Remove support from deregister a Channel from a EventLoop manually

example/src/main/java/io/netty/example/http/upload/HttpUploadServerHandler.java

@@ -88,7 +88,7 @@ public class HttpUploadServerHandler extends SimpleChannelInboundHandler<HttpObj
     }
 
     @Override
-    public void channelUnregistered(ChannelHandlerContext ctx) throws Exception {
+    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
         if (decoder != null) {
             decoder.cleanFiles();
         }

example/src/main/java/io/netty/example/uptime/UptimeClientHandler.java

@@ -68,13 +68,9 @@ public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exc
     }
 
     @Override
-    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
+    public void channelInactive(final ChannelHandlerContext ctx) throws Exception {
         println("Disconnected from: " + ctx.channel().remoteAddress());
-    }
 
-    @Override
-    public void channelUnregistered(final ChannelHandlerContext ctx)
-            throws Exception {
         println("Sleeping for: " + UptimeClient.RECONNECT_DELAY + 's');
 
         final EventLoop loop = ctx.channel().eventLoop();

handler/src/main/java/io/netty/handler/logging/LoggingHandler.java

@@ -200,15 +200,6 @@ public void channelRegistered(ChannelHandlerContext ctx)
         super.channelRegistered(ctx);
     }
 
-    @Override
-    public void channelUnregistered(ChannelHandlerContext ctx)
-            throws Exception {
-        if (logger.isEnabled(internalLevel)) {
-            logger.log(internalLevel, format(ctx, "UNREGISTERED"));
-        }
-        super.channelUnregistered(ctx);
-    }
-
     @Override
     public void channelActive(ChannelHandlerContext ctx)
             throws Exception {
@@ -282,15 +273,6 @@ public void close(ChannelHandlerContext ctx,
         super.close(ctx, promise);
     }
 
-    @Override
-    public void deregister(ChannelHandlerContext ctx,
-             ChannelPromise promise) throws Exception {
-        if (logger.isEnabled(internalLevel)) {
-            logger.log(internalLevel, format(ctx, "DEREGISTER()"));
-        }
-        super.deregister(ctx, promise);
-    }
-
     @Override
     public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
         logMessage(ctx, "RECEIVED", msg);

handler/src/main/java/io/netty/handler/ssl/SslHandler.java

@@ -44,6 +44,7 @@
 import javax.net.ssl.SSLEngineResult;
 import javax.net.ssl.SSLEngineResult.Status;
 import javax.net.ssl.SSLException;
+
 import java.io.IOException;
 import java.net.SocketAddress;
 import java.nio.ByteBuffer;
@@ -58,6 +59,7 @@
 import java.util.concurrent.TimeUnit;
 import java.util.regex.Pattern;
 
+
 /**
  * Adds <a href="http://en.wikipedia.org/wiki/Transport_Layer_Security">SSL
  * &middot; TLS</a> and StartTLS support to a {@link Channel}.  Please refer
@@ -370,11 +372,6 @@ public void connect(ChannelHandlerContext ctx, SocketAddress remoteAddress, Sock
         ctx.connect(remoteAddress, localAddress, promise);
     }
 
-    @Override
-    public void deregister(ChannelHandlerContext ctx, ChannelPromise promise) throws Exception {
-        ctx.deregister(promise);
-    }
-
     @Override
     public void disconnect(final ChannelHandlerContext ctx,
                            final ChannelPromise promise) throws Exception {

transport/src/main/java/io/netty/channel/AbstractChannel.java

@@ -30,6 +30,7 @@
 import java.net.SocketAddress;
 import java.nio.channels.ClosedChannelException;
 import java.nio.channels.NotYetConnectedException;
+import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
 
 /**
  * A skeletal {@link Channel} implementation.
@@ -66,6 +67,9 @@ public abstract class AbstractChannel extends DefaultAttributeMap implements Cha
     private boolean strValActive;
     private String strVal;
 
+    private static final AtomicReferenceFieldUpdater<AbstractChannel, EventLoop> EVENT_LOOP_UPDATER =
+            AtomicReferenceFieldUpdater.newUpdater(AbstractChannel.class, EventLoop.class, "eventLoop");
+
     /**
      * Creates a new instance.
      *
@@ -177,11 +181,6 @@ public ChannelFuture close() {
         return pipeline.close();
     }
 
-    @Override
-    public ChannelFuture deregister() {
-        return pipeline.deregister();
-    }
-
     @Override
     public Channel flush() {
         pipeline.flush();
@@ -213,11 +212,6 @@ public ChannelFuture close(ChannelPromise promise) {
         return pipeline.close(promise);
     }
 
-    @Override
-    public ChannelFuture deregister(ChannelPromise promise) {
-        return pipeline.deregister(promise);
-    }
-
     @Override
     public Channel read() {
         pipeline.read();
@@ -395,17 +389,16 @@ public final void register(EventLoop eventLoop, final ChannelPromise promise) {
             if (eventLoop == null) {
                 throw new NullPointerException("eventLoop");
             }
-            if (isRegistered()) {
-                promise.setFailure(new IllegalStateException("registered to an event loop already"));
-                return;
-            }
+
             if (!isCompatible(eventLoop)) {
-                promise.setFailure(
-                        new IllegalStateException("incompatible event loop type: " + eventLoop.getClass().getName()));
+                promise.setFailure(new IllegalStateException("incompatible event loop type: " +
+                        eventLoop.getClass().getName()));
                 return;
             }
 
-            AbstractChannel.this.eventLoop = eventLoop;
+            if (!AbstractChannel.EVENT_LOOP_UPDATER.compareAndSet(AbstractChannel.this, null, eventLoop)) {
+                return;
+            }
 
             if (eventLoop.inEventLoop()) {
                 register0(promise);
@@ -560,7 +553,7 @@ public void run() {
                     });
                 }
 
-                deregister(voidPromise());
+                deregister();
             }
         }
 
@@ -573,10 +566,8 @@ public final void closeForcibly() {
             }
         }
 
-        @Override
-        public final void deregister(final ChannelPromise promise) {
+        private void deregister() {
             if (!registered) {
-                promise.setSuccess();
                 return;
             }
 
@@ -587,18 +578,6 @@ public final void deregister(final ChannelPromise promise) {
             } finally {
                 if (registered) {
                     registered = false;
-                    promise.setSuccess();
-                    invokeLater(new Runnable() {
-                        @Override
-                        public void run() {
-                            pipeline.fireChannelUnregistered();
-                        }
-                    });
-                } else {
-                    // Some transports like local and AIO does not allow the deregistration of
-                    // an open channel.  Their doDeregister() calls close().  Consequently,
-                    // close() calls deregister() again - no need to fire channelUnregistered.
-                    promise.setSuccess();
                 }
             }
         }

transport/src/main/java/io/netty/channel/Channel.java

@@ -222,13 +222,6 @@ interface Unsafe {
          */
         void closeForcibly();
 
-        /**
-         * Deregister the {@link Channel} of the {@link ChannelPromise} from {@link EventLoop} and notify the
-         * {@link ChannelPromise} once the operation was complete.
-         */
-        @Deprecated
-        void deregister(ChannelPromise promise);
-
         /**
          * Schedules a read operation that fills the inbound buffer of the first {@link ChannelInboundHandler} in the
          * {@link ChannelPipeline}.  If there's already a pending read operation, this method does nothing.

transport/src/main/java/io/netty/channel/ChannelDuplexHandler.java

@@ -73,17 +73,6 @@ public void close(ChannelHandlerContext ctx, ChannelPromise future) throws Excep
         ctx.close(future);
     }
 
-    /**
-     * Calls {@link ChannelHandlerContext#close(ChannelPromise)} to forward
-     * to the next {@link ChannelOutboundHandler} in the {@link ChannelPipeline}.
-     *
-     * Sub-classes may override this method to change behavior.
-     */
-    @Override
-    public void deregister(ChannelHandlerContext ctx, ChannelPromise future) throws Exception {
-        ctx.deregister(future);
-    }
-
     /**
      * Calls {@link ChannelHandlerContext#read()} to forward
      * to the next {@link ChannelOutboundHandler} in the {@link ChannelPipeline}.

transport/src/main/java/io/netty/channel/ChannelHandlerContext.java

@@ -160,10 +160,6 @@ public interface ChannelHandlerContext
     @Override
     ChannelHandlerContext fireChannelRegistered();
 
-    @Override
-    @Deprecated
-    ChannelHandlerContext fireChannelUnregistered();
-
     @Override
     ChannelHandlerContext fireChannelActive();
 

transport/src/main/java/io/netty/channel/ChannelInboundHandler.java

@@ -16,8 +16,8 @@
 package io.netty.channel;
 
 /**
- * {@link ChannelHandler} which adds callbacks for state changes. This allows the user
- * to hook in to state changes easily.
+ * {@link ChannelHandler} which adds callbacks for state changes. This allows the user to hook in to state changes
+ * easily.
  */
 public interface ChannelInboundHandler extends ChannelHandler {
 
@@ -26,14 +26,6 @@ public interface ChannelInboundHandler extends ChannelHandler {
      */
     void channelRegistered(ChannelHandlerContext ctx) throws Exception;
 
-    /**
-     * The {@link Channel} of the {@link ChannelHandlerContext} was unregistered from its {@link EventLoop}
-     *
-     * @deprecated use {@link #channelInactive(ChannelHandlerContext)}
-     */
-    @Deprecated
-    void channelUnregistered(ChannelHandlerContext ctx) throws Exception;
-
     /**
      * The {@link Channel} of the {@link ChannelHandlerContext} is now active
      */

transport/src/main/java/io/netty/channel/ChannelInboundHandlerAdapter.java

@@ -16,7 +16,7 @@
 package io.netty.channel;
 
 /**
- * Abstract base class for {@link ChannelInboundHandler} implementations which provide
+ * Abstract base class for {@link ChannelInboundHandler} implementations that provides
  * implementations of all of their methods.
  *
  * <p>
@@ -42,17 +42,6 @@ public void channelRegistered(ChannelHandlerContext ctx) throws Exception {
         ctx.fireChannelRegistered();
     }
 
-    /**
-     * Calls {@link ChannelHandlerContext#fireChannelUnregistered()} to forward
-     * to the next {@link ChannelInboundHandler} in the {@link ChannelPipeline}.
-     *
-     * Sub-classes may override this method to change behavior.
-     */
-    @Override
-    public void channelUnregistered(ChannelHandlerContext ctx) throws Exception {
-        ctx.fireChannelUnregistered();
-    }
-
     /**
      * Calls {@link ChannelHandlerContext#fireChannelActive()} to forward
      * to the next {@link ChannelInboundHandler} in the {@link ChannelPipeline}.

transport/src/main/java/io/netty/channel/ChannelInboundInvoker.java

@@ -30,16 +30,6 @@ interface ChannelInboundInvoker {
      */
     ChannelInboundInvoker fireChannelRegistered();
 
-    /**
-     * A {@link Channel} was unregistered from its {@link EventLoop}.
-     *
-     * This will result in having the  {@link ChannelInboundHandler#channelUnregistered(ChannelHandlerContext)} method
-     * called of the next  {@link ChannelInboundHandler} contained in the  {@link ChannelPipeline} of the
-     * {@link Channel}.
-     */
-    @Deprecated
-    ChannelInboundInvoker fireChannelUnregistered();
-
     /**
      * A {@link Channel} is active now, which means it is connected.
      *

transport/src/main/java/io/netty/channel/ChannelOutboundHandler.java

@@ -62,15 +62,6 @@ void connect(
      */
     void close(ChannelHandlerContext ctx, ChannelPromise promise) throws Exception;
 
-    /**
-     * Called once a deregister operation is made from the current registered {@link EventLoop}.
-     *
-     * @param ctx               the {@link ChannelHandlerContext} for which the close operation is made
-     * @param promise           the {@link ChannelPromise} to notify once the operation completes
-     * @throws Exception        thrown if an error accour
-     */
-    void deregister(ChannelHandlerContext ctx, ChannelPromise promise) throws Exception;
-
     /**
      * Intercepts {@link ChannelHandlerContext#read()}.
      */

transport/src/main/java/io/netty/channel/ChannelOutboundHandlerAdapter.java

@@ -71,17 +71,6 @@ public void close(ChannelHandlerContext ctx, ChannelPromise promise)
         ctx.close(promise);
     }
 
-    /**
-     * Calls {@link ChannelHandlerContext#close(ChannelPromise)} to forward
-     * to the next {@link ChannelOutboundHandler} in the {@link ChannelPipeline}.
-     *
-     * Sub-classes may override this method to change behavior.
-     */
-    @Override
-    public void deregister(ChannelHandlerContext ctx, ChannelPromise promise) throws Exception {
-        ctx.deregister(promise);
-    }
-
     /**
      * Calls {@link ChannelHandlerContext#read()} to forward
      * to the next {@link ChannelOutboundHandler} in the {@link ChannelPipeline}.

transport/src/main/java/io/netty/channel/ChannelOutboundInvoker.java

@@ -15,8 +15,6 @@
  */
 package io.netty.channel;
 
-import io.netty.util.concurrent.EventExecutor;
-
 import java.net.ConnectException;
 import java.net.SocketAddress;
 
@@ -88,20 +86,6 @@ interface ChannelOutboundInvoker {
      */
     ChannelFuture close();
 
-    /**
-     * Request to deregister this ChannelOutboundInvoker from the previous assigned {@link EventExecutor} and notify the
-     * {@link ChannelFuture} once the operation completes, either because the operation was successful or because of
-     * an error.
-     * <p>
-     * This will result in having the
-     * {@link ChannelOutboundHandler#deregister(ChannelHandlerContext, ChannelPromise)}
-     * method called of the next {@link ChannelOutboundHandler} contained in the  {@link ChannelPipeline} of the
-     * {@link Channel}.
-     *
-     */
-    @Deprecated
-    ChannelFuture deregister();
-
     /**
      * Request to bind to the given {@link SocketAddress} and notify the {@link ChannelFuture} once the operation
      * completes, either because the operation was successful or because of an error.
@@ -175,21 +159,6 @@ interface ChannelOutboundInvoker {
      */
     ChannelFuture close(ChannelPromise promise);
 
-    /**
-     * Request to deregister this ChannelOutboundInvoker from the previous assigned {@link EventExecutor} and notify the
-     * {@link ChannelFuture} once the operation completes, either because the operation was successful or because of
-     * an error.
-     *
-     * The given {@link ChannelPromise} will be notified.
-     * <p>
-     * This will result in having the
-     * {@link ChannelOutboundHandler#deregister(ChannelHandlerContext, ChannelPromise)}
-     * method called of the next {@link ChannelOutboundHandler} contained in the  {@link ChannelPipeline} of the
-     * {@link Channel}.
-     */
-    @Deprecated
-    ChannelFuture deregister(ChannelPromise promise);
-
     /**
      * Request to Read data from the {@link Channel} into the first inbound buffer, triggers an
      * {@link ChannelInboundHandler#channelRead(ChannelHandlerContext, Object)} event if data was