QueueFactory cleanup

- Really attempt to create a queue to determine LTQ can be initialized
  in runtime, and cache the result
- Remove unnecessary Class<T> parameter in createQueue()
- Remove unused createQueue(Collection)

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

@@ -46,7 +46,7 @@ import java.util.concurrent.atomic.AtomicLong;
 public class HttpClientCodec extends CombinedChannelHandler {
 
     /** A queue that is used for correlating a request and a response. */
-    final Queue<HttpMethod> queue = QueueFactory.createQueue(HttpMethod.class);
+    final Queue<HttpMethod> queue = QueueFactory.createQueue();
 
     /** If true, decoding stops (i.e. pass-through) */
     volatile boolean done;

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

@@ -49,7 +49,7 @@ import java.util.Queue;
  */
 public abstract class HttpContentEncoder extends MessageToMessageCodec<HttpMessage, HttpMessage, Object, Object> {
 
-    private final Queue<String> acceptEncodingQueue = QueueFactory.createQueue(String.class);
+    private final Queue<String> acceptEncodingQueue = QueueFactory.createQueue();
     private volatile EncoderEmbedder<ChannelBuffer> encoder;
 
     /**

common/src/main/java/io/netty/util/internal/QueueFactory.java

@@ -15,7 +15,9 @@
  */
 package io.netty.util.internal;
 
-import java.util.Collection;
+import io.netty.logging.InternalLogger;
+import io.netty.logging.InternalLoggerFactory;
+
 import java.util.concurrent.BlockingQueue;
 
 /**
@@ -23,40 +25,45 @@ import java.util.concurrent.BlockingQueue;
  * instance for the running JVM.
  */
 public final class QueueFactory {
-    
-    private static final boolean useUnsafe = DetectionUtil.hasUnsafe();
-    
-    private QueueFactory() {
-        // only use static methods!
+
+    private static final InternalLogger logger =
+            InternalLoggerFactory.getInstance(QueueFactory.class);
+
+    private static final boolean USE_LTQ;
+
+    static {
+        boolean useLTQ = false;
+        try {
+            if (DetectionUtil.hasUnsafe()) {
+                new LinkedTransferQueue<Object>();
+                useLTQ = true;
+            }
+            logger.debug(
+                    "No access to the Unsafe - using " +
+                    LegacyLinkedTransferQueue.class.getSimpleName() + " instead.");
+        } catch (Throwable t) {
+            logger.debug(
+                    "Failed to initialize a " + LinkedTransferQueue.class.getSimpleName() + " - " +
+                    "using " + LegacyLinkedTransferQueue.class.getSimpleName() + " instead.", t);
+        }
+
+        USE_LTQ = useLTQ;
     }
-    
-    
+
     /**
-     * Create a new unbound {@link BlockingQueue} 
-     * 
-     * @param itemClass  the {@link Class} type which will be used as {@link BlockingQueue} items
+     * Create a new unbound {@link BlockingQueue}
+     *
      * @return queue     the {@link BlockingQueue} implementation
      */
-    public static <T> BlockingQueue<T> createQueue(Class<T> itemClass) {
-        if (useUnsafe) {
+    public static <T> BlockingQueue<T> createQueue() {
+        if (USE_LTQ) {
             return new LinkedTransferQueue<T>();
         } else {
             return new LegacyLinkedTransferQueue<T>();
         }
     }
-    
-    /**
-     * Create a new unbound {@link BlockingQueue} 
-     * 
-     * @param collection  the collection which should get copied to the newly created {@link BlockingQueue}
-     * @param itemClass   the {@link Class} type which will be used as {@link BlockingQueue} items
-     * @return queue      the {@link BlockingQueue} implementation
-     */
-    public static <T> BlockingQueue<T> createQueue(Collection<? extends T> collection, Class<T> itemClass) {
-        if (useUnsafe) {
-            return new LinkedTransferQueue<T>(collection);
-        } else {
-            return new LegacyLinkedTransferQueue<T>(collection);
-        }
+
+    private QueueFactory() {
+        // only use static methods!
     }
 }

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

@@ -50,7 +50,7 @@ public abstract class SingleThreadEventLoop extends AbstractExecutorService impl
     }
 
     // Fields for event loop
-    private final BlockingQueue<Runnable> taskQueue = QueueFactory.createQueue(Runnable.class);
+    private final BlockingQueue<Runnable> taskQueue = QueueFactory.createQueue();
     private final Thread thread;
     private final Object stateLock = new Object();
     private final Semaphore threadLock = new Semaphore(0);

transport/src/main/java/io/netty/channel/socket/oio/OioEventLoop.java

@@ -29,8 +29,7 @@ public class OioEventLoop implements EventLoop {
     final ThreadFactory threadFactory;
     final Set<OioChildEventLoop> activeChildren = Collections.newSetFromMap(
             new ConcurrentHashMap<OioChildEventLoop, Boolean>());
-    final Queue<OioChildEventLoop> idleChildren =
-            QueueFactory.createQueue(OioChildEventLoop.class);
+    final Queue<OioChildEventLoop> idleChildren = QueueFactory.createQueue();
     private final ChannelException tooManyChannels;
 
     public OioEventLoop() {