Concurrent read/write on tokio TcpStream

Question

I have a scenario where thread 1 writes to the socket, thread 2 reads from the socket. I have done this in the past via split() which would consume the TcpStream and return the ReadHalf/WriteHalf, which then could be neatly passed to the threads. I am running into issues on 1.39.0(tokio - 0.2.0-alpha.6).

1. Now it has changed to pub fn split(&mut self) -> (ReadHalf, WriteHalf). This doesn't allow passing the ReadHalf/WriteHalf(whose lifetime is tied to the stream) to separate threads, without running into messy lifetime issues

2. The plain read()/write() variants take &mut self, which makes it impossible to do concurrent reads/writes.

Interestingly, UdpSocket still has the old way(pub fn split(self) -> (UdpSocketRecvHalf, UdpSocketSendHalf))

Also found this related(unresolved) thread: https://github.com/tokio-rs/tokio/issues/1108. Not sure it is even possible anymore with TcpStream.

Appreciate any suggestions here.

Thanks.

Answer 1

You can use tokio::io::split

let (read, write) = tokio::io::split(socket);

This ends into ReadHalf and WriteHalf, both of which implement Send and Sync.