Write to a TcpStream while waiting for it to become writable from another task/thread

[OverShifted]

I have a program that tries to "pipe" two streams together (a TcpStream and a bidirectional stream of data to/from libcurl).

I spawn two tasks to do this. One to forward TcpStream's data to libcurl and another to forward data the other way. But my program ends up in a deadlock.

In my first task, I wait for my TcpStream (actually it is wrapped in Arc<tokio::sync::RwLock<TcpStream>>) to become readable:

stream.read().await.readable().await.unwrap();

In my second task, I write to the TcpStream:

let mut stream = stream.write().await;
println!("Locked!");
stream.write_all(&buffer[..num_bytes]).await.unwrap();

But Locked! never gets printed because stream is already locked via stream.read() inside another task. This means I can't write to my TcpStream because I'm waiting for it to become readable from another task.

Are there any "clean" solutions available? I don't consider using UnsafeCells to be neat.
I probably have a similar problem with my other "stream" as well.

[Darksonn]

Wrapping an IO resource in a mutex or rwlock is almost wrong. You are deadlocking because the reader and the writer are blocking each other. You should split your IO resource instead. For the specific case of TcpStream, you can use the TcpStream::into_split method to get a read and write half that can be used independently.

[OverShifted]

Thanks! My tokio-related issue is solved. (But I still have the problem with libcurl)