_type = str
+    basestring_type = str
+else:
+    def u(s):
+        return s.decode('unicode_escape')
+    # These names don't exist in py3, so use noqa comments to disable
+    # warnings in flake8.
+    unicode_type = unicode  # noqa
+    basestring_type = basestring  # noqa
+
+
+def import_object(name):
+    """Imports an object by name.
+
+    import_object('x') is equivalent to 'import x'.
+    import_object('x.y.z') is equivalent to 'from x.y import z'.
+
+    >>> import tornado.escape
+    >>> import_object('tornado.escape') is tornado.escape
+    True
+    >>> import_object('tornado.escape.utf8') is tornado.escape.utf8
+    True
+    >>> import_object('tornado') is tornado
+    True
+    >>> import_object('tornado.missing_module')
+    Traceback (most recent call last):
+        ...
+    ImportError: No module named missing_module
+    """
+    if isinstance(name, unicode_type) and str is not unicode_type:
+        # On python 2 a byte string is required.
+        name = name.encode('utf-8')
+    if name.count('.') == 0:
+        return __import__(name, None, None)
+
+    parts = name.split('.')
+    obj = __import__('.'.join(parts[:-1]), None, None, [parts[-1]], 0)
+    try:
+        return getattr(obj, parts[-1])
+    except AttributeError:
+        raise ImportError("No module named %s" % parts[-1])
+
+
+# Deprecated alias that was used before we dropped py25 support.
+# Left here in case anyone outside Tornado is using it.
+bytes_type = bytes
+
+if sys.version_info > (3,):
+    exec("""
+def raise_exc_info(exc_info):
+    raise exc_info[1].with_traceback(exc_info[2])
+
+def exec_in(code, glob, loc=None):
+    if isinstance(code, str):
+        code = compile(code, '<string>', 'exec', dont_inherit=True)
+    exec(code, glob, loc)
+""")
+else:
+    exec("""
+def raise_exc_info(exc_info):
+    raise exc_info[0], exc_info[1], exc_info[2]
+
+def exec_in(code, glob, loc=None):
+    if isinstance(code, basestring):
+        # exec(string) inherits the caller's future imports; compile
+        # the string first to prevent that.
+        code = compile(code, '<string>', 'exec', dont_inherit=True)
+    exec code in glob, loc
+""")
+
+
+def errno_from_exception(e):
+    """Provides the errno from an Exception object.
+
+    There are cases that the errno attribute was not set so we pull
+    the errno out of the args but if someone instantiates an Exception
+    without any args you will get a tuple error. So this function
+    abstracts all that behavior to give you a safe way to get the
+    errno.
+    """
+
+    if hasattr(e, 'errno'):
+        return e.errno
+    elif e.args:
+        return e.args[0]
+    else:
+        return None
+
+
+class Configurable(object):
+    """Base class for configurable interfaces.
+
+    A configurable interface is an (abstract) class whose constructor
+    acts as a factory function for one of its implementation subclasses.
+    The implementation subclass as well as optional keyword arguments to
+    its initializer can be set globally at runtime with `configure`.
+
+    By using the constructor as the factory method, the interface
+    looks like a normal class, `isinstance` works as usual, etc.  This
+    pattern is most useful when the choice of implementation is likely
+    to be a global decision (e.g. when `~select.epoll` is available,
+    always use it instead of `~select.select`), or when a
+    previously-monolithic class has been split into specialized
+    subclasses.
+
+    Configurable subclasses must define the class methods
+    `configurable_base` and `configurable_default`, and use the instance
+    method `initialize` instead of ``__init__``.
+    """
+    __impl_class = None
+    __impl_kwargs = None
+
+    def __new__(cls, *args, **kwargs):
+        base = cls.configurable_base()
+        init_kwargs = {}
+        if cls is base:
+            impl = cls.configured_class()
+            if base.__impl_kwargs:
+                init_kwargs.update(base.__impl_kwargs)
+        else:
+            impl = cls
+        init_kwargs.update(kwargs)
+        instance = super(Configurable, cls).__new__(impl)
+        # initialize vs __init__ chosen for compatibility with AsyncHTTPClient
+        # singleton magic.  If we get rid of that we can switch to __init__
+        # here too.
+        instance.initialize(*args, **init_kwargs)
+        return instance
+
+    @classmethod
+    def configurable_base(cls):
+        """Returns the base class of a configurable hierarchy.
+
+        This will normally return the class in which it is defined.
+        (which is *not* necessarily the same as the cls classmethod parameter).
+        """
+        raise NotImplementedError()
+
+    @classmethod
+    def configurable_default(cls):
+        """Returns the implementation class to be used if none is configured."""
+        raise NotImplementedError()
+
+    def initialize(self):
+        """Initialize a `Configurable` subclass instance.
+
+        Configurable classes should use `initialize` instead of ``__init__``.
+
+        .. versionchanged:: 4.2
+           Now accepts positional arguments in addition to keyword arguments.
+        """
+
+    @classmethod
+    def configure(cls, impl, **kwargs):
+        """Sets the class to use when the base class is instantiated.
+
+        Keyword arguments will be saved and added to the arguments passed
+        to the constructor.  This can be used to set global defaults for
+        some parameters.
+        """
+        base = cls.configurable_base()
+        if isinstance(impl, (unicode_type, bytes)):
+            impl = import_object(impl)
+        if impl is not None and not issubclass(impl, cls):
+            raise ValueError("Invalid subclass of %s" % cls)
+        base.__impl_class = impl
+        base.__impl_kwargs = kwargs
+
+    @classmethod
+    def configured_class(cls):
+        """Returns the currently configured class."""
+        base = cls.configurable_base()
+        if cls.__impl_class is None:
+            base.__impl_class = cls.configurable_default()
+        return base.__impl_class
+
+    @classmethod
+    def _save_configuration(cls):
+        base = cls.configurable_base()
+        return (base.__impl_class, base.__impl_kwargs)
+
+    @classmethod
+    def _restore_configuration(cls, saved):
+        base = cls.configurable_base()
+        base.__impl_class = saved[0]
+        base.__impl_kwargs = saved[1]
+
+
+def timedelta_to_seconds(td):
+    """Equivalent to td.total_seconds() (introduced in python 2.7)."""
+    return (td.microseconds + (td.seconds + td.days * 24 * 3600) * 10 ** 6) / float(10 ** 6)