@classmethod
    def _try_cleanup_process(cls, pid):
        try:
            ret_pid, status = os.waitpid(pid, os.WNOHANG)
        except __HOLE__ as e:
            if e.args[0] == errno.ECHILD:
                return
        if ret_pid == 0:
            return
        assert ret_pid == pid
        subproc = cls._waiting.pop(pid)
        subproc.io_loop.add_callback_from_signal(
            subproc._set_returncode, status)
dataset/ETHPy150Open D-L/SimpleBookMarks/src/tornado/process.py/Subprocess._try_cleanup_process