debug_twisted.py

def main():
    fork_and_continue_in_child()
    setup_reactor('AsyncioSelectorReactor')
    run_server()

def setup_reactor(reactor_type):
    if reactor_type == 'AsyncioSelectorReactor':
        from twisted.internet import asyncioreactor
        asyncioreactor.install()
    elif reactor_type == 'SelectReactor':
        pass
    else:
        raise ValueError('Unrecognized type of reactor: %s' % reactor_type)

    # Get the current reactor
    from twisted.internet import reactor
    print('Reactor implementation: %r' % reactor)

def fork_and_continue_in_child():
    import os
    import sys
    if os.fork() == 0:
        # Child
        pass
    else:
        # Parent
        sys.exit(0)

def run_server():
    from twisted.internet import reactor
    from twisted.internet.endpoints import serverFromString
    from twisted.web import server, resource

    class Counter(resource.Resource):
        isLeaf = True
        numberRequests = 0

        def render_GET(self, request):
            self.numberRequests += 1
            request.setHeader(b"content-type", b"text/plain")
            content = u"I am request #{}\n".format(self.numberRequests)
            return content.encode("ascii")

    http_factory = server.Site(Counter())

    def listen_success(port):
        host = port.getHost()
        print('Success: %s' % ((host.host, host.port),))

    def listen_error(failure):
        print(failure)

    ep = serverFromString(reactor, 'tcp:8080')
    listener = ep.listen(http_factory)
    listener.addCallback(listen_success)
    listener.addErrback(listen_error)

    reactor.run()

if __name__ == '__main__':
    main()