tornado.platform.twisted — Bridges between Twisted and Tornado

This module lets you run applications and libraries written for Twisted in a Tornado application. It can be used in two modes, depending on which library’s underlying event loop you want to use.

This module has been tested with Twisted versions 11.0.0 and newer.

Twisted on Tornado

class tornado.platform.twisted.TornadoReactor

TornadoReactor implements the Twisted reactor interface on top of the Tornado IOLoop. To use it, simply call install at the beginning of the application:

import tornado.platform.twisted
from twisted.internet import reactor

When the app is ready to start, call IOLoop.instance().start() instead of

It is also possible to create a non-global reactor by calling tornado.platform.twisted.TornadoReactor(io_loop). However, if the IOLoop and reactor are to be short-lived (such as those used in unit tests), additional cleanup may be required. Specifically, it is recommended to call:


before closing the IOLoop.

Tornado on Twisted

class tornado.platform.twisted.TwistedIOLoop

TwistedIOLoop implements the Tornado IOLoop interface on top of the Twisted reactor. Recommended usage:

from tornado.platform.twisted import TwistedIOLoop
from twisted.internet import reactor
# Set up your tornado application as usual using `IOLoop.instance`

TwistedIOLoop always uses the global Twisted reactor.

Twisted DNS resolver

class tornado.platform.twisted.TwistedResolver

This is a non-blocking and non-threaded resolver. It is recommended only when threads cannot be used, since it has limitations compared to the standard getaddrinfo-based Resolver and ThreadedResolver. Specifically, it returns at most one result, and arguments other than host and family are ignored. It may fail to resolve when family is not socket.AF_UNSPEC.

Requires Twisted 12.1 or newer.