thirdparty: move selectors2 module to where it should be
authorYuya Nishihara <yuya@tcha.org>
Thu, 30 Nov 2017 22:43:03 +0900
changeset 35245 414114a7c18f
parent 35244 98f97eb20597
child 35246 d73ccc63b8f9
thirdparty: move selectors2 module to where it should be
mercurial/__init__.py
mercurial/commandserver.py
mercurial/selectors2.py
mercurial/thirdparty/selectors2.py
tests/test-check-code.t
--- a/mercurial/__init__.py	Tue Nov 28 05:50:45 2017 +0530
+++ b/mercurial/__init__.py	Thu Nov 30 22:43:03 2017 +0900
@@ -31,9 +31,6 @@
             # Only handle Mercurial-related modules.
             if not fullname.startswith(('mercurial.', 'hgext.', 'hgext3rd.')):
                 return None
-            # selectors2 is already dual-version clean, don't try and mangle it
-            if fullname.startswith('mercurial.selectors2'):
-                return None
             # third-party packages are expected to be dual-version clean
             if fullname.startswith('mercurial.thirdparty'):
                 return None
--- a/mercurial/commandserver.py	Tue Nov 28 05:50:45 2017 +0530
+++ b/mercurial/commandserver.py	Thu Nov 30 22:43:03 2017 +0900
@@ -17,11 +17,11 @@
 import traceback
 
 from .i18n import _
+from .thirdparty import selectors2
 from . import (
     encoding,
     error,
     pycompat,
-    selectors2,
     util,
 )
 
--- a/mercurial/selectors2.py	Tue Nov 28 05:50:45 2017 +0530
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,745 +0,0 @@
-""" Back-ported, durable, and portable selectors """
-
-# MIT License
-#
-# Copyright (c) 2017 Seth Michael Larson
-#
-# Permission is hereby granted, free of charge, to any person obtaining a copy
-# of this software and associated documentation files (the "Software"), to deal
-# in the Software without restriction, including without limitation the rights
-# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-# copies of the Software, and to permit persons to whom the Software is
-# furnished to do so, subject to the following conditions:
-#
-# The above copyright notice and this permission notice shall be included in all
-# copies or substantial portions of the Software.
-#
-# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-# SOFTWARE.
-
-# no-check-code
-
-from __future__ import absolute_import
-
-import collections
-import errno
-import math
-import select
-import socket
-import sys
-import time
-
-from . import pycompat
-
-namedtuple = collections.namedtuple
-Mapping = collections.Mapping
-
-try:
-    monotonic = time.monotonic
-except AttributeError:
-    monotonic = time.time
-
-__author__ = 'Seth Michael Larson'
-__email__ = 'sethmichaellarson@protonmail.com'
-__version__ = '2.0.0'
-__license__ = 'MIT'
-__url__ = 'https://www.github.com/SethMichaelLarson/selectors2'
-
-__all__ = ['EVENT_READ',
-           'EVENT_WRITE',
-           'SelectorKey',
-           'DefaultSelector',
-           'BaseSelector']
-
-EVENT_READ = (1 << 0)
-EVENT_WRITE = (1 << 1)
-_DEFAULT_SELECTOR = None
-_SYSCALL_SENTINEL = object()  # Sentinel in case a system call returns None.
-_ERROR_TYPES = (OSError, IOError, socket.error)
-
-
-SelectorKey = namedtuple('SelectorKey', ['fileobj', 'fd', 'events', 'data'])
-
-
-class _SelectorMapping(Mapping):
-    """ Mapping of file objects to selector keys """
-
-    def __init__(self, selector):
-        self._selector = selector
-
-    def __len__(self):
-        return len(self._selector._fd_to_key)
-
-    def __getitem__(self, fileobj):
-        try:
-            fd = self._selector._fileobj_lookup(fileobj)
-            return self._selector._fd_to_key[fd]
-        except KeyError:
-            raise KeyError("{0!r} is not registered.".format(fileobj))
-
-    def __iter__(self):
-        return iter(self._selector._fd_to_key)
-
-
-def _fileobj_to_fd(fileobj):
-    """ Return a file descriptor from a file object. If
-    given an integer will simply return that integer back. """
-    if isinstance(fileobj, int):
-        fd = fileobj
-    else:
-        try:
-            fd = int(fileobj.fileno())
-        except (AttributeError, TypeError, ValueError):
-            raise ValueError("Invalid file object: {0!r}".format(fileobj))
-    if fd < 0:
-        raise ValueError("Invalid file descriptor: {0}".format(fd))
-    return fd
-
-
-class BaseSelector(object):
-    """ Abstract Selector class
-
-    A selector supports registering file objects to be monitored
-    for specific I/O events.
-
-    A file object is a file descriptor or any object with a
-    `fileno()` method. An arbitrary object can be attached to the
-    file object which can be used for example to store context info,
-    a callback, etc.
-
-    A selector can use various implementations (select(), poll(), epoll(),
-    and kqueue()) depending on the platform. The 'DefaultSelector' class uses
-    the most efficient implementation for the current platform.
-    """
-    def __init__(self):
-        # Maps file descriptors to keys.
-        self._fd_to_key = {}
-
-        # Read-only mapping returned by get_map()
-        self._map = _SelectorMapping(self)
-
-    def _fileobj_lookup(self, fileobj):
-        """ Return a file descriptor from a file object.
-        This wraps _fileobj_to_fd() to do an exhaustive
-        search in case the object is invalid but we still
-        have it in our map. Used by unregister() so we can
-        unregister an object that was previously registered
-        even if it is closed. It is also used by _SelectorMapping
-        """
-        try:
-            return _fileobj_to_fd(fileobj)
-        except ValueError:
-
-            # Search through all our mapped keys.
-            for key in self._fd_to_key.values():
-                if key.fileobj is fileobj:
-                    return key.fd
-
-            # Raise ValueError after all.
-            raise
-
-    def register(self, fileobj, events, data=None):
-        """ Register a file object for a set of events to monitor. """
-        if (not events) or (events & ~(EVENT_READ | EVENT_WRITE)):
-            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("{0!r} (FD {1}) is already registered"
-                           .format(fileobj, key.fd))
-
-        self._fd_to_key[key.fd] = key
-        return key
-
-    def unregister(self, fileobj):
-        """ Unregister a file object from being monitored. """
-        try:
-            key = self._fd_to_key.pop(self._fileobj_lookup(fileobj))
-        except KeyError:
-            raise KeyError("{0!r} is not registered".format(fileobj))
-
-        # Getting the fileno of a closed socket on Windows errors with EBADF.
-        except socket.error as err:
-            if err.errno != errno.EBADF:
-                raise
-            else:
-                for key in self._fd_to_key.values():
-                    if key.fileobj is fileobj:
-                        self._fd_to_key.pop(key.fd)
-                        break
-                else:
-                    raise KeyError("{0!r} is not registered".format(fileobj))
-        return key
-
-    def modify(self, fileobj, events, data=None):
-        """ Change a registered file object monitored events and data. """
-        # NOTE: Some subclasses optimize this operation even further.
-        try:
-            key = self._fd_to_key[self._fileobj_lookup(fileobj)]
-        except KeyError:
-            raise KeyError("{0!r} is not registered".format(fileobj))
-
-        if events != key.events:
-            self.unregister(fileobj)
-            key = self.register(fileobj, events, data)
-
-        elif data != key.data:
-            # Use a shortcut to update the data.
-            key = key._replace(data=data)
-            self._fd_to_key[key.fd] = key
-
-        return key
-
-    def select(self, timeout=None):
-        """ Perform the actual selection until some monitored file objects
-        are ready or the timeout expires. """
-        raise NotImplementedError()
-
-    def close(self):
-        """ Close the selector. This must be called to ensure that all
-        underlying resources are freed. """
-        self._fd_to_key.clear()
-        self._map = None
-
-    def get_key(self, fileobj):
-        """ Return the key associated with a registered file object. """
-        mapping = self.get_map()
-        if mapping is None:
-            raise RuntimeError("Selector is closed")
-        try:
-            return mapping[fileobj]
-        except KeyError:
-            raise KeyError("{0!r} is not registered".format(fileobj))
-
-    def get_map(self):
-        """ Return a mapping of file objects to selector keys """
-        return self._map
-
-    def _key_from_fd(self, fd):
-        """ Return the key associated to a given file descriptor
-         Return None if it is not found. """
-        try:
-            return self._fd_to_key[fd]
-        except KeyError:
-            return None
-
-    def __enter__(self):
-        return self
-
-    def __exit__(self, *_):
-        self.close()
-
-
-# Almost all platforms have select.select()
-if hasattr(select, "select"):
-    class SelectSelector(BaseSelector):
-        """ Select-based selector. """
-        def __init__(self):
-            super(SelectSelector, self).__init__()
-            self._readers = set()
-            self._writers = set()
-
-        def register(self, fileobj, events, data=None):
-            key = super(SelectSelector, self).register(fileobj, events, data)
-            if events & EVENT_READ:
-                self._readers.add(key.fd)
-            if events & EVENT_WRITE:
-                self._writers.add(key.fd)
-            return key
-
-        def unregister(self, fileobj):
-            key = super(SelectSelector, self).unregister(fileobj)
-            self._readers.discard(key.fd)
-            self._writers.discard(key.fd)
-            return key
-
-        def select(self, timeout=None):
-            # Selecting on empty lists on Windows errors out.
-            if not len(self._readers) and not len(self._writers):
-                return []
-
-            timeout = None if timeout is None else max(timeout, 0.0)
-            ready = []
-            r, w, _ = _syscall_wrapper(self._wrap_select, True, self._readers,
-                                       self._writers, timeout)
-            r = set(r)
-            w = set(w)
-            for fd in r | w:
-                events = 0
-                if fd in r:
-                    events |= EVENT_READ
-                if fd in w:
-                    events |= EVENT_WRITE
-
-                key = self._key_from_fd(fd)
-                if key:
-                    ready.append((key, events & key.events))
-            return ready
-
-        def _wrap_select(self, r, w, timeout=None):
-            """ Wrapper for select.select because timeout is a positional arg """
-            return select.select(r, w, [], timeout)
-
-    __all__.append('SelectSelector')
-
-    # Jython has a different implementation of .fileno() for socket objects.
-    if pycompat.isjython:
-        class _JythonSelectorMapping(object):
-            """ This is an implementation of _SelectorMapping that is built
-            for use specifically with Jython, which does not provide a hashable
-            value from socket.socket.fileno(). """
-
-            def __init__(self, selector):
-                assert isinstance(selector, JythonSelectSelector)
-                self._selector = selector
-
-            def __len__(self):
-                return len(self._selector._sockets)
-
-            def __getitem__(self, fileobj):
-                for sock, key in self._selector._sockets:
-                    if sock is fileobj:
-                        return key
-                else:
-                    raise KeyError("{0!r} is not registered.".format(fileobj))
-
-        class JythonSelectSelector(SelectSelector):
-            """ This is an implementation of SelectSelector that is for Jython
-            which works around that Jython's socket.socket.fileno() does not
-            return an integer fd value. All SelectorKey.fd will be equal to -1
-            and should not be used. This instead uses object id to compare fileobj
-            and will only use select.select as it's the only selector that allows
-            directly passing in socket objects rather than registering fds.
-            See: http://bugs.jython.org/issue1678
-                 https://wiki.python.org/jython/NewSocketModule#socket.fileno.28.29_does_not_return_an_integer
-            """
-
-            def __init__(self):
-                super(JythonSelectSelector, self).__init__()
-
-                self._sockets = []  # Uses a list of tuples instead of dictionary.
-                self._map = _JythonSelectorMapping(self)
-                self._readers = []
-                self._writers = []
-
-                # Jython has a select.cpython_compatible_select function in older versions.
-                self._select_func = getattr(select, 'cpython_compatible_select', select.select)
-
-            def register(self, fileobj, events, data=None):
-                for sock, _ in self._sockets:
-                    if sock is fileobj:
-                        raise KeyError("{0!r} is already registered"
-                                       .format(fileobj, sock))
-
-                key = SelectorKey(fileobj, -1, events, data)
-                self._sockets.append((fileobj, key))
-
-                if events & EVENT_READ:
-                    self._readers.append(fileobj)
-                if events & EVENT_WRITE:
-                    self._writers.append(fileobj)
-                return key
-
-            def unregister(self, fileobj):
-                for i, (sock, key) in enumerate(self._sockets):
-                    if sock is fileobj:
-                        break
-                else:
-                    raise KeyError("{0!r} is not registered.".format(fileobj))
-
-                if key.events & EVENT_READ:
-                    self._readers.remove(fileobj)
-                if key.events & EVENT_WRITE:
-                    self._writers.remove(fileobj)
-
-                del self._sockets[i]
-                return key
-
-            def _wrap_select(self, r, w, timeout=None):
-                """ Wrapper for select.select because timeout is a positional arg """
-                return self._select_func(r, w, [], timeout)
-
-        __all__.append('JythonSelectSelector')
-        SelectSelector = JythonSelectSelector  # Override so the wrong selector isn't used.
-
-
-if hasattr(select, "poll"):
-    class PollSelector(BaseSelector):
-        """ Poll-based selector """
-        def __init__(self):
-            super(PollSelector, self).__init__()
-            self._poll = select.poll()
-
-        def register(self, fileobj, events, data=None):
-            key = super(PollSelector, self).register(fileobj, events, data)
-            event_mask = 0
-            if events & EVENT_READ:
-                event_mask |= select.POLLIN
-            if events & EVENT_WRITE:
-                event_mask |= select.POLLOUT
-            self._poll.register(key.fd, event_mask)
-            return key
-
-        def unregister(self, fileobj):
-            key = super(PollSelector, self).unregister(fileobj)
-            self._poll.unregister(key.fd)
-            return key
-
-        def _wrap_poll(self, timeout=None):
-            """ Wrapper function for select.poll.poll() so that
-            _syscall_wrapper can work with only seconds. """
-            if timeout is not None:
-                if timeout <= 0:
-                    timeout = 0
-                else:
-                    # select.poll.poll() has a resolution of 1 millisecond,
-                    # round away from zero to wait *at least* timeout seconds.
-                    timeout = math.ceil(timeout * 1000)
-
-            result = self._poll.poll(timeout)
-            return result
-
-        def select(self, timeout=None):
-            ready = []
-            fd_events = _syscall_wrapper(self._wrap_poll, True, timeout=timeout)
-            for fd, event_mask in fd_events:
-                events = 0
-                if event_mask & ~select.POLLIN:
-                    events |= EVENT_WRITE
-                if event_mask & ~select.POLLOUT:
-                    events |= EVENT_READ
-
-                key = self._key_from_fd(fd)
-                if key:
-                    ready.append((key, events & key.events))
-
-            return ready
-
-    __all__.append('PollSelector')
-
-if hasattr(select, "epoll"):
-    class EpollSelector(BaseSelector):
-        """ Epoll-based selector """
-        def __init__(self):
-            super(EpollSelector, self).__init__()
-            self._epoll = select.epoll()
-
-        def fileno(self):
-            return self._epoll.fileno()
-
-        def register(self, fileobj, events, data=None):
-            key = super(EpollSelector, self).register(fileobj, events, data)
-            events_mask = 0
-            if events & EVENT_READ:
-                events_mask |= select.EPOLLIN
-            if events & EVENT_WRITE:
-                events_mask |= select.EPOLLOUT
-            _syscall_wrapper(self._epoll.register, False, key.fd, events_mask)
-            return key
-
-        def unregister(self, fileobj):
-            key = super(EpollSelector, self).unregister(fileobj)
-            try:
-                _syscall_wrapper(self._epoll.unregister, False, key.fd)
-            except _ERROR_TYPES:
-                # This can occur when the fd was closed since registry.
-                pass
-            return key
-
-        def select(self, timeout=None):
-            if timeout is not None:
-                if timeout <= 0:
-                    timeout = 0.0
-                else:
-                    # select.epoll.poll() has a resolution of 1 millisecond
-                    # but luckily takes seconds so we don't need a wrapper
-                    # like PollSelector. Just for better rounding.
-                    timeout = math.ceil(timeout * 1000) * 0.001
-                timeout = float(timeout)
-            else:
-                timeout = -1.0  # epoll.poll() must have a float.
-
-            # We always want at least 1 to ensure that select can be called
-            # with no file descriptors registered. Otherwise will fail.
-            max_events = max(len(self._fd_to_key), 1)
-
-            ready = []
-            fd_events = _syscall_wrapper(self._epoll.poll, True,
-                                         timeout=timeout,
-                                         maxevents=max_events)
-            for fd, event_mask in fd_events:
-                events = 0
-                if event_mask & ~select.EPOLLIN:
-                    events |= EVENT_WRITE
-                if event_mask & ~select.EPOLLOUT:
-                    events |= EVENT_READ
-
-                key = self._key_from_fd(fd)
-                if key:
-                    ready.append((key, events & key.events))
-            return ready
-
-        def close(self):
-            self._epoll.close()
-            super(EpollSelector, self).close()
-
-    __all__.append('EpollSelector')
-
-
-if hasattr(select, "devpoll"):
-    class DevpollSelector(BaseSelector):
-        """Solaris /dev/poll selector."""
-
-        def __init__(self):
-            super(DevpollSelector, self).__init__()
-            self._devpoll = select.devpoll()
-
-        def fileno(self):
-            return self._devpoll.fileno()
-
-        def register(self, fileobj, events, data=None):
-            key = super(DevpollSelector, self).register(fileobj, events, data)
-            poll_events = 0
-            if events & EVENT_READ:
-                poll_events |= select.POLLIN
-            if events & EVENT_WRITE:
-                poll_events |= select.POLLOUT
-            self._devpoll.register(key.fd, poll_events)
-            return key
-
-        def unregister(self, fileobj):
-            key = super(DevpollSelector, self).unregister(fileobj)
-            self._devpoll.unregister(key.fd)
-            return key
-
-        def _wrap_poll(self, timeout=None):
-            """ Wrapper function for select.poll.poll() so that
-            _syscall_wrapper can work with only seconds. """
-            if timeout is not None:
-                if timeout <= 0:
-                    timeout = 0
-                else:
-                    # select.devpoll.poll() has a resolution of 1 millisecond,
-                    # round away from zero to wait *at least* timeout seconds.
-                    timeout = math.ceil(timeout * 1000)
-
-            result = self._devpoll.poll(timeout)
-            return result
-
-        def select(self, timeout=None):
-            ready = []
-            fd_events = _syscall_wrapper(self._wrap_poll, True, timeout=timeout)
-            for fd, event_mask in fd_events:
-                events = 0
-                if event_mask & ~select.POLLIN:
-                    events |= EVENT_WRITE
-                if event_mask & ~select.POLLOUT:
-                    events |= EVENT_READ
-
-                key = self._key_from_fd(fd)
-                if key:
-                    ready.append((key, events & key.events))
-
-            return ready
-
-        def close(self):
-            self._devpoll.close()
-            super(DevpollSelector, self).close()
-
-    __all__.append('DevpollSelector')
-
-
-if hasattr(select, "kqueue"):
-    class KqueueSelector(BaseSelector):
-        """ Kqueue / Kevent-based selector """
-        def __init__(self):
-            super(KqueueSelector, self).__init__()
-            self._kqueue = select.kqueue()
-
-        def fileno(self):
-            return self._kqueue.fileno()
-
-        def register(self, fileobj, events, data=None):
-            key = super(KqueueSelector, self).register(fileobj, events, data)
-            if events & EVENT_READ:
-                kevent = select.kevent(key.fd,
-                                       select.KQ_FILTER_READ,
-                                       select.KQ_EV_ADD)
-
-                _syscall_wrapper(self._kqueue.control, False, [kevent], 0, 0)
-
-            if events & EVENT_WRITE:
-                kevent = select.kevent(key.fd,
-                                       select.KQ_FILTER_WRITE,
-                                       select.KQ_EV_ADD)
-
-                _syscall_wrapper(self._kqueue.control, False, [kevent], 0, 0)
-
-            return key
-
-        def unregister(self, fileobj):
-            key = super(KqueueSelector, self).unregister(fileobj)
-            if key.events & EVENT_READ:
-                kevent = select.kevent(key.fd,
-                                       select.KQ_FILTER_READ,
-                                       select.KQ_EV_DELETE)
-                try:
-                    _syscall_wrapper(self._kqueue.control, False, [kevent], 0, 0)
-                except _ERROR_TYPES:
-                    pass
-            if key.events & EVENT_WRITE:
-                kevent = select.kevent(key.fd,
-                                       select.KQ_FILTER_WRITE,
-                                       select.KQ_EV_DELETE)
-                try:
-                    _syscall_wrapper(self._kqueue.control, False, [kevent], 0, 0)
-                except _ERROR_TYPES:
-                    pass
-
-            return key
-
-        def select(self, timeout=None):
-            if timeout is not None:
-                timeout = max(timeout, 0)
-
-            max_events = len(self._fd_to_key) * 2
-            ready_fds = {}
-
-            kevent_list = _syscall_wrapper(self._kqueue.control, True,
-                                           None, max_events, timeout)
-
-            for kevent in kevent_list:
-                fd = kevent.ident
-                event_mask = kevent.filter
-                events = 0
-                if event_mask == select.KQ_FILTER_READ:
-                    events |= EVENT_READ
-                if event_mask == select.KQ_FILTER_WRITE:
-                    events |= EVENT_WRITE
-
-                key = self._key_from_fd(fd)
-                if key:
-                    if key.fd not in ready_fds:
-                        ready_fds[key.fd] = (key, events & key.events)
-                    else:
-                        old_events = ready_fds[key.fd][1]
-                        ready_fds[key.fd] = (key, (events | old_events) & key.events)
-
-            return list(ready_fds.values())
-
-        def close(self):
-            self._kqueue.close()
-            super(KqueueSelector, self).close()
-
-    __all__.append('KqueueSelector')
-
-
-def _can_allocate(struct):
-    """ Checks that select structs can be allocated by the underlying
-    operating system, not just advertised by the select module. We don't
-    check select() because we'll be hopeful that most platforms that
-    don't have it available will not advertise it. (ie: GAE) """
-    try:
-        # select.poll() objects won't fail until used.
-        if struct == 'poll':
-            p = select.poll()
-            p.poll(0)
-
-        # All others will fail on allocation.
-        else:
-            getattr(select, struct)().close()
-        return True
-    except (OSError, AttributeError):
-        return False
-
-
-# Python 3.5 uses a more direct route to wrap system calls to increase speed.
-if sys.version_info >= (3, 5):
-    def _syscall_wrapper(func, _, *args, **kwargs):
-        """ This is the short-circuit version of the below logic
-        because in Python 3.5+ all selectors restart system calls. """
-        return func(*args, **kwargs)
-else:
-    def _syscall_wrapper(func, recalc_timeout, *args, **kwargs):
-        """ Wrapper function for syscalls that could fail due to EINTR.
-        All functions should be retried if there is time left in the timeout
-        in accordance with PEP 475. """
-        timeout = kwargs.get("timeout", None)
-        if timeout is None:
-            expires = None
-            recalc_timeout = False
-        else:
-            timeout = float(timeout)
-            if timeout < 0.0:  # Timeout less than 0 treated as no timeout.
-                expires = None
-            else:
-                expires = monotonic() + timeout
-
-        args = list(args)
-        if recalc_timeout and "timeout" not in kwargs:
-            raise ValueError(
-                "Timeout must be in args or kwargs to be recalculated")
-
-        result = _SYSCALL_SENTINEL
-        while result is _SYSCALL_SENTINEL:
-            try:
-                result = func(*args, **kwargs)
-            # OSError is thrown by select.select
-            # IOError is thrown by select.epoll.poll
-            # select.error is thrown by select.poll.poll
-            # Aren't we thankful for Python 3.x rework for exceptions?
-            except (OSError, IOError, select.error) as e:
-                # select.error wasn't a subclass of OSError in the past.
-                errcode = None
-                if hasattr(e, "errno"):
-                    errcode = e.errno
-                elif hasattr(e, "args"):
-                    errcode = e.args[0]
-
-                # Also test for the Windows equivalent of EINTR.
-                is_interrupt = (errcode == errno.EINTR or (hasattr(errno, "WSAEINTR") and
-                                                           errcode == errno.WSAEINTR))
-
-                if is_interrupt:
-                    if expires is not None:
-                        current_time = monotonic()
-                        if current_time > expires:
-                            raise OSError(errno=errno.ETIMEDOUT)
-                        if recalc_timeout:
-                            if "timeout" in kwargs:
-                                kwargs["timeout"] = expires - current_time
-                    continue
-                raise
-        return result
-
-
-# Choose the best implementation, roughly:
-# kqueue == devpoll == epoll > poll > select
-# select() also can't accept a FD > FD_SETSIZE (usually around 1024)
-def DefaultSelector():
-    """ This function serves as a first call for DefaultSelector to
-    detect if the select module is being monkey-patched incorrectly
-    by eventlet, greenlet, and preserve proper behavior. """
-    global _DEFAULT_SELECTOR
-    if _DEFAULT_SELECTOR is None:
-        if pycompat.isjython:
-            _DEFAULT_SELECTOR = JythonSelectSelector
-        elif _can_allocate('kqueue'):
-            _DEFAULT_SELECTOR = KqueueSelector
-        elif _can_allocate('devpoll'):
-            _DEFAULT_SELECTOR = DevpollSelector
-        elif _can_allocate('epoll'):
-            _DEFAULT_SELECTOR = EpollSelector
-        elif _can_allocate('poll'):
-            _DEFAULT_SELECTOR = PollSelector
-        elif hasattr(select, 'select'):
-            _DEFAULT_SELECTOR = SelectSelector
-        else:  # Platform-specific: AppEngine
-            raise RuntimeError('Platform does not have a selector.')
-    return _DEFAULT_SELECTOR()
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mercurial/thirdparty/selectors2.py	Thu Nov 30 22:43:03 2017 +0900
@@ -0,0 +1,743 @@
+""" Back-ported, durable, and portable selectors """
+
+# MIT License
+#
+# Copyright (c) 2017 Seth Michael Larson
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+from __future__ import absolute_import
+
+import collections
+import errno
+import math
+import select
+import socket
+import sys
+import time
+
+from .. import pycompat
+
+namedtuple = collections.namedtuple
+Mapping = collections.Mapping
+
+try:
+    monotonic = time.monotonic
+except AttributeError:
+    monotonic = time.time
+
+__author__ = 'Seth Michael Larson'
+__email__ = 'sethmichaellarson@protonmail.com'
+__version__ = '2.0.0'
+__license__ = 'MIT'
+__url__ = 'https://www.github.com/SethMichaelLarson/selectors2'
+
+__all__ = ['EVENT_READ',
+           'EVENT_WRITE',
+           'SelectorKey',
+           'DefaultSelector',
+           'BaseSelector']
+
+EVENT_READ = (1 << 0)
+EVENT_WRITE = (1 << 1)
+_DEFAULT_SELECTOR = None
+_SYSCALL_SENTINEL = object()  # Sentinel in case a system call returns None.
+_ERROR_TYPES = (OSError, IOError, socket.error)
+
+
+SelectorKey = namedtuple('SelectorKey', ['fileobj', 'fd', 'events', 'data'])
+
+
+class _SelectorMapping(Mapping):
+    """ Mapping of file objects to selector keys """
+
+    def __init__(self, selector):
+        self._selector = selector
+
+    def __len__(self):
+        return len(self._selector._fd_to_key)
+
+    def __getitem__(self, fileobj):
+        try:
+            fd = self._selector._fileobj_lookup(fileobj)
+            return self._selector._fd_to_key[fd]
+        except KeyError:
+            raise KeyError("{0!r} is not registered.".format(fileobj))
+
+    def __iter__(self):
+        return iter(self._selector._fd_to_key)
+
+
+def _fileobj_to_fd(fileobj):
+    """ Return a file descriptor from a file object. If
+    given an integer will simply return that integer back. """
+    if isinstance(fileobj, int):
+        fd = fileobj
+    else:
+        try:
+            fd = int(fileobj.fileno())
+        except (AttributeError, TypeError, ValueError):
+            raise ValueError("Invalid file object: {0!r}".format(fileobj))
+    if fd < 0:
+        raise ValueError("Invalid file descriptor: {0}".format(fd))
+    return fd
+
+
+class BaseSelector(object):
+    """ Abstract Selector class
+
+    A selector supports registering file objects to be monitored
+    for specific I/O events.
+
+    A file object is a file descriptor or any object with a
+    `fileno()` method. An arbitrary object can be attached to the
+    file object which can be used for example to store context info,
+    a callback, etc.
+
+    A selector can use various implementations (select(), poll(), epoll(),
+    and kqueue()) depending on the platform. The 'DefaultSelector' class uses
+    the most efficient implementation for the current platform.
+    """
+    def __init__(self):
+        # Maps file descriptors to keys.
+        self._fd_to_key = {}
+
+        # Read-only mapping returned by get_map()
+        self._map = _SelectorMapping(self)
+
+    def _fileobj_lookup(self, fileobj):
+        """ Return a file descriptor from a file object.
+        This wraps _fileobj_to_fd() to do an exhaustive
+        search in case the object is invalid but we still
+        have it in our map. Used by unregister() so we can
+        unregister an object that was previously registered
+        even if it is closed. It is also used by _SelectorMapping
+        """
+        try:
+            return _fileobj_to_fd(fileobj)
+        except ValueError:
+
+            # Search through all our mapped keys.
+            for key in self._fd_to_key.values():
+                if key.fileobj is fileobj:
+                    return key.fd
+
+            # Raise ValueError after all.
+            raise
+
+    def register(self, fileobj, events, data=None):
+        """ Register a file object for a set of events to monitor. """
+        if (not events) or (events & ~(EVENT_READ | EVENT_WRITE)):
+            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("{0!r} (FD {1}) is already registered"
+                           .format(fileobj, key.fd))
+
+        self._fd_to_key[key.fd] = key
+        return key
+
+    def unregister(self, fileobj):
+        """ Unregister a file object from being monitored. """
+        try:
+            key = self._fd_to_key.pop(self._fileobj_lookup(fileobj))
+        except KeyError:
+            raise KeyError("{0!r} is not registered".format(fileobj))
+
+        # Getting the fileno of a closed socket on Windows errors with EBADF.
+        except socket.error as err:
+            if err.errno != errno.EBADF:
+                raise
+            else:
+                for key in self._fd_to_key.values():
+                    if key.fileobj is fileobj:
+                        self._fd_to_key.pop(key.fd)
+                        break
+                else:
+                    raise KeyError("{0!r} is not registered".format(fileobj))
+        return key
+
+    def modify(self, fileobj, events, data=None):
+        """ Change a registered file object monitored events and data. """
+        # NOTE: Some subclasses optimize this operation even further.
+        try:
+            key = self._fd_to_key[self._fileobj_lookup(fileobj)]
+        except KeyError:
+            raise KeyError("{0!r} is not registered".format(fileobj))
+
+        if events != key.events:
+            self.unregister(fileobj)
+            key = self.register(fileobj, events, data)
+
+        elif data != key.data:
+            # Use a shortcut to update the data.
+            key = key._replace(data=data)
+            self._fd_to_key[key.fd] = key
+
+        return key
+
+    def select(self, timeout=None):
+        """ Perform the actual selection until some monitored file objects
+        are ready or the timeout expires. """
+        raise NotImplementedError()
+
+    def close(self):
+        """ Close the selector. This must be called to ensure that all
+        underlying resources are freed. """
+        self._fd_to_key.clear()
+        self._map = None
+
+    def get_key(self, fileobj):
+        """ Return the key associated with a registered file object. """
+        mapping = self.get_map()
+        if mapping is None:
+            raise RuntimeError("Selector is closed")
+        try:
+            return mapping[fileobj]
+        except KeyError:
+            raise KeyError("{0!r} is not registered".format(fileobj))
+
+    def get_map(self):
+        """ Return a mapping of file objects to selector keys """
+        return self._map
+
+    def _key_from_fd(self, fd):
+        """ Return the key associated to a given file descriptor
+         Return None if it is not found. """
+        try:
+            return self._fd_to_key[fd]
+        except KeyError:
+            return None
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *_):
+        self.close()
+
+
+# Almost all platforms have select.select()
+if hasattr(select, "select"):
+    class SelectSelector(BaseSelector):
+        """ Select-based selector. """
+        def __init__(self):
+            super(SelectSelector, self).__init__()
+            self._readers = set()
+            self._writers = set()
+
+        def register(self, fileobj, events, data=None):
+            key = super(SelectSelector, self).register(fileobj, events, data)
+            if events & EVENT_READ:
+                self._readers.add(key.fd)
+            if events & EVENT_WRITE:
+                self._writers.add(key.fd)
+            return key
+
+        def unregister(self, fileobj):
+            key = super(SelectSelector, self).unregister(fileobj)
+            self._readers.discard(key.fd)
+            self._writers.discard(key.fd)
+            return key
+
+        def select(self, timeout=None):
+            # Selecting on empty lists on Windows errors out.
+            if not len(self._readers) and not len(self._writers):
+                return []
+
+            timeout = None if timeout is None else max(timeout, 0.0)
+            ready = []
+            r, w, _ = _syscall_wrapper(self._wrap_select, True, self._readers,
+                                       self._writers, timeout)
+            r = set(r)
+            w = set(w)
+            for fd in r | w:
+                events = 0
+                if fd in r:
+                    events |= EVENT_READ
+                if fd in w:
+                    events |= EVENT_WRITE
+
+                key = self._key_from_fd(fd)
+                if key:
+                    ready.append((key, events & key.events))
+            return ready
+
+        def _wrap_select(self, r, w, timeout=None):
+            """ Wrapper for select.select because timeout is a positional arg """
+            return select.select(r, w, [], timeout)
+
+    __all__.append('SelectSelector')
+
+    # Jython has a different implementation of .fileno() for socket objects.
+    if pycompat.isjython:
+        class _JythonSelectorMapping(object):
+            """ This is an implementation of _SelectorMapping that is built
+            for use specifically with Jython, which does not provide a hashable
+            value from socket.socket.fileno(). """
+
+            def __init__(self, selector):
+                assert isinstance(selector, JythonSelectSelector)
+                self._selector = selector
+
+            def __len__(self):
+                return len(self._selector._sockets)
+
+            def __getitem__(self, fileobj):
+                for sock, key in self._selector._sockets:
+                    if sock is fileobj:
+                        return key
+                else:
+                    raise KeyError("{0!r} is not registered.".format(fileobj))
+
+        class JythonSelectSelector(SelectSelector):
+            """ This is an implementation of SelectSelector that is for Jython
+            which works around that Jython's socket.socket.fileno() does not
+            return an integer fd value. All SelectorKey.fd will be equal to -1
+            and should not be used. This instead uses object id to compare fileobj
+            and will only use select.select as it's the only selector that allows
+            directly passing in socket objects rather than registering fds.
+            See: http://bugs.jython.org/issue1678
+                 https://wiki.python.org/jython/NewSocketModule#socket.fileno.28.29_does_not_return_an_integer
+            """
+
+            def __init__(self):
+                super(JythonSelectSelector, self).__init__()
+
+                self._sockets = []  # Uses a list of tuples instead of dictionary.
+                self._map = _JythonSelectorMapping(self)
+                self._readers = []
+                self._writers = []
+
+                # Jython has a select.cpython_compatible_select function in older versions.
+                self._select_func = getattr(select, 'cpython_compatible_select', select.select)
+
+            def register(self, fileobj, events, data=None):
+                for sock, _ in self._sockets:
+                    if sock is fileobj:
+                        raise KeyError("{0!r} is already registered"
+                                       .format(fileobj, sock))
+
+                key = SelectorKey(fileobj, -1, events, data)
+                self._sockets.append((fileobj, key))
+
+                if events & EVENT_READ:
+                    self._readers.append(fileobj)
+                if events & EVENT_WRITE:
+                    self._writers.append(fileobj)
+                return key
+
+            def unregister(self, fileobj):
+                for i, (sock, key) in enumerate(self._sockets):
+                    if sock is fileobj:
+                        break
+                else:
+                    raise KeyError("{0!r} is not registered.".format(fileobj))
+
+                if key.events & EVENT_READ:
+                    self._readers.remove(fileobj)
+                if key.events & EVENT_WRITE:
+                    self._writers.remove(fileobj)
+
+                del self._sockets[i]
+                return key
+
+            def _wrap_select(self, r, w, timeout=None):
+                """ Wrapper for select.select because timeout is a positional arg """
+                return self._select_func(r, w, [], timeout)
+
+        __all__.append('JythonSelectSelector')
+        SelectSelector = JythonSelectSelector  # Override so the wrong selector isn't used.
+
+
+if hasattr(select, "poll"):
+    class PollSelector(BaseSelector):
+        """ Poll-based selector """
+        def __init__(self):
+            super(PollSelector, self).__init__()
+            self._poll = select.poll()
+
+        def register(self, fileobj, events, data=None):
+            key = super(PollSelector, self).register(fileobj, events, data)
+            event_mask = 0
+            if events & EVENT_READ:
+                event_mask |= select.POLLIN
+            if events & EVENT_WRITE:
+                event_mask |= select.POLLOUT
+            self._poll.register(key.fd, event_mask)
+            return key
+
+        def unregister(self, fileobj):
+            key = super(PollSelector, self).unregister(fileobj)
+            self._poll.unregister(key.fd)
+            return key
+
+        def _wrap_poll(self, timeout=None):
+            """ Wrapper function for select.poll.poll() so that
+            _syscall_wrapper can work with only seconds. """
+            if timeout is not None:
+                if timeout <= 0:
+                    timeout = 0
+                else:
+                    # select.poll.poll() has a resolution of 1 millisecond,
+                    # round away from zero to wait *at least* timeout seconds.
+                    timeout = math.ceil(timeout * 1000)
+
+            result = self._poll.poll(timeout)
+            return result
+
+        def select(self, timeout=None):
+            ready = []
+            fd_events = _syscall_wrapper(self._wrap_poll, True, timeout=timeout)
+            for fd, event_mask in fd_events:
+                events = 0
+                if event_mask & ~select.POLLIN:
+                    events |= EVENT_WRITE
+                if event_mask & ~select.POLLOUT:
+                    events |= EVENT_READ
+
+                key = self._key_from_fd(fd)
+                if key:
+                    ready.append((key, events & key.events))
+
+            return ready
+
+    __all__.append('PollSelector')
+
+if hasattr(select, "epoll"):
+    class EpollSelector(BaseSelector):
+        """ Epoll-based selector """
+        def __init__(self):
+            super(EpollSelector, self).__init__()
+            self._epoll = select.epoll()
+
+        def fileno(self):
+            return self._epoll.fileno()
+
+        def register(self, fileobj, events, data=None):
+            key = super(EpollSelector, self).register(fileobj, events, data)
+            events_mask = 0
+            if events & EVENT_READ:
+                events_mask |= select.EPOLLIN
+            if events & EVENT_WRITE:
+                events_mask |= select.EPOLLOUT
+            _syscall_wrapper(self._epoll.register, False, key.fd, events_mask)
+            return key
+
+        def unregister(self, fileobj):
+            key = super(EpollSelector, self).unregister(fileobj)
+            try:
+                _syscall_wrapper(self._epoll.unregister, False, key.fd)
+            except _ERROR_TYPES:
+                # This can occur when the fd was closed since registry.
+                pass
+            return key
+
+        def select(self, timeout=None):
+            if timeout is not None:
+                if timeout <= 0:
+                    timeout = 0.0
+                else:
+                    # select.epoll.poll() has a resolution of 1 millisecond
+                    # but luckily takes seconds so we don't need a wrapper
+                    # like PollSelector. Just for better rounding.
+                    timeout = math.ceil(timeout * 1000) * 0.001
+                timeout = float(timeout)
+            else:
+                timeout = -1.0  # epoll.poll() must have a float.
+
+            # We always want at least 1 to ensure that select can be called
+            # with no file descriptors registered. Otherwise will fail.
+            max_events = max(len(self._fd_to_key), 1)
+
+            ready = []
+            fd_events = _syscall_wrapper(self._epoll.poll, True,
+                                         timeout=timeout,
+                                         maxevents=max_events)
+            for fd, event_mask in fd_events:
+                events = 0
+                if event_mask & ~select.EPOLLIN:
+                    events |= EVENT_WRITE
+                if event_mask & ~select.EPOLLOUT:
+                    events |= EVENT_READ
+
+                key = self._key_from_fd(fd)
+                if key:
+                    ready.append((key, events & key.events))
+            return ready
+
+        def close(self):
+            self._epoll.close()
+            super(EpollSelector, self).close()
+
+    __all__.append('EpollSelector')
+
+
+if hasattr(select, "devpoll"):
+    class DevpollSelector(BaseSelector):
+        """Solaris /dev/poll selector."""
+
+        def __init__(self):
+            super(DevpollSelector, self).__init__()
+            self._devpoll = select.devpoll()
+
+        def fileno(self):
+            return self._devpoll.fileno()
+
+        def register(self, fileobj, events, data=None):
+            key = super(DevpollSelector, self).register(fileobj, events, data)
+            poll_events = 0
+            if events & EVENT_READ:
+                poll_events |= select.POLLIN
+            if events & EVENT_WRITE:
+                poll_events |= select.POLLOUT
+            self._devpoll.register(key.fd, poll_events)
+            return key
+
+        def unregister(self, fileobj):
+            key = super(DevpollSelector, self).unregister(fileobj)
+            self._devpoll.unregister(key.fd)
+            return key
+
+        def _wrap_poll(self, timeout=None):
+            """ Wrapper function for select.poll.poll() so that
+            _syscall_wrapper can work with only seconds. """
+            if timeout is not None:
+                if timeout <= 0:
+                    timeout = 0
+                else:
+                    # select.devpoll.poll() has a resolution of 1 millisecond,
+                    # round away from zero to wait *at least* timeout seconds.
+                    timeout = math.ceil(timeout * 1000)
+
+            result = self._devpoll.poll(timeout)
+            return result
+
+        def select(self, timeout=None):
+            ready = []
+            fd_events = _syscall_wrapper(self._wrap_poll, True, timeout=timeout)
+            for fd, event_mask in fd_events:
+                events = 0
+                if event_mask & ~select.POLLIN:
+                    events |= EVENT_WRITE
+                if event_mask & ~select.POLLOUT:
+                    events |= EVENT_READ
+
+                key = self._key_from_fd(fd)
+                if key:
+                    ready.append((key, events & key.events))
+
+            return ready
+
+        def close(self):
+            self._devpoll.close()
+            super(DevpollSelector, self).close()
+
+    __all__.append('DevpollSelector')
+
+
+if hasattr(select, "kqueue"):
+    class KqueueSelector(BaseSelector):
+        """ Kqueue / Kevent-based selector """
+        def __init__(self):
+            super(KqueueSelector, self).__init__()
+            self._kqueue = select.kqueue()
+
+        def fileno(self):
+            return self._kqueue.fileno()
+
+        def register(self, fileobj, events, data=None):
+            key = super(KqueueSelector, self).register(fileobj, events, data)
+            if events & EVENT_READ:
+                kevent = select.kevent(key.fd,
+                                       select.KQ_FILTER_READ,
+                                       select.KQ_EV_ADD)
+
+                _syscall_wrapper(self._kqueue.control, False, [kevent], 0, 0)
+
+            if events & EVENT_WRITE:
+                kevent = select.kevent(key.fd,
+                                       select.KQ_FILTER_WRITE,
+                                       select.KQ_EV_ADD)
+
+                _syscall_wrapper(self._kqueue.control, False, [kevent], 0, 0)
+
+            return key
+
+        def unregister(self, fileobj):
+            key = super(KqueueSelector, self).unregister(fileobj)
+            if key.events & EVENT_READ:
+                kevent = select.kevent(key.fd,
+                                       select.KQ_FILTER_READ,
+                                       select.KQ_EV_DELETE)
+                try:
+                    _syscall_wrapper(self._kqueue.control, False, [kevent], 0, 0)
+                except _ERROR_TYPES:
+                    pass
+            if key.events & EVENT_WRITE:
+                kevent = select.kevent(key.fd,
+                                       select.KQ_FILTER_WRITE,
+                                       select.KQ_EV_DELETE)
+                try:
+                    _syscall_wrapper(self._kqueue.control, False, [kevent], 0, 0)
+                except _ERROR_TYPES:
+                    pass
+
+            return key
+
+        def select(self, timeout=None):
+            if timeout is not None:
+                timeout = max(timeout, 0)
+
+            max_events = len(self._fd_to_key) * 2
+            ready_fds = {}
+
+            kevent_list = _syscall_wrapper(self._kqueue.control, True,
+                                           None, max_events, timeout)
+
+            for kevent in kevent_list:
+                fd = kevent.ident
+                event_mask = kevent.filter
+                events = 0
+                if event_mask == select.KQ_FILTER_READ:
+                    events |= EVENT_READ
+                if event_mask == select.KQ_FILTER_WRITE:
+                    events |= EVENT_WRITE
+
+                key = self._key_from_fd(fd)
+                if key:
+                    if key.fd not in ready_fds:
+                        ready_fds[key.fd] = (key, events & key.events)
+                    else:
+                        old_events = ready_fds[key.fd][1]
+                        ready_fds[key.fd] = (key, (events | old_events) & key.events)
+
+            return list(ready_fds.values())
+
+        def close(self):
+            self._kqueue.close()
+            super(KqueueSelector, self).close()
+
+    __all__.append('KqueueSelector')
+
+
+def _can_allocate(struct):
+    """ Checks that select structs can be allocated by the underlying
+    operating system, not just advertised by the select module. We don't
+    check select() because we'll be hopeful that most platforms that
+    don't have it available will not advertise it. (ie: GAE) """
+    try:
+        # select.poll() objects won't fail until used.
+        if struct == 'poll':
+            p = select.poll()
+            p.poll(0)
+
+        # All others will fail on allocation.
+        else:
+            getattr(select, struct)().close()
+        return True
+    except (OSError, AttributeError):
+        return False
+
+
+# Python 3.5 uses a more direct route to wrap system calls to increase speed.
+if sys.version_info >= (3, 5):
+    def _syscall_wrapper(func, _, *args, **kwargs):
+        """ This is the short-circuit version of the below logic
+        because in Python 3.5+ all selectors restart system calls. """
+        return func(*args, **kwargs)
+else:
+    def _syscall_wrapper(func, recalc_timeout, *args, **kwargs):
+        """ Wrapper function for syscalls that could fail due to EINTR.
+        All functions should be retried if there is time left in the timeout
+        in accordance with PEP 475. """
+        timeout = kwargs.get("timeout", None)
+        if timeout is None:
+            expires = None
+            recalc_timeout = False
+        else:
+            timeout = float(timeout)
+            if timeout < 0.0:  # Timeout less than 0 treated as no timeout.
+                expires = None
+            else:
+                expires = monotonic() + timeout
+
+        args = list(args)
+        if recalc_timeout and "timeout" not in kwargs:
+            raise ValueError(
+                "Timeout must be in args or kwargs to be recalculated")
+
+        result = _SYSCALL_SENTINEL
+        while result is _SYSCALL_SENTINEL:
+            try:
+                result = func(*args, **kwargs)
+            # OSError is thrown by select.select
+            # IOError is thrown by select.epoll.poll
+            # select.error is thrown by select.poll.poll
+            # Aren't we thankful for Python 3.x rework for exceptions?
+            except (OSError, IOError, select.error) as e:
+                # select.error wasn't a subclass of OSError in the past.
+                errcode = None
+                if hasattr(e, "errno"):
+                    errcode = e.errno
+                elif hasattr(e, "args"):
+                    errcode = e.args[0]
+
+                # Also test for the Windows equivalent of EINTR.
+                is_interrupt = (errcode == errno.EINTR or (hasattr(errno, "WSAEINTR") and
+                                                           errcode == errno.WSAEINTR))
+
+                if is_interrupt:
+                    if expires is not None:
+                        current_time = monotonic()
+                        if current_time > expires:
+                            raise OSError(errno=errno.ETIMEDOUT)
+                        if recalc_timeout:
+                            if "timeout" in kwargs:
+                                kwargs["timeout"] = expires - current_time
+                    continue
+                raise
+        return result
+
+
+# Choose the best implementation, roughly:
+# kqueue == devpoll == epoll > poll > select
+# select() also can't accept a FD > FD_SETSIZE (usually around 1024)
+def DefaultSelector():
+    """ This function serves as a first call for DefaultSelector to
+    detect if the select module is being monkey-patched incorrectly
+    by eventlet, greenlet, and preserve proper behavior. """
+    global _DEFAULT_SELECTOR
+    if _DEFAULT_SELECTOR is None:
+        if pycompat.isjython:
+            _DEFAULT_SELECTOR = JythonSelectSelector
+        elif _can_allocate('kqueue'):
+            _DEFAULT_SELECTOR = KqueueSelector
+        elif _can_allocate('devpoll'):
+            _DEFAULT_SELECTOR = DevpollSelector
+        elif _can_allocate('epoll'):
+            _DEFAULT_SELECTOR = EpollSelector
+        elif _can_allocate('poll'):
+            _DEFAULT_SELECTOR = PollSelector
+        elif hasattr(select, 'select'):
+            _DEFAULT_SELECTOR = SelectSelector
+        else:  # Platform-specific: AppEngine
+            raise RuntimeError('Platform does not have a selector.')
+    return _DEFAULT_SELECTOR()
--- a/tests/test-check-code.t	Tue Nov 28 05:50:45 2017 +0530
+++ b/tests/test-check-code.t	Thu Nov 30 22:43:03 2017 +0900
@@ -15,7 +15,6 @@
   Skipping i18n/polib.py it has no-che?k-code (glob)
   Skipping mercurial/httpclient/__init__.py it has no-che?k-code (glob)
   Skipping mercurial/httpclient/_readers.py it has no-che?k-code (glob)
-  Skipping mercurial/selectors2.py it has no-che?k-code (glob)
   Skipping mercurial/statprof.py it has no-che?k-code (glob)
   Skipping tests/badserverext.py it has no-che?k-code (glob)