def __next(self, isRunning=False):
        """Dequeue and start the next executor.

        `isRunning` is checked against the current execution status before
        dequeuing and starting the next executor."""
        self.__exec_mutex.acquire()
        if isRunning != (self.__current_exec is None):
            try:
                self.__current_exec, args, keys = self.get_nowait()
            except Empty:
                self.__current_exec = None
                return
            finally:
                self.__exec_mutex.release()
            self.__current_exec(*args, **keys)
        else:
            self.__exec_mutex.release()
Dequeue and start the next executor.

        `isRunning` is checked against the current execution status before
        dequeuing and starting the next executor.
recipes/Python/576965_Multicontext_eg_asynchronous_inline/recipe-576965.py