bug with tokio oneshot

[ActivePeter]

I implemented concurrent registration and event notification using key_waitings with DashMap and Tokio’s oneshot in the following code:

• key_waitings: Link
• Registration of waiters: Link
• Notification of events: Link

The issue occurs intermittently when running RUST_BACKTRACE=1 cargo test test_kv_user_client -- --nocapture

When I changed the notification code from getting the corresponding oneshot with get_mut from the map to deleting the corresponding oneshot from the map, the issue was resolved.

// if let Some(mut key_waitings) = self.key_waitings.get_mut(key) {
if let Some((_, key_waitings)) = self.key_waitings.remove(key) { // no panic 
    for wait_tx in key_waitings.drain(..) {
        wait_tx
            .send((kvversion, KvValue::RawData(value.clone())))
            .unwrap_or_else(|_| panic!("send new key event failed"));
    }
}