[#1061] Add workaround to not use PooledUnsafeDirectByteBuf when running on latest OpenJDK6 because of missing Unsafe method

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

@@ -376,7 +376,7 @@ abstract class PoolArena<T> {
 
         @Override
         protected PooledByteBuf<ByteBuffer> newByteBuf(int maxCapacity) {
-            if (PlatformDependent.isUnaligned()) {
+            if (PlatformDependent.isUnaligned() && PlatformDependent.unsafeHasCopyMethods()) {
                 return new PooledUnsafeDirectByteBuf(maxCapacity);
             } else {
                 return new PooledDirectByteBuf(maxCapacity);
@@ -389,7 +389,7 @@ abstract class PoolArena<T> {
                 return;
             }
 
-            if (PlatformDependent.isUnaligned()) {
+            if (PlatformDependent.isUnaligned() && PlatformDependent.unsafeHasCopyMethods()) {
                 PlatformDependent.copyMemory(
                         PlatformDependent.directBufferAddress(src) + srcOffset,
                         PlatformDependent.directBufferAddress(dst) + dstOffset, length);

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

@@ -30,7 +30,6 @@ import java.nio.channels.ScatteringByteChannel;
 final class PooledUnsafeDirectByteBuf extends PooledByteBuf<ByteBuffer> {
 
     private static final boolean NATIVE_ORDER = ByteOrder.nativeOrder() == ByteOrder.BIG_ENDIAN;
-
     private long memoryAddress;
 
     PooledUnsafeDirectByteBuf(int maxCapacity) {

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

@@ -46,6 +46,7 @@ public final class PlatformDependent {
 
     private static final boolean HAS_UNSAFE = hasUnsafe0();
     private static final boolean CAN_FREE_DIRECT_BUFFER = canFreeDirectBuffer0();
+    private static final boolean UNSAFE_HASE_COPY_METHODS = unsafeHasCopyMethods0();
     private static final boolean IS_UNALIGNED = isUnaligned0();
     private static final long ARRAY_BASE_OFFSET = arrayBaseOffset0();
 
@@ -109,6 +110,13 @@ public final class PlatformDependent {
         return IS_UNALIGNED;
     }
 
+    /**
+     * Returns {@code true} if unsafe has all needed copy methods which is not the case on latest openjdk6 atm.
+     */
+    public static boolean unsafeHasCopyMethods() {
+        return UNSAFE_HASE_COPY_METHODS;
+    }
+
     /**
      * Returns {@code true} if and only if Javassist is available.
      */
@@ -293,6 +301,13 @@ public final class PlatformDependent {
         return PlatformDependent0.isUnaligned();
     }
 
+    private static boolean unsafeHasCopyMethods0() {
+        if (!hasUnsafe()) {
+            return false;
+        }
+
+        return PlatformDependent0.hasCopyMethods();
+    }
     private static long arrayBaseOffset0() {
         if (!hasUnsafe()) {
             return -1;

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

@@ -32,6 +32,7 @@ final class PlatformDependent0 {
     private static final long CLEANER_FIELD_OFFSET;
     private static final long ADDRESS_FIELD_OFFSET;
     private static final boolean UNALIGNED;
+    private static final boolean HAS_COPY_METHODS;
 
     static {
         Unsafe unsafe;
@@ -48,6 +49,7 @@ final class PlatformDependent0 {
             CLEANER_FIELD_OFFSET = -1;
             ADDRESS_FIELD_OFFSET = -1;
             UNALIGNED = false;
+            HAS_COPY_METHODS = false;
         } else {
             ByteBuffer direct = ByteBuffer.allocateDirect(1);
             Field cleanerField;
@@ -94,6 +96,18 @@ final class PlatformDependent0 {
             }
 
             UNALIGNED = unaligned;
+            boolean hasCopyMethods;
+            try {
+                // Unsafe does not shop all copy methods in latest openjdk update..
+                // https://github.com/netty/netty/issues/1061
+                // http://www.mail-archive.com/jdk6-dev@openjdk.java.net/msg00698.html
+                UNSAFE.getClass().getDeclaredMethod("copyMemory",
+                        new Class[] { Object.class, long.class, Object.class, long.class, long.class });
+                hasCopyMethods = true;
+            } catch (Throwable ignore) {
+                hasCopyMethods = false;
+            }
+            HAS_COPY_METHODS = hasCopyMethods;
         }
     }
 
@@ -127,6 +141,10 @@ final class PlatformDependent0 {
         return UNALIGNED;
     }
 
+    static boolean hasCopyMethods() {
+        return HAS_COPY_METHODS;
+    }
+
     static long arrayBaseOffset() {
         return UNSAFE.arrayBaseOffset(byte[].class);
     }