Added support for Tornado.

Took less than a beer.

examples/tornado/basic.py

@@ -0,0 +1,11 @@
+
+import tornado.web
+
+class MainHandler(tornado.web.RequestHandler):
+    def get(self):
+        self.write("Hello, world")
+
+app = tornado.web.Application([
+    (r"/", MainHandler)
+])
+

gunicorn/workers/gtornado.py

@@ -0,0 +1,29 @@
+# -*- coding: utf-8 -
+#
+# This file is part of gunicorn released under the MIT license. 
+# See the NOTICE for more information.
+
+from tornado.httpserver import HTTPServer
+from tornado.ioloop import IOLoop, PeriodicCallback
+
+from gunicorn.workers.base import Worker
+
+class TornadoWorker(Worker):
+    
+    def watchdog(self):
+        self.notify()
+            
+        if self.ppid != os.getppid():
+            self.log.info("Parent changed, shutting down: %s" % self)
+            self.ioloop.stop()
+    
+    def run(self):
+        self.socket.setblocking(0)
+        self.ioloop = IOLoop.instance()
+        PeriodicCallback(self.watchdog, 1000, io_loop=self.ioloop).start()
+
+        server = HTTPServer(self.app, io_loop=self.ioloop)
+        server._socket = self.socket
+        server.start(num_processes=1)
+
+        self.ioloop.start()

setup.py

@@ -52,6 +52,7 @@ setup(
     sync=gunicorn.workers.sync:SyncWorker
     eventlet=gunicorn.workers.geventlet:EventletWorker
     gevent=gunicorn.workers.ggevent:GEventWorker
+    tornado=gunicorn.workers.gtornado:TornadoWorker
 
     [paste.server_runner]
     main=gunicorn.main:paste_server