Add an example tcp_echo_server_non_blocking

Cargo.toml

@@ -24,6 +24,7 @@ wstd-macro.workspace = true
 anyhow.workspace = true
 futures-lite.workspace = true
 serde_json.workspace = true
+futures-concurrency.workspace = true
 
 [workspace]
 members = [
@@ -50,6 +51,7 @@ anyhow = "1"
 cargo_metadata = "0.18.1"
 futures-core = "0.3.19"
 futures-lite = "1.12.0"
+futures-concurrency = "7.6.2"
 heck = "0.5"
 http = "1.1"
 pin-project-lite = "0.2.8"

examples/tcp_echo_server_non_blocking.rs

@@ -0,0 +1,55 @@
+use futures_concurrency::future::FutureGroup;
+use futures_lite::{FutureExt, StreamExt};
+use std::{
+    cell::RefCell,
+    future::Future,
+    pin::{pin, Pin},
+    rc::Rc,
+    task::Poll,
+};
+use wstd::io;
+use wstd::iter::AsyncIterator;
+use wstd::net::TcpListener;
+
+type StreamTasks = Rc<RefCell<FutureGroup<Pin<Box<dyn Future<Output = io::Result<()>>>>>>>;
+
+#[wstd::main]
+async fn main() -> io::Result<()> {
+    let listener = TcpListener::bind("127.0.0.1:8080").await?;
+    println!("Listening on {}", listener.local_addr()?);
+    println!("type `nc localhost 8080` to create a TCP client");
+
+    let stream_tasks: StreamTasks = StreamTasks::default();
+    let mut listening_task = pin!(start_listening(listener, stream_tasks.clone()));
+
+    futures_lite::future::poll_fn(|cx| {
+        if let Poll::Ready(_) = listening_task.as_mut().poll(cx) {
+            return Poll::Ready(());
+        };
+
+        let mut stream_tasks_ref = stream_tasks.borrow_mut();
+        if let Poll::Ready(Some(res)) = stream_tasks_ref.poll_next(cx) {
+            println!("Task finished: {:?}", res);
+            println!("Tasks len: {}", stream_tasks_ref.len());
+        }
+
+        Poll::Pending
+    })
+    .await;
+    Ok(())
+}
+
+async fn start_listening(listener: TcpListener, stream_tasks: StreamTasks) -> io::Result<()> {
+    let mut incoming = listener.incoming();
+    while let Some(stream) = incoming.next().await {
+        let stream = stream?;
+        println!("Accepted from: {}", stream.peer_addr()?);
+
+        let stream_task = async move { io::copy(&stream, &stream).await }.boxed_local();
+
+        stream_tasks.borrow_mut().insert(stream_task);
+        println!("Task added");
+        println!("Tasks len: {}", stream_tasks.borrow().len());
+    }
+    Ok(())
+}

test-programs/Cargo.toml

@@ -8,3 +8,4 @@ publish = false
 futures-lite.workspace = true
 serde_json.workspace = true
 wstd.workspace = true
+futures-concurrency.workspace = true