Replace and merge DetectionUtil and DirectByteBufUtil into PlatformDependent and PlatformDependent0

PlatformDependent delegates the operations requires sun.misc.* to PlatformDependent0 to avoid runtime errors due to missing sun.misc.* classes.

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

@@ -15,7 +15,7 @@
  */
 package io.netty.buffer;
 
-import io.netty.util.internal.DetectionUtil;
+import io.netty.util.internal.PlatformDependent;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -699,7 +699,7 @@ public class DefaultCompositeByteBuf extends AbstractByteBuf implements Composit
     @Override
     public int getBytes(int index, GatheringByteChannel out, int length)
             throws IOException {
-        if (DetectionUtil.javaVersion() < 7) {
+        if (PlatformDependent.javaVersion() < 7) {
             // XXX Gathering write is not supported because of a known issue.
             //     See http://bugs.sun.com/view_bug.do?bug_id=6210541
             return out.write(copiedNioBuffer(index, length));

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

@@ -16,6 +16,7 @@
 
 package io.netty.buffer;
 
+import io.netty.util.internal.PlatformDependent;
 import io.netty.util.internal.StringUtil;
 
 import java.nio.ByteBuffer;
@@ -370,7 +371,7 @@ abstract class PoolArena<T> {
 
         @Override
         protected void destroyChunk(PoolChunk<ByteBuffer> chunk) {
-            UnpooledDirectByteBuf.freeDirect(chunk.memory);
+            PlatformDependent.freeDirectBuffer(chunk.memory);
         }
 
         @Override

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

@@ -15,7 +15,7 @@
  */
 package io.netty.buffer;
 
-import io.netty.util.internal.DetectionUtil;
+import io.netty.util.internal.PlatformDependent;
 
 /**
  * Simplistic {@link ByteBufAllocator} implementation that does not pool anything.
@@ -41,7 +41,7 @@ public final class UnpooledByteBufAllocator extends AbstractByteBufAllocator {
 
     @Override
     public ByteBuf ioBuffer() {
-        if (DetectionUtil.canFreeDirectBuffer()) {
+        if (PlatformDependent.canFreeDirectBuffer()) {
             return directBuffer(0);
         }
 

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

@@ -15,8 +15,7 @@
  */
 package io.netty.buffer;
 
-import io.netty.util.internal.DetectionUtil;
+import io.netty.util.internal.PlatformDependent;
-import io.netty.util.internal.DirectByteBufUtil;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -109,7 +108,7 @@ final class UnpooledDirectByteBuf extends AbstractByteBuf {
                 doNotFree = false;
             } else {
                 if (suspendedDeallocations == null) {
-                    freeDirect(oldBuffer);
+                    PlatformDependent.freeDirectBuffer(oldBuffer);
                 } else {
                     suspendedDeallocations.add(oldBuffer);
                 }
@@ -471,7 +470,7 @@ final class UnpooledDirectByteBuf extends AbstractByteBuf {
         }
 
         resumeIntermediaryDeallocations();
-        freeDirect(buffer);
+        PlatformDependent.freeDirectBuffer(buffer);
     }
 
     @Override
@@ -492,7 +491,7 @@ final class UnpooledDirectByteBuf extends AbstractByteBuf {
         this.suspendedDeallocations = null;
 
         for (ByteBuffer buf: suspendedDeallocations) {
-            freeDirect(buf);
+            PlatformDependent.freeDirectBuffer(buf);
         }
         return this;
     }
@@ -501,10 +500,4 @@ final class UnpooledDirectByteBuf extends AbstractByteBuf {
     public ByteBuf unwrap() {
         return null;
     }
-
-    static void freeDirect(ByteBuffer buffer) {
-        if (DetectionUtil.canFreeDirectBuffer()) {
-            DirectByteBufUtil.freeDirect(buffer);
-        }
-    }
 }

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

@@ -16,14 +16,14 @@
 package io.netty.handler.codec.spdy;
 
 import io.netty.buffer.ByteBuf;
-import io.netty.util.internal.DetectionUtil;
+import io.netty.util.internal.PlatformDependent;
 
 abstract class SpdyHeaderBlockCompressor {
 
     static SpdyHeaderBlockCompressor newInstance(
             int version, int compressionLevel, int windowBits, int memLevel) {
 
-        if (DetectionUtil.javaVersion() >= 7) {
+        if (PlatformDependent.javaVersion() >= 7) {
             return new SpdyHeaderBlockZlibCompressor(
                     version, compressionLevel);
         } else {

codec/src/main/java/io/netty/handler/codec/compression/ZlibCodecFactory.java

@@ -15,7 +15,7 @@
  */
 package io.netty.handler.codec.compression;
 
-import io.netty.util.internal.DetectionUtil;
+import io.netty.util.internal.PlatformDependent;
 
 /**
  * Creates a new {@link ZlibEncoder} and a new {@link ZlibDecoder}.
@@ -23,7 +23,7 @@ import io.netty.util.internal.DetectionUtil;
 public final class ZlibCodecFactory {
 
     public static ZlibEncoder newZlibEncoder(int compressionLevel) {
-        if (DetectionUtil.javaVersion() < 7) {
+        if (PlatformDependent.javaVersion() < 7) {
             return new JZlibEncoder(compressionLevel);
         } else {
             return new JdkZlibEncoder(compressionLevel);
@@ -31,7 +31,7 @@ public final class ZlibCodecFactory {
     }
 
     public static ZlibEncoder newZlibEncoder(ZlibWrapper wrapper) {
-        if (DetectionUtil.javaVersion() < 7) {
+        if (PlatformDependent.javaVersion() < 7) {
             return new JZlibEncoder(wrapper);
         } else {
             return new JdkZlibEncoder(wrapper);
@@ -39,7 +39,7 @@ public final class ZlibCodecFactory {
     }
 
     public static ZlibEncoder newZlibEncoder(ZlibWrapper wrapper, int compressionLevel) {
-        if (DetectionUtil.javaVersion() < 7) {
+        if (PlatformDependent.javaVersion() < 7) {
             return new JZlibEncoder(wrapper, compressionLevel);
         } else {
             return new JdkZlibEncoder(wrapper, compressionLevel);
@@ -47,7 +47,7 @@ public final class ZlibCodecFactory {
     }
 
     public static ZlibEncoder newZlibEncoder(ZlibWrapper wrapper, int compressionLevel, int windowBits, int memLevel) {
-        if (DetectionUtil.javaVersion() < 7) {
+        if (PlatformDependent.javaVersion() < 7) {
             return new JZlibEncoder(wrapper, compressionLevel, windowBits, memLevel);
         } else {
             return new JdkZlibEncoder(wrapper, compressionLevel);
@@ -55,7 +55,7 @@ public final class ZlibCodecFactory {
     }
 
     public static ZlibEncoder newZlibEncoder(byte[] dictionary) {
-        if (DetectionUtil.javaVersion() < 7) {
+        if (PlatformDependent.javaVersion() < 7) {
             return new JZlibEncoder(dictionary);
         } else {
             return new JdkZlibEncoder(dictionary);
@@ -63,7 +63,7 @@ public final class ZlibCodecFactory {
     }
 
     public static ZlibEncoder newZlibEncoder(int compressionLevel, byte[] dictionary) {
-        if (DetectionUtil.javaVersion() < 7) {
+        if (PlatformDependent.javaVersion() < 7) {
             return new JZlibEncoder(compressionLevel, dictionary);
         } else {
             return new JdkZlibEncoder(compressionLevel, dictionary);
@@ -71,7 +71,7 @@ public final class ZlibCodecFactory {
     }
 
     public static ZlibEncoder newZlibEncoder(int compressionLevel, int windowBits, int memLevel, byte[] dictionary) {
-        if (DetectionUtil.javaVersion() < 7) {
+        if (PlatformDependent.javaVersion() < 7) {
             return new JZlibEncoder(compressionLevel, windowBits, memLevel, dictionary);
         } else {
             return new JdkZlibEncoder(compressionLevel, dictionary);

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

@@ -21,7 +21,7 @@ import io.netty.monitor.EventRateMonitor;
 import io.netty.monitor.MonitorName;
 import io.netty.monitor.MonitorRegistry;
 import io.netty.monitor.ValueDistributionMonitor;
-import io.netty.util.internal.DetectionUtil;
+import io.netty.util.internal.PlatformDependent;
 import io.netty.util.internal.SharedResourceMisuseDetector;
 
 import java.util.ArrayList;
@@ -548,7 +548,7 @@ public class HashedWheelTimer implements Timer {
                 // the JVM if it runs on windows.
                 //
                 // See https://github.com/netty/netty/issues/356
-                if (DetectionUtil.isWindows()) {
+                if (PlatformDependent.isWindows()) {
                     sleepTime = sleepTime / 10 * 10;
                 }
 

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

@@ -1,73 +0,0 @@
-/*
- * 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.internal;
-
-import sun.misc.Cleaner;
-
-import java.lang.reflect.Field;
-import java.nio.ByteBuffer;
-
-// This resist in common because otherwise we would produce a cycle dependency between common and buffer.
-public final class DirectByteBufUtil {
-
-    private static final Field CLEANER_FIELD;
-
-    static {
-        ByteBuffer direct = ByteBuffer.allocateDirect(1);
-        Field cleanerField;
-        try {
-            cleanerField = direct.getClass().getDeclaredField("cleaner");
-            cleanerField.setAccessible(true);
-            Cleaner cleaner = (Cleaner) cleanerField.get(direct);
-            cleaner.clean();
-        } catch (Throwable t) {
-            cleanerField = null;
-        }
-        CLEANER_FIELD = cleanerField;
-    }
-
-    /**
-     * Try to clean a direct {@link ByteBuffer}.
-     *
-     * Only try to access this method when {@link DetectionUtil#canFreeDirectBuffer()} returns
-     * {@code true}
-     *
-     */
-    public static void freeDirect(ByteBuffer buffer) {
-        if (!buffer.isDirect()) {
-            return;
-        }
-        if (CLEANER_FIELD == null) {
-            // Doomed to wait for GC.
-            return;
-        }
-
-        Cleaner cleaner;
-        try {
-            cleaner = (Cleaner) CLEANER_FIELD.get(buffer);
-            cleaner.clean();
-        } catch (Throwable t) {
-            // Nothing we can do here.
-        }
-    }
-
-    static boolean canFreeDirect() {
-        return CLEANER_FIELD != null;
-    }
-
-    private DirectByteBufUtil() {
-    }
-}

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

@@ -15,14 +15,12 @@
  */
 package io.netty.util.internal;
 
+import java.lang.reflect.Field;
 import java.net.InetSocketAddress;
 import java.net.ServerSocket;
-import java.security.AccessController;
+import java.nio.ByteBuffer;
-import java.security.PrivilegedActionException;
-import java.security.PrivilegedExceptionAction;
 import java.util.Locale;
 import java.util.concurrent.BlockingQueue;
-import java.util.concurrent.atomic.AtomicInteger;
 import java.util.regex.Pattern;
 
 
@@ -34,22 +32,108 @@ import java.util.regex.Pattern;
  * You can disable the use of {@code sun.misc.Unsafe} if you specify
  * the system property <strong>io.netty.noUnsafe</strong>.
  */
-public final class DetectionUtil {
+public final class PlatformDependent {
+
+    private static final ClassLoader LOADER = ClassLoader.getSystemClassLoader();
+
+    private static final boolean IS_ANDROID = isAndroid0();
+    private static final boolean IS_WINDOWS = isWindows0();
+    private static final boolean IS_ROOT = isRoot0();
 
     private static final int JAVA_VERSION = javaVersion0();
-    private static final boolean HAS_UNSAFE = hasUnsafe(AtomicInteger.class.getClassLoader());
-    private static final boolean CAN_FREE_DIRECT_BUFFER;
-    private static final boolean IS_WINDOWS;
-    private static final boolean IS_ROOT;
 
-    static {
+    private static final boolean HAS_UNSAFE = hasUnsafe0();
+    private static final boolean CAN_FREE_DIRECT_BUFFER = canFreeDirectBuffer0();
+    private static final boolean IS_UNALIGNED = isUnaligned0();
+
+    /**
+     * Returns {@code true} if and only if the current platform is Android
+     */
+    public static boolean isAndroid() {
+        return IS_ANDROID;
+    }
+
+    /**
+     * Return {@code true} if the JVM is running on Windows
+     */
+    public static boolean isWindows() {
+        return IS_WINDOWS;
+    }
+
+    /**
+     * Return {@code true} if the current user is root.  Note that this method returns
+     * {@code false} if on Windows.
+     */
+    public static boolean isRoot() {
+        return IS_ROOT;
+    }
+
+    /**
+     * Return the version of Java under which this library is used.
+     */
+    public static int javaVersion() {
+        return JAVA_VERSION;
+    }
+
+    /**
+     * Return {@code true} if {@code sun.misc.Unsafe} was found on the classpath and can be used.
+     */
+    public static boolean hasUnsafe() {
+        return HAS_UNSAFE;
+    }
+
+    /**
+     * Return {@code true} if direct buffers can be freed using an optimized way and so memory footprint will be very
+     * small.
+     */
+    public static boolean canFreeDirectBuffer() {
+        return CAN_FREE_DIRECT_BUFFER;
+    }
+
+    /**
+     * Returns {@code true} if and only if {@code java.nio.Bits.unaligned()} is true.
+     */
+    public static boolean isUnaligned() {
+        return IS_UNALIGNED;
+    }
+
+    /**
+     * Try to deallocate the specified direct {@link ByteBuffer}.  Please note this method does nothing if
+     * the current platform does not support this operation or the specified buffer is not a direct buffer.
+     */
+    public static void freeDirectBuffer(ByteBuffer buffer) {
+        if (canFreeDirectBuffer() && buffer.isDirect()) {
+            PlatformDependent0.freeDirectBuffer(buffer);
+        }
+    }
+
+    public static Object getObject(Object object, long fieldOffset) {
+        return PlatformDependent0.getObject(object, fieldOffset);
+    }
+
+    public static long objectFieldOffset(Field field) {
+        return PlatformDependent0.objectFieldOffset(field);
+    }
+
+    private static boolean isAndroid0() {
+        boolean android;
+        try {
+            Class.forName("android.app.Application", false, LOADER);
+            android = true;
+        } catch (Exception e) {
+            android = false;
+        }
+        return android;
+    }
+
+    private static boolean isWindows0() {
+        return SystemPropertyUtil.get("os.name", "").toLowerCase(Locale.US).contains("win");
+    }
+
+    private static boolean isRoot0() {
         Pattern PERMISSION_DENIED = Pattern.compile(".*permission.*denied.*");
-        String os = SystemPropertyUtil.get("os.name", "").toLowerCase(Locale.UK);
-        // windows
-        IS_WINDOWS = os.contains("win");
-
         boolean root = false;
-        if (!IS_WINDOWS) {
+        if (!isWindows()) {
             for (int i = 1023; i > 0; i --) {
                 ServerSocket ss = null;
                 try {
@@ -80,97 +164,7 @@ public final class DetectionUtil {
                 }
             }
         }
-
+        return root;
-        IS_ROOT = root;
-
-        boolean canFreeDirectBuffer = false;
-
-        // Only try to use DirectByteBufUtil if it is not android as otherwise it will give errors because
-        // it try to access sun.misc.Cleaner
-        if (!isAndroid()) {
-            try {
-                canFreeDirectBuffer = DirectByteBufUtil.canFreeDirect();
-            } catch (Throwable t) {
-                // Ignore.
-            }
-        }
-
-        CAN_FREE_DIRECT_BUFFER = canFreeDirectBuffer;
-    }
-
-    /**
-     * Return {@code true} if the JVM is running on Windows
-     */
-    public static boolean isWindows() {
-        return IS_WINDOWS;
-    }
-
-    /**
-     * Return {@code true} if the current user is root.  Note that this method returns
-     * {@code false} if on Windows.
-     */
-    public static boolean isRoot() {
-        return IS_ROOT;
-    }
-
-    /**
-     * Return {@code true} if {@link sun.misc.Unsafe} was found on the classpath and can be used.
-     */
-    public static boolean hasUnsafe() {
-        return HAS_UNSAFE;
-    }
-
-    /**
-     * Return the version of Java under which this library is used.
-     */
-    public static int javaVersion() {
-        return JAVA_VERSION;
-    }
-
-    /**
-     * Return {@code true} if direct buffers can be freed using an optimized way and so memory footprint will be very
-     * small.
-     */
-    public static boolean canFreeDirectBuffer() {
-        return CAN_FREE_DIRECT_BUFFER;
-    }
-
-    private static boolean hasUnsafe(ClassLoader loader) {
-        boolean noUnsafe = SystemPropertyUtil.getBoolean("io.netty.noUnsafe", false);
-        if (noUnsafe) {
-            return false;
-        }
-
-        // Legacy properties
-        boolean tryUnsafe;
-        if (SystemPropertyUtil.contains("io.netty.tryUnsafe")) {
-            tryUnsafe = SystemPropertyUtil.getBoolean("io.netty.tryUnsafe", true);
-        } else {
-            tryUnsafe = SystemPropertyUtil.getBoolean("org.jboss.netty.tryUnsafe", true);
-        }
-
-        if (!tryUnsafe) {
-            return false;
-        }
-
-        try {
-            Class<?> unsafeClazz = Class.forName("sun.misc.Unsafe", true, loader);
-            return hasUnsafeField(unsafeClazz);
-        } catch (Exception e) {
-            // Ignore
-        }
-
-        return false;
-    }
-
-    private static boolean hasUnsafeField(final Class<?> unsafeClass) throws PrivilegedActionException {
-        return AccessController.doPrivileged(new PrivilegedExceptionAction<Boolean>() {
-            @Override
-            public Boolean run() throws Exception {
-                unsafeClass.getDeclaredField("theUnsafe");
-                return true;
-            }
-        });
     }
 
     private static int javaVersion0() {
@@ -191,18 +185,48 @@ public final class DetectionUtil {
         return 6;
     }
 
-    private static boolean isAndroid() {
+    private static boolean hasUnsafe0() {
-        // Android
+        if (isAndroid()) {
-        try {
+            return false;
-            Class.forName("android.app.Application", false, ClassLoader.getSystemClassLoader());
-            return true;
-        } catch (Exception e) {
-            // Ignore
         }
-        return false;
+
+        boolean noUnsafe = SystemPropertyUtil.getBoolean("io.netty.noUnsafe", false);
+        if (noUnsafe) {
+            return false;
+        }
+
+        // Legacy properties
+        boolean tryUnsafe;
+        if (SystemPropertyUtil.contains("io.netty.tryUnsafe")) {
+            tryUnsafe = SystemPropertyUtil.getBoolean("io.netty.tryUnsafe", true);
+        } else {
+            tryUnsafe = SystemPropertyUtil.getBoolean("org.jboss.netty.tryUnsafe", true);
+        }
+
+        if (!tryUnsafe) {
+            return false;
+        }
+
+        return PlatformDependent0.hasUnsafe();
     }
 
-    private DetectionUtil() {
+    private static boolean canFreeDirectBuffer0() {
+        if (isAndroid()) {
+            return false;
+        }
+
+        return PlatformDependent0.canFreeDirectBuffer();
+    }
+
+    private static boolean isUnaligned0() {
+        if (!hasUnsafe()) {
+            return false;
+        }
+
+        return PlatformDependent0.isUnaligned();
+    }
+
+    private PlatformDependent() {
         // only static method supported
     }
 }

common/src/main/java/io/netty/util/internal/PlatformDependent0.java

@@ -0,0 +1,102 @@
+/*
+ * 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.internal;
+
+import sun.misc.Cleaner;
+import sun.misc.Unsafe;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+import java.nio.ByteBuffer;
+
+/**
+ * The {@link PlatformDependent} operations which requires access to {@code sun.misc.*}.
+ */
+final class PlatformDependent0 {
+
+    private static final Unsafe UNSAFE;
+    private static final Field CLEANER_FIELD;
+    private static final boolean UNALIGNED;
+
+    static {
+        Unsafe unsafe;
+        try {
+            Field singleoneInstanceField = Unsafe.class.getDeclaredField("theUnsafe");
+            singleoneInstanceField.setAccessible(true);
+            unsafe = (Unsafe) singleoneInstanceField.get(null);
+        } catch (Throwable cause) {
+            unsafe = null;
+        }
+        UNSAFE = unsafe;
+
+        ByteBuffer direct = ByteBuffer.allocateDirect(1);
+        Field cleanerField;
+        try {
+            cleanerField = direct.getClass().getDeclaredField("cleaner");
+            cleanerField.setAccessible(true);
+            Cleaner cleaner = (Cleaner) cleanerField.get(direct);
+            cleaner.clean();
+        } catch (Throwable t) {
+            cleanerField = null;
+        }
+        CLEANER_FIELD = cleanerField;
+
+        boolean unaligned;
+        try {
+            Class<?> bitsClass = Class.forName("java.nio.Bits", false, ClassLoader.getSystemClassLoader());
+            Method unalignedMethod = bitsClass.getDeclaredMethod("unaligned");
+            unalignedMethod.setAccessible(true);
+            unaligned = Boolean.TRUE.equals(unalignedMethod.invoke(null));
+        } catch (Throwable t) {
+            unaligned = false;
+        }
+        UNALIGNED = unaligned;
+    }
+
+    static boolean hasUnsafe() {
+        return UNSAFE != null;
+    }
+
+    static boolean canFreeDirectBuffer() {
+        return CLEANER_FIELD != null;
+    }
+
+    static void freeDirectBuffer(ByteBuffer buffer) {
+        Cleaner cleaner;
+        try {
+            cleaner = (Cleaner) CLEANER_FIELD.get(buffer);
+            cleaner.clean();
+        } catch (Throwable t) {
+            // Nothing we can do here.
+        }
+    }
+
+    static boolean isUnaligned() {
+        return UNALIGNED;
+    }
+
+    static Object getObject(Object object, long fieldOffset) {
+        return UNSAFE.getObject(object, fieldOffset);
+    }
+
+    static long objectFieldOffset(Field field) {
+        return UNSAFE.objectFieldOffset(field);
+    }
+
+
+    private PlatformDependent0() {
+    }
+}

handler/src/main/java/io/netty/handler/ssl/SslHandler.java

@@ -30,7 +30,7 @@ import io.netty.channel.ChannelPromise;
 import io.netty.channel.DefaultChannelPromise;
 import io.netty.logging.InternalLogger;
 import io.netty.logging.InternalLoggerFactory;
-import io.netty.util.internal.DetectionUtil;
+import io.netty.util.internal.PlatformDependent;
 
 import javax.net.ssl.SSLEngine;
 import javax.net.ssl.SSLEngineResult;
@@ -659,7 +659,7 @@ public class SslHandler
                     }
 
                     // also match against SctpChannel via String matching as it may not present.
-                    if (DetectionUtil.javaVersion() >= 7
+                    if (PlatformDependent.javaVersion() >= 7
                             && "com.sun.nio.sctp.SctpChannel".equals(clazz.getSuperclass().getName())) {
                         return true;
                     }

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

@@ -21,7 +21,7 @@ import io.netty.buffer.MessageBuf;
 import io.netty.logging.InternalLogger;
 import io.netty.logging.InternalLoggerFactory;
 import io.netty.util.DefaultAttributeMap;
-import io.netty.util.internal.DetectionUtil;
+import io.netty.util.internal.PlatformDependent;
 
 import java.io.EOFException;
 import java.io.IOException;
@@ -631,7 +631,7 @@ public abstract class AbstractChannel extends DefaultAttributeMap implements Cha
                     boolean wasActive = isActive();
 
                     // See: https://github.com/netty/netty/issues/576
-                    if (!DetectionUtil.isWindows() && !DetectionUtil.isRoot() &&
+                    if (!PlatformDependent.isWindows() && !PlatformDependent.isRoot() &&
                         Boolean.TRUE.equals(config().getOption(ChannelOption.SO_BROADCAST)) &&
                         localAddress instanceof InetSocketAddress &&
                         !((InetSocketAddress) localAddress).getAddress().isAnyLocalAddress()) {

transport/src/main/java/io/netty/channel/socket/DefaultDatagramChannelConfig.java

@@ -21,7 +21,7 @@ import io.netty.channel.ChannelOption;
 import io.netty.channel.DefaultChannelConfig;
 import io.netty.logging.InternalLogger;
 import io.netty.logging.InternalLoggerFactory;
-import io.netty.util.internal.DetectionUtil;
+import io.netty.util.internal.PlatformDependent;
 
 import java.io.IOException;
 import java.net.DatagramSocket;
@@ -146,7 +146,7 @@ public class DefaultDatagramChannelConfig extends DefaultChannelConfig implement
         try {
             // See: https://github.com/netty/netty/issues/576
             if (broadcast &&
-                !DetectionUtil.isWindows() && !DetectionUtil.isRoot() &&
+                !PlatformDependent.isWindows() && !PlatformDependent.isRoot() &&
                 !javaSocket.getLocalAddress().isAnyLocalAddress()) {
                 // Warn a user about the fact that a non-root user can't receive a
                 // broadcast packet on *nix if the socket is bound on non-wildcard address.

transport/src/main/java/io/netty/channel/socket/aio/AioEventLoopGroup.java

@@ -22,7 +22,7 @@ import io.netty.channel.EventLoopException;
 import io.netty.channel.MultithreadEventLoopGroup;
 import io.netty.logging.InternalLogger;
 import io.netty.logging.InternalLoggerFactory;
-import io.netty.util.internal.DetectionUtil;
+import io.netty.util.internal.PlatformDependent;
 
 import java.io.IOException;
 import java.nio.channels.AsynchronousChannelGroup;
@@ -44,7 +44,7 @@ public class AioEventLoopGroup extends MultithreadEventLoopGroup {
     static {
         AioChannelFinder finder;
         try {
-            if (DetectionUtil.hasUnsafe()) {
+            if (PlatformDependent.hasUnsafe()) {
                 finder = new UnsafeAioChannelFinder();
             } else {
                 finder = new ReflectiveAioChannelFinder();

transport/src/main/java/io/netty/channel/socket/aio/UnsafeAioChannelFinder.java

@@ -15,19 +15,16 @@
  */
 package io.netty.channel.socket.aio;
 
+import io.netty.util.internal.PlatformDependent;
+
 import java.lang.reflect.Field;
 import java.util.HashMap;
 import java.util.Map;
 
-import sun.misc.Unsafe;
-
 /**
- * {@link AioChannelFinder} implementation which will use {@link Unsafe}.
+ * {@link AioChannelFinder} implementation which uses {@code sun.misc.Unsafe}.
  */
-@SuppressWarnings("restriction")
 final class UnsafeAioChannelFinder implements AioChannelFinder {
-    private static final Unsafe UNSAFE = getUnsafe();
-
     private static volatile Map<Class<?>, Long> offsetCache = new HashMap<Class<?>, Long>();
 
     @Override
@@ -38,7 +35,7 @@ final class UnsafeAioChannelFinder implements AioChannelFinder {
             if (offset == null) {
                 return null;
             }
-            Object next = UNSAFE.getObject(command, offset);
+            Object next = PlatformDependent.getObject(command, offset);
             if (next instanceof AbstractAioChannel) {
                 return (AbstractAioChannel) next;
             }
@@ -56,7 +53,7 @@ final class UnsafeAioChannelFinder implements AioChannelFinder {
 
         for (Field f: commandType.getDeclaredFields()) {
             if (f.getType() == Runnable.class) {
-                res = UNSAFE.objectFieldOffset(f);
+                res = PlatformDependent.objectFieldOffset(f);
                 put(offsetCache, commandType, res);
                 return res;
             }
@@ -65,7 +62,7 @@ final class UnsafeAioChannelFinder implements AioChannelFinder {
                 f.setAccessible(true);
                 Object candidate = f.get(command);
                 if (candidate instanceof AbstractAioChannel) {
-                    res = UNSAFE.objectFieldOffset(f);
+                    res = PlatformDependent.objectFieldOffset(f);
                     put(offsetCache, commandType, res);
                     return res;
                 }
@@ -80,14 +77,4 @@ final class UnsafeAioChannelFinder implements AioChannelFinder {
         newCache.put(key, value);
         offsetCache = newCache;
     }
-
-    private static Unsafe getUnsafe() {
-        try {
-            Field singleoneInstanceField = Unsafe.class.getDeclaredField("theUnsafe");
-            singleoneInstanceField.setAccessible(true);
-            return (Unsafe) singleoneInstanceField.get(null);
-        } catch (Throwable cause) {
-            throw new RuntimeException("Error while obtaining sun.misc.Unsafe", cause);
-        }
-    }
 }

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

@@ -25,7 +25,7 @@ import io.netty.channel.ChannelPromise;
 import io.netty.channel.socket.DatagramChannelConfig;
 import io.netty.channel.socket.DatagramPacket;
 import io.netty.channel.socket.InternetProtocolFamily;
-import io.netty.util.internal.DetectionUtil;
+import io.netty.util.internal.PlatformDependent;
 
 import java.io.IOException;
 import java.net.InetAddress;
@@ -69,7 +69,7 @@ public final class NioDatagramChannel
             return newSocket();
         }
 
-        if (DetectionUtil.javaVersion() < 7) {
+        if (PlatformDependent.javaVersion() < 7) {
             throw new UnsupportedOperationException();
         }
 
@@ -309,7 +309,7 @@ public final class NioDatagramChannel
     public ChannelFuture joinGroup(
             InetAddress multicastAddress, NetworkInterface networkInterface,
             InetAddress source, ChannelPromise promise) {
-        if (DetectionUtil.javaVersion() >= 7) {
+        if (PlatformDependent.javaVersion() >= 7) {
             if (multicastAddress == null) {
                 throw new NullPointerException("multicastAddress");
             }
@@ -384,7 +384,7 @@ public final class NioDatagramChannel
     public ChannelFuture leaveGroup(
             InetAddress multicastAddress, NetworkInterface networkInterface, InetAddress source,
             ChannelPromise promise) {
-        if (DetectionUtil.javaVersion() < 7) {
+        if (PlatformDependent.javaVersion() < 7) {
             throw new UnsupportedOperationException();
         }
         if (multicastAddress == null) {
@@ -438,7 +438,7 @@ public final class NioDatagramChannel
     public ChannelFuture block(
             InetAddress multicastAddress, NetworkInterface networkInterface,
             InetAddress sourceToBlock, ChannelPromise promise) {
-        if (DetectionUtil.javaVersion() < 7) {
+        if (PlatformDependent.javaVersion() < 7) {
             throw new UnsupportedOperationException();
         } else {
             if (multicastAddress == null) {

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

@@ -18,7 +18,7 @@ package io.netty.channel.socket.nio;
 import io.netty.channel.ChannelException;
 import io.netty.channel.socket.DatagramChannelConfig;
 import io.netty.channel.socket.DefaultDatagramChannelConfig;
-import io.netty.util.internal.DetectionUtil;
+import io.netty.util.internal.PlatformDependent;
 
 import java.lang.reflect.Method;
 import java.net.InetAddress;
@@ -162,7 +162,7 @@ class NioDatagramChannelConfig extends DefaultDatagramChannelConfig {
     }
 
     private Object getOption0(Object option) {
-        if (DetectionUtil.javaVersion() < 7) {
+        if (PlatformDependent.javaVersion() < 7) {
             throw new UnsupportedOperationException();
         } else {
             try {
@@ -174,7 +174,7 @@ class NioDatagramChannelConfig extends DefaultDatagramChannelConfig {
     }
 
     private void setOption0(Object option, Object value) {
-        if (DetectionUtil.javaVersion() < 7) {
+        if (PlatformDependent.javaVersion() < 7) {
             throw new UnsupportedOperationException();
         } else {
             try {