Allow to share Workers by using a WorkerPool.

transport/src/main/java/io/netty/channel/socket/nio/AbstractNioWorker.java

@@ -115,8 +115,15 @@ abstract class AbstractNioWorker implements Worker {
 
     private final SocketSendBufferPool sendBufferPool = new SocketSendBufferPool();
 
+    private final boolean allowShutdownOnIdle;
+
     AbstractNioWorker(Executor executor) {
+        this(executor, true);
+    }
+
+    public AbstractNioWorker(Executor executor, boolean allowShutdownOnIdle) {
         this.executor = executor;
+        this.allowShutdownOnIdle = allowShutdownOnIdle;
     }
 
     void register(AbstractNioChannel<?> channel, ChannelFuture future) {
@@ -251,9 +258,11 @@ abstract class AbstractNioWorker implements Worker {
                             }
                         }
                     } else {
+                        if (allowShutdownOnIdle) {
                             // Give one more second.
                             shutdown = true;
                         }
+                    }
                 } else {
                     shutdown = false;
                 }

transport/src/main/java/io/netty/channel/socket/nio/AbstractWorkerPool.java

@@ -0,0 +1,83 @@
+/*
+ * Copyright 2011 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.channel.socket.nio;
+
+import io.netty.channel.Channel;
+import io.netty.channel.socket.Worker;
+import io.netty.util.ExternalResourceReleasable;
+import io.netty.util.internal.ExecutorUtil;
+
+import java.util.concurrent.Executor;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * Abstract base class for {@link WorkerPool} implementations that create the {@link Worker}'s up-front and return them in a "fair" fashion when calling
+ * {@link #nextWorker()}
+ *
+ */
+public abstract class AbstractWorkerPool<E extends AbstractNioWorker> implements WorkerPool<E> , ExternalResourceReleasable{
+
+    private final AbstractNioWorker[] workers;
+    private final AtomicInteger workerIndex = new AtomicInteger();
+    private final Executor workerExecutor;
+    
+    /**
+     * Create a new instance
+     * 
+     * @param workerExecutor the {@link Executor} to use for the {@link Worker}'s
+     * @param allowShutdownOnIdle allow the {@link Worker}'s to shutdown when there is not {@link Channel} is registered with it
+     * @param workerCount the count of {@link Worker}'s to create
+     */
+    AbstractWorkerPool(Executor workerExecutor, int workerCount, boolean allowShutDownOnIdle) {
+        if (workerExecutor == null) {
+            throw new NullPointerException("workerExecutor");
+        }
+        if (workerCount <= 0) {
+            throw new IllegalArgumentException(
+                    "workerCount (" + workerCount + ") " +
+                    "must be a positive integer.");
+        }        
+        workers = new AbstractNioWorker[workerCount];
+
+        for (int i = 0; i < workers.length; i++) {
+            workers[i] = createWorker(workerExecutor, allowShutDownOnIdle);
+        }
+        this.workerExecutor = workerExecutor;
+
+    }
+
+    /**
+     * Create a new {@link Worker} which uses the given {@link Executor} to service IO
+     * 
+     * 
+     * @param executor the {@link Executor} to use
+     * @param allowShutdownOnIdle allow the {@link Worker} to shutdown when there is not {@link Channel} is registered with it
+     * @return worker the new {@link Worker} 
+     */
+    protected abstract E createWorker(Executor executor, boolean allowShutdownOnIdle);
+
+    @SuppressWarnings("unchecked")
+    public E nextWorker() {
+        return (E) workers[Math.abs(workerIndex.getAndIncrement() % workers.length)];
+    }
+
+    @Override
+    public void releaseExternalResources() {
+        ExecutorUtil.terminate(workerExecutor);
+    }
+
+}

transport/src/main/java/io/netty/channel/socket/nio/NioClientSocketChannelFactory.java

@@ -25,6 +25,7 @@ import io.netty.channel.ChannelPipeline;
 import io.netty.channel.group.ChannelGroup;
 import io.netty.channel.socket.ClientSocketChannelFactory;
 import io.netty.channel.socket.SocketChannel;
+import io.netty.util.ExternalResourceReleasable;
 import io.netty.util.internal.ExecutorUtil;
 
 /**
@@ -82,7 +83,7 @@ public class NioClientSocketChannelFactory implements ClientSocketChannelFactory
     private static final int DEFAULT_BOSS_COUNT = 1;
 
     private final Executor bossExecutor;
-    private final Executor workerExecutor;
+    private final WorkerPool<NioWorker> workerPool;
     private final NioClientSocketPipelineSink sink;
 
     /**
@@ -136,27 +137,30 @@ public class NioClientSocketChannelFactory implements ClientSocketChannelFactory
             Executor bossExecutor, Executor workerExecutor,
             int bossCount, int workerCount) {
 
+        this(bossExecutor, bossCount, new NioWorkerPool(workerExecutor, workerCount, true));
+    }
+
+    public NioClientSocketChannelFactory(
+            Executor bossExecutor, int bossCount, 
+            WorkerPool<NioWorker> workerPool) {
+
         if (bossExecutor == null) {
             throw new NullPointerException("bossExecutor");
         }
-        if (workerExecutor == null) {
+        if (workerPool == null) {
-            throw new NullPointerException("workerExecutor");
+            throw new NullPointerException("workerPool");
         }
         if (bossCount <= 0) {
             throw new IllegalArgumentException(
                     "bossCount (" + bossCount + ") " +
                     "must be a positive integer.");
         }
-        if (workerCount <= 0) {
+        
-            throw new IllegalArgumentException(
-                    "workerCount (" + workerCount + ") " +
-                    "must be a positive integer.");
-        }
 
         this.bossExecutor = bossExecutor;
-        this.workerExecutor = workerExecutor;
+        this.workerPool = workerPool;
         sink = new NioClientSocketPipelineSink(
-                bossExecutor, workerExecutor, bossCount, workerCount);
+                bossExecutor, bossCount, workerPool);
     }
     
 
@@ -167,6 +171,9 @@ public class NioClientSocketChannelFactory implements ClientSocketChannelFactory
 
     @Override
     public void releaseExternalResources() {
-        ExecutorUtil.terminate(bossExecutor, workerExecutor);
+        ExecutorUtil.terminate(bossExecutor);
+        if (workerPool instanceof ExternalResourceReleasable) {
+            ((ExternalResourceReleasable) workerPool).releaseExternalResources();
+        }
     }
 }

transport/src/main/java/io/netty/channel/socket/nio/NioClientSocketPipelineSink.java

@@ -52,14 +52,12 @@ class NioClientSocketPipelineSink extends AbstractNioChannelSink {
     final Executor bossExecutor;
 
     private final Boss[] bosses;    
-    private final NioWorker[] workers;
-    
     private final AtomicInteger bossIndex = new AtomicInteger();
-    private final AtomicInteger workerIndex = new AtomicInteger();
+
+    private final WorkerPool<NioWorker> workerPool;
 
     NioClientSocketPipelineSink(
-            Executor bossExecutor, Executor workerExecutor,
+            Executor bossExecutor, int bossCount, WorkerPool<NioWorker> workerPool) {
-            int bossCount, int workerCount) {
 
         this.bossExecutor = bossExecutor;
 
@@ -68,10 +66,7 @@ class NioClientSocketPipelineSink extends AbstractNioChannelSink {
             bosses[i] = new Boss();
         }
 
-        workers = new NioWorker[workerCount];
+        this.workerPool = workerPool;
-        for (int i = 0; i < workers.length; i ++) {
-            workers[i] = new NioWorker(workerExecutor);
-        }
     }
 
     @Override
@@ -162,8 +157,7 @@ class NioClientSocketPipelineSink extends AbstractNioChannelSink {
     }
 
     NioWorker nextWorker() {
-        return workers[Math.abs(
+        return workerPool.nextWorker();
-                workerIndex.getAndIncrement() % workers.length)];
     }
     
     Boss nextBoss() {

transport/src/main/java/io/netty/channel/socket/nio/NioDatagramChannelFactory.java

@@ -24,8 +24,9 @@ import io.netty.channel.ChannelPipeline;
 import io.netty.channel.group.ChannelGroup;
 import io.netty.channel.socket.DatagramChannel;
 import io.netty.channel.socket.DatagramChannelFactory;
+import io.netty.channel.socket.Worker;
 import io.netty.channel.socket.oio.OioDatagramChannelFactory;
-import io.netty.util.internal.ExecutorUtil;
+import io.netty.util.ExternalResourceReleasable;
 
 /**
  * A {@link DatagramChannelFactory} that creates a NIO-based connectionless
@@ -75,8 +76,8 @@ import io.netty.util.internal.ExecutorUtil;
  */
 public class NioDatagramChannelFactory implements DatagramChannelFactory {
 
-    private final Executor workerExecutor;
     private final NioDatagramPipelineSink sink;
+    private final WorkerPool<NioDatagramWorker> workerPool;
 
     /**
      * Creates a new instance.  Calling this constructor is same with calling
@@ -101,19 +102,18 @@ public class NioDatagramChannelFactory implements DatagramChannelFactory {
      */
     public NioDatagramChannelFactory(final Executor workerExecutor,
             final int workerCount) {
-        if (workerCount <= 0) {
+        this(new NioDatagramWorkerPool(workerExecutor, workerCount, true));
-            throw new IllegalArgumentException(String
-                    .format("workerCount (%s) must be a positive integer.",
-                            workerCount));
     }
 
-        if (workerExecutor == null) {
+    /**
-            throw new NullPointerException(
+     * Creates a new instance.
-                    "workerExecutor argument must not be null");
+     * 
-        }
+     * @param workerPool
-        this.workerExecutor = workerExecutor;
+     *        the {@link WorkerPool} which will be used to obtain the {@link Worker} that execute the I/O worker threads
-
+     */
-        sink = new NioDatagramPipelineSink(workerExecutor, workerCount);
+    public NioDatagramChannelFactory(WorkerPool<NioDatagramWorker> workerPool) {
+        this.workerPool = workerPool;
+        sink = new NioDatagramPipelineSink(workerPool);
     }
     
     @Override
@@ -123,6 +123,9 @@ public class NioDatagramChannelFactory implements DatagramChannelFactory {
 
     @Override
     public void releaseExternalResources() {
-        ExecutorUtil.terminate(workerExecutor);
+        if (workerPool instanceof ExternalResourceReleasable) {
+            ((ExternalResourceReleasable) workerPool).releaseExternalResources();
+        }
+        
     }
 }

transport/src/main/java/io/netty/channel/socket/nio/NioDatagramPipelineSink.java

@@ -20,7 +20,6 @@ import static io.netty.channel.Channels.*;
 import java.net.InetSocketAddress;
 import java.net.SocketAddress;
 import java.util.concurrent.Executor;
-import java.util.concurrent.atomic.AtomicInteger;
 
 import io.netty.channel.ChannelEvent;
 import io.netty.channel.ChannelFuture;
@@ -36,8 +35,7 @@ import io.netty.channel.MessageEvent;
  */
 class NioDatagramPipelineSink extends AbstractNioChannelSink {
 
-    private final NioDatagramWorker[] workers;
+    private final WorkerPool<NioDatagramWorker> workerPool;
-    private final AtomicInteger workerIndex = new AtomicInteger();
 
     /**
      * Creates a new {@link NioDatagramPipelineSink} with a the number of {@link NioDatagramWorker}s specified in workerCount.
@@ -49,11 +47,8 @@ class NioDatagramPipelineSink extends AbstractNioChannelSink {
      * @param workerCount
      *        the number of {@link NioDatagramWorker}s for this sink
      */
-    NioDatagramPipelineSink(final Executor workerExecutor, final int workerCount) {
+    NioDatagramPipelineSink(final WorkerPool<NioDatagramWorker> workerPool) {
-        workers = new NioDatagramWorker[workerCount];
+        this.workerPool = workerPool;
-        for (int i = 0; i < workers.length; i ++) {
-            workers[i] = new NioDatagramWorker(workerExecutor);
-        }
     }
 
     /**
@@ -191,7 +186,7 @@ class NioDatagramPipelineSink extends AbstractNioChannelSink {
     }
 
     NioDatagramWorker nextWorker() {
-        return workers[Math.abs(workerIndex.getAndIncrement() % workers.length)];
+        return workerPool.nextWorker();
     }
 
 }

transport/src/main/java/io/netty/channel/socket/nio/NioDatagramWorker.java

@@ -38,7 +38,7 @@ import java.util.concurrent.Executor;
  * A class responsible for registering channels with {@link Selector}.
  * It also implements the {@link Selector} loop.
  */
-class NioDatagramWorker extends AbstractNioWorker {
+public class NioDatagramWorker extends AbstractNioWorker {
 
     /**
      * Sole constructor.
@@ -50,6 +50,9 @@ class NioDatagramWorker extends AbstractNioWorker {
         super(executor);
     }
 
+    NioDatagramWorker(final Executor executor, boolean allowShutdownOnIdle) {
+        super(executor, allowShutdownOnIdle);
+    }
     @Override
     protected boolean read(final SelectionKey key) {
         final NioDatagramChannel channel = (NioDatagramChannel) key.attachment();

transport/src/main/java/io/netty/channel/socket/nio/NioDatagramWorkerPool.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2011 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.channel.socket.nio;
+
+import java.util.concurrent.Executor;
+
+
+/**
+ * Default implementation which hands of {@link NioDatagramWorker}'s
+ * 
+ *
+ */
+public class NioDatagramWorkerPool extends AbstractWorkerPool<NioDatagramWorker>{
+
+    protected NioDatagramWorkerPool(Executor executor, int workerCount, boolean allowShutdownOnIdle) {
+        super(executor, workerCount, allowShutdownOnIdle);
+    }
+
+    @Override
+    protected NioDatagramWorker createWorker(Executor executor, boolean allowShutdownOnIdle) {
+        return new NioDatagramWorker(executor, allowShutdownOnIdle);
+    }
+
+}

transport/src/main/java/io/netty/channel/socket/nio/NioServerSocketChannelFactory.java

@@ -26,6 +26,8 @@ import io.netty.channel.ChannelSink;
 import io.netty.channel.group.ChannelGroup;
 import io.netty.channel.socket.ServerSocketChannel;
 import io.netty.channel.socket.ServerSocketChannelFactory;
+import io.netty.channel.socket.Worker;
+import io.netty.util.ExternalResourceReleasable;
 import io.netty.util.internal.ExecutorUtil;
 
 /**
@@ -84,7 +86,7 @@ import io.netty.util.internal.ExecutorUtil;
 public class NioServerSocketChannelFactory implements ServerSocketChannelFactory {
 
     final Executor bossExecutor;
-    private final Executor workerExecutor;
+    private final WorkerPool<NioWorker> workerPool;
     private final ChannelSink sink;
 
     /**
@@ -116,22 +118,32 @@ public class NioServerSocketChannelFactory implements ServerSocketChannelFactory
     public NioServerSocketChannelFactory(
             Executor bossExecutor, Executor workerExecutor,
             int workerCount) {
+        this(bossExecutor, new NioWorkerPool(workerExecutor, workerCount, true));
+    }
+
+    /**
+     * Creates a new instance.
+     *
+     * @param bossExecutor
+     *        the {@link Executor} which will execute the boss threads
+     * @param workerPool
+     *        the {@link WorkerPool} which will be used to obtain the {@link Worker} that execute the I/O worker threads
+     */
+    public NioServerSocketChannelFactory(
+            Executor bossExecutor, WorkerPool<NioWorker> workerPool) {
         if (bossExecutor == null) {
             throw new NullPointerException("bossExecutor");
         }
-        if (workerExecutor == null) {
+        if (workerPool == null) {
-            throw new NullPointerException("workerExecutor");
+            throw new NullPointerException("workerPool");
-        }
-        if (workerCount <= 0) {
-            throw new IllegalArgumentException(
-                    "workerCount (" + workerCount + ") " +
-                    "must be a positive integer.");
         }
+       
         this.bossExecutor = bossExecutor;
-        this.workerExecutor = workerExecutor;
+        this.workerPool = workerPool;
-        sink = new NioServerSocketPipelineSink(workerExecutor, workerCount);
+        sink = new NioServerSocketPipelineSink(workerPool);
     }
 
+    
     @Override
     public ServerSocketChannel newChannel(ChannelPipeline pipeline) {
         return NioServerSocketChannel.create(this, pipeline, sink);
@@ -139,6 +151,10 @@ public class NioServerSocketChannelFactory implements ServerSocketChannelFactory
 
     @Override
     public void releaseExternalResources() {
-        ExecutorUtil.terminate(bossExecutor, workerExecutor);
+        ExecutorUtil.terminate(bossExecutor);
+        if (workerPool instanceof ExternalResourceReleasable) {
+            ((ExternalResourceReleasable) workerPool).releaseExternalResources();
+        }
+        
     }
 }

transport/src/main/java/io/netty/channel/socket/nio/NioServerSocketPipelineSink.java

@@ -27,7 +27,6 @@ import java.nio.channels.SelectionKey;
 import java.nio.channels.Selector;
 import java.nio.channels.SocketChannel;
 import java.util.concurrent.Executor;
-import java.util.concurrent.atomic.AtomicInteger;
 
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelEvent;
@@ -45,14 +44,10 @@ class NioServerSocketPipelineSink extends AbstractNioChannelSink {
     static final InternalLogger logger =
         InternalLoggerFactory.getInstance(NioServerSocketPipelineSink.class);
 
-    private final NioWorker[] workers;
+    private final WorkerPool<NioWorker> workerPool;
-    private final AtomicInteger workerIndex = new AtomicInteger();
 
-    NioServerSocketPipelineSink(Executor workerExecutor, int workerCount) {
+    NioServerSocketPipelineSink(WorkerPool<NioWorker> workerPool) {
-        workers = new NioWorker[workerCount];
+        this.workerPool = workerPool;
-        for (int i = 0; i < workers.length; i ++) {
-            workers[i] = new NioWorker(workerExecutor);
-        }
     }
 
     @Override
@@ -189,8 +184,7 @@ class NioServerSocketPipelineSink extends AbstractNioChannelSink {
     }
 
     NioWorker nextWorker() {
-        return workers[Math.abs(
+        return workerPool.nextWorker();
-                workerIndex.getAndIncrement() % workers.length)];
     }
 
     private final class Boss implements Runnable {

transport/src/main/java/io/netty/channel/socket/nio/NioWorker.java

@@ -35,7 +35,7 @@ import java.nio.channels.Selector;
 import java.nio.channels.SocketChannel;
 import java.util.concurrent.Executor;
 
-class NioWorker extends AbstractNioWorker {
+public class NioWorker extends AbstractNioWorker {
 
     private final SocketReceiveBufferPool recvBufferPool = new SocketReceiveBufferPool();
 
@@ -43,6 +43,11 @@ class NioWorker extends AbstractNioWorker {
         super(executor);
     }
     
+    NioWorker(Executor executor, boolean allowShutdownOnIdle) {
+        super(executor, allowShutdownOnIdle);
+    }
+
+
     @Override
     protected boolean read(SelectionKey k) {
         final SocketChannel ch = (SocketChannel) k.channel();

transport/src/main/java/io/netty/channel/socket/nio/NioWorkerPool.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2011 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.channel.socket.nio;
+
+import java.util.concurrent.Executor;
+
+
+/**
+ * Default implementation which hands of {@link NioWorker}'s
+ * 
+ *
+ */
+public class NioWorkerPool extends AbstractWorkerPool<NioWorker>{
+
+    NioWorkerPool(Executor executor, int workerCount, boolean allowShutdownOnIdle) {
+        super(executor, workerCount, allowShutdownOnIdle);
+    }
+
+    @Override
+    protected NioWorker createWorker(Executor executor, boolean allowShutdownOnIdle) {
+        return new NioWorker(executor, allowShutdownOnIdle);
+    }
+
+}

transport/src/main/java/io/netty/channel/socket/nio/ShareableWorkerPool.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2011 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.channel.socket.nio;
+
+import io.netty.channel.socket.Worker;
+import io.netty.util.ExternalResourceReleasable;
+
+/**
+ * This implementation of a {@link WorkerPool} should be used if you plan to share a {@link WorkerPool} between different Factories. You will need to call {@link #destroy()} by your own once
+ * you want to release any resources of it.
+ * 
+ * 
+ */
+public final class ShareableWorkerPool<E extends Worker> implements WorkerPool<E>{
+
+    private final WorkerPool<E> wrapped;
+
+    public ShareableWorkerPool(WorkerPool<E> wrapped) {
+        this.wrapped = wrapped;
+    }
+    
+    @Override
+    public E nextWorker() {
+        return wrapped.nextWorker();
+    }
+
+    /**
+     * Destroy the {@link ShareableWorkerPool} and release all resources. After this is called its not usable anymore
+     */
+    public void destroy() {
+        if (wrapped instanceof ExternalResourceReleasable) {
+            ((ExternalResourceReleasable) wrapped).releaseExternalResources();
+        }
+    }
+}

transport/src/main/java/io/netty/channel/socket/nio/WorkerPool.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2011 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.channel.socket.nio;
+
+import io.netty.channel.socket.Worker;
+
+/**
+ * The {@link WorkerPool} is responsible to hand of {@link Worker}'s on demand
+ *
+ */
+public interface WorkerPool<E extends Worker> {
+
+    /**
+     * Return the next {@link Worker} to use
+     * 
+     * @return worker
+     */
+    E nextWorker();
+    
+
+}