Oneshot: UB triggered when using Axum

[nastynaz]

I used the AsyncSender and AsyncReceiver channels and this code started panicking when using kanal. I tried it with Flume and Tokio mpsc channels and there's no issue.

It happens when a client cancels their HTTP request, causing Axum to cancel the future that calls this:

  pub async fn pnl_report(&self) -> HashMap<Coin, CurrentPnl> {
      let (tx, rx) = tokio::sync::oneshot::channel();
      self.query_sender // <-- kanal async sender
          .send(PNLQuery::Report(tx))
          .await
          .expect("BUG: query sender channel should never be closed");

      rx.await
          .expect("BUG: oneshot query sender should never be closed") // <- this panics
  }

It appears that somehow the .send() is getting cancelled but the rx.await isn't.

[fereidani]

I'm dropping oneshot feature, going to continue it in another package. Its design need to change and it is not compatible with mpmc channel signal design.

[fereidani]

there are already report open for this bug.