TCP server is not working

[mneumann]

I am trying to write a very simple TCP server (code given below), which just reads from a
socket, but somehow the read() blocks forever. Any idea what I am doing wrong?
I also tried to create a task for each new incoming connection, but the same happens.
I actually found this example on the internet...

When I do "wget http://127.0.0.1:4000/" it prints

• Server is listening
• New client
• Accepted!
• Unwrapped

and then it blocks forever. I also cannot create new connections at this point.

Best,

Michael

/*
 * Simple TCP server
 */
extern mod std;
use std::net::tcp;
use std::net::ip;
use std::uv;

fn main() {
    tcp::listen(ip::v4::parse_addr("127.0.0.1"), 4000, 100, uv::global_loop::get(),
            |_comm_chan|{
                error!("Server is listening");
            },
            |new_client, _comm_chan|{
              error!("New client");
                let result = tcp::accept(new_client);
                if result.is_ok(){
                    error!("Accepted!");
                    let socket = result::unwrap(move result);
                    error!("Unwrapped");
                    // Now do stuff with this socket
                    let data = socket.read(100); // XXX: This blocks
                    io::println(fmt!("%?", data));
                }else{
                    error!("Not accepted!");
                }
              } */
            });
}

[jesse99]

I expect that the socket.read is happening on the same thread as the listen. Try spawning a new task for the connection using a dedicated thread using something like task::spawn_sched(task::ManualThreads(1)).

Likely related to #3599.

[mneumann]

Am 27.12.2012 19:09, schrieb Jesse Jones:

I expect that the socket.read is happening on the same thread as the
listen. Try spawning a new task for the connection using a dedicated
thread using something like |task::spawn_sched(task::ManualThreads(1))|.

Thanks, that indeed works, BUT, starting a new native thread for each
connection is very expensive and basically renders libuv useless,
isn't it?

Best,

Michael

[pcwalton]

I think this is a dupe of #3599.