tornado.platform.twisted — Bridges between Twisted and Tornado

Bridges between the Twisted reactor and Tornado IOLoop.

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

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
tornado.platform.twisted.install()
from twisted.internet import reactor

When the app is ready to start, call IOLoop.current().start() instead of reactor.run().

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:

reactor.fireSystemEvent('shutdown')
reactor.disconnectAll()

before closing the IOLoop.

Tornado on Twisted

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
TwistedIOLoop().install()
# Set up your tornado application as usual using `IOLoop.instance`
reactor.run()

TwistedIOLoop always uses the global Twisted reactor.

Twisted on Tornado

class tornado.platform.twisted.TornadoReactor(io_loop=None)

Twisted reactor built on the Tornado IOLoop.

Since it is intended to be used in applications where the top-level event loop is io_loop.start() rather than reactor.run(), it is implemented a little differently than other Twisted reactors. We override mainLoop instead of doIteration and must implement timed call functionality on top of IOLoop.add_timeout rather than using the implementation in PosixReactorBase.

Changed in version 4.1: The io_loop argument is deprecated.

callFromThread(f, *args, **kw)

See twisted.internet.interfaces.IReactorThreads.callFromThread

addReader(reader)

Add a FileDescriptor for notification of data available to read.

addWriter(writer)

Add a FileDescriptor for notification of data available to write.

removeReader(reader)

Remove a Selectable for notification of data available to read.

removeWriter(writer)

Remove a Selectable for notification of data available to write.

tornado.platform.twisted.install(io_loop=None)

Install this package as the default Twisted reactor.

Changed in version 4.1: The io_loop argument is deprecated.

Tornado on Twisted

class tornado.platform.twisted.TwistedIOLoop

IOLoop implementation that runs on Twisted.

Uses the global Twisted reactor by default. To create multiple TwistedIOLoops in the same process, you must pass a unique reactor when constructing each one.

Not compatible with tornado.process.Subprocess.set_exit_callback because the SIGCHLD handlers used by Tornado and Twisted conflict with each other.

Twisted DNS resolver

class tornado.platform.twisted.TwistedResolver

Twisted-based asynchronous resolver.

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.

Changed in version 4.1: The io_loop argument is deprecated.