process.py 文件源码

def wait_for_exit(self, raise_error=True):
        """Returns a `.Future` which resolves when the process exits.

        Usage::

            ret = yield proc.wait_for_exit()

        This is a coroutine-friendly alternative to `set_exit_callback`
        (and a replacement for the blocking `subprocess.Popen.wait`).

        By default, raises `subprocess.CalledProcessError` if the process
        has a non-zero exit status. Use ``wait_for_exit(raise_error=False)``
        to suppress this behavior and return the exit status without raising.

        .. versionadded:: 4.2
        """
        future = Future()

        def callback(ret):
            if ret != 0 and raise_error:
                # Unfortunately we don't have the original args any more.
                future.set_exception(CalledProcessError(ret, None))
            else:
                future.set_result(ret)
        self.set_exit_callback(callback)
        return future