refactor(tcp): reducing branching in Transport::create_socket

transports/tcp/src/lib.rs

@@ -346,13 +346,12 @@ where
         }
     }
 
-    fn create_socket(&self, socket_addr: &SocketAddr) -> io::Result<Socket> {
-        let domain = if socket_addr.is_ipv4() {
-            Domain::IPV4
-        } else {
-            Domain::IPV6
-        };
-        let socket = Socket::new(domain, Type::STREAM, Some(socket2::Protocol::TCP))?;
+    fn create_socket(&self, socket_addr: SocketAddr) -> io::Result<Socket> {
+        let socket = Socket::new(
+            Domain::for_address(socket_addr),
+            Type::STREAM,
+            Some(socket2::Protocol::TCP),
+        )?;
         if socket_addr.is_ipv6() {
             socket.set_only_v6(true)?;
         }
@@ -375,7 +374,7 @@ where
         id: ListenerId,
         socket_addr: SocketAddr,
     ) -> io::Result<ListenStream<T>> {
-        let socket = self.create_socket(&socket_addr)?;
+        let socket = self.create_socket(socket_addr)?;
         socket.bind(&socket_addr.into())?;
         socket.listen(self.config.backlog as _)?;
         socket.set_nonblocking(true)?;
@@ -476,7 +475,7 @@ where
         log::debug!("dialing {}", socket_addr);
 
         let socket = self
-            .create_socket(&socket_addr)
+            .create_socket(socket_addr)
             .map_err(TransportError::Other)?;
 
         if let Some(addr) = self.port_reuse.local_dial_addr(&socket_addr.ip()) {
@@ -1329,4 +1328,35 @@ mod tests {
             assert!(rt.block_on(cycle_listeners::<tokio::Tcp>()));
         }
     }
+
+    #[test]
+    fn test_listens_ipv4_ipv6_separately() {
+        fn test<T: Provider>(port: u16) {
+            let mut tcp = Transport::<T>::default().boxed();
+            let listener_id = ListenerId::next();
+            tcp.listen_on(
+                listener_id,
+                format!("/ip4/0.0.0.0/tcp/{port}").parse().unwrap(),
+            )
+            .unwrap();
+            tcp.listen_on(
+                ListenerId::next(),
+                format!("/ip6/::/tcp/{port}").parse().unwrap(),
+            )
+            .unwrap();
+        }
+        #[cfg(feature = "async-io")]
+        {
+            async_std::task::block_on(async {
+                test::<async_io::Tcp>(3001);
+            })
+        }
+        let rt = ::tokio::runtime::Builder::new_current_thread()
+            .enable_io()
+            .build()
+            .unwrap();
+        rt.block_on(async {
+            test::<async_io::Tcp>(4001);
+        });
+    }
 }