Introduce new utility class calles ReferenceCountUtil and move utility methods from ByteBufUtil to it.

The ones in ByteBufUtil were marked as @deprecated

buffer/src/main/java/io/netty/buffer/ByteBufUtil.java

@@ -16,6 +16,7 @@
 package io.netty.buffer;
 
 import io.netty.util.CharsetUtil;
+import io.netty.util.ReferenceCountUtil;
 import io.netty.util.ReferenceCounted;
 
 import java.nio.ByteBuffer;
@@ -45,47 +46,47 @@ public final class ByteBufUtil {
     /**
      * Try to call {@link ReferenceCounted#retain()} if the specified message implements {@link ReferenceCounted}.
      * If the specified message doesn't implement {@link ReferenceCounted}, this method does nothing.
+     *
+     * @deprecated use {@link ReferenceCountUtil#retain(Object)}
      */
     @SuppressWarnings("unchecked")
+    @Deprecated
     public static <T> T retain(T msg) {
-        if (msg instanceof ReferenceCounted) {
+        return ReferenceCountUtil.retain(msg);
-            return (T) ((ReferenceCounted) msg).retain();
-        }
-        return msg;
     }
 
     /**
      * Try to call {@link ReferenceCounted#retain()} if the specified message implements {@link ReferenceCounted}.
      * If the specified message doesn't implement {@link ReferenceCounted}, this method does nothing.
+     *
+     * @deprecated use {@link ReferenceCountUtil#retain(Object, int)}
      */
     @SuppressWarnings("unchecked")
+    @Deprecated
     public static <T> T retain(T msg, int increment) {
-        if (msg instanceof ReferenceCounted) {
+        return ReferenceCountUtil.retain(msg, increment);
-            return (T) ((ReferenceCounted) msg).retain(increment);
-        }
-        return msg;
     }
 
     /**
      * Try to call {@link ReferenceCounted#release()} if the specified message implements {@link ReferenceCounted}.
      * If the specified message doesn't implement {@link ReferenceCounted}, this method does nothing.
+     *
+     * @deprecated use {@link ReferenceCountUtil#release(Object)}
      */
+    @Deprecated
     public static boolean release(Object msg) {
-        if (msg instanceof ReferenceCounted) {
+        return ReferenceCountUtil.release(msg);
-            return ((ReferenceCounted) msg).release();
-        }
-        return false;
     }
 
     /**
      * Try to call {@link ReferenceCounted#release()} if the specified message implements {@link ReferenceCounted}.
      * If the specified message doesn't implement {@link ReferenceCounted}, this method does nothing.
+     *
+     * @deprecated use {@link ReferenceCountUtil#release(Object, int)}
      */
+    @Deprecated
     public static boolean release(Object msg, int decrement) {
-        if (msg instanceof ReferenceCounted) {
+        return ReferenceCountUtil.release(msg, decrement);
-            return ((ReferenceCounted) msg).release(decrement);
-        }
-        return false;
     }
 
     /**

codec-http/src/main/java/io/netty/handler/codec/http/HttpContentDecoder.java

@@ -17,12 +17,12 @@ package io.netty.handler.codec.http;
 
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.ByteBufHolder;
-import io.netty.buffer.ByteBufUtil;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.MessageList;
 import io.netty.channel.embedded.EmbeddedChannel;
 import io.netty.handler.codec.MessageToMessageDecoder;
+import io.netty.util.ReferenceCountUtil;
 
 /**
  * Decodes the content of the received {@link HttpRequest} and {@link HttpContent}.
@@ -58,7 +58,7 @@ public abstract class HttpContentDecoder extends MessageToMessageDecoder<HttpObj
                 continueResponse = true;
             }
             // 100-continue response must be passed through.
-            out.add(ByteBufUtil.retain(msg));
+            out.add(ReferenceCountUtil.retain(msg));
             return;
         }
 
@@ -67,7 +67,7 @@ public abstract class HttpContentDecoder extends MessageToMessageDecoder<HttpObj
                 continueResponse = false;
             }
             // 100-continue response must be passed through.
-            out.add(ByteBufUtil.retain(msg));
+            out.add(ReferenceCountUtil.retain(msg));
             return;
         }
 

codec-http/src/main/java/io/netty/handler/codec/http/HttpContentEncoder.java

@@ -17,7 +17,6 @@ package io.netty.handler.codec.http;
 
 import io.netty.buffer.ByteBuf;
 import io.netty.buffer.ByteBufHolder;
-import io.netty.buffer.ByteBufUtil;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.MessageList;
@@ -25,6 +24,7 @@ import io.netty.channel.embedded.EmbeddedChannel;
 import io.netty.handler.codec.MessageToMessageCodec;
 import io.netty.handler.codec.http.HttpHeaders.Names;
 import io.netty.handler.codec.http.HttpHeaders.Values;
+import io.netty.util.ReferenceCountUtil;
 
 import java.util.ArrayDeque;
 import java.util.Queue;
@@ -77,7 +77,7 @@ public abstract class HttpContentEncoder extends MessageToMessageCodec<HttpReque
             acceptedEncoding = HttpHeaders.Values.IDENTITY;
         }
         acceptEncodingQueue.add(acceptedEncoding);
-        out.add(ByteBufUtil.retain(msg));
+        out.add(ReferenceCountUtil.retain(msg));
     }
 
     @Override
@@ -92,7 +92,7 @@ public abstract class HttpContentEncoder extends MessageToMessageCodec<HttpReque
 
                 if (res.getStatus().code() == 100) {
                     if (isFull) {
-                        out.add(ByteBufUtil.retain(res));
+                        out.add(ReferenceCountUtil.retain(res));
                     } else {
                         out.add(res);
                         // Pass through all following contents.
@@ -113,7 +113,7 @@ public abstract class HttpContentEncoder extends MessageToMessageCodec<HttpReque
                         // Set the content length to 0.
                         res.headers().remove(Names.TRANSFER_ENCODING);
                         res.headers().set(Names.CONTENT_LENGTH, "0");
-                        out.add(ByteBufUtil.retain(res));
+                        out.add(ReferenceCountUtil.retain(res));
                         break;
                     }
                 }
@@ -127,7 +127,7 @@ public abstract class HttpContentEncoder extends MessageToMessageCodec<HttpReque
                         // As an unchunked response
                         res.headers().remove(Names.TRANSFER_ENCODING);
                         res.headers().set(Names.CONTENT_LENGTH, ((ByteBufHolder) res).content().readableBytes());
-                        out.add(ByteBufUtil.retain(res));
+                        out.add(ReferenceCountUtil.retain(res));
                     } else {
                         // As a chunked response
                         res.headers().remove(Names.CONTENT_LENGTH);
@@ -172,7 +172,7 @@ public abstract class HttpContentEncoder extends MessageToMessageCodec<HttpReque
             }
             case PASS_THROUGH: {
                 ensureContent(msg);
-                out.add(ByteBufUtil.retain(msg));
+                out.add(ReferenceCountUtil.retain(msg));
                 // Passed through all following contents of the current response.
                 if (msg instanceof LastHttpContent) {
                     state = State.AWAIT_HEADERS;

codec-http/src/main/java/io/netty/handler/codec/http/HttpObjectAggregator.java

@@ -16,7 +16,6 @@
 package io.netty.handler.codec.http;
 
 import io.netty.buffer.ByteBuf;
-import io.netty.buffer.ByteBufUtil;
 import io.netty.buffer.CompositeByteBuf;
 import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelHandler;
@@ -27,6 +26,7 @@ import io.netty.handler.codec.DecoderResult;
 import io.netty.handler.codec.MessageToMessageDecoder;
 import io.netty.handler.codec.TooLongFrameException;
 import io.netty.util.CharsetUtil;
+import io.netty.util.ReferenceCountUtil;
 
 import static io.netty.handler.codec.http.HttpHeaders.*;
 
@@ -129,7 +129,7 @@ public class HttpObjectAggregator extends MessageToMessageDecoder<HttpObject> {
             if (!m.getDecoderResult().isSuccess()) {
                 removeTransferEncodingChunked(m);
                 this.currentMessage = null;
-                out.add(ByteBufUtil.retain(m));
+                out.add(ReferenceCountUtil.retain(m));
                 return;
             }
             if (msg instanceof HttpRequest) {

codec-http/src/main/java/io/netty/handler/codec/spdy/SpdyHttpResponseStreamIdHandler.java

@@ -15,11 +15,11 @@
  */
 package io.netty.handler.codec.spdy;
 
-import io.netty.buffer.ByteBufUtil;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.MessageList;
 import io.netty.handler.codec.MessageToMessageCodec;
 import io.netty.handler.codec.http.HttpMessage;
+import io.netty.util.ReferenceCountUtil;
 
 import java.util.LinkedList;
 import java.util.Queue;
@@ -46,7 +46,7 @@ public class SpdyHttpResponseStreamIdHandler extends
             SpdyHttpHeaders.setStreamId(msg, id);
         }
 
-        out.add(ByteBufUtil.retain(msg));
+        out.add(ReferenceCountUtil.retain(msg));
     }
 
     @Override
@@ -62,6 +62,6 @@ public class SpdyHttpResponseStreamIdHandler extends
             ids.remove(((SpdyRstStreamFrame) msg).getStreamId());
         }
 
-        out.add(ByteBufUtil.retain(msg));
+        out.add(ReferenceCountUtil.retain(msg));
     }
 }

common/src/main/java/io/netty/util/ReferenceCountUtil.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2013 The Netty Project
+ *
+ * The Netty Project licenses this file to you under the Apache License,
+ * version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at:
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ */
+package io.netty.util;
+
+/**
+ * Collection of method to handle objects that may implement {@link ReferenceCounted}.
+ */
+public final class ReferenceCountUtil {
+
+    /**
+     * Try to call {@link ReferenceCounted#retain()} if the specified message implements {@link ReferenceCounted}.
+     * If the specified message doesn't implement {@link ReferenceCounted}, this method does nothing.
+     */
+    @SuppressWarnings("unchecked")
+    public static <T> T retain(T msg) {
+        if (msg instanceof ReferenceCounted) {
+            return (T) ((ReferenceCounted) msg).retain();
+        }
+        return msg;
+    }
+
+    /**
+     * Try to call {@link ReferenceCounted#retain()} if the specified message implements {@link ReferenceCounted}.
+     * If the specified message doesn't implement {@link ReferenceCounted}, this method does nothing.
+     */
+    @SuppressWarnings("unchecked")
+    public static <T> T retain(T msg, int increment) {
+        if (msg instanceof ReferenceCounted) {
+            return (T) ((ReferenceCounted) msg).retain(increment);
+        }
+        return msg;
+    }
+
+    /**
+     * Try to call {@link ReferenceCounted#release()} if the specified message implements {@link ReferenceCounted}.
+     * If the specified message doesn't implement {@link ReferenceCounted}, this method does nothing.
+     */
+    public static boolean release(Object msg) {
+        if (msg instanceof ReferenceCounted) {
+            return ((ReferenceCounted) msg).release();
+        }
+        return false;
+    }
+
+    /**
+     * Try to call {@link ReferenceCounted#release()} if the specified message implements {@link ReferenceCounted}.
+     * If the specified message doesn't implement {@link ReferenceCounted}, this method does nothing.
+     */
+    public static boolean release(Object msg, int decrement) {
+        if (msg instanceof ReferenceCounted) {
+            return ((ReferenceCounted) msg).release(decrement);
+        }
+        return false;
+    }
+
+    private ReferenceCountUtil() { }
+}

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

@@ -16,7 +16,7 @@
 
 package io.netty.channel;
 
-import io.netty.buffer.ByteBufUtil;
+import io.netty.util.ReferenceCountUtil;
 import io.netty.util.ReferenceCounted;
 import io.netty.util.internal.StringUtil;
 
@@ -82,24 +82,24 @@ public class DefaultAddressedEnvelope<M, A extends SocketAddress> implements Add
 
     @Override
     public AddressedEnvelope<M, A> retain() {
-        ByteBufUtil.retain(message);
+        ReferenceCountUtil.retain(message);
         return this;
     }
 
     @Override
     public AddressedEnvelope<M, A> retain(int increment) {
-        ByteBufUtil.retain(message, increment);
+        ReferenceCountUtil.retain(message, increment);
         return this;
     }
 
     @Override
     public boolean release() {
-        return ByteBufUtil.release(message);
+        return ReferenceCountUtil.release(message);
     }
 
     @Override
     public boolean release(int decrement) {
-        return ByteBufUtil.release(message, decrement);
+        return ReferenceCountUtil.release(message, decrement);
     }
 
     @Override

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

@@ -17,9 +17,9 @@
 package io.netty.channel;
 
 import io.netty.buffer.ByteBuf;
-import io.netty.buffer.ByteBufUtil;
 import io.netty.util.Recycler;
 import io.netty.util.Recycler.Handle;
+import io.netty.util.ReferenceCountUtil;
 import io.netty.util.Signal;
 import io.netty.util.internal.PlatformDependent;
 
@@ -74,49 +74,50 @@ public final class MessageList<T> implements Iterable<T> {
     }
 
     /**
-     * Call {@link ByteBufUtil#retain(Object)} on all messages in this {@link MessageList} and return itself.
+     * Call {@link ReferenceCountUtil#retain(Object)} on all messages in this {@link MessageList} and return itself.
      */
     public MessageList<T> retainAll() {
         int size = this.size;
         for (int i = 0; i < size; i ++) {
-            ByteBufUtil.retain(elements[i]);
+            ReferenceCountUtil.retain(elements[i]);
         }
         return this;
     }
 
     /**
-     * Call {@link ByteBufUtil#retain(Object), int} on all messages in this {@link MessageList} and return itself.
+     * Call {@link ReferenceCountUtil#retain(Object), int} on all messages in this {@link MessageList} and return
+     * itself.
      */
     public MessageList<T> retainAll(int increment) {
         int size = this.size;
         for (int i = 0; i < size; i ++) {
-            ByteBufUtil.retain(elements[i], increment);
+            ReferenceCountUtil.retain(elements[i], increment);
         }
         return this;
     }
 
     /**
-     * Call {@link ByteBufUtil#release(Object)} on all messages in this {@link MessageList} and return {@code true}
+     * Call {@link ReferenceCountUtil#release(Object)} on all messages in this {@link MessageList} and return
-     * if all messages were released.
+     * {@code true} if all messages were released.
      */
     public boolean releaseAll() {
         boolean releasedAll = true;
         int size = this.size;
         for (int i = 0; i < size; i++) {
-            releasedAll &= ByteBufUtil.release(elements[i]);
+            releasedAll &= ReferenceCountUtil.release(elements[i]);
         }
         return releasedAll;
     }
 
     /**
-     * Call {@link ByteBufUtil#release(Object, int)} on all messages in this {@link MessageList} and return
+     * Call {@link ReferenceCountUtil#release(Object, int)} on all messages in this {@link MessageList} and return
      * {@code true} if all messages were released.
      */
     public boolean releaseAll(int decrement) {
         boolean releasedAll = true;
         int size = this.size;
         for (int i = 0; i < size; i++) {
-            releasedAll &= ByteBufUtil.release(elements[i], decrement);
+            releasedAll &= ReferenceCountUtil.release(elements[i], decrement);
         }
         return releasedAll;
     }

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

@@ -15,12 +15,12 @@
  */
 package io.netty.channel.group;
 
-import io.netty.buffer.ByteBufUtil;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.MessageList;
 import io.netty.channel.ServerChannel;
+import io.netty.util.ReferenceCountUtil;
 import io.netty.util.concurrent.EventExecutor;
 import io.netty.util.internal.PlatformDependent;
 
@@ -216,11 +216,11 @@ public class DefaultChannelGroup extends AbstractSet<Channel> implements Channel
 
         Map<Integer, ChannelFuture> futures = new LinkedHashMap<Integer, ChannelFuture>(size());
         for (Channel c: nonServerChannels.values()) {
-            ByteBufUtil.retain(message);
+            ReferenceCountUtil.retain(message);
             futures.put(c.id(), c.write(message));
         }
 
-        ByteBufUtil.release(message);
+        ReferenceCountUtil.release(message);
         return new DefaultChannelGroupFuture(this, futures, executor);
     }