scheduler.py 文件源码

def _find_next_job(self):
        """Lookup for available jobs to execute"""
        with self._ctx:
            workers = self._coll.distinct('who')
            unused = [pid for pid in workers
                      if not (pid and psutil.pid_exists(pid))]
            job = self._coll.find_one_and_update(
                {
                    'when': {'$lte': datetime.datetime.now()},
                    'who': {'$in': unused},
                },
                {
                    '$set': {'who': os.getpid()}
                },
                sort=[('when', -1)])
        return job