Add ChannelGroup.deregister()

transport/src/main/java/io/netty/channel/group/ChannelGroup.java

@@ -21,6 +21,7 @@ import io.netty.buffer.Unpooled;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelStateHandlerAdapter;
+import io.netty.channel.EventLoop;
 import io.netty.channel.FileRegion;
 import io.netty.channel.ServerChannel;
 import io.netty.util.CharsetUtil;
@@ -153,4 +154,13 @@ public interface ChannelGroup extends Set<Channel>, Comparable<ChannelGroup> {
      *         the operation is done for all channels
      */
     ChannelGroupFuture close();
+
+    /**
+     * Deregister all {@link Channel}s in this group from their {@link EventLoop}.
+     * Please note that this operation is asynchronous as {@link Channel#deregister()} is.
+     *
+     * @return the {@link ChannelGroupFuture} instance that notifies when
+     *         the operation is done for all channels
+     */
+    ChannelGroupFuture deregister();
 }

transport/src/main/java/io/netty/channel/group/DefaultChannelGroup.java

@@ -248,6 +248,21 @@ public class DefaultChannelGroup extends AbstractSet<Channel> implements Channel
         return new DefaultChannelGroupFuture(this, futures);
     }
 
+    @Override
+    public ChannelGroupFuture deregister() {
+        Map<Integer, ChannelFuture> futures =
+                new LinkedHashMap<Integer, ChannelFuture>(size());
+
+        for (Channel c: serverChannels.values()) {
+            futures.put(c.id(), c.deregister());
+        }
+        for (Channel c: nonServerChannels.values()) {
+            futures.put(c.id(), c.deregister());
+        }
+
+        return new DefaultChannelGroupFuture(this, futures);
+    }
+
     @Override
     public int hashCode() {
         return System.identityHashCode(this);