Added Spawning example

Author: Nereuxofficial

examples/06_04_spawning/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "example_06_04_spawning"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+futures = "0.3"
+
+[dependencies.async-std]
+version = "1.12.0"
+features = ["attributes"]

examples/06_04_spawning/src/lib.rs

@@ -0,0 +1,33 @@
+#![cfg(test)]
+#![allow(dead_code)]
+
+// ANCHOR: example
+use async_std::{task, net::TcpListener, net::TcpStream};
+use futures::AsyncWriteExt;
+
+async fn process_request(stream: &mut TcpStream) -> Result<(), std::io::Error>{
+    stream.write_all(b"HTTP/1.1 200 OK\r\n\r\n").await?;
+    stream.write_all(b"Hello World").await?;
+    Ok(())
+}
+
+async fn main() {
+    let listener = TcpListener::bind("127.0.0.1:8080").await.unwrap();
+    loop {
+        // Accept a new connection
+        let (mut stream, _) = listener.accept().await.unwrap();
+        // Now process this request without blocking the main loop
+        task::spawn(async move {process_request(&mut stream).await});
+    }
+}
+// ANCHOR_END: example
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[async_std::test]
+    async fn run_example() {
+        main().await
+    }
+}

examples/Cargo.toml

@@ -10,6 +10,7 @@ members = [
   "05_02_iteration_and_concurrency",
   "06_02_join",
   "06_03_select",
+  "06_04_spawning",
   "07_05_recursion",
   "09_01_sync_tcp_server",
   "09_02_async_tcp_server",

src/06_multiple_futures/04_spawning.md

@@ -0,0 +1,13 @@
+# `Spawning`
+
+Spawning allows you to run a new asynchronous task in the background. This allows us to continue executing other code 
+while it is running.
+
+Say we have a webserver that wants to accept connections without blocking the main thread.
+We can do this by using the `async_std::task::spawn` function to spawn a new task that runs
+the connection handler. This function takes a future and returns a `JoinHandle` that can be
+used to await the result of the spawned task.
+
+```rust,edition2018
+{{#include ../../examples/06_04_spawning/src/lib.rs:example}}
+```

src/SUMMARY.md

@@ -16,7 +16,7 @@
 - [Executing Multiple Futures at a Time](06_multiple_futures/01_chapter.md)
   - [`join!`](06_multiple_futures/02_join.md)
   - [`select!`](06_multiple_futures/03_select.md)
-  - [TODO: Spawning]()
+  - [Spawning](06_multiple_futures/04_spawning.md)
   - [TODO: Cancellation and Timeouts]()
   - [TODO: `FuturesUnordered`]()
 - [Workarounds to Know and Love](07_workarounds/01_chapter.md)