Fixed NETTY-336 Fine-grained control over thread renaming

Added NamedThreadFactory so that a user can customize I/O thread names easily

src/main/java/org/jboss/netty/util/NamedThreadFactory.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2011 Red Hat, Inc.
+ *
+ * Red Hat 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 org.jboss.netty.util;
+
+import org.jboss.netty.channel.ChannelFactory;
+import org.jboss.netty.channel.socket.nio.NioServerSocketChannelFactory;
+
+import java.util.concurrent.Executors;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * A {@link ThreadFactory} that creates a new {@link Thread} with the specified name and thread ID.
+ * This class is useful when you want to customize the name of the I/O threads:
+ * <pre>
+ * {@link ChannelFactory} f = new {@link NioServerSocketChannelFactory}(
+ *         {@link Executors}.{@link Executors#newCachedThreadPool(java.util.concurrent.ThreadFactory) newCachedThreadPool}(new {@link NamedThreadFactory}("myServerBoss-")),
+ *         {@link Executors}.{@link Executors#newCachedThreadPool(java.util.concurrent.ThreadFactory) newCachedThreadPool}(new {@link NamedThreadFactory}("myServerWorker-")));
+ * </pre>
+ *
+ * @author <a href="http://jboss.org/netty/">The Netty Project</a>
+ * @author <a href="http://gleamynode.net/">Trustin Lee</a>
+ */
+public class NamedThreadFactory implements ThreadFactory {
+
+    private final ThreadGroup group;
+    private final AtomicInteger threadId = new AtomicInteger(1);
+    private final String prefix;
+
+    /**
+     * Creates a new factory that creates a {@link Thread} with the specified name prefix.
+     */
+    public NamedThreadFactory(String prefix) {
+        if (prefix == null) {
+            throw new NullPointerException("prefix");
+        }
+        this.prefix = prefix;
+
+        SecurityManager s = System.getSecurityManager();
+        if (s != null) {
+            group = s.getThreadGroup();
+        } else {
+            group = Thread.currentThread().getThreadGroup();
+        }
+    }
+
+    /**
+     * {@inheritDoc} The name of the thread is {@code "prefix + threadId"}. (e.g. {@code "ioThread-1"} if
+     * {@code prefix} is {@code "ioThread-"}.
+     */
+    public Thread newThread(Runnable r) {
+        Thread t = new Thread(group, r, prefix + threadId.getAndIncrement());
+        if (t.isDaemon()) {
+            t.setDaemon(false);
+        }
+
+        if (t.getPriority() != Thread.NORM_PRIORITY) {
+            t.setPriority(Thread.NORM_PRIORITY);
+        }
+        return t;
+    }
+}