task.py 文件源码

def _tick(self):
        """
        Run one scheduler tick.
        """
        self._delayedCall = None
        for taskObj in self._tasks():
            iterator, doneDeferred = taskObj
            try:
                result = iterator.next()
            except StopIteration:
                self.iterators.remove(taskObj)
                doneDeferred.callback(iterator)
            except:
                self.iterators.remove(taskObj)
                doneDeferred.errback()
            else:
                if isinstance(result, defer.Deferred):
                    self.iterators.remove(taskObj)
                    def cbContinue(result, taskObj=taskObj):
                        self.coiterate(*taskObj)
                    result.addCallbacks(cbContinue, doneDeferred.errback)
        self._reschedule()