from twisted.application import service, internet
from twisted.internet import defer, task, reactor

def sleep(t):
    return task.deferLater(reactor, t, lambda: None)

class WorkerApp(service.Service):
    myd = None

    def __init__(self, reactor):
        self._reactor = reactor
        print("workerapp init")

    async def _startService(self):
        self.running = True
        self.myd = defer.Deferred()

        while self.running:
            self.myd = defer.Deferred()
            try:
                print("1")
                await sleep(2)
                #raise Exception('my exception')
                print("2")
                await sleep(2)
                print("3")
                await sleep(2)
            except:
                # Put logging here
                self.running = False
                self.myd.callback(self)
                self._reactor.stop()
            else:
                self.myd.callback(self)

    def startService(self):
        defer.ensureDeferred(self._startService())

    async def _stopService(self):
        print("stop service")
        #try:
        #    await sleep(1)
        #except Exception as e:
        #    raise
        self.myd.addCallback(setattr, "running", False)
        return self.myd

    def stopService(self):
       defer.ensureDeferred(self._stopService())
       #return self._stopService()


application = service.Application("my twisted app")
service = WorkerApp(reactor)
service.setServiceParent(application)