Make client able to use non-Send executor

examples/single_threaded.rs

@@ -1,17 +1,22 @@
 #![deny(warnings)]
 
+use http_body_util::BodyExt;
 use hyper::server::conn::http2;
 use std::cell::Cell;
 use std::net::SocketAddr;
 use std::rc::Rc;
+use tokio::io::{self, AsyncRead, AsyncWrite, AsyncWriteExt};
 use tokio::net::TcpListener;
 
 use hyper::body::{Body as HttpBody, Bytes, Frame};
 use hyper::service::service_fn;
+use hyper::Request;
 use hyper::{Error, Response};
 use std::marker::PhantomData;
 use std::pin::Pin;
 use std::task::{Context, Poll};
+use std::thread;
+use tokio::net::TcpStream;
 
 struct Body {
     // Our Body type is !Send and !Sync:
@@ -40,28 +45,57 @@ impl HttpBody for Body {
     }
 }
 
-fn main() -> Result<(), Box<dyn std::error::Error>> {
+fn main() {
     pretty_env_logger::init();
 
-    // Configure a runtime that runs everything on the current thread
-    let rt = tokio::runtime::Builder::new_current_thread()
-        .enable_all()
-        .build()
-        .expect("build runtime");
-
-    // Combine it with a `LocalSet,  which means it can spawn !Send futures...
-    let local = tokio::task::LocalSet::new();
-    local.block_on(&rt, run())
+    let server = thread::spawn(move || {
+        // Configure a runtime for the server that runs everything on the current thread
+        let rt = tokio::runtime::Builder::new_current_thread()
+            .enable_all()
+            .build()
+            .expect("build runtime");
+
+        // Combine it with a `LocalSet,  which means it can spawn !Send futures...
+        let local = tokio::task::LocalSet::new();
+        local.block_on(&rt, server()).unwrap();
+    });
+
+    let client = thread::spawn(move || {
+        // Configure a runtime for the client that runs everything on the current thread
+        let rt = tokio::runtime::Builder::new_current_thread()
+            .enable_all()
+            .build()
+            .expect("build runtime");
+
+        // Combine it with a `LocalSet,  which means it can spawn !Send futures...
+        let local = tokio::task::LocalSet::new();
+        local
+            .block_on(
+                &rt,
+                client("http://localhost:3000".parse::<hyper::Uri>().unwrap()),
+            )
+            .unwrap();
+    });
+
+    server.join().unwrap();
+    client.join().unwrap();
 }
 
-async fn run() -> Result<(), Box<dyn std::error::Error>> {
-    let addr: SocketAddr = ([127, 0, 0, 1], 3000).into();
+async fn server() -> Result<(), Box<dyn std::error::Error>> {
+    let mut stdout = io::stdout();
 
+    let addr: SocketAddr = ([127, 0, 0, 1], 3000).into();
     // Using a !Send request counter is fine on 1 thread...
     let counter = Rc::new(Cell::new(0));
 
     let listener = TcpListener::bind(addr).await?;
-    println!("Listening on http://{}", addr);
+
+    stdout
+        .write_all(format!("Listening on http://{}", addr).as_bytes())
+        .await
+        .unwrap();
+    stdout.flush().await.unwrap();
+
     loop {
         let (stream, _) = listener.accept().await?;
 
@@ -80,12 +114,121 @@ async fn run() -> Result<(), Box<dyn std::error::Error>> {
                 .serve_connection(stream, service)
                 .await
             {
-                println!("Error serving connection: {:?}", err);
+                let mut stdout = io::stdout();
+                stdout
+                    .write_all(format!("Error serving connection: {:?}", err).as_bytes())
+                    .await
+                    .unwrap();
+                stdout.flush().await.unwrap();
             }
         });
     }
 }
 
+struct IOTypeNotSend {
+    _marker: PhantomData<*const ()>,
+    stream: TcpStream,
+}
+
+impl IOTypeNotSend {
+    fn new(stream: TcpStream) -> Self {
+        Self {
+            _marker: PhantomData,
+            stream,
+        }
+    }
+}
+
+impl AsyncWrite for IOTypeNotSend {
+    fn poll_write(
+        mut self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+        buf: &[u8],
+    ) -> Poll<Result<usize, std::io::Error>> {
+        Pin::new(&mut self.stream).poll_write(cx, buf)
+    }
+
+    fn poll_flush(
+        mut self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+    ) -> Poll<Result<(), std::io::Error>> {
+        Pin::new(&mut self.stream).poll_flush(cx)
+    }
+
+    fn poll_shutdown(
+        mut self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+    ) -> Poll<Result<(), std::io::Error>> {
+        Pin::new(&mut self.stream).poll_shutdown(cx)
+    }
+}
+
+impl AsyncRead for IOTypeNotSend {
+    fn poll_read(
+        mut self: Pin<&mut Self>,
+        cx: &mut Context<'_>,
+        buf: &mut tokio::io::ReadBuf<'_>,
+    ) -> Poll<std::io::Result<()>> {
+        Pin::new(&mut self.stream).poll_read(cx, buf)
+    }
+}
+
+async fn client(url: hyper::Uri) -> Result<(), Box<dyn std::error::Error>> {
+    let host = url.host().expect("uri has no host");
+    let port = url.port_u16().unwrap_or(80);
+    let addr = format!("{}:{}", host, port);
+    let stream = TcpStream::connect(addr).await?;
+
+    let stream = IOTypeNotSend::new(stream);
+
+    let (mut sender, conn) = hyper::client::conn::http2::handshake(LocalExec, stream).await?;
+
+    tokio::task::spawn_local(async move {
+        if let Err(err) = conn.await {
+            let mut stdout = io::stdout();
+            stdout
+                .write_all(format!("Connection failed: {:?}", err).as_bytes())
+                .await
+                .unwrap();
+            stdout.flush().await.unwrap();
+        }
+    });
+
+    let authority = url.authority().unwrap().clone();
+
+    // Make 4 requests
+    for _ in 0..4 {
+        let req = Request::builder()
+            .uri(url.clone())
+            .header(hyper::header::HOST, authority.as_str())
+            .body(Body::from("test".to_string()))?;
+
+        let mut res = sender.send_request(req).await?;
+
+        let mut stdout = io::stdout();
+        stdout
+            .write_all(format!("Response: {}\n", res.status()).as_bytes())
+            .await
+            .unwrap();
+        stdout
+            .write_all(format!("Headers: {:#?}\n", res.headers()).as_bytes())
+            .await
+            .unwrap();
+        stdout.flush().await.unwrap();
+
+        // Print the response body
+        while let Some(next) = res.frame().await {
+            let frame = next?;
+            if let Some(chunk) = frame.data_ref() {
+                stdout.write_all(&chunk).await.unwrap();
+            }
+        }
+        stdout.write_all(b"\n-----------------\n").await.unwrap();
+        stdout.flush().await.unwrap();
+    }
+    Ok(())
+}
+
 // NOTE: This part is only needed for HTTP/2. HTTP/1 doesn't need an executor.
 //
 // Since the Server needs to spawn some background tasks, we needed