def poll(self, pid):
        try:
            sts  = self._status[pid]
        except KeyError:
            return -errno.ENOENT
        if sts is None:
            return -errno.EAGAIN
        else: # finished
            del self._status[pid]
            return sts
Poll for async process.
dataset/ETHPy150Open kdart/pycopia/QA/pycopia/remote/PosixServer.py/PosixAgent.poll