changeset 13780:dcf2d62a3e5b

Merge
author amurillo
date Thu, 18 Feb 2016 15:19:41 -0800
parents 48699da559b8 f32f683182d2
children a2a823780a7c c234831ff203 6e19808c749b
files make/mapfiles/libjava/mapfile-vers src/java.base/share/native/libjava/Bits.c
diffstat 7 files changed, 925 insertions(+), 269 deletions(-) [+]
line wrap: on
line diff
--- a/make/lib/CoreLibraries.gmk	Thu Feb 18 13:41:11 2016 -0800
+++ b/make/lib/CoreLibraries.gmk	Thu Feb 18 15:19:41 2016 -0800
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2011, 2015, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2011, 2016, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -137,12 +137,6 @@
   endif
 endif
 
-ifeq ($(OPENJDK_TARGET_OS), linux)
-  ifeq ($(OPENJDK_TARGET_CPU), x86_64)
-    BUILD_LIBJAVA_Bits.c_CFLAGS := $(C_O_FLAG_NORM)
-  endif
-endif
-
 $(eval $(call SetupNativeCompilation,BUILD_LIBJAVA, \
     LIBRARY := java, \
     OUTPUT_DIR := $(INSTALL_LIBRARIES_HERE), \
--- a/make/mapfiles/libjava/mapfile-vers	Thu Feb 18 13:41:11 2016 -0800
+++ b/make/mapfiles/libjava/mapfile-vers	Thu Feb 18 15:19:41 2016 -0800
@@ -229,12 +229,6 @@
 		Java_java_lang_Throwable_fillInStackTrace;
                 Java_java_lang_Throwable_getStackTraceDepth;
                 Java_java_lang_Throwable_getStackTraceElement;
-                Java_java_nio_Bits_copyFromShortArray;
-                Java_java_nio_Bits_copyToShortArray;
-                Java_java_nio_Bits_copyFromIntArray;
-                Java_java_nio_Bits_copyToIntArray;
-                Java_java_nio_Bits_copyFromLongArray;
-                Java_java_nio_Bits_copyToLongArray;
 		Java_java_security_AccessController_doPrivileged__Ljava_security_PrivilegedAction_2;
 		Java_java_security_AccessController_doPrivileged__Ljava_security_PrivilegedAction_2Ljava_security_AccessControlContext_2;
 		Java_java_security_AccessController_doPrivileged__Ljava_security_PrivilegedExceptionAction_2;
--- a/src/java.base/share/classes/java/lang/invoke/MethodHandleImpl.java	Thu Feb 18 13:41:11 2016 -0800
+++ b/src/java.base/share/classes/java/lang/invoke/MethodHandleImpl.java	Thu Feb 18 15:19:41 2016 -0800
@@ -778,8 +778,21 @@
             return (asTypeCache = wrapper);
         }
 
+        // Customize target if counting happens for too long.
+        private int invocations = CUSTOMIZE_THRESHOLD;
+        private void maybeCustomizeTarget() {
+            int c = invocations;
+            if (c >= 0) {
+                if (c == 1) {
+                    target.customize();
+                }
+                invocations = c - 1;
+            }
+        }
+
         boolean countDown() {
             int c = count;
+            maybeCustomizeTarget();
             if (c <= 1) {
                 // Try to limit number of updates. MethodHandle.updateForm() doesn't guarantee LF update visibility.
                 if (isCounting) {
--- a/src/java.base/share/classes/java/nio/Bits.java	Thu Feb 18 13:41:11 2016 -0800
+++ b/src/java.base/share/classes/java/nio/Bits.java	Thu Feb 18 15:19:41 2016 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -807,31 +807,131 @@
         }
     }
 
-    static void copyFromCharArray(Object src, long srcPos, long dstAddr,
-                                  long length)
-    {
-        copyFromShortArray(src, srcPos, dstAddr, length);
+    /**
+     * Copy and unconditionally byte swap 16 bit elements from a heap array to off-heap memory
+     *
+     * @param src
+     *        the source array, must be a 16-bit primitive array type
+     * @param srcPos
+     *        byte offset within source array of the first element to read
+     * @param dstAddr
+     *        destination address
+     * @param length
+     *        number of bytes to copy
+     */
+    static void copyFromCharArray(Object src, long srcPos, long dstAddr, long length) {
+        unsafe.copySwapMemory(src, unsafe.arrayBaseOffset(src.getClass()) + srcPos, null, dstAddr, length, 2);
     }
 
-    static void copyToCharArray(long srcAddr, Object dst, long dstPos,
-                                long length)
-    {
-        copyToShortArray(srcAddr, dst, dstPos, length);
+    /**
+     * Copy and unconditionally byte swap 16 bit elements from off-heap memory to a heap array
+     *
+     * @param srcAddr
+     *        source address
+     * @param dst
+     *        destination array, must be a 16-bit primitive array type
+     * @param dstPos
+     *        byte offset within the destination array of the first element to write
+     * @param length
+     *        number of bytes to copy
+     */
+    static void copyToCharArray(long srcAddr, Object dst, long dstPos, long length) {
+        unsafe.copySwapMemory(null, srcAddr, dst, unsafe.arrayBaseOffset(dst.getClass()) + dstPos, length, 2);
     }
 
-    static native void copyFromShortArray(Object src, long srcPos, long dstAddr,
-                                          long length);
-    static native void copyToShortArray(long srcAddr, Object dst, long dstPos,
-                                        long length);
+    /**
+     * Copy and unconditionally byte swap 16 bit elements from a heap array to off-heap memory
+     *
+     * @param src
+     *        the source array, must be a 16-bit primitive array type
+     * @param srcPos
+     *        byte offset within source array of the first element to read
+     * @param dstAddr
+     *        destination address
+     * @param length
+     *        number of bytes to copy
+     */
+    static void copyFromShortArray(Object src, long srcPos, long dstAddr, long length) {
+        unsafe.copySwapMemory(src, unsafe.arrayBaseOffset(src.getClass()) + srcPos, null, dstAddr, length, 2);
+    }
 
-    static native void copyFromIntArray(Object src, long srcPos, long dstAddr,
-                                        long length);
-    static native void copyToIntArray(long srcAddr, Object dst, long dstPos,
-                                      long length);
+    /**
+     * Copy and unconditionally byte swap 16 bit elements from off-heap memory to a heap array
+     *
+     * @param srcAddr
+     *        source address
+     * @param dst
+     *        destination array, must be a 16-bit primitive array type
+     * @param dstPos
+     *        byte offset within the destination array of the first element to write
+     * @param length
+     *        number of bytes to copy
+     */
+    static void copyToShortArray(long srcAddr, Object dst, long dstPos, long length) {
+        unsafe.copySwapMemory(null, srcAddr, dst, unsafe.arrayBaseOffset(dst.getClass()) + dstPos, length, 2);
+    }
 
-    static native void copyFromLongArray(Object src, long srcPos, long dstAddr,
-                                         long length);
-    static native void copyToLongArray(long srcAddr, Object dst, long dstPos,
-                                       long length);
+    /**
+     * Copy and unconditionally byte swap 32 bit elements from a heap array to off-heap memory
+     *
+     * @param src
+     *        the source array, must be a 32-bit primitive array type
+     * @param srcPos
+     *        byte offset within source array of the first element to read
+     * @param dstAddr
+     *        destination address
+     * @param length
+     *        number of bytes to copy
+     */
+    static void copyFromIntArray(Object src, long srcPos, long dstAddr, long length) {
+        unsafe.copySwapMemory(src, unsafe.arrayBaseOffset(src.getClass()) + srcPos, null, dstAddr, length, 4);
+    }
 
+    /**
+     * Copy and unconditionally byte swap 32 bit elements from off-heap memory to a heap array
+     *
+     * @param srcAddr
+     *        source address
+     * @param dst
+     *        destination array, must be a 32-bit primitive array type
+     * @param dstPos
+     *        byte offset within the destination array of the first element to write
+     * @param length
+     *        number of bytes to copy
+     */
+    static void copyToIntArray(long srcAddr, Object dst, long dstPos, long length) {
+        unsafe.copySwapMemory(null, srcAddr, dst, unsafe.arrayBaseOffset(dst.getClass()) + dstPos, length, 4);
+    }
+
+    /**
+     * Copy and unconditionally byte swap 64 bit elements from a heap array to off-heap memory
+     *
+     * @param src
+     *        the source array, must be a 64-bit primitive array type
+     * @param srcPos
+     *        byte offset within source array of the first element to read
+     * @param dstAddr
+     *        destination address
+     * @param length
+     *        number of bytes to copy
+     */
+    static void copyFromLongArray(Object src, long srcPos, long dstAddr, long length) {
+        unsafe.copySwapMemory(src, unsafe.arrayBaseOffset(src.getClass()) + srcPos, null, dstAddr, length, 8);
+    }
+
+    /**
+     * Copy and unconditionally byte swap 64 bit elements from off-heap memory to a heap array
+     *
+     * @param srcAddr
+     *        source address
+     * @param dst
+     *        destination array, must be a 64-bit primitive array type
+     * @param dstPos
+     *        byte offset within the destination array of the first element to write
+     * @param length
+     *        number of bytes to copy
+     */
+    static void copyToLongArray(long srcAddr, Object dst, long dstPos, long length) {
+        unsafe.copySwapMemory(null, srcAddr, dst, unsafe.arrayBaseOffset(dst.getClass()) + dstPos, length, 8);
+    }
 }
--- a/src/java.base/share/classes/jdk/internal/misc/Unsafe.java	Thu Feb 18 13:41:11 2016 -0800
+++ b/src/java.base/share/classes/jdk/internal/misc/Unsafe.java	Thu Feb 18 15:19:41 2016 -0800
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -458,6 +458,78 @@
         copyMemory(null, srcAddress, null, destAddress, bytes);
     }
 
+    private boolean isPrimitiveArray(Class<?> c) {
+        Class<?> componentType = c.getComponentType();
+        return componentType != null && componentType.isPrimitive();
+    }
+
+    private native void copySwapMemory0(Object srcBase, long srcOffset,
+                                        Object destBase, long destOffset,
+                                        long bytes, long elemSize);
+
+    /**
+     * Copies all elements from one block of memory to another block,
+     * *unconditionally* byte swapping the elements on the fly.
+     *
+     * <p>This method determines each block's base address by means of two parameters,
+     * and so it provides (in effect) a <em>double-register</em> addressing mode,
+     * as discussed in {@link #getInt(Object,long)}.  When the object reference is null,
+     * the offset supplies an absolute base address.
+     *
+     * @since 9
+     */
+    public void copySwapMemory(Object srcBase, long srcOffset,
+                               Object destBase, long destOffset,
+                               long bytes, long elemSize) {
+        if (bytes < 0) {
+            throw new IllegalArgumentException();
+        }
+        if (elemSize != 2 && elemSize != 4 && elemSize != 8) {
+            throw new IllegalArgumentException();
+        }
+        if (bytes % elemSize != 0) {
+            throw new IllegalArgumentException();
+        }
+        if ((srcBase == null && srcOffset == 0) ||
+            (destBase == null && destOffset == 0)) {
+            throw new NullPointerException();
+        }
+
+        // Must be off-heap, or primitive heap arrays
+        if (srcBase != null && (srcOffset < 0 || !isPrimitiveArray(srcBase.getClass()))) {
+            throw new IllegalArgumentException();
+        }
+        if (destBase != null && (destOffset < 0 || !isPrimitiveArray(destBase.getClass()))) {
+            throw new IllegalArgumentException();
+        }
+
+        // Sanity check size and offsets on 32-bit platforms. Most
+        // significant 32 bits must be zero.
+        if (ADDRESS_SIZE == 4 &&
+            (bytes >>> 32 != 0 || srcOffset >>> 32 != 0 || destOffset >>> 32 != 0)) {
+            throw new IllegalArgumentException();
+        }
+
+        if (bytes == 0) {
+            return;
+        }
+
+        copySwapMemory0(srcBase, srcOffset, destBase, destOffset, bytes, elemSize);
+    }
+
+   /**
+     * Copies all elements from one block of memory to another block, byte swapping the
+     * elements on the fly.
+     *
+     * This provides a <em>single-register</em> addressing mode, as
+     * discussed in {@link #getInt(Object,long)}.
+     *
+     * Equivalent to {@code copySwapMemory(null, srcAddress, null, destAddress, bytes, elemSize)}.
+     */
+    public void copySwapMemory(long srcAddress, long destAddress, long bytes, long elemSize) {
+        copySwapMemory(null, srcAddress, null, destAddress, bytes, elemSize);
+    }
+
     /**
      * Disposes of a block of native memory, as obtained from {@link
      * #allocateMemory} or {@link #reallocateMemory}.  The address passed to
@@ -1159,7 +1231,12 @@
     /** @see #getLongUnaligned(Object, long) */
     @HotSpotIntrinsicCandidate
     public final char getCharUnaligned(Object o, long offset) {
-        return (char)getShortUnaligned(o, offset);
+        if ((offset & 1) == 0) {
+            return getChar(o, offset);
+        } else {
+            return (char)makeShort(getByte(o, offset),
+                                   getByte(o, offset + 1));
+        }
     }
 
     /** @see #getLongUnaligned(Object, long, boolean) */
--- a/src/java.base/share/native/libjava/Bits.c	Thu Feb 18 13:41:11 2016 -0800
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,233 +0,0 @@
-/*
- * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.  Oracle designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Oracle in the LICENSE file that accompanied this code.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- */
-
-/*
- */
-
-#include "jni.h"
-#include "jni_util.h"
-#include "jlong.h"
-#include <string.h>
-
-#define MBYTE 1048576
-
-#define GETCRITICAL_OR_RETURN(bytes, env, obj) { \
-    bytes = (*env)->GetPrimitiveArrayCritical(env, obj, NULL); \
-    if (bytes == NULL)  { \
-        if ((*env)->ExceptionOccurred(env) == NULL) \
-            JNU_ThrowInternalError(env, "Unable to get array"); \
-        return; \
-    } \
-}
-
-#define RELEASECRITICAL(bytes, env, obj, mode) { \
-    (*env)->ReleasePrimitiveArrayCritical(env, obj, bytes, mode); \
-}
-
-#define SWAPSHORT(x) ((jshort)(((x) << 8) | (((x) >> 8) & 0xff)))
-#define SWAPINT(x)   ((jint)((SWAPSHORT((jshort)(x)) << 16) | \
-                            (SWAPSHORT((jshort)((x) >> 16)) & 0xffff)))
-#define SWAPLONG(x)  ((jlong)(((jlong)SWAPINT((jint)(x)) << 32) | \
-                              ((jlong)SWAPINT((jint)((x) >> 32)) & 0xffffffff)))
-
-JNIEXPORT void JNICALL
-Java_java_nio_Bits_copyFromShortArray(JNIEnv *env, jclass clazz, jobject src,
-                                      jlong srcPos, jlong dstAddr, jlong length)
-{
-    jbyte *bytes;
-    size_t size;
-    jshort *srcShort, *dstShort, *endShort;
-    jshort tmpShort;
-
-    dstShort = (jshort *)jlong_to_ptr(dstAddr);
-
-    while (length > 0) {
-        size = (length < MBYTE) ? (size_t)length : (size_t)MBYTE;
-
-        GETCRITICAL_OR_RETURN(bytes, env, src);
-
-        srcShort = (jshort *)(bytes + srcPos);
-        endShort = srcShort + (size / sizeof(jshort));
-        while (srcShort < endShort) {
-          tmpShort = *srcShort++;
-          *dstShort++ = SWAPSHORT(tmpShort);
-        }
-
-        RELEASECRITICAL(bytes, env, src, JNI_ABORT);
-
-        length -= size;
-        srcPos += size;
-    }
-}
-
-JNIEXPORT void JNICALL
-Java_java_nio_Bits_copyToShortArray(JNIEnv *env, jclass clazz, jlong srcAddr,
-                                    jobject dst, jlong dstPos, jlong length)
-{
-    jbyte *bytes;
-    size_t size;
-    jshort *srcShort, *dstShort, *endShort;
-    jshort tmpShort;
-
-    srcShort = (jshort *)jlong_to_ptr(srcAddr);
-
-    while (length > 0) {
-        size = (length < MBYTE) ? (size_t)length : (size_t)MBYTE;
-
-        GETCRITICAL_OR_RETURN(bytes, env, dst);
-
-        dstShort = (jshort *)(bytes + dstPos);
-        endShort = srcShort + (size / sizeof(jshort));
-        while (srcShort < endShort) {
-            tmpShort = *srcShort++;
-            *dstShort++ = SWAPSHORT(tmpShort);
-        }
-
-        RELEASECRITICAL(bytes, env, dst, 0);
-
-        length -= size;
-        dstPos += size;
-    }
-}
-
-JNIEXPORT void JNICALL
-Java_java_nio_Bits_copyFromIntArray(JNIEnv *env, jclass clazz, jobject src,
-                                    jlong srcPos, jlong dstAddr, jlong length)
-{
-    jbyte *bytes;
-    size_t size;
-    jint *srcInt, *dstInt, *endInt;
-    jint tmpInt;
-
-    dstInt = (jint *)jlong_to_ptr(dstAddr);
-
-    while (length > 0) {
-        size = (length < MBYTE) ? (size_t)length : (size_t)MBYTE;
-
-        GETCRITICAL_OR_RETURN(bytes, env, src);
-
-        srcInt = (jint *)(bytes + srcPos);
-        endInt = srcInt + (size / sizeof(jint));
-        while (srcInt < endInt) {
-            tmpInt = *srcInt++;
-            *dstInt++ = SWAPINT(tmpInt);
-        }
-
-        RELEASECRITICAL(bytes, env, src, JNI_ABORT);
-
-        length -= size;
-        srcPos += size;
-    }
-}
-
-JNIEXPORT void JNICALL
-Java_java_nio_Bits_copyToIntArray(JNIEnv *env, jclass clazz, jlong srcAddr,
-                                  jobject dst, jlong dstPos, jlong length)
-{
-    jbyte *bytes;
-    size_t size;
-    jint *srcInt, *dstInt, *endInt;
-    jint tmpInt;
-
-    srcInt = (jint *)jlong_to_ptr(srcAddr);
-
-    while (length > 0) {
-        size = (length < MBYTE) ? (size_t)length : (size_t)MBYTE;
-
-        GETCRITICAL_OR_RETURN(bytes, env, dst);
-
-        dstInt = (jint *)(bytes + dstPos);
-        endInt = srcInt + (size / sizeof(jint));
-        while (srcInt < endInt) {
-            tmpInt = *srcInt++;
-            *dstInt++ = SWAPINT(tmpInt);
-        }
-
-        RELEASECRITICAL(bytes, env, dst, 0);
-
-        length -= size;
-        dstPos += size;
-    }
-}
-
-JNIEXPORT void JNICALL
-Java_java_nio_Bits_copyFromLongArray(JNIEnv *env, jclass clazz, jobject src,
-                                     jlong srcPos, jlong dstAddr, jlong length)
-{
-    jbyte *bytes;
-    size_t size;
-    jlong *srcLong, *dstLong, *endLong;
-    jlong tmpLong;
-
-    dstLong = (jlong *)jlong_to_ptr(dstAddr);
-
-    while (length > 0) {
-        size = (length < MBYTE) ? (size_t)length : (size_t)MBYTE;
-
-        GETCRITICAL_OR_RETURN(bytes, env, src);
-
-        srcLong = (jlong *)(bytes + srcPos);
-        endLong = srcLong + (size / sizeof(jlong));
-        while (srcLong < endLong) {
-            tmpLong = *srcLong++;
-            *dstLong++ = SWAPLONG(tmpLong);
-        }
-
-        RELEASECRITICAL(bytes, env, src, JNI_ABORT);
-
-        length -= size;
-        srcPos += size;
-    }
-}
-
-JNIEXPORT void JNICALL
-Java_java_nio_Bits_copyToLongArray(JNIEnv *env, jclass clazz, jlong srcAddr,
-                                   jobject dst, jlong dstPos, jlong length)
-{
-    jbyte *bytes;
-    size_t size;
-    jlong *srcLong, *dstLong, *endLong;
-    jlong tmpLong;
-
-    srcLong = (jlong *)jlong_to_ptr(srcAddr);
-
-    while (length > 0) {
-        size = (length < MBYTE) ? (size_t)length : (size_t)MBYTE;
-
-        GETCRITICAL_OR_RETURN(bytes, env, dst);
-
-        dstLong = (jlong *)(bytes + dstPos);
-        endLong = srcLong + (size / sizeof(jlong));
-        while (srcLong < endLong) {
-            tmpLong = *srcLong++;
-            *dstLong++ = SWAPLONG(tmpLong);
-        }
-
-        RELEASECRITICAL(bytes, env, dst, 0);
-
-        length -= size;
-        dstPos += size;
-    }
-}
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/internal/misc/Unsafe/CopySwap.java	Thu Feb 18 15:19:41 2016 -0800
@@ -0,0 +1,711 @@
+/*
+ * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import jdk.internal.misc.Unsafe;
+import java.lang.reflect.Field;
+
+/*
+ * @test
+ * @summary Test Unsafe.copySwapMemory
+ * @modules java.base/jdk.internal.misc
+ */
+public class CopySwap {
+    private static final boolean DEBUG = Boolean.getBoolean("CopySwap.DEBUG");
+
+    public static final long KB = 1024;
+    public static final long MB = KB * 1024;
+    public static final long GB = MB * 1024;
+
+    private static final Unsafe UNSAFE;
+    private static final int SMALL_COPY_SIZE = 32;
+    private static final int BASE_ALIGNMENT = 16;
+
+    static {
+        try {
+            Field f = jdk.internal.misc.Unsafe.class.getDeclaredField("theUnsafe");
+            f.setAccessible(true);
+            UNSAFE = (jdk.internal.misc.Unsafe) f.get(null);
+        } catch (Exception e) {
+            throw new RuntimeException("Unable to get Unsafe instance.", e);
+        }
+    }
+
+    private static long alignDown(long value, long alignment) {
+        return value & ~(alignment - 1);
+    }
+
+    private static long alignUp(long value, long alignment) {
+        return (value + alignment - 1) & ~(alignment - 1);
+    }
+
+    private static boolean isAligned(long value, long alignment) {
+        return value == alignDown(value, alignment);
+    }
+
+    private CopySwap() {
+    }
+
+    /**
+     * Generate verification data for a given offset
+     *
+     * The verification data is used to verify that the correct bytes
+     * have indeed been copied and byte swapped.
+     *
+     * The data is generated based on the offset (in bytes) into the
+     * source buffer. For a native buffer the offset is relative to
+     * the base pointer. For a heap array it is relative to the
+     * address of the first array element.
+     *
+     * This method will return the result of doing an elementSize byte
+     * read starting at offset (in bytes).
+     *
+     * @param offset offset into buffer
+     * @param elemSize size (in bytes) of the element
+     *
+     * @return the verification data, only the least significant
+     * elemSize*8 bits are set, zero extended
+     */
+    private long getVerificationDataForOffset(long offset, long elemSize) {
+        byte[] bytes = new byte[(int)elemSize];
+
+        for (long i = 0; i < elemSize; i++) {
+            bytes[(int)i] = (byte)(offset + i);
+        }
+
+        long o = UNSAFE.arrayBaseOffset(byte[].class);
+
+        switch ((int)elemSize) {
+        case 1: return Byte.toUnsignedLong(UNSAFE.getByte(bytes, o));
+        case 2: return Short.toUnsignedLong(UNSAFE.getShortUnaligned(bytes, o));
+        case 4: return Integer.toUnsignedLong(UNSAFE.getIntUnaligned(bytes, o));
+        case 8: return UNSAFE.getLongUnaligned(bytes, o);
+        default: throw new IllegalArgumentException("Invalid element size: " + elemSize);
+        }
+    }
+
+    /**
+     * Verify byte swapped data
+     *
+     * @param ptr the data to verify
+     * @param srcOffset the srcOffset (in bytes) from which the copy started,
+     *        used as key to regenerate the verification data
+     * @param dstOffset the offset (in bytes) in the array at which to start
+     *        the verification, relative to the first element in the array
+     * @param size size (in bytes) of data to to verify
+     * @param elemSize size (in bytes) of the individual array elements
+     *
+     * @throws RuntimeException if an error is found
+     */
+    private void verifySwappedData(GenericPointer ptr, long srcOffset, long dstOffset, long size, long elemSize) {
+        for (long offset = 0; offset < size; offset += elemSize) {
+            long expectedUnswapped = getVerificationDataForOffset(srcOffset + offset, elemSize);
+            long expected = byteSwap(expectedUnswapped, elemSize);
+
+            long actual = getArrayElem(ptr, dstOffset + offset, elemSize);
+
+            if (expected != actual) {
+                throw new RuntimeException("srcOffset: 0x" + Long.toHexString(srcOffset) +
+                                           " dstOffset: 0x" + Long.toHexString(dstOffset) +
+                                           " size: 0x" + Long.toHexString(size) +
+                                           " offset: 0x" + Long.toHexString(offset) +
+                                           " expectedUnswapped: 0x" + Long.toHexString(expectedUnswapped) +
+                                           " expected: 0x" + Long.toHexString(expected) +
+                                           " != actual: 0x" + Long.toHexString(actual));
+            }
+        }
+    }
+
+    /**
+     * Initialize an array with verification friendly data
+     *
+     * @param ptr pointer to the data to initialize
+     * @param size size (in bytes) of the data
+     * @param elemSize size (in bytes) of the individual elements
+     */
+    private void initVerificationData(GenericPointer ptr, long size, long elemSize) {
+        for (long offset = 0; offset < size; offset++) {
+            byte data = (byte)getVerificationDataForOffset(offset, 1);
+
+            if (ptr.isOnHeap()) {
+                UNSAFE.putByte(ptr.getObject(), ptr.getOffset() + offset, data);
+            } else {
+                UNSAFE.putByte(ptr.getOffset() + offset, data);
+            }
+        }
+    }
+
+    /**
+     * Allocate a primitive array
+     *
+     * @param size size (in bytes) of all the array elements (elemSize * length)
+     * @param elemSize the size of the array elements
+     *
+     * @return a newly allocated primitive array
+     */
+    Object allocArray(long size, long elemSize) {
+        int length = (int)(size / elemSize);
+
+        switch ((int)elemSize) {
+        case 2: return new short[length];
+        case 4: return new int[length];
+        case 8: return new long[length];
+        default:
+            throw new IllegalArgumentException("Invalid element size: " + elemSize);
+        }
+    }
+
+    /**
+     * Get the value of a primitive array entry
+     *
+     * @param ptr pointer to the data
+     * @param offset offset (in bytes) of the array element, relative to the first element in the array
+     *
+     * @return the array element, as an unsigned long
+     */
+    private long getArrayElem(GenericPointer ptr, long offset, long elemSize) {
+        if (ptr.isOnHeap()) {
+            Object o = ptr.getObject();
+            int index = (int)(offset / elemSize);
+
+            if (o instanceof short[]) {
+                short[] arr = (short[])o;
+                return Short.toUnsignedLong(arr[index]);
+            } else if (o instanceof int[]) {
+                int[] arr = (int[])o;
+                return Integer.toUnsignedLong(arr[index]);
+            } else if (o instanceof long[]) {
+                long[] arr = (long[])o;
+                return arr[index];
+            } else {
+                throw new IllegalArgumentException("Invalid object type: " + o.getClass().getName());
+            }
+        } else {
+            long addr = ptr.getOffset() + offset;
+
+            switch ((int)elemSize) {
+            case 1: return Byte.toUnsignedLong(UNSAFE.getByte(addr));
+            case 2: return Short.toUnsignedLong(UNSAFE.getShortUnaligned(null, addr));
+            case 4: return Integer.toUnsignedLong(UNSAFE.getIntUnaligned(null, addr));
+            case 8: return UNSAFE.getLongUnaligned(null, addr);
+            default: throw new IllegalArgumentException("Invalid element size: " + elemSize);
+            }
+        }
+    }
+
+    private void putValue(long addr, long elemSize, long value) {
+        switch ((int)elemSize) {
+        case 1: UNSAFE.putByte(addr, (byte)value); break;
+        case 2: UNSAFE.putShortUnaligned(null, addr, (short)value); break;
+        case 4: UNSAFE.putIntUnaligned(null, addr, (int)value); break;
+        case 8: UNSAFE.putLongUnaligned(null, addr, value); break;
+        default: throw new IllegalArgumentException("Invalid element size: " + elemSize);
+        }
+    }
+
+    /**
+     * Get the size of the elements for an array
+     *
+     * @param o a primitive heap array
+     *
+     * @return the size (in bytes) of the individual array elements
+     */
+    private long getArrayElemSize(Object o) {
+        if (o instanceof short[]) {
+            return 2;
+        } else if (o instanceof int[]) {
+            return 4;
+        } else if (o instanceof long[]) {
+            return 8;
+        } else {
+            throw new IllegalArgumentException("Invalid object type: " + o.getClass().getName());
+        }
+    }
+
+    /**
+     * Byte swap a value
+     *
+     * @param value the value to swap, only the bytes*8 least significant bits are used
+     * @param size size (in bytes) of the value
+     *
+     * @return the byte swapped value in the bytes*8 least significant bits
+     */
+    private long byteSwap(long value, long size) {
+        switch ((int)size) {
+        case 2: return Short.toUnsignedLong(Short.reverseBytes((short)value));
+        case 4: return Integer.toUnsignedLong(Integer.reverseBytes((int)value));
+        case 8: return Long.reverseBytes(value);
+        default: throw new IllegalArgumentException("Invalid element size: " + size);
+        }
+    }
+
+    /**
+     * Verify data in a heap array which has *not* been byte swapped
+     *
+     * @param ptr the data to verify
+     * @param startOffset the offset (in bytes) at which to start the verification
+     * @param size size (in bytes) of the data to verify
+     *
+     * @throws RuntimeException if an error is found
+     */
+    private void verifyUnswappedData(GenericPointer ptr, long startOffset, long size) {
+        for (long elemOffset = startOffset; elemOffset < startOffset + size; elemOffset++) {
+            byte expected = (byte)getVerificationDataForOffset(elemOffset, 1);
+
+            byte actual;
+            if (ptr.isOnHeap()) {
+                actual = UNSAFE.getByte(ptr.getObject(), ptr.getOffset() + elemOffset);
+            } else {
+                actual = UNSAFE.getByte(ptr.getOffset() + elemOffset);
+            }
+
+            if (expected != actual) {
+                throw new RuntimeException("startOffset: 0x" + Long.toHexString(startOffset) +
+                                           " size: 0x" + Long.toHexString(size) +
+                                           " elemOffset: 0x" + Long.toHexString(elemOffset) +
+                                           " expected: 0x" + Long.toHexString(expected) +
+                                           " != actual: 0x" + Long.toHexString(actual));
+            }
+        }
+    }
+
+
+    /**
+     * Copy and byte swap data from the source to the destination
+     *
+     * This method will pre-populate the whole source and destination
+     * buffers with verification friendly data. It will then use
+     * copySwapMemory to fill part of the destination buffer with
+     * swapped data from the source. Some space (padding) will be
+     * left before and after the data in the destination buffer, which
+     * should not be touched/overwritten by the copy call.
+     *
+     * Note: Both source and destination buffers will be overwritten!
+     *
+     * @param src source buffer to copy from
+     * @param srcOffset the offset (in bytes) in the source buffer, relative to
+     *        the first array element, at which to start reading data
+     * @param dst destination buffer to copy to
+     * @param dstOffset the offset (in bytes) in the destination
+     *        buffer, relative to the first array element, at which to
+     *        start writing data
+     * @param bufSize the size (in bytes) of the src and dst arrays
+     * @param copyBytes the size (in bytes) of the copy to perform,
+     *        must be a multiple of elemSize
+     * @param elemSize the size (in bytes) of the elements to byte swap
+     *
+     * @throws RuntimeException if an error is found
+     */
+    private void testCopySwap(GenericPointer src, long srcOffset,
+                              GenericPointer dst, long dstOffset,
+                              long bufSize, long copyBytes, long elemSize) {
+        if (!isAligned(copyBytes, elemSize)) {
+            throw new IllegalArgumentException(
+                "copyBytes (" + copyBytes + ") must be a multiple of elemSize (" + elemSize + ")");
+        }
+        if (src.isOnHeap() && !isAligned(srcOffset, elemSize)) {
+            throw new IllegalArgumentException(
+                "srcOffset (" + srcOffset + ") must be a multiple of elemSize (" + elemSize + ")");
+        }
+        if (dst.isOnHeap() && !isAligned(dstOffset, elemSize)) {
+            throw new IllegalArgumentException(
+                "dstOffset (" + dstOffset + ") must be a multiple of elemSize (" + elemSize + ")");
+        }
+        if (srcOffset + copyBytes > bufSize) {
+            throw new IllegalArgumentException(
+                "srcOffset (" + srcOffset + ") + copyBytes (" + copyBytes + ") > bufSize (" + bufSize + ")");
+        }
+        if (dstOffset + copyBytes > bufSize) {
+            throw new IllegalArgumentException(
+                "dstOffset (" + dstOffset + ") + copyBytes (" + copyBytes + ") > bufSize (" + bufSize + ")");
+        }
+
+        // Initialize the whole source buffer with a verification friendly pattern (no 0x00 bytes)
+        initVerificationData(src, bufSize, elemSize);
+        if (!src.equals(dst)) {
+            initVerificationData(dst, bufSize, elemSize);
+        }
+
+        if (DEBUG) {
+            System.out.println("===before===");
+            for (int offset = 0; offset < bufSize; offset += elemSize) {
+                long srcValue = getArrayElem(src, offset, elemSize);
+                long dstValue = getArrayElem(dst, offset, elemSize);
+
+                System.out.println("offs=0x" + Long.toHexString(Integer.toUnsignedLong(offset)) +
+                                 " src=0x" + Long.toHexString(srcValue) +
+                                 " dst=0x" + Long.toHexString(dstValue));
+            }
+        }
+
+        // Copy & swap data into the middle of the destination buffer
+        UNSAFE.copySwapMemory(src.getObject(),
+                              src.getOffset() + srcOffset,
+                              dst.getObject(),
+                              dst.getOffset() + dstOffset,
+                              copyBytes,
+                              elemSize);
+
+        if (DEBUG) {
+            System.out.println("===after===");
+            for (int offset = 0; offset < bufSize; offset += elemSize) {
+                long srcValue = getArrayElem(src, offset, elemSize);
+                long dstValue = getArrayElem(dst, offset, elemSize);
+
+                System.out.println("offs=0x" + Long.toHexString(Integer.toUnsignedLong(offset)) +
+                                 " src=0x" + Long.toHexString(srcValue) +
+                                 " dst=0x" + Long.toHexString(dstValue));
+            }
+        }
+
+        // Verify the the front padding is unchanged
+        verifyUnswappedData(dst, 0, dstOffset);
+
+        // Verify swapped data
+        verifySwappedData(dst, srcOffset, dstOffset, copyBytes, elemSize);
+
+        // Verify that the back back padding is unchanged
+        long frontAndDataBytes = dstOffset + copyBytes;
+        long trailingBytes = bufSize - frontAndDataBytes;
+        verifyUnswappedData(dst, frontAndDataBytes, trailingBytes);
+    }
+
+    /**
+     * Test various configurations copy-swapping from one buffer to the other
+     *
+     * @param src the source buffer to copy from
+     * @param dst the destination buffer to copy to
+     * @param size size (in bytes) of the buffers
+     * @param elemSize size (in bytes) of the individual elements
+     *
+     * @throws RuntimeException if an error is found
+     */
+    public void testBufferPair(GenericPointer src, GenericPointer dst, long size, long elemSize) {
+        // offset in source from which to start reading data
+        for (long srcOffset = 0; srcOffset < size; srcOffset += (src.isOnHeap() ? elemSize : 1)) {
+
+            // offset in destination at which to start writing data
+            for (int dstOffset = 0; dstOffset < size; dstOffset += (dst.isOnHeap() ? elemSize : 1)) {
+
+                // number of bytes to copy
+                long maxCopyBytes = Math.min(size - srcOffset, size - dstOffset);
+                for (long copyBytes = 0; copyBytes < maxCopyBytes; copyBytes += elemSize) {
+                    try {
+                        testCopySwap(src, srcOffset, dst, dstOffset, size, copyBytes, elemSize);
+                    } catch (RuntimeException e) {
+                        // Wrap the exception in another exception to catch the relevant configuration data
+                        throw new RuntimeException("testBufferPair: " +
+                                                   "src=" + src +
+                                                   " dst=" + dst +
+                                                   " elemSize=0x" + Long.toHexString(elemSize) +
+                                                   " copyBytes=0x" + Long.toHexString(copyBytes) +
+                                                   " srcOffset=0x" + Long.toHexString(srcOffset) +
+                                                   " dstOffset=0x" + Long.toHexString(dstOffset),
+                                                   e);
+                    }
+                }
+            }
+        }
+    }
+
+    /**
+     * Test copying between various permutations of buffers
+     *
+     * @param buffers buffers to permute (src x dst)
+     * @param size size (in bytes) of buffers
+     * @param elemSize size (in bytes) of individual elements
+     *
+     * @throws RuntimeException if an error is found
+     */
+    public void testPermuteBuffers(GenericPointer[] buffers, long size, long elemSize) {
+        for (int srcIndex = 0; srcIndex < buffers.length; srcIndex++) {
+            for (int dstIndex = 0; dstIndex < buffers.length; dstIndex++) {
+                testBufferPair(buffers[srcIndex], buffers[dstIndex], size, elemSize);
+            }
+        }
+    }
+
+    /**
+     * Test copying of a specific element size
+     *
+     * @param size size (in bytes) of buffers to allocate
+     * @param elemSize size (in bytes) of individual elements
+     *
+     * @throws RuntimeException if an error is found
+     */
+    private void testElemSize(long size, long elemSize) {
+        long buf1Raw = 0;
+        long buf2Raw = 0;
+
+        try {
+            buf1Raw = UNSAFE.allocateMemory(size + BASE_ALIGNMENT);
+            long buf1 = alignUp(buf1Raw, BASE_ALIGNMENT);
+
+            buf2Raw = UNSAFE.allocateMemory(size + BASE_ALIGNMENT);
+            long buf2 = alignUp(buf2Raw, BASE_ALIGNMENT);
+
+            GenericPointer[] buffers = {
+                new GenericPointer(buf1),
+                new GenericPointer(buf2),
+                new GenericPointer(allocArray(size, elemSize)),
+                new GenericPointer(allocArray(size, elemSize))
+            };
+
+            testPermuteBuffers(buffers, size, elemSize);
+        } finally {
+            if (buf1Raw != 0) {
+                UNSAFE.freeMemory(buf1Raw);
+            }
+            if (buf2Raw != 0) {
+                UNSAFE.freeMemory(buf2Raw);
+            }
+        }
+    }
+
+    /**
+     * Verify that small copy swaps work
+     */
+    private void testSmallCopy() {
+        int smallBufSize = SMALL_COPY_SIZE;
+
+        // Test various element types and heap/native combinations
+        for (long elemSize = 2; elemSize <= 8; elemSize <<= 1) {
+            testElemSize(smallBufSize, elemSize);
+        }
+    }
+
+
+    /**
+     * Verify that large copy swaps work
+     */
+    private void testLargeCopy() {
+        long size = 2 * GB + 8;
+        long bufRaw = 0;
+
+        // Check that a large native copy succeeds
+        try {
+            try {
+                bufRaw = UNSAFE.allocateMemory(size + BASE_ALIGNMENT);
+            } catch (OutOfMemoryError e) {
+                // Accept failure, skip test
+                return;
+            }
+
+            long buf = alignUp(bufRaw, BASE_ALIGNMENT);
+
+            UNSAFE.copySwapMemory(null, buf, null, buf, size, 8);
+        } catch (Exception e) {
+            throw new RuntimeException("copySwapMemory of large buffer failed");
+        } finally {
+            if (bufRaw != 0) {
+                UNSAFE.freeMemory(bufRaw);
+            }
+        }
+    }
+
+    /**
+     * Run positive tests
+     *
+     * @throws RuntimeException if an error is found
+     */
+    private void testPositive() {
+        testSmallCopy();
+        testLargeCopy();
+    }
+
+    /**
+     * Run negative tests, testing corner cases and the various exceptions
+     *
+     * @throws RuntimeException if an error is found
+     */
+    private void testNegative() {
+        long bufRaw = 0;
+
+        try {
+            bufRaw = UNSAFE.allocateMemory(1024);
+            long buf = alignUp(bufRaw, BASE_ALIGNMENT);
+            short[] arr = new short[16];
+
+            // Check various illegal element sizes
+            for (int elemSize = 2; elemSize <= 8; elemSize <<= 1) {
+                long[] illegalSizes = { -1, 1, elemSize - 1, elemSize + 1, elemSize * 2 - 1 };
+                for (long size : illegalSizes) {
+                    try {
+                        // Check that illegal elemSize throws an IAE
+                        UNSAFE.copySwapMemory(null, buf, null, buf, size, elemSize);
+                        throw new RuntimeException("copySwapMemory failed to throw IAE for size=" + size + " elemSize=" + elemSize);
+                    } catch (IllegalArgumentException e) {
+                        // good
+                    }
+                }
+            }
+
+            try {
+                // Check that negative srcOffset throws an IAE
+                UNSAFE.copySwapMemory(arr, -1, arr, UNSAFE.arrayBaseOffset(arr.getClass()), 16, 2);
+                throw new RuntimeException("copySwapMemory failed to throw IAE for srcOffset=-1");
+            } catch (IllegalArgumentException e) {
+                // good
+            }
+
+            try {
+                // Check that negative dstOffset throws an IAE
+                UNSAFE.copySwapMemory(arr, UNSAFE.arrayBaseOffset(arr.getClass()), arr, -1, 16, 2);
+                throw new RuntimeException("copySwapMemory failed to throw IAE for destOffset=-1");
+            } catch (IllegalArgumentException e) {
+                // good
+            }
+
+            long illegalElemSizes[] = { 0, 1, 3, 5, 6, 7, 9, 10, -1 };
+            for (long elemSize : illegalElemSizes) {
+                try {
+                    // Check that elemSize 1 throws an IAE
+                    UNSAFE.copySwapMemory(null, buf, null, buf, 16, elemSize);
+                    throw new RuntimeException("copySwapMemory failed to throw NPE");
+                } catch (IllegalArgumentException e) {
+                    // good
+                }
+            }
+
+            try {
+                // Check that a NULL source throws NPE
+                UNSAFE.copySwapMemory(null, 0, null, buf, 16, 2);
+                throw new RuntimeException("copySwapMemory failed to throw NPE");
+            } catch (NullPointerException e) {
+                // good
+            }
+
+            try {
+                // Check that a NULL destination throws NPE
+                UNSAFE.copySwapMemory(null, buf, null, 0, 16, 2);
+                throw new RuntimeException("copySwapMemory failed to throw NPE");
+            } catch (NullPointerException e) {
+                // good
+            }
+
+            try {
+                // Check that a reference array destination throws IAE
+                UNSAFE.copySwapMemory(null, buf, new Object[16], UNSAFE.arrayBaseOffset(Object[].class), 16, 8);
+                throw new RuntimeException("copySwapMemory failed to throw NPE");
+            } catch (IllegalArgumentException e) {
+                // good
+            }
+
+            // Check that invalid source & dest pointers throw IAEs (only relevant on 32-bit platforms)
+            if (UNSAFE.addressSize() == 4) {
+                long invalidPtr = (long)1 << 35; // Pick a random bit in upper 32 bits
+
+                try {
+                    // Check that an invalid (not 32-bit clean) source pointer throws IAE
+                    UNSAFE.copySwapMemory(null, invalidPtr, null, buf, 16, 2);
+                    throw new RuntimeException("copySwapMemory failed to throw IAE for srcOffset 0x" +
+                                               Long.toHexString(invalidPtr));
+                } catch (IllegalArgumentException e) {
+                    // good
+                }
+
+                try {
+                    // Check that an invalid (not 32-bit clean) source pointer throws IAE
+                    UNSAFE.copySwapMemory(null, buf, null, invalidPtr, 16, 2);
+                    throw new RuntimeException("copySwapMemory failed to throw IAE for destOffset 0x" +
+                                               Long.toHexString(invalidPtr));
+                } catch (IllegalArgumentException e) {
+                    // good
+                }
+            }
+        } finally {
+            if (bufRaw != 0) {
+                UNSAFE.freeMemory(bufRaw);
+            }
+        }
+    }
+
+    /**
+     * Run all tests
+     *
+     * @throws RuntimeException if an error is found
+     */
+    private void test() {
+        testPositive();
+        testNegative();
+    }
+
+    public static void main(String[] args) {
+        CopySwap cs = new CopySwap();
+        cs.test();
+    }
+
+    /**
+     * Helper class to represent a "pointer" - either a heap array or
+     * a pointer to a native buffer.
+     *
+     * In the case of a native pointer, the Object is null and the offset is
+     * the absolute address of the native buffer.
+     *
+     * In the case of a heap object, the Object is a primitive array, and
+     * the offset will be set to the base offset to the first element, meaning
+     * the object and the offset together form a double-register pointer.
+     */
+    static class GenericPointer {
+        private final Object o;
+        private final long offset;
+
+        private GenericPointer(Object o, long offset) {
+            this.o = o;
+            this.offset = offset;
+        }
+
+        public String toString() {
+            return "GenericPointer(o={" + o + "}, offset=0x" + Long.toHexString(offset) + ")";
+        }
+
+        public boolean equals(Object other) {
+            if (!(other instanceof GenericPointer)) {
+                return false;
+            }
+
+            GenericPointer otherp = (GenericPointer)other;
+
+            return o == otherp.o && offset == otherp.offset;
+        }
+
+        GenericPointer(Object o) {
+            this(o, UNSAFE.arrayBaseOffset(o.getClass()));
+        }
+
+        GenericPointer(long offset) {
+            this(null, offset);
+        }
+
+        public boolean isOnHeap() {
+            return o != null;
+        }
+
+        public Object getObject() {
+            return o;
+        }
+
+        public long getOffset() {
+            return offset;
+        }
+    }
+}