From 80e1cf5d7823675da9de7156ccff3d7c0f32efc7 Mon Sep 17 00:00:00 2001
From: whitequark <whitequark@whitequark.org>
Date: Wed, 9 Mar 2016 02:34:22 +0000
Subject: [PATCH] Monkey-patch asyncio create_server (fixes #253).

---
 artiq/tools.py | 108 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 108 insertions(+)

diff --git a/artiq/tools.py b/artiq/tools.py
index ef666cabf..8d2424cdc 100644
--- a/artiq/tools.py
+++ b/artiq/tools.py
@@ -7,6 +7,8 @@ import asyncio
 import time
 import collections
 import os
+import socket
+import itertools
 import atexit
 import string
 
@@ -243,3 +245,109 @@ def get_windows_drives():
             drives.append(letter)
         bitmask >>= 1
     return drives
+
+if sys.version_info[:3] == (3, 5, 1):
+    # See https://github.com/m-labs/artiq/issues/253
+    @asyncio.coroutines.coroutine
+    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,
+                      reuse_port=None):
+        """Create a TCP server.
+        The host parameter can be a string, in that case the TCP server is bound
+        to host and port.
+        The host parameter can also be a sequence of strings and in that case
+        the TCP server is bound to all hosts of the sequence. If a host
+        appears multiple times (possibly indirectly e.g. when hostnames
+        resolve to the same IP address), the server is only bound once to that
+        host.
+        Return a Server object which can be used to stop the service.
+        This method is a coroutine.
+        """
+        if isinstance(ssl, bool):
+            raise TypeError('ssl argument must be an SSLContext or None')
+        if host is not None or port is not None:
+            if sock is not None:
+                raise ValueError(
+                    'host/port and sock can not be specified at the same time')
+
+            AF_INET6 = getattr(socket, 'AF_INET6', 0)
+            if reuse_address is None:
+                reuse_address = os.name == 'posix' and sys.platform != 'cygwin'
+            sockets = []
+            if host == '':
+                hosts = [None]
+            elif (isinstance(host, str) or
+                  not isinstance(host, collections.Iterable)):
+                hosts = [host]
+            else:
+                hosts = host
+
+            fs = [self._create_server_getaddrinfo(host, port, family=family,
+                                                  flags=flags)
+                  for host in hosts]
+            infos = yield from asyncio.tasks.gather(*fs, loop=self)
+            infos = set(itertools.chain.from_iterable(infos))
+
+            completed = False
+            try:
+                for res in infos:
+                    af, socktype, proto, canonname, sa = res
+                    try:
+                        sock = socket.socket(af, socktype, proto)
+                    except socket.error:
+                        # Assume it's a bad family/type/protocol combination.
+                        if self._debug:
+                            asyncio.log.logger.warning('create_server() failed to create '
+                                           'socket.socket(%r, %r, %r)',
+                                           af, socktype, proto, exc_info=True)
+                        continue
+                    sockets.append(sock)
+                    if reuse_address:
+                        sock.setsockopt(
+                            socket.SOL_SOCKET, socket.SO_REUSEADDR, True)
+                    if reuse_port:
+                        if not hasattr(socket, 'SO_REUSEPORT'):
+                            raise ValueError(
+                                'reuse_port not supported by socket module')
+                        else:
+                            sock.setsockopt(
+                                socket.SOL_SOCKET, socket.SO_REUSEPORT, True)
+                    # Disable IPv4/IPv6 dual stack support (enabled by
+                    # default on Linux) which makes a single socket
+                    # listen on both address families.
+                    if af == AF_INET6 and hasattr(socket, 'IPPROTO_IPV6'):
+                        sock.setsockopt(socket.IPPROTO_IPV6,
+                                        socket.IPV6_V6ONLY,
+                                        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()))
+                completed = True
+            finally:
+                if not completed:
+                    for sock in sockets:
+                        sock.close()
+        else:
+            if sock is None:
+                raise ValueError('Neither host/port nor sock were specified')
+            sockets = [sock]
+
+        server = asyncio.base_events.Server(self, sockets)
+        for sock in sockets:
+            sock.listen(backlog)
+            sock.setblocking(False)
+            self._start_serving(protocol_factory, sock, ssl, server)
+        if self._debug:
+            asyncio.log.logger.info("%r is serving", server)
+        return server
+
+    asyncio.base_events.BaseEventLoop.create_server = create_server