Method handle_event

vhost_user_block/src/lib.rs:349–403

(
        &mut self,
        device_event: u16,
        evset: EventSet,
        vrings: &[VringRwLock<GuestMemoryAtomic<GuestMemoryMmap>>],
        thread_id: usize,
    )

    }

    fn handle_event(
        &mut self,
        device_event: u16,
        evset: EventSet,
        vrings: &[VringRwLock<GuestMemoryAtomic<GuestMemoryMmap>>],
        thread_id: usize,
    ) -> VhostUserBackendResult<()> {
        if evset != EventSet::IN {
            return Err(Error::HandleEventNotEpollIn.into());
        }

        debug!("event received: {device_event:?}");

        let thread = self.threads[thread_id].get_mut().unwrap();
        match device_event {
            0 => {
                let mut vring = vrings[0].get_mut();

                if self.poll_queue {
                    // Actively poll the queue until POLL_QUEUE_US has passed
                    // without seeing a new request.
                    let mut now = Instant::now();
                    loop {
                        if thread.process_queue(&mut vring) {
                            now = Instant::now();
                        } else if now.elapsed().as_micros() > POLL_QUEUE_US {
                            break;
                        }
                    }
                }

                if thread.event_idx {
                    // vm-virtio's Queue implementation only checks avail_index
                    // once, so to properly support EVENT_IDX we need to keep
                    // calling process_queue() until it stops finding new
                    // requests on the queue.
                    loop {
                        vring
                            .get_queue_mut()
                            .enable_notification(self.mem.memory().deref())
                            .unwrap();
                        if !thread.process_queue(&mut vring) {
                            break;
                        }
                    }
                } else {
                    // Without EVENT_IDX, a single call is enough.
                    thread.process_queue(&mut vring);
                }

                Ok(())
            }
            _ => Err(Error::HandleEventUnknownEvent.into()),
        }
    }

    fn get_config(&self, offset: u32, size: u32) -> Vec<u8> {
        let subset = self