feat(lib): add optional tcp feature, split from runtime

The `HttpConnector` and `AddrListener` types which make use of
`tokio::tcp` have been made their own optional feature. This allows
using them without requiring the *full* tokio runtime.

src/server/conn.rs

@@ -11,14 +11,14 @@
 use std::error::Error as StdError;
 use std::fmt;
 use std::mem;
-#[cfg(feature = "runtime")] use std::net::SocketAddr;
-#[cfg(feature = "runtime")] use std::time::Duration;
+#[cfg(feature = "tcp")] use std::net::SocketAddr;
+#[cfg(feature = "tcp")] use std::time::Duration;
 
 use bytes::Bytes;
 use futures_core::Stream;
 use tokio_io::{AsyncRead, AsyncWrite};
 use pin_project::{pin_project, project};
-#[cfg(feature = "runtime")] use tokio_net::driver::Handle;
+#[cfg(feature = "tcp")] use tokio_net::driver::Handle;
 
 use crate::body::{Body, Payload};
 use crate::common::exec::{Exec, H2Exec, NewSvcExec};
@@ -35,7 +35,7 @@ use self::spawn_all::NewSvcTask;
 pub(super) use self::spawn_all::Watcher;
 pub(super) use self::upgrades::UpgradeableConnection;
 
-#[cfg(feature = "runtime")] pub use super::tcp::{AddrIncoming, AddrStream};
+#[cfg(feature = "tcp")] pub use super::tcp::{AddrIncoming, AddrStream};
 
 /// A lower-level configuration of the HTTP protocol.
 ///
@@ -341,9 +341,7 @@ impl<E> Http<E> {
     /// # use hyper::{Body, Request, Response};
     /// # use hyper::service::Service;
     /// # use hyper::server::conn::Http;
-    /// # #[cfg(feature = "runtime")]
     /// # use tokio_io::{AsyncRead, AsyncWrite};
-    /// # #[cfg(feature = "runtime")]
     /// # async fn run<I, S>(some_io: I, some_service: S)
     /// # where
     /// #     I: AsyncRead + AsyncWrite + Unpin + Send + 'static,
@@ -404,7 +402,7 @@ impl<E> Http<E> {
         }
     }
 
-    #[cfg(feature = "runtime")]
+    #[cfg(feature = "tcp")]
     #[doc(hidden)]
     #[deprecated]
     #[allow(deprecated)]
@@ -426,7 +424,7 @@ impl<E> Http<E> {
         Ok(self.serve_incoming(incoming, make_service))
     }
 
-    #[cfg(feature = "runtime")]
+    #[cfg(feature = "tcp")]
     #[doc(hidden)]
     #[deprecated]
     #[allow(deprecated)]
@@ -792,7 +790,7 @@ where
 
 // ===== impl SpawnAll =====
 
-#[cfg(feature = "runtime")]
+#[cfg(feature = "tcp")]
 impl<S, E> SpawnAll<AddrIncoming, S, E> {
     pub(super) fn local_addr(&self) -> SocketAddr {
         self.serve.incoming.local_addr()

src/server/mod.rs

@@ -23,7 +23,7 @@
 //! use hyper::service::{make_service_fn, service_fn};
 //!
 //! # #[cfg(feature = "runtime")]
-//! # #[tokio::main]
+//! #[tokio::main]
 //! async fn main() {
 //!     // Construct our SocketAddr to listen on...
 //!     let addr = ([127, 0, 0, 1], 3000).into();
@@ -51,13 +51,13 @@
 pub mod accept;
 pub mod conn;
 mod shutdown;
-#[cfg(feature = "runtime")] mod tcp;
+#[cfg(feature = "tcp")] mod tcp;
 
 use std::error::Error as StdError;
 use std::fmt;
-#[cfg(feature = "runtime")] use std::net::{SocketAddr, TcpListener as StdTcpListener};
+#[cfg(feature = "tcp")] use std::net::{SocketAddr, TcpListener as StdTcpListener};
 
-#[cfg(feature = "runtime")] use std::time::Duration;
+#[cfg(feature = "tcp")] use std::time::Duration;
 
 use tokio_io::{AsyncRead, AsyncWrite};
 use pin_project::pin_project;
@@ -71,7 +71,7 @@ use self::accept::Accept;
 // error that `hyper::server::Http` is private...
 use self::conn::{Http as Http_, NoopWatcher, SpawnAll};
 use self::shutdown::{Graceful, GracefulWatcher};
-#[cfg(feature = "runtime")] use self::tcp::AddrIncoming;
+#[cfg(feature = "tcp")] use self::tcp::AddrIncoming;
 
 /// A listening HTTP server that accepts connections in both HTTP1 and HTTP2 by default.
 ///
@@ -104,7 +104,7 @@ impl<I> Server<I, ()> {
     }
 }
 
-#[cfg(feature = "runtime")]
+#[cfg(feature = "tcp")]
 impl Server<AddrIncoming, ()> {
     /// Binds to the provided address, and returns a [`Builder`](Builder).
     ///
@@ -134,7 +134,7 @@ impl Server<AddrIncoming, ()> {
     }
 }
 
-#[cfg(feature = "runtime")]
+#[cfg(feature = "tcp")]
 impl<S> Server<AddrIncoming, S> {
     /// Returns the local address that this server is bound to.
     pub fn local_addr(&self) -> SocketAddr {
@@ -162,7 +162,7 @@ where
     ///
     /// ```
     /// # fn main() {}
-    /// # #[cfg(feature = "runtime")]
+    /// # #[cfg(feature = "tcp")]
     /// # async fn run() {
     /// # use hyper::{Body, Response, Server, Error};
     /// # use hyper::service::{make_service_fn, service_fn};
@@ -356,11 +356,8 @@ impl<I, E> Builder<I, E> {
     /// # Example
     ///
     /// ```
-    /// # #[cfg(not(feature = "runtime"))]
-    /// # fn main() {}
-    /// # #[cfg(feature = "runtime")]
-    /// # #[tokio::main]
-    /// # async fn main() {
+    /// # #[cfg(feature = "tcp")]
+    /// # async fn run() {
     /// use hyper::{Body, Error, Response, Server};
     /// use hyper::service::{make_service_fn, service_fn};
     ///
@@ -378,7 +375,10 @@ impl<I, E> Builder<I, E> {
     /// let server = Server::bind(&addr)
     ///     .serve(make_svc);
     ///
-    /// // Finally, spawn `server` onto an Executor...
+    /// // Run forever-ish...
+    /// if let Err(err) = server.await {
+    ///     eprintln!("server error: {}", err);
+    /// }
     /// # }
     /// ```
     pub fn serve<S, B>(self, new_service: S) -> Server<I, S, E>
@@ -402,7 +402,7 @@ impl<I, E> Builder<I, E> {
     }
 }
 
-#[cfg(feature = "runtime")]
+#[cfg(feature = "tcp")]
 impl<E> Builder<AddrIncoming, E> {
     /// Set whether TCP keepalive messages are enabled on accepted connections.
     ///