schedulers.py 文件源码

def schedule_changed(self):
        try:
            # If MySQL is running with transaction isolation level
            # REPEATABLE-READ (default), then we won't see changes done by
            # other transactions until the current transaction is
            # committed (Issue #41).
            try:
                transaction.commit()
            except transaction.TransactionManagementError:
                pass  # not in transaction management.

            last, ts = self._last_timestamp, self.Changes.last_change()
        except DatabaseError as exc:
            logger.exception('Database gave error: %r', exc)
            return False
        try:
            if ts and ts > (last if last else ts):
                return True
        finally:
            self._last_timestamp = ts
        return False