100% CPU usage after connection lost while sending large amount of data

[PonyPC]

100% CPU usage after connection lost while sending large amount of data

The issue is in

russh/russh/src/channels/io/tx.rs

Line 64 in ff95994

// TODO fix this busywait

It won't triggle connection lost event.

[EpicEric]

Shouldn't this trigger an Err(BrokenPipe)? Or am I missing some other way that would lead to the condition being reached?

[PonyPC]

Nothing triggered. If you add a check like:

            if self.sender.is_closed() {
                return Poll::Ready((ChannelMsg::Eof, 0));
            }

It only mitigates the tcp has a connection lost event. But when you try it such as blocking the connection by using a firewall realtime rules, the CPU usage is still high until tcp timeout error. As it not sufficient on dealing with sending data, is there any other ways to eliminate this situation?