Remove the constructors that uses ImmediateEventExecutor from DefaultChannelGroup

.. which is incorrect in my opinion.

+ minor cleanup

common/src/main/java/io/netty/util/concurrent/ImmediateEventExecutor.java

@@ -23,7 +23,7 @@ import java.util.concurrent.TimeUnit;
 public final class ImmediateEventExecutor extends AbstractEventExecutor {
     public static final ImmediateEventExecutor INSTANCE = new ImmediateEventExecutor();
 
-    private  ImmediateEventExecutor() {
+    private ImmediateEventExecutor() {
         // use static instance
     }
 

example/src/main/java/io/netty/example/securechat/SecureChatServerHandler.java

@@ -24,6 +24,7 @@ import io.netty.channel.group.DefaultChannelGroup;
 import io.netty.handler.ssl.SslHandler;
 import io.netty.util.concurrent.Future;
 import io.netty.util.concurrent.GenericFutureListener;
+import io.netty.util.concurrent.GlobalEventExecutor;
 
 import java.net.InetAddress;
 import java.util.logging.Level;
@@ -37,7 +38,7 @@ public class SecureChatServerHandler extends ChannelInboundHandlerAdapter {
     private static final Logger logger = Logger.getLogger(
             SecureChatServerHandler.class.getName());
 
-    static final ChannelGroup channels = new DefaultChannelGroup();
+    static final ChannelGroup channels = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);
 
     @Override
     public void channelActive(final ChannelHandlerContext ctx) throws Exception {

testsuite/src/test/java/io/netty/testsuite/transport/udt/UDTClientServerConnectionTest.java

@@ -33,11 +33,13 @@ import io.netty.handler.codec.Delimiters;
 import io.netty.handler.codec.string.StringDecoder;
 import io.netty.handler.codec.string.StringEncoder;
 import io.netty.util.CharsetUtil;
+import io.netty.util.concurrent.DefaultThreadFactory;
+import io.netty.util.concurrent.GlobalEventExecutor;
 import org.junit.Test;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.ThreadFactory;
 
 import static org.junit.Assert.*;
 
@@ -65,7 +67,7 @@ public class UDTClientServerConnectionTest {
         @Override
         public void run() {
             final Bootstrap boot = new Bootstrap();
-            final ThreadFactory clientFactory = new ThreadFactory("client");
+            final ThreadFactory clientFactory = new DefaultThreadFactory("client");
             final NioEventLoopGroup connectGroup = new NioEventLoopGroup(1,
                     clientFactory, NioUdtProvider.BYTE_PROVIDER);
             try {
@@ -143,9 +145,6 @@ public class UDTClientServerConnectionTest {
 
         volatile boolean isActive;
 
-        ClientHandler() {
-        }
-
         @Override
         public void channelActive(final ChannelHandlerContext ctx)
                 throws Exception {
@@ -182,7 +181,7 @@ public class UDTClientServerConnectionTest {
 
         static final Logger log = LoggerFactory.getLogger(Server.class);
 
-        final ChannelGroup group = new DefaultChannelGroup("server group");
+        final ChannelGroup group = new DefaultChannelGroup("server group", GlobalEventExecutor.INSTANCE);
 
         final String host;
         final int port;
@@ -199,8 +198,8 @@ public class UDTClientServerConnectionTest {
         @Override
         public void run() {
             final ServerBootstrap boot = new ServerBootstrap();
-            final ThreadFactory acceptFactory = new ThreadFactory("accept");
+            final ThreadFactory acceptFactory = new DefaultThreadFactory("accept");
-            final ThreadFactory serverFactory = new ThreadFactory("server");
+            final ThreadFactory serverFactory = new DefaultThreadFactory("server");
             final NioEventLoopGroup acceptGroup = new NioEventLoopGroup(1,
                     acceptFactory, NioUdtProvider.BYTE_PROVIDER);
             final NioEventLoopGroup connectGroup = new NioEventLoopGroup(1,
@@ -258,7 +257,7 @@ public class UDTClientServerConnectionTest {
                         }
                     }
                 } else {
-                    if (group.size() == 0) {
+                    if (group.isEmpty()) {
                         return;
                     }
                 }
@@ -330,30 +329,13 @@ public class UDTClientServerConnectionTest {
             msgs.releaseAllAndRecycle();
         }
     }
-
-    static class ThreadFactory implements java.util.concurrent.ThreadFactory {
-
-        static final AtomicInteger counter = new AtomicInteger();
-
-        final String name;
-
-        ThreadFactory(final String name) {
-            this.name = name;
-        }
-
-        @Override
-        public Thread newThread(final Runnable runnable) {
-            return new Thread(runnable, name + '-' + counter.getAndIncrement());
-        }
-    }
-
     static final Logger log = LoggerFactory
             .getLogger(UDTClientServerConnectionTest.class);
 
     /**
      * Maximum wait time is 5 seconds.
      * <p>
-     * wait-time = {@link #WAIT_COUNT} * {@value #WAIT_SLEEP}
+     * wait-time = {@code WAIT_COUNT} * {@value #WAIT_SLEEP}
      */
     static final int WAIT_COUNT = 50;
     static final int WAIT_SLEEP = 100;

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

@@ -22,7 +22,6 @@ import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.MessageList;
 import io.netty.channel.ServerChannel;
 import io.netty.util.concurrent.EventExecutor;
-import io.netty.util.concurrent.ImmediateEventExecutor;
 import io.netty.util.internal.PlatformDependent;
 
 import java.util.AbstractSet;
@@ -51,13 +50,6 @@ public class DefaultChannelGroup extends AbstractSet<Channel> implements Channel
         }
     };
 
-    /**
-     * Creates a new group with a generated name.
-     */
-    public DefaultChannelGroup() {
-        this("group-0x" + Integer.toHexString(nextId.incrementAndGet()));
-    }
-
     /**
      * Creates a new group with a generated name amd the provided {@link EventExecutor} to notify the
      * {@link ChannelGroupFuture}s.
@@ -66,15 +58,6 @@ public class DefaultChannelGroup extends AbstractSet<Channel> implements Channel
         this("group-0x" + Integer.toHexString(nextId.incrementAndGet()), executor);
     }
 
-    /**
-     * Creates a new group with the specified {@code name}.  Please note that
-     * different groups can have the same name, which means no duplicate check
-     * is done against group names.
-     */
-    public DefaultChannelGroup(String name) {
-        this(name, ImmediateEventExecutor.INSTANCE);
-    }
-
     /**
      * Creates a new group with the specified {@code name} and {@link EventExecutor} to notify the
      * {@link ChannelGroupFuture}s.  Please note that different groups can have the same name, which means no

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

@@ -236,7 +236,7 @@ final class DefaultChannelGroupFuture extends DefaultPromise<Void> implements Ch
     @Override
     protected void checkDeadLock() {
         EventExecutor e = executor();
-        if (e != null && !(e instanceof ImmediateEventExecutor) && e.inEventLoop()) {
+        if (e != null && e != ImmediateEventExecutor.INSTANCE && e.inEventLoop()) {
             throw new BlockingOperationException();
         }
     }

transport/src/test/java/io/netty/channel/group/DefaultChannnelGroupTest.java

@@ -22,6 +22,7 @@ import io.netty.channel.ChannelInboundHandlerAdapter;
 import io.netty.channel.EventLoopGroup;
 import io.netty.channel.nio.NioEventLoopGroup;
 import io.netty.channel.socket.nio.NioServerSocketChannel;
+import io.netty.util.concurrent.GlobalEventExecutor;
 import org.junit.Test;
 
 public class DefaultChannnelGroupTest {
@@ -32,7 +33,7 @@ public class DefaultChannnelGroupTest {
         EventLoopGroup bossGroup = new NioEventLoopGroup();
         EventLoopGroup workerGroup = new NioEventLoopGroup();
 
-        final ChannelGroup allChannels = new DefaultChannelGroup();
+        final ChannelGroup allChannels = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);
 
         ServerBootstrap b = new ServerBootstrap();
         b.group(bossGroup, workerGroup);

transport/src/test/java/io/netty/channel/nio/NioDatagramChannelTest.java

@@ -23,6 +23,7 @@ import io.netty.channel.MessageList;
 import io.netty.channel.group.DefaultChannelGroup;
 import io.netty.channel.socket.DatagramChannel;
 import io.netty.channel.socket.nio.NioDatagramChannel;
+import io.netty.util.concurrent.GlobalEventExecutor;
 import org.junit.Assert;
 import org.junit.Test;
 
@@ -36,7 +37,7 @@ public class NioDatagramChannelTest {
      */
     @Test
     public void testBindMultiple() {
-        DefaultChannelGroup channelGroup = new DefaultChannelGroup();
+        DefaultChannelGroup channelGroup = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);
         NioEventLoopGroup group = new NioEventLoopGroup();
         try {
             for (int i = 0; i < 100; i++) {