refactor ssl support

CHANGES.md

@@ -4,9 +4,12 @@
 
 ### Added
 
-* Added `HttpServer::max_connections()` and `HttpServer::max_sslrate()`, 
+* Added `HttpServer::maxconn()` and `HttpServer::maxconnrate()`,
   accept backpressure #250
 
+* Allow to customize connection handshake process via `HttpServer::listen_with()` 
+  and `HttpServer::bind_with()` methods
+
 ### Fixed
 
 * Use zlib instead of raw deflate for decoding and encoding payloads with

src/server/accept.rs

@@ -9,8 +9,8 @@ use tokio_timer::Delay;
 
 use actix::{msgs::Execute, Arbiter, System};
 
-use super::srv::{ServerCommand, Socket};
+use super::srv::ServerCommand;
-use super::worker::{Conn, WorkerClient};
+use super::worker::{Conn, Socket, Token, WorkerClient};
 
 pub(crate) enum Command {
     Pause,
@@ -21,7 +21,7 @@ pub(crate) enum Command {
 
 struct ServerSocketInfo {
     addr: net::SocketAddr,
-    token: usize,
+    token: Token,
     sock: mio::net::TcpListener,
     timeout: Option<Instant>,
 }
@@ -31,20 +31,24 @@ pub(crate) struct AcceptNotify {
     ready: mio::SetReadiness,
     maxconn: usize,
     maxconn_low: usize,
-    maxsslrate: usize,
+    maxconnrate: usize,
-    maxsslrate_low: usize,
+    maxconnrate_low: usize,
 }
 
 impl AcceptNotify {
-    pub fn new(ready: mio::SetReadiness, maxconn: usize, maxsslrate: usize) -> Self {
+    pub fn new(ready: mio::SetReadiness, maxconn: usize, maxconnrate: usize) -> Self {
         let maxconn_low = if maxconn > 10 { maxconn - 10 } else { 0 };
-        let maxsslrate_low = if maxsslrate > 10 { maxsslrate - 10 } else { 0 };
+        let maxconnrate_low = if maxconnrate > 10 {
+            maxconnrate - 10
+        } else {
+            0
+        };
         AcceptNotify {
             ready,
             maxconn,
             maxconn_low,
-            maxsslrate,
+            maxconnrate,
-            maxsslrate_low,
+            maxconnrate_low,
         }
     }
 
@@ -53,8 +57,8 @@ impl AcceptNotify {
             let _ = self.ready.set_readiness(mio::Ready::readable());
         }
     }
-    pub fn notify_maxsslrate(&self, sslrate: usize) {
+    pub fn notify_maxconnrate(&self, connrate: usize) {
-        if sslrate > self.maxsslrate_low && sslrate <= self.maxsslrate {
+        if connrate > self.maxconnrate_low && connrate <= self.maxconnrate {
             let _ = self.ready.set_readiness(mio::Ready::readable());
         }
     }
@@ -78,7 +82,7 @@ pub(crate) struct AcceptLoop {
         mpsc::UnboundedReceiver<ServerCommand>,
     )>,
     maxconn: usize,
-    maxsslrate: usize,
+    maxconnrate: usize,
 }
 
 impl AcceptLoop {
@@ -94,7 +98,7 @@ impl AcceptLoop {
             notify_ready,
             notify_reg: Some(notify_reg),
             maxconn: 102_400,
-            maxsslrate: 256,
+            maxconnrate: 256,
             rx: Some(rx),
             srv: Some(mpsc::unbounded()),
         }
@@ -106,19 +110,19 @@ impl AcceptLoop {
     }
 
     pub fn get_notify(&self) -> AcceptNotify {
-        AcceptNotify::new(self.notify_ready.clone(), self.maxconn, self.maxsslrate)
+        AcceptNotify::new(self.notify_ready.clone(), self.maxconn, self.maxconnrate)
     }
 
-    pub fn max_connections(&mut self, num: usize) {
+    pub fn maxconn(&mut self, num: usize) {
         self.maxconn = num;
     }
 
-    pub fn max_sslrate(&mut self, num: usize) {
+    pub fn maxconnrate(&mut self, num: usize) {
-        self.maxsslrate = num;
+        self.maxconnrate = num;
     }
 
     pub(crate) fn start(
-        &mut self, socks: Vec<(usize, Socket)>, workers: Vec<WorkerClient>,
+        &mut self, socks: Vec<Socket>, workers: Vec<WorkerClient>,
     ) -> mpsc::UnboundedReceiver<ServerCommand> {
         let (tx, rx) = self.srv.take().expect("Can not re-use AcceptInfo");
 
@@ -127,7 +131,7 @@ impl AcceptLoop {
             self.cmd_reg.take().expect("Can not re-use AcceptInfo"),
             self.notify_reg.take().expect("Can not re-use AcceptInfo"),
             self.maxconn,
-            self.maxsslrate,
+            self.maxconnrate,
             socks,
             tx,
             workers,
@@ -145,7 +149,7 @@ struct Accept {
     timer: (mio::Registration, mio::SetReadiness),
     next: usize,
     maxconn: usize,
-    maxsslrate: usize,
+    maxconnrate: usize,
     backpressure: bool,
 }
 
@@ -171,8 +175,8 @@ impl Accept {
     #![cfg_attr(feature = "cargo-clippy", allow(too_many_arguments))]
     pub(crate) fn start(
         rx: sync_mpsc::Receiver<Command>, cmd_reg: mio::Registration,
-        notify_reg: mio::Registration, maxconn: usize, maxsslrate: usize,
+        notify_reg: mio::Registration, maxconn: usize, maxconnrate: usize,
-        socks: Vec<(usize, Socket)>, srv: mpsc::UnboundedSender<ServerCommand>,
+        socks: Vec<Socket>, srv: mpsc::UnboundedSender<ServerCommand>,
         workers: Vec<WorkerClient>,
     ) {
         let sys = System::current();
@@ -184,7 +188,7 @@ impl Accept {
                 System::set_current(sys);
                 let mut accept = Accept::new(rx, socks, workers, srv);
                 accept.maxconn = maxconn;
-                accept.maxsslrate = maxsslrate;
+                accept.maxconnrate = maxconnrate;
 
                 // Start listening for incoming commands
                 if let Err(err) = accept.poll.register(
@@ -211,7 +215,7 @@ impl Accept {
     }
 
     fn new(
-        rx: sync_mpsc::Receiver<Command>, socks: Vec<(usize, Socket)>,
+        rx: sync_mpsc::Receiver<Command>, socks: Vec<Socket>,
         workers: Vec<WorkerClient>, srv: mpsc::UnboundedSender<ServerCommand>,
     ) -> Accept {
         // Create a poll instance
@@ -222,7 +226,7 @@ impl Accept {
 
         // Start accept
         let mut sockets = Slab::new();
-        for (stoken, sock) in socks {
+        for sock in socks {
             let server = mio::net::TcpListener::from_std(sock.lst)
                 .expect("Can not create mio::net::TcpListener");
 
@@ -240,7 +244,7 @@ impl Accept {
             }
 
             entry.insert(ServerSocketInfo {
-                token: stoken,
+                token: sock.token,
                 addr: sock.addr,
                 sock: server,
                 timeout: None,
@@ -264,7 +268,7 @@ impl Accept {
             next: 0,
             timer: (tm, tmr),
             maxconn: 102_400,
-            maxsslrate: 256,
+            maxconnrate: 256,
             backpressure: false,
         }
     }
@@ -427,7 +431,7 @@ impl Accept {
             let mut idx = 0;
             while idx < self.workers.len() {
                 idx += 1;
-                if self.workers[self.next].available(self.maxconn, self.maxsslrate) {
+                if self.workers[self.next].available(self.maxconn, self.maxconnrate) {
                     match self.workers[self.next].send(msg) {
                         Ok(_) => {
                             self.next = (self.next + 1) % self.workers.len();

src/server/h1.rs

@@ -375,7 +375,7 @@ where
                     self.keepalive_timer.take();
 
                     // search handler for request
-                    for h in self.settings.handlers().iter_mut() {
+                    for h in self.settings.handlers().iter() {
                         msg = match h.handle(msg) {
                             Ok(mut pipe) => {
                                 if self.tasks.is_empty() {

src/server/h2.rs

@@ -347,7 +347,7 @@ impl<H: HttpHandler + 'static> Entry<H> {
 
         // start request processing
         let mut task = None;
-        for h in settings.handlers().iter_mut() {
+        for h in settings.handlers().iter() {
             msg = match h.handle(msg) {
                 Ok(t) => {
                     task = Some(t);

src/server/mod.rs

@@ -1,10 +1,11 @@
 //! Http server
 use std::net::Shutdown;
-use std::{io, time};
+use std::{io, net, time};
 
 use bytes::{BufMut, BytesMut};
-use futures::{Async, Poll};
+use futures::{Async, Future, Poll};
 use tokio_io::{AsyncRead, AsyncWrite};
+use tokio_reactor::Handle;
 use tokio_tcp::TcpStream;
 
 pub(crate) mod accept;
@@ -21,11 +22,13 @@ pub(crate) mod message;
 pub(crate) mod output;
 pub(crate) mod settings;
 mod srv;
+mod ssl;
 mod worker;
 
 pub use self::message::Request;
 pub use self::settings::ServerSettings;
 pub use self::srv::HttpServer;
+pub use self::ssl::*;
 
 #[doc(hidden)]
 pub use self::helpers::write_content_length;
@@ -72,6 +75,13 @@ where
     HttpServer::new(factory)
 }
 
+bitflags! {
+    pub struct ServerFlags: u8 {
+        const HTTP1 = 0b0000_0001;
+        const HTTP2 = 0b0000_0010;
+    }
+}
+
 #[derive(Debug, PartialEq, Clone, Copy)]
 /// Server keep-alive setting
 pub enum KeepAlive {
@@ -179,6 +189,34 @@ impl<T: HttpHandler> IntoHttpHandler for T {
     }
 }
 
+pub(crate) trait IntoAsyncIo {
+    type Io: AsyncRead + AsyncWrite;
+
+    fn into_async_io(self) -> Result<Self::Io, io::Error>;
+}
+
+impl IntoAsyncIo for net::TcpStream {
+    type Io = TcpStream;
+
+    fn into_async_io(self) -> Result<Self::Io, io::Error> {
+        TcpStream::from_std(self, &Handle::default())
+    }
+}
+
+/// Trait implemented by types that could accept incomming socket connections.
+pub trait AcceptorService<Io: AsyncRead + AsyncWrite>: Clone {
+    /// Established connection type
+    type Accepted: IoStream;
+    /// Future describes async accept process.
+    type Future: Future<Item = Self::Accepted, Error = io::Error> + 'static;
+
+    /// Establish new connection
+    fn accept(&self, io: Io) -> Self::Future;
+
+    /// Scheme
+    fn scheme(&self) -> &'static str;
+}
+
 #[doc(hidden)]
 #[derive(Debug)]
 pub enum WriterState {
@@ -267,90 +305,3 @@ impl IoStream for TcpStream {
         TcpStream::set_linger(self, dur)
     }
 }
-
-#[cfg(feature = "alpn")]
-use tokio_openssl::SslStream;
-
-#[cfg(feature = "alpn")]
-impl IoStream for SslStream<TcpStream> {
-    #[inline]
-    fn shutdown(&mut self, _how: Shutdown) -> io::Result<()> {
-        let _ = self.get_mut().shutdown();
-        Ok(())
-    }
-
-    #[inline]
-    fn set_nodelay(&mut self, nodelay: bool) -> io::Result<()> {
-        self.get_mut().get_mut().set_nodelay(nodelay)
-    }
-
-    #[inline]
-    fn set_linger(&mut self, dur: Option<time::Duration>) -> io::Result<()> {
-        self.get_mut().get_mut().set_linger(dur)
-    }
-}
-
-#[cfg(feature = "tls")]
-use tokio_tls::TlsStream;
-
-#[cfg(feature = "tls")]
-impl IoStream for TlsStream<TcpStream> {
-    #[inline]
-    fn shutdown(&mut self, _how: Shutdown) -> io::Result<()> {
-        let _ = self.get_mut().shutdown();
-        Ok(())
-    }
-
-    #[inline]
-    fn set_nodelay(&mut self, nodelay: bool) -> io::Result<()> {
-        self.get_mut().get_mut().set_nodelay(nodelay)
-    }
-
-    #[inline]
-    fn set_linger(&mut self, dur: Option<time::Duration>) -> io::Result<()> {
-        self.get_mut().get_mut().set_linger(dur)
-    }
-}
-
-#[cfg(feature = "rust-tls")]
-use rustls::{ClientSession, ServerSession};
-#[cfg(feature = "rust-tls")]
-use tokio_rustls::TlsStream as RustlsStream;
-
-#[cfg(feature = "rust-tls")]
-impl IoStream for RustlsStream<TcpStream, ClientSession> {
-    #[inline]
-    fn shutdown(&mut self, _how: Shutdown) -> io::Result<()> {
-        let _ = <Self as AsyncWrite>::shutdown(self);
-        Ok(())
-    }
-
-    #[inline]
-    fn set_nodelay(&mut self, nodelay: bool) -> io::Result<()> {
-        self.get_mut().0.set_nodelay(nodelay)
-    }
-
-    #[inline]
-    fn set_linger(&mut self, dur: Option<time::Duration>) -> io::Result<()> {
-        self.get_mut().0.set_linger(dur)
-    }
-}
-
-#[cfg(feature = "rust-tls")]
-impl IoStream for RustlsStream<TcpStream, ServerSession> {
-    #[inline]
-    fn shutdown(&mut self, _how: Shutdown) -> io::Result<()> {
-        let _ = <Self as AsyncWrite>::shutdown(self);
-        Ok(())
-    }
-
-    #[inline]
-    fn set_nodelay(&mut self, nodelay: bool) -> io::Result<()> {
-        self.get_mut().0.set_nodelay(nodelay)
-    }
-
-    #[inline]
-    fn set_linger(&mut self, dur: Option<time::Duration>) -> io::Result<()> {
-        self.get_mut().0.set_linger(dur)
-    }
-}

src/server/settings.rs

@@ -132,7 +132,7 @@ impl ServerSettings {
 const DATE_VALUE_LENGTH: usize = 29;
 
 pub(crate) struct WorkerSettings<H> {
-    h: RefCell<Vec<H>>,
+    h: Vec<H>,
     keep_alive: u64,
     ka_enabled: bool,
     bytes: Rc<SharedBytesPool>,
@@ -140,14 +140,14 @@ pub(crate) struct WorkerSettings<H> {
     channels: Arc<AtomicUsize>,
     node: RefCell<Node<()>>,
     date: UnsafeCell<Date>,
-    sslrate: Arc<AtomicUsize>,
+    connrate: Arc<AtomicUsize>,
     notify: AcceptNotify,
 }
 
 impl<H> WorkerSettings<H> {
     pub(crate) fn new(
         h: Vec<H>, keep_alive: KeepAlive, settings: ServerSettings,
-        notify: AcceptNotify, channels: Arc<AtomicUsize>, sslrate: Arc<AtomicUsize>,
+        notify: AcceptNotify, channels: Arc<AtomicUsize>, connrate: Arc<AtomicUsize>,
     ) -> WorkerSettings<H> {
         let (keep_alive, ka_enabled) = match keep_alive {
             KeepAlive::Timeout(val) => (val as u64, true),
@@ -156,7 +156,7 @@ impl<H> WorkerSettings<H> {
         };
 
         WorkerSettings {
-            h: RefCell::new(h),
+            h,
             bytes: Rc::new(SharedBytesPool::new()),
             messages: RequestPool::pool(settings),
             node: RefCell::new(Node::head()),
@@ -164,7 +164,7 @@ impl<H> WorkerSettings<H> {
             keep_alive,
             ka_enabled,
             channels,
-            sslrate,
+            connrate,
             notify,
         }
     }
@@ -177,8 +177,8 @@ impl<H> WorkerSettings<H> {
         self.node.borrow_mut()
     }
 
-    pub fn handlers(&self) -> RefMut<Vec<H>> {
+    pub fn handlers(&self) -> &Vec<H> {
-        self.h.borrow_mut()
+        &self.h
     }
 
     pub fn keep_alive(&self) -> u64 {
@@ -230,13 +230,13 @@ impl<H> WorkerSettings<H> {
     }
 
     #[allow(dead_code)]
-    pub(crate) fn ssl_conn_add(&self) {
+    pub(crate) fn conn_rate_add(&self) {
-        self.sslrate.fetch_add(1, Ordering::Relaxed);
+        self.connrate.fetch_add(1, Ordering::Relaxed);
     }
     #[allow(dead_code)]
-    pub(crate) fn ssl_conn_del(&self) {
+    pub(crate) fn conn_rate_del(&self) {
-        let val = self.sslrate.fetch_sub(1, Ordering::Relaxed);
+        let val = self.connrate.fetch_sub(1, Ordering::Relaxed);
-        self.notify.notify_maxsslrate(val);
+        self.notify.notify_maxconnrate(val);
     }
 }
 

src/server/srv.rs

@@ -10,15 +10,15 @@ use actix::{
 
 use futures::sync::mpsc;
 use futures::{Future, Sink, Stream};
-use net2::TcpBuilder;
 use num_cpus;
 use tokio_io::{AsyncRead, AsyncWrite};
+use tokio_tcp::TcpStream;
 
 #[cfg(feature = "tls")]
 use native_tls::TlsAcceptor;
 
 #[cfg(feature = "alpn")]
-use openssl::ssl::{AlpnError, SslAcceptorBuilder};
+use openssl::ssl::SslAcceptorBuilder;
 
 #[cfg(feature = "rust-tls")]
 use rustls::ServerConfig;
@@ -26,43 +26,25 @@ use rustls::ServerConfig;
 use super::accept::{AcceptLoop, AcceptNotify, Command};
 use super::channel::{HttpChannel, WrapperStream};
 use super::settings::{ServerSettings, WorkerSettings};
-use super::worker::{
+use super::worker::{Conn, StopWorker, Token, Worker, WorkerClient, WorkerFactory};
-    Conn, StopWorker, StreamHandlerType, Worker, WorkerClient, WorkersPool,
+use super::{AcceptorService, IntoHttpHandler, IoStream, KeepAlive};
-};
-use super::{IntoHttpHandler, IoStream, KeepAlive};
 use super::{PauseServer, ResumeServer, StopServer};
 
-#[cfg(feature = "alpn")]
-fn configure_alpn(builder: &mut SslAcceptorBuilder) -> io::Result<()> {
-    builder.set_alpn_protos(b"\x02h2\x08http/1.1")?;
-    builder.set_alpn_select_callback(|_, protos| {
-        const H2: &[u8] = b"\x02h2";
-        if protos.windows(3).any(|window| window == H2) {
-            Ok(b"h2")
-        } else {
-            Err(AlpnError::NOACK)
-        }
-    });
-    Ok(())
-}
-
 /// An HTTP Server
 pub struct HttpServer<H>
 where
     H: IntoHttpHandler + 'static,
 {
-    h: Option<Rc<WorkerSettings<H::Handler>>>,
     threads: usize,
-    backlog: i32,
+    factory: WorkerFactory<H>,
-    sockets: Vec<Socket>,
+    workers: Vec<(usize, Addr<Worker>)>,
-    pool: WorkersPool<H>,
-    workers: Vec<(usize, Addr<Worker<H::Handler>>)>,
     accept: AcceptLoop,
     exit: bool,
     shutdown_timeout: u16,
     signals: Option<Addr<signal::ProcessSignals>>,
     no_http2: bool,
     no_signals: bool,
+    settings: Option<Rc<WorkerSettings<H::Handler>>>,
 }
 
 pub(crate) enum ServerCommand {
@@ -76,12 +58,6 @@ where
     type Context = Context<Self>;
 }
 
-pub(crate) struct Socket {
-    pub lst: net::TcpListener,
-    pub addr: net::SocketAddr,
-    pub tp: StreamHandlerType,
-}
-
 impl<H> HttpServer<H>
 where
     H: IntoHttpHandler + 'static,
@@ -95,18 +71,16 @@ where
         let f = move || (factory)().into_iter().collect();
 
         HttpServer {
-            h: None,
             threads: num_cpus::get(),
-            backlog: 2048,
+            factory: WorkerFactory::new(f),
-            pool: WorkersPool::new(f),
             workers: Vec::new(),
-            sockets: Vec::new(),
             accept: AcceptLoop::new(),
             exit: false,
             shutdown_timeout: 30,
             signals: None,
             no_http2: false,
             no_signals: false,
+            settings: None,
         }
     }
 
@@ -130,7 +104,7 @@ where
     ///
     /// This method should be called before `bind()` method call.
     pub fn backlog(mut self, num: i32) -> Self {
-        self.backlog = num;
+        self.factory.backlog = num;
         self
     }
 
@@ -140,20 +114,19 @@ where
     /// for each worker.
     ///
     /// By default max connections is set to a 100k.
-    pub fn max_connections(mut self, num: usize) -> Self {
+    pub fn maxconn(mut self, num: usize) -> Self {
-        self.accept.max_connections(num);
+        self.accept.maxconn(num);
         self
     }
 
-    /// Sets the maximum concurrent per-worker number of SSL handshakes.
+    /// Sets the maximum per-worker concurrent connection establish process.
     ///
     /// All listeners will stop accepting connections when this limit is reached. It
-    /// can be used to limit the global SSL CPU usage regardless of each worker
+    /// can be used to limit the global SSL CPU usage.
-    /// capacity.
     ///
     /// By default max connections is set to a 256.
-    pub fn max_sslrate(mut self, num: usize) -> Self {
+    pub fn maxconnrate(mut self, num: usize) -> Self {
-        self.accept.max_sslrate(num);
+        self.accept.maxconnrate(num);
         self
     }
 
@@ -161,7 +134,7 @@ where
     ///
     /// By default keep alive is set to a `Os`.
     pub fn keep_alive<T: Into<KeepAlive>>(mut self, val: T) -> Self {
-        self.pool.keep_alive = val.into();
+        self.factory.keep_alive = val.into();
         self
     }
 
@@ -171,7 +144,7 @@ where
     /// generation. Check [ConnectionInfo](./dev/struct.ConnectionInfo.
     /// html#method.host) documentation for more information.
     pub fn server_hostname(mut self, val: String) -> Self {
-        self.pool.host = Some(val);
+        self.factory.host = Some(val);
         self
     }
 
@@ -215,7 +188,7 @@ where
 
     /// Get addresses of bound sockets.
     pub fn addrs(&self) -> Vec<net::SocketAddr> {
-        self.sockets.iter().map(|s| s.addr).collect()
+        self.factory.addrs()
     }
 
     /// Get addresses of bound sockets and the scheme for it.
@@ -225,10 +198,7 @@ where
     /// and the user should be presented with an enumeration of which
     /// socket requires which protocol.
     pub fn addrs_with_scheme(&self) -> Vec<(net::SocketAddr, &str)> {
-        self.sockets
+        self.factory.addrs_with_scheme()
-            .iter()
-            .map(|s| (s.addr, s.tp.scheme()))
-            .collect()
     }
 
     /// Use listener for accepting incoming connection requests
@@ -236,175 +206,177 @@ where
     /// HttpServer does not change any configuration for TcpListener,
     /// it needs to be configured before passing it to listen() method.
     pub fn listen(mut self, lst: net::TcpListener) -> Self {
-        let addr = lst.local_addr().unwrap();
+        self.factory.listen(lst);
-        self.sockets.push(Socket {
-            addr,
-            lst,
-            tp: StreamHandlerType::Normal,
-        });
         self
     }
 
+    /// Use listener for accepting incoming connection requests
+    pub fn listen_with<A>(
+        mut self, lst: net::TcpListener, acceptor: A,
+    ) -> io::Result<Self>
+    where
+        A: AcceptorService<TcpStream> + Send + 'static,
+    {
+        self.factory.listen_with(lst, acceptor);
+        Ok(self)
+    }
+
     #[cfg(feature = "tls")]
+    #[doc(hidden)]
+    #[deprecated(
+        since = "0.7.4",
+        note = "please use `actix_web::HttpServer::listen_with()` and `actix_web::server::NativeTlsAcceptor` instead"
+    )]
     /// Use listener for accepting incoming tls connection requests
     ///
     /// HttpServer does not change any configuration for TcpListener,
     /// it needs to be configured before passing it to listen() method.
-    pub fn listen_tls(mut self, lst: net::TcpListener, acceptor: TlsAcceptor) -> Self {
+    pub fn listen_tls(
-        let addr = lst.local_addr().unwrap();
+        self, lst: net::TcpListener, acceptor: TlsAcceptor,
-        self.sockets.push(Socket {
+    ) -> io::Result<Self> {
-            addr,
+        use super::NativeTlsAcceptor;
-            lst,
+
-            tp: StreamHandlerType::Tls(acceptor.clone()),
+        self.listen_with(lst, NativeTlsAcceptor::new(acceptor))
-        });
-        self
     }
 
     #[cfg(feature = "alpn")]
+    #[doc(hidden)]
+    #[deprecated(
+        since = "0.7.4",
+        note = "please use `actix_web::HttpServer::listen_with()` and `actix_web::server::OpensslAcceptor` instead"
+    )]
     /// Use listener for accepting incoming tls connection requests
     ///
     /// This method sets alpn protocols to "h2" and "http/1.1"
     pub fn listen_ssl(
-        mut self, lst: net::TcpListener, mut builder: SslAcceptorBuilder,
+        self, lst: net::TcpListener, builder: SslAcceptorBuilder,
     ) -> io::Result<Self> {
+        use super::{OpensslAcceptor, ServerFlags};
+
         // alpn support
-        if !self.no_http2 {
+        let flags = if !self.no_http2 {
-            configure_alpn(&mut builder)?;
+            ServerFlags::HTTP1
-        }
+        } else {
-        let acceptor = builder.build();
+            ServerFlags::HTTP1 | ServerFlags::HTTP2
-        let addr = lst.local_addr().unwrap();
+        };
-        self.sockets.push(Socket {
+
-            addr,
+        self.listen_with(lst, OpensslAcceptor::with_flags(builder, flags)?)
-            lst,
-            tp: StreamHandlerType::Alpn(acceptor.clone()),
-        });
-        Ok(self)
     }
 
     #[cfg(feature = "rust-tls")]
+    #[doc(hidden)]
+    #[deprecated(
+        since = "0.7.4",
+        note = "please use `actix_web::HttpServer::listen_with()` and `actix_web::server::RustlsAcceptor` instead"
+    )]
     /// Use listener for accepting incoming tls connection requests
     ///
     /// This method sets alpn protocols to "h2" and "http/1.1"
     pub fn listen_rustls(
-        mut self, lst: net::TcpListener, mut builder: ServerConfig,
+        self, lst: net::TcpListener, builder: ServerConfig,
     ) -> io::Result<Self> {
+        use super::{RustlsAcceptor, ServerFlags};
+
         // alpn support
-        if !self.no_http2 {
+        let flags = if !self.no_http2 {
-            builder.set_protocols(&vec!["h2".to_string(), "http/1.1".to_string()]);
+            ServerFlags::HTTP1
-        }
-        let addr = lst.local_addr().unwrap();
-        self.sockets.push(Socket {
-            addr,
-            lst,
-            tp: StreamHandlerType::Rustls(Arc::new(builder)),
-        });
-        Ok(self)
-    }
-
-    fn bind2<S: net::ToSocketAddrs>(&mut self, addr: S) -> io::Result<Vec<Socket>> {
-        let mut err = None;
-        let mut succ = false;
-        let mut sockets = Vec::new();
-        for addr in addr.to_socket_addrs()? {
-            match create_tcp_listener(addr, self.backlog) {
-                Ok(lst) => {
-                    succ = true;
-                    let addr = lst.local_addr().unwrap();
-                    sockets.push(Socket {
-                        lst,
-                        addr,
-                        tp: StreamHandlerType::Normal,
-                    });
-                }
-                Err(e) => err = Some(e),
-            }
-        }
-
-        if !succ {
-            if let Some(e) = err.take() {
-                Err(e)
-            } else {
-                Err(io::Error::new(
-                    io::ErrorKind::Other,
-                    "Can not bind to address.",
-                ))
-            }
         } else {
-            Ok(sockets)
+            ServerFlags::HTTP1 | ServerFlags::HTTP2
-        }
+        };
+
+        self.listen_with(lst, RustlsAcceptor::with_flags(builder, flags))
     }
 
     /// The socket address to bind
     ///
     /// To bind multiple addresses this method can be called multiple times.
     pub fn bind<S: net::ToSocketAddrs>(mut self, addr: S) -> io::Result<Self> {
-        let sockets = self.bind2(addr)?;
+        self.factory.bind(addr)?;
-        self.sockets.extend(sockets);
+        Ok(self)
+    }
+
+    /// Start listening for incoming connections with supplied acceptor.
+    #[cfg_attr(feature = "cargo-clippy", allow(needless_pass_by_value))]
+    pub fn bind_with<S, A>(mut self, addr: S, acceptor: A) -> io::Result<Self>
+    where
+        S: net::ToSocketAddrs,
+        A: AcceptorService<TcpStream> + Send + 'static,
+    {
+        self.factory.bind_with(addr, &acceptor)?;
         Ok(self)
     }
 
     #[cfg(feature = "tls")]
+    #[doc(hidden)]
+    #[deprecated(
+        since = "0.7.4",
+        note = "please use `actix_web::HttpServer::bind_with()` and `actix_web::server::NativeTlsAcceptor` instead"
+    )]
     /// The ssl socket address to bind
     ///
     /// To bind multiple addresses this method can be called multiple times.
     pub fn bind_tls<S: net::ToSocketAddrs>(
-        mut self, addr: S, acceptor: TlsAcceptor,
+        self, addr: S, acceptor: TlsAcceptor,
     ) -> io::Result<Self> {
-        let sockets = self.bind2(addr)?;
+        use super::NativeTlsAcceptor;
-        self.sockets.extend(sockets.into_iter().map(|mut s| {
+
-            s.tp = StreamHandlerType::Tls(acceptor.clone());
+        self.bind_with(addr, NativeTlsAcceptor::new(acceptor))
-            s
-        }));
-        Ok(self)
     }
 
     #[cfg(feature = "alpn")]
+    #[doc(hidden)]
+    #[deprecated(
+        since = "0.7.4",
+        note = "please use `actix_web::HttpServer::bind_with()` and `actix_web::server::OpensslAcceptor` instead"
+    )]
     /// Start listening for incoming tls connections.
     ///
     /// This method sets alpn protocols to "h2" and "http/1.1"
-    pub fn bind_ssl<S: net::ToSocketAddrs>(
+    pub fn bind_ssl<S>(self, addr: S, builder: SslAcceptorBuilder) -> io::Result<Self>
-        mut self, addr: S, mut builder: SslAcceptorBuilder,
+    where
-    ) -> io::Result<Self> {
+        S: net::ToSocketAddrs,
-        // alpn support
+    {
-        if !self.no_http2 {
+        use super::{OpensslAcceptor, ServerFlags};
-            configure_alpn(&mut builder)?;
-        }
 
-        let acceptor = builder.build();
+        // alpn support
-        let sockets = self.bind2(addr)?;
+        let flags = if !self.no_http2 {
-        self.sockets.extend(sockets.into_iter().map(|mut s| {
+            ServerFlags::HTTP1
-            s.tp = StreamHandlerType::Alpn(acceptor.clone());
+        } else {
-            s
+            ServerFlags::HTTP1 | ServerFlags::HTTP2
-        }));
+        };
-        Ok(self)
+
+        self.bind_with(addr, OpensslAcceptor::with_flags(builder, flags)?)
     }
 
     #[cfg(feature = "rust-tls")]
+    #[doc(hidden)]
+    #[deprecated(
+        since = "0.7.4",
+        note = "please use `actix_web::HttpServer::bind_with()` and `actix_web::server::RustlsAcceptor` instead"
+    )]
     /// Start listening for incoming tls connections.
     ///
     /// This method sets alpn protocols to "h2" and "http/1.1"
     pub fn bind_rustls<S: net::ToSocketAddrs>(
-        mut self, addr: S, mut builder: ServerConfig,
+        self, addr: S, builder: ServerConfig,
     ) -> io::Result<Self> {
-        // alpn support
+        use super::{RustlsAcceptor, ServerFlags};
-        if !self.no_http2 {
-            builder.set_protocols(&vec!["h2".to_string(), "http/1.1".to_string()]);
-        }
 
-        let builder = Arc::new(builder);
+        // alpn support
-        let sockets = self.bind2(addr)?;
+        let flags = if !self.no_http2 {
-        self.sockets.extend(sockets.into_iter().map(move |mut s| {
+            ServerFlags::HTTP1
-            s.tp = StreamHandlerType::Rustls(builder.clone());
+        } else {
-            s
+            ServerFlags::HTTP1 | ServerFlags::HTTP2
-        }));
+        };
-        Ok(self)
+
+        self.bind_with(addr, RustlsAcceptor::with_flags(builder, flags))
     }
 
     fn start_workers(&mut self, notify: &AcceptNotify) -> Vec<WorkerClient> {
         // start workers
         let mut workers = Vec::new();
         for idx in 0..self.threads {
-            let (worker, addr) = self.pool.start(idx, notify.clone());
+            let (worker, addr) = self.factory.start(idx, notify.clone());
             workers.push(worker);
             self.workers.push((idx, addr));
         }
@@ -453,23 +425,18 @@ impl<H: IntoHttpHandler> HttpServer<H> {
     /// }
     /// ```
     pub fn start(mut self) -> Addr<Self> {
-        if self.sockets.is_empty() {
+        let sockets = self.factory.take_sockets();
+        if sockets.is_empty() {
             panic!("HttpServer::bind() has to be called before start()");
         } else {
-            let mut addrs: Vec<(usize, Socket)> = Vec::new();
-
-            for socket in self.sockets.drain(..) {
-                let token = self.pool.insert(socket.addr, socket.tp.clone());
-                addrs.push((token, socket));
-            }
             let notify = self.accept.get_notify();
             let workers = self.start_workers(&notify);
 
             // start accept thread
-            for (_, sock) in &addrs {
+            for sock in &sockets {
                 info!("Starting server on http://{}", sock.addr);
             }
-            let rx = self.accept.start(addrs, workers.clone());
+            let rx = self.accept.start(sockets, workers.clone());
 
             // start http server actor
             let signals = self.subscribe_to_signals();
@@ -511,64 +478,6 @@ impl<H: IntoHttpHandler> HttpServer<H> {
     }
 }
 
-#[doc(hidden)]
-#[cfg(feature = "tls")]
-#[deprecated(
-    since = "0.6.0",
-    note = "please use `actix_web::HttpServer::bind_tls` instead"
-)]
-impl<H: IntoHttpHandler> HttpServer<H> {
-    /// Start listening for incoming tls connections.
-    pub fn start_tls(mut self, acceptor: TlsAcceptor) -> io::Result<Addr<Self>> {
-        for sock in &mut self.sockets {
-            match sock.tp {
-                StreamHandlerType::Normal => (),
-                _ => continue,
-            }
-            sock.tp = StreamHandlerType::Tls(acceptor.clone());
-        }
-        Ok(self.start())
-    }
-}
-
-#[doc(hidden)]
-#[cfg(feature = "alpn")]
-#[deprecated(
-    since = "0.6.0",
-    note = "please use `actix_web::HttpServer::bind_ssl` instead"
-)]
-impl<H: IntoHttpHandler> HttpServer<H> {
-    /// Start listening for incoming tls connections.
-    ///
-    /// This method sets alpn protocols to "h2" and "http/1.1"
-    pub fn start_ssl(
-        mut self, mut builder: SslAcceptorBuilder,
-    ) -> io::Result<Addr<Self>> {
-        // alpn support
-        if !self.no_http2 {
-            builder.set_alpn_protos(b"\x02h2\x08http/1.1")?;
-            builder.set_alpn_select_callback(|_, protos| {
-                const H2: &[u8] = b"\x02h2";
-                if protos.windows(3).any(|window| window == H2) {
-                    Ok(b"h2")
-                } else {
-                    Err(AlpnError::NOACK)
-                }
-            });
-        }
-
-        let acceptor = builder.build();
-        for sock in &mut self.sockets {
-            match sock.tp {
-                StreamHandlerType::Normal => (),
-                _ => continue,
-            }
-            sock.tp = StreamHandlerType::Alpn(acceptor.clone());
-        }
-        Ok(self.start())
-    }
-}
-
 impl<H: IntoHttpHandler> HttpServer<H> {
     /// Start listening for incoming connections from a stream.
     ///
@@ -580,14 +489,14 @@ impl<H: IntoHttpHandler> HttpServer<H> {
     {
         // set server settings
         let addr: net::SocketAddr = "127.0.0.1:8080".parse().unwrap();
-        let settings = ServerSettings::new(Some(addr), &self.pool.host, secure);
+        let settings = ServerSettings::new(Some(addr), &self.factory.host, secure);
-        let apps: Vec<_> = (*self.pool.factory)()
+        let apps: Vec<_> = (*self.factory.factory)()
             .into_iter()
             .map(|h| h.into_handler())
             .collect();
-        self.h = Some(Rc::new(WorkerSettings::new(
+        self.settings = Some(Rc::new(WorkerSettings::new(
             apps,
-            self.pool.keep_alive,
+            self.factory.keep_alive,
             settings,
             AcceptNotify::default(),
             Arc::new(AtomicUsize::new(0)),
@@ -599,7 +508,7 @@ impl<H: IntoHttpHandler> HttpServer<H> {
         let addr = HttpServer::create(move |ctx| {
             ctx.add_message_stream(stream.map_err(|_| ()).map(move |t| Conn {
                 io: WrapperStream::new(t),
-                token: 0,
+                token: Token::new(0),
                 peer: None,
                 http2: false,
             }));
@@ -672,7 +581,7 @@ impl<H: IntoHttpHandler> StreamHandler<ServerCommand, ()> for HttpServer<H> {
                     }
 
                     let (worker, addr) =
-                        self.pool.start(new_idx, self.accept.get_notify());
+                        self.factory.start(new_idx, self.accept.get_notify());
                     self.workers.push((new_idx, addr));
                     self.accept.send(Command::Worker(worker));
                 }
@@ -690,7 +599,7 @@ where
 
     fn handle(&mut self, msg: Conn<T>, _: &mut Context<Self>) -> Self::Result {
         Arbiter::spawn(HttpChannel::new(
-            Rc::clone(self.h.as_ref().unwrap()),
+            Rc::clone(self.settings.as_ref().unwrap()),
             msg.io,
             msg.peer,
             msg.http2,
@@ -766,15 +675,3 @@ impl<H: IntoHttpHandler> Handler<StopServer> for HttpServer<H> {
         }
     }
 }
-
-fn create_tcp_listener(
-    addr: net::SocketAddr, backlog: i32,
-) -> io::Result<net::TcpListener> {
-    let builder = match addr {
-        net::SocketAddr::V4(_) => TcpBuilder::new_v4()?,
-        net::SocketAddr::V6(_) => TcpBuilder::new_v6()?,
-    };
-    builder.reuse_address(true)?;
-    builder.bind(addr)?;
-    Ok(builder.listen(backlog)?)
-}

src/server/ssl/mod.rs

@@ -0,0 +1,14 @@
+#[cfg(feature = "alpn")]
+mod openssl;
+#[cfg(feature = "alpn")]
+pub use self::openssl::OpensslAcceptor;
+
+#[cfg(feature = "tls")]
+mod nativetls;
+#[cfg(feature = "tls")]
+pub use self::nativetls::NativeTlsAcceptor;
+
+#[cfg(feature = "rust-tls")]
+mod rustls;
+#[cfg(feature = "rust-tls")]
+pub use self::rustls::RustlsAcceptor;

src/server/ssl/nativetls.rs

@@ -0,0 +1,67 @@
+use std::net::Shutdown;
+use std::{io, time};
+
+use futures::{Future, Poll};
+use native_tls::TlsAcceptor;
+use tokio_tls::{AcceptAsync, TlsAcceptorExt, TlsStream};
+
+use server::{AcceptorService, IoStream};
+
+#[derive(Clone)]
+/// Support `SSL` connections via native-tls package
+///
+/// `tls` feature enables `NativeTlsAcceptor` type
+pub struct NativeTlsAcceptor {
+    acceptor: TlsAcceptor,
+}
+
+impl NativeTlsAcceptor {
+    /// Create `NativeTlsAcceptor` instance
+    pub fn new(acceptor: TlsAcceptor) -> Self {
+        NativeTlsAcceptor { acceptor }
+    }
+}
+
+pub struct AcceptorFut<Io>(AcceptAsync<Io>);
+
+impl<Io: IoStream> Future for AcceptorFut<Io> {
+    type Item = TlsStream<Io>;
+    type Error = io::Error;
+
+    fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
+        self.0
+            .poll()
+            .map_err(|e| io::Error::new(io::ErrorKind::Other, e))
+    }
+}
+
+impl<Io: IoStream> AcceptorService<Io> for NativeTlsAcceptor {
+    type Accepted = TlsStream<Io>;
+    type Future = AcceptorFut<Io>;
+
+    fn scheme(&self) -> &'static str {
+        "https"
+    }
+
+    fn accept(&self, io: Io) -> Self::Future {
+        AcceptorFut(TlsAcceptorExt::accept_async(&self.acceptor, io))
+    }
+}
+
+impl<Io: IoStream> IoStream for TlsStream<Io> {
+    #[inline]
+    fn shutdown(&mut self, _how: Shutdown) -> io::Result<()> {
+        let _ = self.get_mut().shutdown();
+        Ok(())
+    }
+
+    #[inline]
+    fn set_nodelay(&mut self, nodelay: bool) -> io::Result<()> {
+        self.get_mut().get_mut().set_nodelay(nodelay)
+    }
+
+    #[inline]
+    fn set_linger(&mut self, dur: Option<time::Duration>) -> io::Result<()> {
+        self.get_mut().get_mut().set_linger(dur)
+    }
+}

src/server/ssl/openssl.rs

@@ -0,0 +1,96 @@
+use std::net::Shutdown;
+use std::{io, time};
+
+use futures::{Future, Poll};
+use openssl::ssl::{AlpnError, SslAcceptor, SslAcceptorBuilder};
+use tokio_openssl::{AcceptAsync, SslAcceptorExt, SslStream};
+
+use server::{AcceptorService, IoStream, ServerFlags};
+
+#[derive(Clone)]
+/// Support `SSL` connections via openssl package
+///
+/// `alpn` feature enables `OpensslAcceptor` type
+pub struct OpensslAcceptor {
+    acceptor: SslAcceptor,
+}
+
+impl OpensslAcceptor {
+    /// Create `OpensslAcceptor` with enabled `HTTP/2` and `HTTP1.1` support.
+    pub fn new(builder: SslAcceptorBuilder) -> io::Result<Self> {
+        OpensslAcceptor::with_flags(builder, ServerFlags::HTTP1 | ServerFlags::HTTP2)
+    }
+
+    /// Create `OpensslAcceptor` with custom server flags.
+    pub fn with_flags(
+        mut builder: SslAcceptorBuilder, flags: ServerFlags,
+    ) -> io::Result<Self> {
+        let mut protos = Vec::new();
+        if flags.contains(ServerFlags::HTTP1) {
+            protos.extend(b"\x08http/1.1");
+        }
+        if flags.contains(ServerFlags::HTTP2) {
+            protos.extend(b"\x02h2");
+            builder.set_alpn_select_callback(|_, protos| {
+                const H2: &[u8] = b"\x02h2";
+                if protos.windows(3).any(|window| window == H2) {
+                    Ok(b"h2")
+                } else {
+                    Err(AlpnError::NOACK)
+                }
+            });
+        }
+
+        if !protos.is_empty() {
+            builder.set_alpn_protos(&protos)?;
+        }
+
+        Ok(OpensslAcceptor {
+            acceptor: builder.build(),
+        })
+    }
+}
+
+pub struct AcceptorFut<Io>(AcceptAsync<Io>);
+
+impl<Io: IoStream> Future for AcceptorFut<Io> {
+    type Item = SslStream<Io>;
+    type Error = io::Error;
+
+    fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
+        self.0
+            .poll()
+            .map_err(|e| io::Error::new(io::ErrorKind::Other, e))
+    }
+}
+
+impl<Io: IoStream> AcceptorService<Io> for OpensslAcceptor {
+    type Accepted = SslStream<Io>;
+    type Future = AcceptorFut<Io>;
+
+    fn scheme(&self) -> &'static str {
+        "https"
+    }
+
+    fn accept(&self, io: Io) -> Self::Future {
+        AcceptorFut(SslAcceptorExt::accept_async(&self.acceptor, io))
+    }
+}
+
+impl<T: IoStream> IoStream for SslStream<T> {
+    #[inline]
+    fn shutdown(&mut self, _how: Shutdown) -> io::Result<()> {
+        let _ = self.get_mut().shutdown();
+        Ok(())
+    }
+
+    #[inline]
+    fn set_nodelay(&mut self, nodelay: bool) -> io::Result<()> {
+        self.get_mut().get_mut().set_nodelay(nodelay)
+    }
+
+    #[inline]
+    fn set_linger(&mut self, dur: Option<time::Duration>) -> io::Result<()> {
+        self.get_mut().get_mut().set_linger(dur)
+    }
+}

src/server/ssl/rustls.rs

@@ -0,0 +1,92 @@
+use std::net::Shutdown;
+use std::sync::Arc;
+use std::{io, time};
+
+use rustls::{ClientSession, ServerConfig, ServerSession};
+use tokio_io::AsyncWrite;
+use tokio_rustls::{AcceptAsync, ServerConfigExt, TlsStream};
+
+use server::{AcceptorService, IoStream, ServerFlags};
+
+#[derive(Clone)]
+/// Support `SSL` connections via rustls package
+///
+/// `rust-tls` feature enables `RustlsAcceptor` type
+pub struct RustlsAcceptor {
+    config: Arc<ServerConfig>,
+}
+
+impl RustlsAcceptor {
+    /// Create `OpensslAcceptor` with enabled `HTTP/2` and `HTTP1.1` support.
+    pub fn new(config: ServerConfig) -> Self {
+        RustlsAcceptor::with_flags(config, ServerFlags::HTTP1 | ServerFlags::HTTP2)
+    }
+
+    /// Create `OpensslAcceptor` with custom server flags.
+    pub fn with_flags(mut config: ServerConfig, flags: ServerFlags) -> Self {
+        let mut protos = Vec::new();
+        if flags.contains(ServerFlags::HTTP1) {
+            protos.push("http/1.1".to_string());
+        }
+        if flags.contains(ServerFlags::HTTP2) {
+            protos.push("h2".to_string());
+        }
+
+        if !protos.is_empty() {
+            config.set_protocols(&protos);
+        }
+
+        RustlsAcceptor {
+            config: Arc::new(config),
+        }
+    }
+}
+
+impl<Io: IoStream> AcceptorService<Io> for RustlsAcceptor {
+    type Accepted = TlsStream<Io, ServerSession>;
+    type Future = AcceptAsync<Io>;
+
+    fn scheme(&self) -> &'static str {
+        "https"
+    }
+
+    fn accept(&self, io: Io) -> Self::Future {
+        ServerConfigExt::accept_async(&self.config, io)
+    }
+}
+
+impl<Io: IoStream> IoStream for TlsStream<Io, ClientSession> {
+    #[inline]
+    fn shutdown(&mut self, _how: Shutdown) -> io::Result<()> {
+        let _ = <Self as AsyncWrite>::shutdown(self);
+        Ok(())
+    }
+
+    #[inline]
+    fn set_nodelay(&mut self, nodelay: bool) -> io::Result<()> {
+        self.get_mut().0.set_nodelay(nodelay)
+    }
+
+    #[inline]
+    fn set_linger(&mut self, dur: Option<time::Duration>) -> io::Result<()> {
+        self.get_mut().0.set_linger(dur)
+    }
+}
+
+impl<Io: IoStream> IoStream for TlsStream<Io, ServerSession> {
+    #[inline]
+    fn shutdown(&mut self, _how: Shutdown) -> io::Result<()> {
+        let _ = <Self as AsyncWrite>::shutdown(self);
+        Ok(())
+    }
+
+    #[inline]
+    fn set_nodelay(&mut self, nodelay: bool) -> io::Result<()> {
+        self.get_mut().0.set_nodelay(nodelay)
+    }
+
+    #[inline]
+    fn set_linger(&mut self, dur: Option<time::Duration>) -> io::Result<()> {
+        self.get_mut().0.set_linger(dur)
+    }
+}

src/server/worker.rs

@@ -1,102 +1,195 @@
+use std::marker::PhantomData;
 use std::rc::Rc;
 use std::sync::{atomic::AtomicUsize, atomic::Ordering, Arc};
-use std::{net, time};
+use std::{io, mem, net, time};
 
 use futures::sync::mpsc::{unbounded, SendError, UnboundedSender};
 use futures::sync::oneshot;
 use futures::Future;
-use net2::TcpStreamExt;
+use net2::{TcpBuilder, TcpStreamExt};
-use slab::Slab;
 use tokio::executor::current_thread;
-use tokio_reactor::Handle;
 use tokio_tcp::TcpStream;
 
-#[cfg(any(feature = "tls", feature = "alpn", feature = "rust-tls"))]
-use futures::future;
-
-#[cfg(feature = "tls")]
-use native_tls::TlsAcceptor;
-#[cfg(feature = "tls")]
-use tokio_tls::TlsAcceptorExt;
-
-#[cfg(feature = "alpn")]
-use openssl::ssl::SslAcceptor;
-#[cfg(feature = "alpn")]
-use tokio_openssl::SslAcceptorExt;
-
-#[cfg(feature = "rust-tls")]
-use rustls::{ServerConfig, Session};
-#[cfg(feature = "rust-tls")]
-use tokio_rustls::ServerConfigExt;
-
 use actix::msgs::StopArbiter;
 use actix::{Actor, Addr, Arbiter, AsyncContext, Context, Handler, Message, Response};
 
 use super::accept::AcceptNotify;
 use super::channel::HttpChannel;
 use super::settings::{ServerSettings, WorkerSettings};
-use super::{HttpHandler, IntoHttpHandler, KeepAlive};
+use super::{
+    AcceptorService, HttpHandler, IntoAsyncIo, IntoHttpHandler, IoStream, KeepAlive,
+};
 
 #[derive(Message)]
 pub(crate) struct Conn<T> {
     pub io: T,
-    pub token: usize,
+    pub token: Token,
     pub peer: Option<net::SocketAddr>,
     pub http2: bool,
 }
 
-#[derive(Clone)]
+#[derive(Clone, Copy)]
-pub(crate) struct SocketInfo {
+pub struct Token(usize);
-    pub addr: net::SocketAddr,
+
-    pub htype: StreamHandlerType,
+impl Token {
+    pub(crate) fn new(val: usize) -> Token {
+        Token(val)
+    }
 }
 
-pub(crate) struct WorkersPool<H: IntoHttpHandler + 'static> {
+pub(crate) struct Socket {
-    sockets: Slab<SocketInfo>,
+    pub lst: net::TcpListener,
+    pub addr: net::SocketAddr,
+    pub token: Token,
+}
+
+pub(crate) struct WorkerFactory<H: IntoHttpHandler + 'static> {
     pub factory: Arc<Fn() -> Vec<H> + Send + Sync>,
     pub host: Option<String>,
     pub keep_alive: KeepAlive,
+    pub backlog: i32,
+    sockets: Vec<Socket>,
+    handlers: Vec<Box<IoStreamHandler<H::Handler, net::TcpStream>>>,
 }
 
-impl<H: IntoHttpHandler + 'static> WorkersPool<H> {
+impl<H: IntoHttpHandler + 'static> WorkerFactory<H> {
     pub fn new<F>(factory: F) -> Self
     where
         F: Fn() -> Vec<H> + Send + Sync + 'static,
     {
-        WorkersPool {
+        WorkerFactory {
             factory: Arc::new(factory),
             host: None,
+            backlog: 2048,
             keep_alive: KeepAlive::Os,
-            sockets: Slab::new(),
+            sockets: Vec::new(),
+            handlers: Vec::new(),
         }
     }
 
-    pub fn insert(&mut self, addr: net::SocketAddr, htype: StreamHandlerType) -> usize {
+    pub fn addrs(&self) -> Vec<net::SocketAddr> {
-        let entry = self.sockets.vacant_entry();
+        self.sockets.iter().map(|s| s.addr).collect()
-        let token = entry.key();
+    }
-        entry.insert(SocketInfo { addr, htype });
+
-        token
+    pub fn addrs_with_scheme(&self) -> Vec<(net::SocketAddr, &str)> {
+        self.handlers
+            .iter()
+            .map(|s| (s.addr(), s.scheme()))
+            .collect()
+    }
+
+    pub fn take_sockets(&mut self) -> Vec<Socket> {
+        mem::replace(&mut self.sockets, Vec::new())
+    }
+
+    pub fn listen(&mut self, lst: net::TcpListener) {
+        let token = Token(self.handlers.len());
+        let addr = lst.local_addr().unwrap();
+        self.handlers
+            .push(Box::new(SimpleHandler::new(lst.local_addr().unwrap())));
+        self.sockets.push(Socket { lst, addr, token })
+    }
+
+    pub fn listen_with<A>(&mut self, lst: net::TcpListener, acceptor: A)
+    where
+        A: AcceptorService<TcpStream> + Send + 'static,
+    {
+        let token = Token(self.handlers.len());
+        let addr = lst.local_addr().unwrap();
+        self.handlers.push(Box::new(StreamHandler::new(
+            lst.local_addr().unwrap(),
+            acceptor,
+        )));
+        self.sockets.push(Socket { lst, addr, token })
+    }
+
+    pub fn bind<S>(&mut self, addr: S) -> io::Result<()>
+    where
+        S: net::ToSocketAddrs,
+    {
+        let sockets = self.bind2(addr)?;
+
+        for lst in sockets {
+            let token = Token(self.handlers.len());
+            let addr = lst.local_addr().unwrap();
+            self.handlers
+                .push(Box::new(SimpleHandler::new(lst.local_addr().unwrap())));
+            self.sockets.push(Socket { lst, addr, token })
+        }
+        Ok(())
+    }
+
+    pub fn bind_with<S, A>(&mut self, addr: S, acceptor: &A) -> io::Result<()>
+    where
+        S: net::ToSocketAddrs,
+        A: AcceptorService<TcpStream> + Send + 'static,
+    {
+        let sockets = self.bind2(addr)?;
+
+        for lst in sockets {
+            let token = Token(self.handlers.len());
+            let addr = lst.local_addr().unwrap();
+            self.handlers.push(Box::new(StreamHandler::new(
+                lst.local_addr().unwrap(),
+                acceptor.clone(),
+            )));
+            self.sockets.push(Socket { lst, addr, token })
+        }
+        Ok(())
+    }
+
+    fn bind2<S: net::ToSocketAddrs>(
+        &self, addr: S,
+    ) -> io::Result<Vec<net::TcpListener>> {
+        let mut err = None;
+        let mut succ = false;
+        let mut sockets = Vec::new();
+        for addr in addr.to_socket_addrs()? {
+            match create_tcp_listener(addr, self.backlog) {
+                Ok(lst) => {
+                    succ = true;
+                    sockets.push(lst);
+                }
+                Err(e) => err = Some(e),
+            }
+        }
+
+        if !succ {
+            if let Some(e) = err.take() {
+                Err(e)
+            } else {
+                Err(io::Error::new(
+                    io::ErrorKind::Other,
+                    "Can not bind to address.",
+                ))
+            }
+        } else {
+            Ok(sockets)
+        }
     }
 
     pub fn start(
         &mut self, idx: usize, notify: AcceptNotify,
-    ) -> (WorkerClient, Addr<Worker<H::Handler>>) {
+    ) -> (WorkerClient, Addr<Worker>) {
         let host = self.host.clone();
-        let addr = self.sockets[0].addr;
+        let addr = self.handlers[0].addr();
         let factory = Arc::clone(&self.factory);
-        let socks = self.sockets.clone();
         let ka = self.keep_alive;
         let (tx, rx) = unbounded::<Conn<net::TcpStream>>();
-        let client = WorkerClient::new(idx, tx, self.sockets.clone());
+        let client = WorkerClient::new(idx, tx);
         let conn = client.conn.clone();
         let sslrate = client.sslrate.clone();
+        let handlers: Vec<_> = self.handlers.iter().map(|v| v.clone()).collect();
 
         let addr = Arbiter::start(move |ctx: &mut Context<_>| {
             let s = ServerSettings::new(Some(addr), &host, false);
             let apps: Vec<_> =
                 (*factory)().into_iter().map(|h| h.into_handler()).collect();
             ctx.add_message_stream(rx);
-            Worker::new(apps, socks, ka, s, conn, sslrate, notify)
+            let inner = WorkerInner::new(apps, handlers, ka, s, conn, sslrate, notify);
+            Worker {
+                inner: Box::new(inner),
+            }
         });
 
         (client, addr)
@@ -107,19 +200,15 @@ impl<H: IntoHttpHandler + 'static> WorkersPool<H> {
 pub(crate) struct WorkerClient {
     pub idx: usize,
     tx: UnboundedSender<Conn<net::TcpStream>>,
-    info: Slab<SocketInfo>,
     pub conn: Arc<AtomicUsize>,
     pub sslrate: Arc<AtomicUsize>,
 }
 
 impl WorkerClient {
-    fn new(
+    fn new(idx: usize, tx: UnboundedSender<Conn<net::TcpStream>>) -> Self {
-        idx: usize, tx: UnboundedSender<Conn<net::TcpStream>>, info: Slab<SocketInfo>,
-    ) -> Self {
         WorkerClient {
             idx,
             tx,
-            info,
             conn: Arc::new(AtomicUsize::new(0)),
             sslrate: Arc::new(AtomicUsize::new(0)),
         }
@@ -154,47 +243,30 @@ impl Message for StopWorker {
 ///
 /// Worker accepts Socket objects via unbounded channel and start requests
 /// processing.
-pub(crate) struct Worker<H>
+pub(crate) struct Worker {
-where
+    inner: Box<WorkerHandler>,
-    H: HttpHandler + 'static,
-{
-    settings: Rc<WorkerSettings<H>>,
-    socks: Slab<SocketInfo>,
-    tcp_ka: Option<time::Duration>,
 }
 
-impl<H: HttpHandler + 'static> Worker<H> {
+impl Actor for Worker {
-    pub(crate) fn new(
+    type Context = Context<Self>;
-        h: Vec<H>, socks: Slab<SocketInfo>, keep_alive: KeepAlive,
-        settings: ServerSettings, conn: Arc<AtomicUsize>, sslrate: Arc<AtomicUsize>,
-        notify: AcceptNotify,
-    ) -> Worker<H> {
-        let tcp_ka = if let KeepAlive::Tcp(val) = keep_alive {
-            Some(time::Duration::new(val as u64, 0))
-        } else {
-            None
-        };
 
-        Worker {
+    fn started(&mut self, ctx: &mut Self::Context) {
-            settings: Rc::new(WorkerSettings::new(
+        self.update_date(ctx);
-                h, keep_alive, settings, notify, conn, sslrate,
-            )),
-            socks,
-            tcp_ka,
-        }
     }
+}
 
-    fn update_time(&self, ctx: &mut Context<Self>) {
+impl Worker {
-        self.settings.update_date();
+    fn update_date(&self, ctx: &mut Context<Self>) {
-        ctx.run_later(time::Duration::new(1, 0), |slf, ctx| slf.update_time(ctx));
+        self.inner.update_date();
+        ctx.run_later(time::Duration::new(1, 0), |slf, ctx| slf.update_date(ctx));
     }
 
     fn shutdown_timeout(
-        &self, ctx: &mut Context<Self>, tx: oneshot::Sender<bool>, dur: time::Duration,
+        &self, ctx: &mut Context<Worker>, tx: oneshot::Sender<bool>, dur: time::Duration,
     ) {
         // sleep for 1 second and then check again
         ctx.run_later(time::Duration::new(1, 0), move |slf, ctx| {
-            let num = slf.settings.num_channels();
+            let num = slf.inner.num_channels();
             if num == 0 {
                 let _ = tx.send(true);
                 Arbiter::current().do_send(StopArbiter(0));
@@ -202,7 +274,7 @@ impl<H: HttpHandler + 'static> Worker<H> {
                 slf.shutdown_timeout(ctx, tx, d);
             } else {
                 info!("Force shutdown http worker, {} connections", num);
-                slf.settings.head().traverse::<TcpStream, H>();
+                slf.inner.force_shutdown();
                 let _ = tx.send(false);
                 Arbiter::current().do_send(StopArbiter(0));
             }
@@ -210,44 +282,20 @@ impl<H: HttpHandler + 'static> Worker<H> {
     }
 }
 
-impl<H: 'static> Actor for Worker<H>
+impl Handler<Conn<net::TcpStream>> for Worker {
-where
-    H: HttpHandler + 'static,
-{
-    type Context = Context<Self>;
-
-    fn started(&mut self, ctx: &mut Self::Context) {
-        self.update_time(ctx);
-    }
-}
-
-impl<H> Handler<Conn<net::TcpStream>> for Worker<H>
-where
-    H: HttpHandler + 'static,
-{
     type Result = ();
 
     fn handle(&mut self, msg: Conn<net::TcpStream>, _: &mut Context<Self>) {
-        if self.tcp_ka.is_some() && msg.io.set_keepalive(self.tcp_ka).is_err() {
+        self.inner.handle_connect(msg)
-            error!("Can not set socket keep-alive option");
-        }
-        self.socks
-            .get_mut(msg.token)
-            .unwrap()
-            .htype
-            .handle(Rc::clone(&self.settings), msg);
     }
 }
 
 /// `StopWorker` message handler
-impl<H> Handler<StopWorker> for Worker<H>
+impl Handler<StopWorker> for Worker {
-where
-    H: HttpHandler + 'static,
-{
     type Result = Response<bool, ()>;
 
     fn handle(&mut self, msg: StopWorker, ctx: &mut Context<Self>) -> Self::Result {
-        let num = self.settings.num_channels();
+        let num = self.inner.num_channels();
         if num == 0 {
             info!("Shutting down http worker, 0 connections");
             Response::reply(Ok(true))
@@ -258,148 +306,242 @@ where
             Response::async(rx.map_err(|_| ()))
         } else {
             info!("Force shutdown http worker, {} connections", num);
-            self.settings.head().traverse::<TcpStream, H>();
+            self.inner.force_shutdown();
             Response::reply(Ok(false))
         }
     }
 }
 
-#[derive(Clone)]
+trait WorkerHandler {
-pub(crate) enum StreamHandlerType {
+    fn update_date(&self);
-    Normal,
+
-    #[cfg(feature = "tls")]
+    fn handle_connect(&mut self, Conn<net::TcpStream>);
-    Tls(TlsAcceptor),
+
-    #[cfg(feature = "alpn")]
+    fn force_shutdown(&self);
-    Alpn(SslAcceptor),
+
-    #[cfg(feature = "rust-tls")]
+    fn num_channels(&self) -> usize;
-    Rustls(Arc<ServerConfig>),
 }
 
-impl StreamHandlerType {
+struct WorkerInner<H>
-    pub fn is_ssl(&self) -> bool {
+where
-        match *self {
+    H: HttpHandler + 'static,
-            StreamHandlerType::Normal => false,
+{
-            #[cfg(feature = "tls")]
+    settings: Rc<WorkerSettings<H>>,
-            StreamHandlerType::Tls(_) => true,
+    socks: Vec<Box<IoStreamHandler<H, net::TcpStream>>>,
-            #[cfg(feature = "alpn")]
+    tcp_ka: Option<time::Duration>,
-            StreamHandlerType::Alpn(_) => true,
+}
-            #[cfg(feature = "rust-tls")]
-            StreamHandlerType::Rustls(_) => true,
-        }
-    }
 
-    fn handle<H: HttpHandler>(
+impl<H: HttpHandler + 'static> WorkerInner<H> {
-        &mut self, h: Rc<WorkerSettings<H>>, msg: Conn<net::TcpStream>,
+    pub(crate) fn new(
-    ) {
+        h: Vec<H>, socks: Vec<Box<IoStreamHandler<H, net::TcpStream>>>,
-        match *self {
+        keep_alive: KeepAlive, settings: ServerSettings, conn: Arc<AtomicUsize>,
-            StreamHandlerType::Normal => {
+        sslrate: Arc<AtomicUsize>, notify: AcceptNotify,
-                let _ = msg.io.set_nodelay(true);
+    ) -> WorkerInner<H> {
-                let io = TcpStream::from_std(msg.io, &Handle::default())
+        let tcp_ka = if let KeepAlive::Tcp(val) = keep_alive {
-                    .expect("failed to associate TCP stream");
+            Some(time::Duration::new(val as u64, 0))
+        } else {
+            None
+        };
 
-                current_thread::spawn(HttpChannel::new(h, io, msg.peer, msg.http2));
+        WorkerInner {
-            }
+            settings: Rc::new(WorkerSettings::new(
-            #[cfg(feature = "tls")]
+                h, keep_alive, settings, notify, conn, sslrate,
-            StreamHandlerType::Tls(ref acceptor) => {
+            )),
-                let Conn {
+            socks,
-                    io, peer, http2, ..
+            tcp_ka,
-                } = msg;
-                let _ = io.set_nodelay(true);
-                let io = TcpStream::from_std(io, &Handle::default())
-                    .expect("failed to associate TCP stream");
-                h.ssl_conn_add();
-
-                current_thread::spawn(TlsAcceptorExt::accept_async(acceptor, io).then(
-                    move |res| {
-                        h.ssl_conn_del();
-                        match res {
-                            Ok(io) => current_thread::spawn(HttpChannel::new(
-                                h, io, peer, http2,
-                            )),
-                            Err(err) => {
-                                trace!("Error during handling tls connection: {}", err)
-                            }
-                        };
-                        future::result(Ok(()))
-                    },
-                ));
-            }
-            #[cfg(feature = "alpn")]
-            StreamHandlerType::Alpn(ref acceptor) => {
-                let Conn { io, peer, .. } = msg;
-                let _ = io.set_nodelay(true);
-                let io = TcpStream::from_std(io, &Handle::default())
-                    .expect("failed to associate TCP stream");
-                h.ssl_conn_add();
-
-                current_thread::spawn(SslAcceptorExt::accept_async(acceptor, io).then(
-                    move |res| {
-                        h.ssl_conn_del();
-                        match res {
-                            Ok(io) => {
-                                let http2 = if let Some(p) =
-                                    io.get_ref().ssl().selected_alpn_protocol()
-                                {
-                                    p.len() == 2 && &p == b"h2"
-                                } else {
-                                    false
-                                };
-                                current_thread::spawn(HttpChannel::new(
-                                    h, io, peer, http2,
-                                ));
-                            }
-                            Err(err) => {
-                                trace!("Error during handling tls connection: {}", err)
-                            }
-                        };
-                        future::result(Ok(()))
-                    },
-                ));
-            }
-            #[cfg(feature = "rust-tls")]
-            StreamHandlerType::Rustls(ref acceptor) => {
-                let Conn { io, peer, .. } = msg;
-                let _ = io.set_nodelay(true);
-                let io = TcpStream::from_std(io, &Handle::default())
-                    .expect("failed to associate TCP stream");
-                h.ssl_conn_add();
-
-                current_thread::spawn(ServerConfigExt::accept_async(acceptor, io).then(
-                    move |res| {
-                        h.ssl_conn_del();
-                        match res {
-                            Ok(io) => {
-                                let http2 = if let Some(p) =
-                                    io.get_ref().1.get_alpn_protocol()
-                                {
-                                    p.len() == 2 && &p == &"h2"
-                                } else {
-                                    false
-                                };
-                                current_thread::spawn(HttpChannel::new(
-                                    h, io, peer, http2,
-                                ));
-                            }
-                            Err(err) => {
-                                trace!("Error during handling tls connection: {}", err)
-                            }
-                        };
-                        future::result(Ok(()))
-                    },
-                ));
-            }
-        }
-    }
-
-    pub(crate) fn scheme(&self) -> &'static str {
-        match *self {
-            StreamHandlerType::Normal => "http",
-            #[cfg(feature = "tls")]
-            StreamHandlerType::Tls(_) => "https",
-            #[cfg(feature = "alpn")]
-            StreamHandlerType::Alpn(_) => "https",
-            #[cfg(feature = "rust-tls")]
-            StreamHandlerType::Rustls(_) => "https",
         }
     }
 }
+
+impl<H> WorkerHandler for WorkerInner<H>
+where
+    H: HttpHandler + 'static,
+{
+    fn update_date(&self) {
+        self.settings.update_date();
+    }
+
+    fn handle_connect(&mut self, msg: Conn<net::TcpStream>) {
+        if self.tcp_ka.is_some() && msg.io.set_keepalive(self.tcp_ka).is_err() {
+            error!("Can not set socket keep-alive option");
+        }
+        self.socks[msg.token.0].handle(Rc::clone(&self.settings), msg.io, msg.peer);
+    }
+
+    fn num_channels(&self) -> usize {
+        self.settings.num_channels()
+    }
+
+    fn force_shutdown(&self) {
+        self.settings.head().traverse::<TcpStream, H>();
+    }
+}
+
+struct SimpleHandler<Io> {
+    addr: net::SocketAddr,
+    io: PhantomData<Io>,
+}
+
+impl<Io: IntoAsyncIo> Clone for SimpleHandler<Io> {
+    fn clone(&self) -> Self {
+        SimpleHandler {
+            addr: self.addr,
+            io: PhantomData,
+        }
+    }
+}
+
+impl<Io: IntoAsyncIo> SimpleHandler<Io> {
+    fn new(addr: net::SocketAddr) -> Self {
+        SimpleHandler {
+            addr,
+            io: PhantomData,
+        }
+    }
+}
+
+impl<H, Io> IoStreamHandler<H, Io> for SimpleHandler<Io>
+where
+    H: HttpHandler,
+    Io: IntoAsyncIo + Send + 'static,
+    Io::Io: IoStream,
+{
+    fn addr(&self) -> net::SocketAddr {
+        self.addr
+    }
+
+    fn clone(&self) -> Box<IoStreamHandler<H, Io>> {
+        Box::new(Clone::clone(self))
+    }
+
+    fn scheme(&self) -> &'static str {
+        "http"
+    }
+
+    fn handle(&self, h: Rc<WorkerSettings<H>>, io: Io, peer: Option<net::SocketAddr>) {
+        let mut io = match io.into_async_io() {
+            Ok(io) => io,
+            Err(err) => {
+                trace!("Failed to create async io: {}", err);
+                return;
+            }
+        };
+        let _ = io.set_nodelay(true);
+
+        current_thread::spawn(HttpChannel::new(h, io, peer, false));
+    }
+}
+
+struct StreamHandler<A, Io> {
+    acceptor: A,
+    addr: net::SocketAddr,
+    io: PhantomData<Io>,
+}
+
+impl<Io: IntoAsyncIo, A: AcceptorService<Io::Io>> StreamHandler<A, Io> {
+    fn new(addr: net::SocketAddr, acceptor: A) -> Self {
+        StreamHandler {
+            addr,
+            acceptor,
+            io: PhantomData,
+        }
+    }
+}
+
+impl<Io: IntoAsyncIo, A: AcceptorService<Io::Io>> Clone for StreamHandler<A, Io> {
+    fn clone(&self) -> Self {
+        StreamHandler {
+            addr: self.addr,
+            acceptor: self.acceptor.clone(),
+            io: PhantomData,
+        }
+    }
+}
+
+impl<H, Io, A> IoStreamHandler<H, Io> for StreamHandler<A, Io>
+where
+    H: HttpHandler,
+    Io: IntoAsyncIo + Send + 'static,
+    Io::Io: IoStream,
+    A: AcceptorService<Io::Io> + Send + 'static,
+{
+    fn addr(&self) -> net::SocketAddr {
+        self.addr
+    }
+
+    fn clone(&self) -> Box<IoStreamHandler<H, Io>> {
+        Box::new(Clone::clone(self))
+    }
+
+    fn scheme(&self) -> &'static str {
+        self.acceptor.scheme()
+    }
+
+    fn handle(&self, h: Rc<WorkerSettings<H>>, io: Io, peer: Option<net::SocketAddr>) {
+        let mut io = match io.into_async_io() {
+            Ok(io) => io,
+            Err(err) => {
+                trace!("Failed to create async io: {}", err);
+                return;
+            }
+        };
+        let _ = io.set_nodelay(true);
+
+        h.conn_rate_add();
+        current_thread::spawn(self.acceptor.accept(io).then(move |res| {
+            h.conn_rate_del();
+            match res {
+                Ok(io) => current_thread::spawn(HttpChannel::new(h, io, peer, false)),
+                Err(err) => trace!("Can not establish connection: {}", err),
+            }
+            Ok(())
+        }))
+    }
+}
+
+impl<H, Io: 'static> IoStreamHandler<H, Io> for Box<IoStreamHandler<H, Io>>
+where
+    H: HttpHandler,
+    Io: IntoAsyncIo,
+{
+    fn addr(&self) -> net::SocketAddr {
+        self.as_ref().addr()
+    }
+
+    fn clone(&self) -> Box<IoStreamHandler<H, Io>> {
+        self.as_ref().clone()
+    }
+
+    fn scheme(&self) -> &'static str {
+        self.as_ref().scheme()
+    }
+
+    fn handle(&self, h: Rc<WorkerSettings<H>>, io: Io, peer: Option<net::SocketAddr>) {
+        self.as_ref().handle(h, io, peer)
+    }
+}
+
+pub(crate) trait IoStreamHandler<H, Io>: Send
+where
+    H: HttpHandler,
+{
+    fn clone(&self) -> Box<IoStreamHandler<H, Io>>;
+
+    fn addr(&self) -> net::SocketAddr;
+
+    fn scheme(&self) -> &'static str;
+
+    fn handle(&self, h: Rc<WorkerSettings<H>>, io: Io, peer: Option<net::SocketAddr>);
+}
+
+fn create_tcp_listener(
+    addr: net::SocketAddr, backlog: i32,
+) -> io::Result<net::TcpListener> {
+    let builder = match addr {
+        net::SocketAddr::V4(_) => TcpBuilder::new_v4()?,
+        net::SocketAddr::V6(_) => TcpBuilder::new_v6()?,
+    };
+    builder.reuse_address(true)?;
+    builder.bind(addr)?;
+    Ok(builder.listen(backlog)?)
+}