Remove remnants of shutdown process (#1020)

core/src/protocols_handler/mod.rs

@@ -138,20 +138,18 @@ pub trait ProtocolsHandler {
 
     /// Returns until when the connection should be kept alive.
     ///
-    /// If returns `Until`, that indicates that this connection may invoke `shutdown()` after the
-    /// returned `Instant` has elapsed if they think that they will no longer need the connection
-    /// in the future. Returning `Forever` is equivalent to "infinite". Returning `Now` is
-    /// equivalent to `Until(Instant::now())`.
+    /// If returns `Until`, that indicates that this connection may be closed and this handler
+    /// destroyed after the returned `Instant` has elapsed if they think that they will no longer
+    /// need the connection in the future. Returning `Forever` is equivalent to "infinite".
+    /// Returning `Now` is equivalent to `Until(Instant::now())`.
     ///
     /// On the other hand, the return value is only an indication and doesn't mean that the user
-    /// will not call `shutdown()`.
+    /// will not close the connection.
     ///
     /// When multiple `ProtocolsHandler` are combined together, the largest `KeepAlive` should be
     /// used.
     ///
     /// The result of this method should be checked every time `poll()` is invoked.
-    ///
-    /// After `shutdown()` is called, the result of this method doesn't matter anymore.
     fn connection_keep_alive(&self) -> KeepAlive;
 
     /// Should behave like `Stream::poll()`.

core/src/protocols_handler/one_shot.rs

@@ -34,8 +34,6 @@ where TOutProto: OutboundUpgrade<TSubstream>
 {
     /// The upgrade for inbound substreams.
     listen_protocol: TInProto,
-    /// If true, we should return as soon as possible.
-    shutting_down: bool,
     /// If `Some`, something bad happened and we should shut down the handler with an error.
     pending_error: Option<ProtocolsHandlerUpgrErr<<TOutProto as OutboundUpgrade<TSubstream>>::Error>>,
     /// Queue of events to produce in `poll()`.
@@ -63,7 +61,6 @@ where TOutProto: OutboundUpgrade<TSubstream>
     pub fn new(listen_protocol: TInProto) -> Self {
         OneShotHandler {
             listen_protocol,
-            shutting_down: false,
             pending_error: None,
             events_out: SmallVec::new(),
             dial_queue: SmallVec::new(),
@@ -146,10 +143,6 @@ where
         &mut self,
         out: <Self::InboundProtocol as InboundUpgrade<Self::Substream>>::Output
     ) {
-        if self.shutting_down {
-            return;
-        }
-
         // If we're shutting down the connection for inactivity, reset the timeout.
         if !self.keep_alive.is_forever() {
             self.keep_alive = KeepAlive::Until(Instant::now() + self.inactive_timeout);
@@ -170,10 +163,6 @@ where
             self.keep_alive = KeepAlive::Until(Instant::now() + self.inactive_timeout);
         }
 
-        if self.shutting_down {
-            return;
-        }
-
         self.events_out.push(out.into());
     }
 
@@ -206,7 +195,7 @@ where
         }
 
         if !self.dial_queue.is_empty() {
-            if !self.shutting_down && self.dial_negotiated < self.max_dial_negotiated {
+            if self.dial_negotiated < self.max_dial_negotiated {
                 self.dial_negotiated += 1;
                 return Ok(Async::Ready(ProtocolsHandlerEvent::OutboundSubstreamRequest {
                     upgrade: self.dial_queue.remove(0),