diff --git a/docs/index.rst b/docs/index.rst
index 026bef1..2f39b6b 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -560,6 +560,29 @@ functions in the standard library with equivalent asynchronous versions. While
 python-socketio does not require monkey patching, other libraries such as
 database drivers are likely to require it.
 
+Gevent with uWSGI
+~~~~~~~~~~~~~~~~~
+
+When using the uWSGI server in combination with gevent, the Socket.IO server
+can take advantage of uWSGI's native WebSocket support.
+
+Instances of class ``socketio.Server`` will automatically use this option for
+asynchronous operations if both gevent and uWSGI are installed and eventlet is
+not installed. To request this asynchoronous mode explicitly, the
+``async_mode`` option can be given in the constructor::
+
+    # gevent with uWSGI
+    sio = socketio.Server(async_mode='gevent_uwsgi')
+
+A complete explanation of the configuration and usage of the uWSGI server is
+beyond the scope of this documentation. The uWSGI server is a fairly complex
+package that provides a large and comprehensive set of options. It must be
+compiled with WebSocket and SSL support for the WebSocket transport to be
+available. As way of an introduction, the following command starts a uWSGI
+server for the ``latency.py`` example on port 5000::
+
+    $ uwsgi --http :5000 --gevent 1000 --http-websockets --master --wsgi-file latency.py --callable app
+
 Standard Threading Library
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
 
diff --git a/examples/app.py b/examples/app.py
index 5f3f63e..7f4fe4a 100755
--- a/examples/app.py
+++ b/examples/app.py
@@ -1,5 +1,6 @@
-# set async_mode to 'threading', 'eventlet' or 'gevent' to force a mode
-# else, the best mode is selected automatically from what's installed
+# set async_mode to 'threading', 'eventlet', 'gevent' or 'gevent_uwsgi' to
+# force a mode else, the best mode is selected automatically from what's
+# installed
 async_mode = None
 
 import time
@@ -108,5 +109,9 @@ if __name__ == '__main__':
                               handler_class=WebSocketHandler).serve_forever()
         else:
             pywsgi.WSGIServer(('', 5000), app).serve_forever()
+    elif sio.async_mode == 'gevent_uwsgi':
+        print('Start the application through the uwsgi server. Example:')
+        print('uwsgi --http :5000 --gevent 1000 --http-websockets --master '
+              '--wsgi-file app.py --callable app')
     else:
         print('Unknown async_mode: ' + sio.async_mode)
diff --git a/examples/latency.py b/examples/latency.py
index e43a2f3..45252f9 100755
--- a/examples/latency.py
+++ b/examples/latency.py
@@ -1,11 +1,11 @@
-from flask import Flask, render_template
+# set async_mode to 'threading', 'eventlet', 'gevent' or 'gevent_uwsgi' to
+# force a mode else, the best mode is selected automatically from what's
+# installed
+async_mode = None
 
+from flask import Flask, render_template
 import socketio
 
-# set async_mode to 'threading', 'eventlet' or 'gevent' to force a mode
-# else, the best mode is selected automatically from what's installed
-async_mode = None
-
 sio = socketio.Server(async_mode=async_mode)
 app = Flask(__name__)
 app.wsgi_app = socketio.Middleware(sio, app.wsgi_app)
@@ -43,5 +43,9 @@ if __name__ == '__main__':
                               handler_class=WebSocketHandler).serve_forever()
         else:
             pywsgi.WSGIServer(('', 5000), app).serve_forever()
+    elif sio.async_mode == 'gevent_uwsgi':
+        print('Start the application through the uwsgi server. Example:')
+        print('uwsgi --http :5000 --gevent 1000 --http-websockets --master '
+              '--wsgi-file latency.py --callable app')
     else:
         print('Unknown async_mode: ' + sio.async_mode)
diff --git a/setup.py b/setup.py
index cc620d0..15478a3 100755
--- a/setup.py
+++ b/setup.py
@@ -4,15 +4,19 @@ python-socketio
 
 Socket.IO server.
 """
+import re
 from setuptools import setup
 
+with open('socketio/__init__.py', 'r') as f:
+    version = re.search(r'^__version__\s*=\s*[\'"]([^\'"]*)[\'"]',
+                        f.read(), re.MULTILINE).group(1)
 
 with open('README.rst', 'r') as f:
     long_description = f.read()
 
 setup(
     name='python-socketio',
-    version='1.4.4',
+    version=version,
     url='http://github.com/miguelgrinberg/python-socketio/',
     license='MIT',
     author='Miguel Grinberg',
@@ -25,7 +29,7 @@ setup(
     platforms='any',
     install_requires=[
         'six>=1.9.0',
-        'python-engineio>=0.8.0'
+        'python-engineio>=1.0.0'
     ],
     tests_require=[
         'mock',
diff --git a/socketio/__init__.py b/socketio/__init__.py
index b4b0362..e4cda4c 100644
--- a/socketio/__init__.py
+++ b/socketio/__init__.py
@@ -8,6 +8,8 @@ from .redis_manager import RedisManager
 from .server import Server
 from .util import apply_interceptor, ignore_interceptor
 
-__all__ = [Interceptor, Middleware, Namespace, Server, BaseManager,
-           PubSubManager, KombuManager, RedisManager,
+__version__ = '1.5.1'
+
+__all__ = [__version__, Interceptor, Middleware, Namespace, Server,
+           BaseManager, PubSubManager, KombuManager, RedisManager,
            apply_interceptor, ignore_interceptor]
diff --git a/socketio/base_manager.py b/socketio/base_manager.py
index cdbaa80..5b98990 100644
--- a/socketio/base_manager.py
+++ b/socketio/base_manager.py
@@ -16,6 +16,7 @@ class BaseManager(object):
         self.server = None
         self.rooms = {}
         self.callbacks = {}
+        self.pending_disconnect = {}
 
     def initialize(self, server):
         self.server = server
@@ -35,11 +36,26 @@ class BaseManager(object):
         self.enter_room(sid, namespace, sid)
 
     def is_connected(self, sid, namespace):
+        if namespace in self.pending_disconnect and \
+                sid in self.pending_disconnect[namespace]:
+            # the client is in the process of being disconnected
+            return False
         try:
             return self.rooms[namespace][None][sid]
         except KeyError:
             pass
 
+    def pre_disconnect(self, sid, namespace):
+        """Put the client in the to-be-disconnected list.
+
+        This allows the client data structures to be present while the
+        disconnect handler is invoked, but still recognize the fact that the
+        client is soon going away.
+        """
+        if namespace not in self.pending_disconnect:
+            self.pending_disconnect[namespace] = []
+        self.pending_disconnect[namespace].append(sid)
+
     def disconnect(self, sid, namespace):
         """Register a client disconnect from a namespace."""
         rooms = []
@@ -52,6 +68,11 @@ class BaseManager(object):
             del self.callbacks[sid][namespace]
             if len(self.callbacks[sid]) == 0:
                 del self.callbacks[sid]
+        if namespace in self.pending_disconnect and \
+                sid in self.pending_disconnect[namespace]:
+            self.pending_disconnect[namespace].remove(sid)
+            if len(self.pending_disconnect[namespace]) == 0:
+                del self.pending_disconnect[namespace]
 
     def enter_room(self, sid, namespace, room):
         """Add a client to a room."""
diff --git a/socketio/server.py b/socketio/server.py
index bbd08f4..3e69e31 100644
--- a/socketio/server.py
+++ b/socketio/server.py
@@ -31,15 +31,21 @@ class Server(object):
                  packets. Custom json modules must have ``dumps`` and ``loads``
                  functions that are compatible with the standard library
                  versions.
+    :param async_handlers: If set to ``True``, event handlers are executed in
+                           separate threads. To run handlers synchronously,
+                           set to ``False``. The default is ``False``.
     :param kwargs: Connection parameters for the underlying Engine.IO server.
 
     The Engine.IO configuration supports the following settings:
 
-    :param async_mode: The library used for asynchronous operations. Valid
-                       options are "threading", "eventlet" and "gevent". If
-                       this argument is not given, "eventlet" is tried first,
-                       then "gevent", and finally "threading". The websocket
-                       transport is only supported in "eventlet" mode.
+    :param async_mode: The asynchronous model to use. See the Deployment
+                       section in the documentation for a description of the
+                       available options. Valid async modes are "threading",
+                       "eventlet", "gevent" and "gevent_uwsgi". If this
+                       argument is not given, "eventlet" is tried first, then
+                       "gevent_uwsgi", then "gevent", and finally "threading".
+                       The first async mode that has all its dependencies
+                       installed is then one that is chosen.
     :param ping_timeout: The time in seconds that the client waits for the
                          server to respond before disconnecting.
     :param ping_interval: The interval in seconds at which the client pings
@@ -63,7 +69,7 @@ class Server(object):
                             ``False``.
     """
     def __init__(self, client_manager=None, logger=False, binary=False,
-                 json=None, **kwargs):
+                 json=None, async_handlers=False, **kwargs):
         engineio_options = kwargs
         engineio_logger = engineio_options.pop('engineio_logger', None)
         if engineio_logger is not None:
@@ -71,6 +77,7 @@ class Server(object):
         if json is not None:
             packet.Packet.json = json
             engineio_options['json'] = json
+        engineio_options['async_handlers'] = False
         self.eio = engineio.Server(**engineio_options)
         self.eio.on('connect', self._handle_eio_connect)
         self.eio.on('message', self._handle_eio_message)
@@ -101,6 +108,8 @@ class Server(object):
         self.manager = client_manager
         self.manager_initialized = False
 
+        self.async_handlers = async_handlers
+
         self.async_mode = self.eio.async_mode
 
     def on(self, event, handler=None, namespace=None):
@@ -293,11 +302,13 @@ class Server(object):
                           argument is omitted the default namespace is used.
         """
         namespace = namespace or '/'
-        self.logger.info('Disconnecting %s [%s]', sid, namespace)
-        self._send_packet(sid, packet.Packet(packet.DISCONNECT,
-                                             namespace=namespace))
-        self._trigger_event('disconnect', namespace, sid)
-        self.manager.disconnect(sid, namespace=namespace)
+        if self.manager.is_connected(sid, namespace=namespace):
+            self.logger.info('Disconnecting %s [%s]', sid, namespace)
+            self.manager.pre_disconnect(sid, namespace=namespace)
+            self._send_packet(sid, packet.Packet(packet.DISCONNECT,
+                                                 namespace=namespace))
+            self._trigger_event('disconnect', namespace, sid)
+            self.manager.disconnect(sid, namespace=namespace)
 
     def transport(self, sid):
         """Return the name of the transport used by the client.
@@ -418,7 +429,14 @@ class Server(object):
         namespace = namespace or '/'
         self.logger.info('received event "%s" from %s [%s]', data[0], sid,
                          namespace)
-        r = self._trigger_event(data[0], namespace, sid, *data[1:])
+        if self.async_handlers:
+            self.start_background_task(self._handle_event_internal, self, sid,
+                                       data, namespace, id)
+        else:
+            self._handle_event_internal(self, sid, data, namespace, id)
+
+    def _handle_event_internal(self, server, sid, data, namespace, id):
+        r = server._trigger_event(data[0], namespace, sid, *data[1:])
         if id is not None:
             # send ACK packet with the response returned by the handler
             # tuples are expanded as multiple arguments
@@ -432,10 +450,10 @@ class Server(object):
                 binary = False  # pragma: nocover
             else:
                 binary = None
-            self._send_packet(sid, packet.Packet(packet.ACK,
-                                                 namespace=namespace,
-                                                 id=id, data=data,
-                                                 binary=binary))
+            server._send_packet(sid, packet.Packet(packet.ACK,
+                                                   namespace=namespace,
+                                                   id=id, data=data,
+                                                   binary=binary))
 
     def _handle_ack(self, sid, namespace, id, data):
         """Handle ACK packets from the client."""
diff --git a/tests/test_base_manager.py b/tests/test_base_manager.py
index b916ddc..2a801be 100644
--- a/tests/test_base_manager.py
+++ b/tests/test_base_manager.py
@@ -24,6 +24,20 @@ class TestBaseManager(unittest.TestCase):
         self.assertEqual(self.bm.rooms['/foo'], {None: {'123': True},
                                                  '123': {'123': True}})
 
+    def test_pre_disconnect(self):
+        self.bm.connect('123', '/foo')
+        self.bm.connect('456', '/foo')
+        self.bm.pre_disconnect('123', '/foo')
+        self.assertEqual(self.bm.pending_disconnect, {'/foo': ['123']})
+        self.assertFalse(self.bm.is_connected('123', '/foo'))
+        self.bm.pre_disconnect('456', '/foo')
+        self.assertEqual(self.bm.pending_disconnect, {'/foo': ['123', '456']})
+        self.assertFalse(self.bm.is_connected('456', '/foo'))
+        self.bm.disconnect('123', '/foo')
+        self.assertEqual(self.bm.pending_disconnect, {'/foo': ['456']})
+        self.bm.disconnect('456', '/foo')
+        self.assertEqual(self.bm.pending_disconnect, {})
+
     def test_disconnect(self):
         self.bm.connect('123', '/foo')
         self.bm.connect('456', '/foo')
diff --git a/tests/test_server.py b/tests/test_server.py
index b10a8cd..ec3baaf 100644
--- a/tests/test_server.py
+++ b/tests/test_server.py
@@ -23,13 +23,15 @@ class TestServer(unittest.TestCase):
 
     def test_create(self, eio):
         mgr = mock.MagicMock()
-        s = server.Server(client_manager=mgr, binary=True, foo='bar')
+        s = server.Server(client_manager=mgr, binary=True,
+                          async_handlers=True, foo='bar')
         s.handle_request({}, None)
         s.handle_request({}, None)
-        eio.assert_called_once_with(**{'foo': 'bar'})
+        eio.assert_called_once_with(**{'foo': 'bar', 'async_handlers': False})
         self.assertEqual(s.manager, mgr)
         self.assertEqual(s.eio.on.call_count, 3)
         self.assertEqual(s.binary, True)
+        self.assertEqual(s.async_handlers, True)
         self.assertEqual(mgr.initialize.call_count, 1)
 
     def test_on_event(self, eio):
@@ -486,6 +488,23 @@ class TestServer(unittest.TestCase):
         s.disconnect('123', namespace='/foo')
         s.eio.send.assert_any_call('123', '1/foo', binary=False)
 
+    def test_disconnect_twice(self, eio):
+        s = server.Server()
+        s._handle_eio_connect('123', 'environ')
+        s.disconnect('123')
+        calls = s.eio.send.call_count
+        s.disconnect('123')
+        self.assertEqual(calls, s.eio.send.call_count)
+
+    def test_disconnect_twice_namespace(self, eio):
+        s = server.Server()
+        s._handle_eio_connect('123', 'environ')
+        s._handle_eio_message('123', '0/foo')
+        s.disconnect('123', namespace='/foo')
+        calls = s.eio.send.call_count
+        s.disconnect('123', namespace='/foo')
+        self.assertEqual(calls, s.eio.send.call_count)
+
     def test_namespace_handler(self, eio):
         result = {}
 
@@ -527,6 +546,8 @@ class TestServer(unittest.TestCase):
         self.assertRaises(ValueError, s.register_namespace, 123)
         self.assertRaises(ValueError, s.register_namespace, Dummy)
         self.assertRaises(ValueError, s.register_namespace, Dummy())
+        self.assertRaises(ValueError, s.register_namespace,
+                          namespace.Namespace)
 
     def test_logger(self, eio):
         s = server.Server(logger=False)
@@ -543,7 +564,8 @@ class TestServer(unittest.TestCase):
 
     def test_engineio_logger(self, eio):
         server.Server(engineio_logger='foo')
-        eio.assert_called_once_with(**{'logger': 'foo'})
+        eio.assert_called_once_with(**{'logger': 'foo',
+                                       'async_handlers': False})
 
     def test_custom_json(self, eio):
         # Warning: this test cannot run in parallel with other tests, as it
@@ -559,7 +581,8 @@ class TestServer(unittest.TestCase):
                 return '+++ decoded +++'
 
         server.Server(json=CustomJSON)
-        eio.assert_called_once_with(**{'json': CustomJSON})
+        eio.assert_called_once_with(**{'json': CustomJSON,
+                                       'async_handlers': False})
 
         pkt = packet.Packet(packet_type=packet.EVENT,
                             data={six.text_type('foo'): six.text_type('bar')})
@@ -570,6 +593,13 @@ class TestServer(unittest.TestCase):
         # restore the default JSON module
         packet.Packet.json = json
 
+    def test_async_handlers(self, eio):
+        s = server.Server(async_handlers=True)
+        s._handle_eio_message('123', '2["my message","a","b","c"]')
+        s.eio.start_background_task.assert_called_once_with(
+            s._handle_event_internal, s, '123', ['my message', 'a', 'b', 'c'],
+            '/', None)
+
     def test_start_background_task(self, eio):
         s = server.Server()
         s.start_background_task('foo', 'bar', baz='baz')