- /*
- * @(#)Bits.java 1.11 03/01/29
- *
- * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
- * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
- */
-
- package java.nio;
-
- import java.security.AccessController;
- import java.security.PrivilegedAction;
- import sun.misc.Unsafe;
- import sun.misc.VM;
-
- /**
- * Access to bits, native and otherwise.
- */
-
- class Bits { // package-private
-
- private Bits() { }
-
-
- // -- Swapping --
-
- static short swap(short x) {
- return (short)((x << 8) |
- ((x >> 8) & 0xff));
- }
-
- static char swap(char x) {
- return (char)((x << 8) |
- ((x >> 8) & 0xff));
- }
-
- static int swap(int x) {
- return (int)((swap((short)x) << 16) |
- (swap((short)(x >> 16)) & 0xffff));
- }
-
- static long swap(long x) {
- return (long)(((long)swap((int)(x)) << 32) |
- ((long)swap((int)(x >> 32)) & 0xffffffffL));
- }
-
-
- // -- get/put char --
-
- static private char makeChar(byte b1, byte b0) {
- return (char)((b1 << 8) | (b0 & 0xff));
- }
-
- static char getCharL(ByteBuffer bb, int bi) {
- return makeChar(bb._get(bi + 1),
- bb._get(bi + 0));
- }
-
- static char getCharL(long a) {
- return makeChar(_get(a + 1),
- _get(a + 0));
- }
-
- static char getCharB(ByteBuffer bb, int bi) {
- return makeChar(bb._get(bi + 0),
- bb._get(bi + 1));
- }
-
- static char getCharB(long a) {
- return makeChar(_get(a + 0),
- _get(a + 1));
- }
-
- static char getChar(ByteBuffer bb, int bi, boolean bigEndian) {
- return (bigEndian ? getCharB(bb, bi) : getCharL(bb, bi));
- }
-
- static char getChar(long a, boolean bigEndian) {
- return (bigEndian ? getCharB(a) : getCharL(a));
- }
-
- private static byte char1(char x) { return (byte)(x >> 8); }
- private static byte char0(char x) { return (byte)(x >> 0); }
-
- static void putCharL(ByteBuffer bb, int bi, char x) {
- bb._put(bi + 0, char0(x));
- bb._put(bi + 1, char1(x));
- }
-
- static void putCharL(long a, char x) {
- _put(a + 0, char0(x));
- _put(a + 1, char1(x));
- }
-
- static void putCharB(ByteBuffer bb, int bi, char x) {
- bb._put(bi + 0, char1(x));
- bb._put(bi + 1, char0(x));
- }
-
- static void putCharB(long a, char x) {
- _put(a + 0, char1(x));
- _put(a + 1, char0(x));
- }
-
- static void putChar(ByteBuffer bb, int bi, char x, boolean bigEndian) {
- if (bigEndian)
- putCharB(bb, bi, x);
- else
- putCharL(bb, bi, x);
- }
-
- static void putChar(long a, char x, boolean bigEndian) {
- if (bigEndian)
- putCharB(a, x);
- else
- putCharL(a, x);
- }
-
-
- // -- get/put short --
-
- static private short makeShort(byte b1, byte b0) {
- return (short)((b1 << 8) | (b0 & 0xff));
- }
-
- static short getShortL(ByteBuffer bb, int bi) {
- return makeShort(bb._get(bi + 1),
- bb._get(bi + 0));
- }
-
- static short getShortL(long a) {
- return makeShort(_get(a + 1),
- _get(a));
- }
-
- static short getShortB(ByteBuffer bb, int bi) {
- return makeShort(bb._get(bi + 0),
- bb._get(bi + 1));
- }
-
- static short getShortB(long a) {
- return makeShort(_get(a),
- _get(a + 1));
- }
-
- static short getShort(ByteBuffer bb, int bi, boolean bigEndian) {
- return (bigEndian ? getShortB(bb, bi) : getShortL(bb, bi));
- }
-
- static short getShort(long a, boolean bigEndian) {
- return (bigEndian ? getShortB(a) : getShortL(a));
- }
-
- private static byte short1(short x) { return (byte)(x >> 8); }
- private static byte short0(short x) { return (byte)(x >> 0); }
-
- static void putShortL(ByteBuffer bb, int bi, short x) {
- bb._put(bi + 0, short0(x));
- bb._put(bi + 1, short1(x));
- }
-
- static void putShortL(long a, short x) {
- _put(a, short0(x));
- _put(a + 1, short1(x));
- }
-
- static void putShortB(ByteBuffer bb, int bi, short x) {
- bb._put(bi + 0, short1(x));
- bb._put(bi + 1, short0(x));
- }
-
- static void putShortB(long a, short x) {
- _put(a, short1(x));
- _put(a + 1, short0(x));
- }
-
- static void putShort(ByteBuffer bb, int bi, short x, boolean bigEndian) {
- if (bigEndian)
- putShortB(bb, bi, x);
- else
- putShortL(bb, bi, x);
- }
-
- static void putShort(long a, short x, boolean bigEndian) {
- if (bigEndian)
- putShortB(a, x);
- else
- putShortL(a, x);
- }
-
-
- // -- get/put int --
-
- static private int makeInt(byte b3, byte b2, byte b1, byte b0) {
- return (int)((((b3 & 0xff) << 24) |
- ((b2 & 0xff) << 16) |
- ((b1 & 0xff) << 8) |
- ((b0 & 0xff) << 0)));
- }
-
- static int getIntL(ByteBuffer bb, int bi) {
- return makeInt(bb._get(bi + 3),
- bb._get(bi + 2),
- bb._get(bi + 1),
- bb._get(bi + 0));
- }
-
- static int getIntL(long a) {
- return makeInt(_get(a + 3),
- _get(a + 2),
- _get(a + 1),
- _get(a + 0));
- }
-
- static int getIntB(ByteBuffer bb, int bi) {
- return makeInt(bb._get(bi + 0),
- bb._get(bi + 1),
- bb._get(bi + 2),
- bb._get(bi + 3));
- }
-
- static int getIntB(long a) {
- return makeInt(_get(a + 0),
- _get(a + 1),
- _get(a + 2),
- _get(a + 3));
- }
-
- static int getInt(ByteBuffer bb, int bi, boolean bigEndian) {
- return (bigEndian ? getIntB(bb, bi) : getIntL(bb, bi));
- }
-
- static int getInt(long a, boolean bigEndian) {
- return (bigEndian ? getIntB(a) : getIntL(a));
- }
-
- private static byte int3(int x) { return (byte)(x >> 24); }
- private static byte int2(int x) { return (byte)(x >> 16); }
- private static byte int1(int x) { return (byte)(x >> 8); }
- private static byte int0(int x) { return (byte)(x >> 0); }
-
- static void putIntL(ByteBuffer bb, int bi, int x) {
- bb._put(bi + 3, int3(x));
- bb._put(bi + 2, int2(x));
- bb._put(bi + 1, int1(x));
- bb._put(bi + 0, int0(x));
- }
-
- static void putIntL(long a, int x) {
- _put(a + 3, int3(x));
- _put(a + 2, int2(x));
- _put(a + 1, int1(x));
- _put(a + 0, int0(x));
- }
-
- static void putIntB(ByteBuffer bb, int bi, int x) {
- bb._put(bi + 0, int3(x));
- bb._put(bi + 1, int2(x));
- bb._put(bi + 2, int1(x));
- bb._put(bi + 3, int0(x));
- }
-
- static void putIntB(long a, int x) {
- _put(a + 0, int3(x));
- _put(a + 1, int2(x));
- _put(a + 2, int1(x));
- _put(a + 3, int0(x));
- }
-
- static void putInt(ByteBuffer bb, int bi, int x, boolean bigEndian) {
- if (bigEndian)
- putIntB(bb, bi, x);
- else
- putIntL(bb, bi, x);
- }
-
- static void putInt(long a, int x, boolean bigEndian) {
- if (bigEndian)
- putIntB(a, x);
- else
- putIntL(a, x);
- }
-
-
- // -- get/put long --
-
- static private long makeLong(byte b7, byte b6, byte b5, byte b4,
- byte b3, byte b2, byte b1, byte b0)
- {
- return ((((long)b7 & 0xff) << 56) |
- (((long)b6 & 0xff) << 48) |
- (((long)b5 & 0xff) << 40) |
- (((long)b4 & 0xff) << 32) |
- (((long)b3 & 0xff) << 24) |
- (((long)b2 & 0xff) << 16) |
- (((long)b1 & 0xff) << 8) |
- (((long)b0 & 0xff) << 0));
- }
-
- static long getLongL(ByteBuffer bb, int bi) {
- return makeLong(bb._get(bi + 7),
- bb._get(bi + 6),
- bb._get(bi + 5),
- bb._get(bi + 4),
- bb._get(bi + 3),
- bb._get(bi + 2),
- bb._get(bi + 1),
- bb._get(bi + 0));
- }
-
- static long getLongL(long a) {
- return makeLong(_get(a + 7),
- _get(a + 6),
- _get(a + 5),
- _get(a + 4),
- _get(a + 3),
- _get(a + 2),
- _get(a + 1),
- _get(a + 0));
- }
-
- static long getLongB(ByteBuffer bb, int bi) {
- return makeLong(bb._get(bi + 0),
- bb._get(bi + 1),
- bb._get(bi + 2),
- bb._get(bi + 3),
- bb._get(bi + 4),
- bb._get(bi + 5),
- bb._get(bi + 6),
- bb._get(bi + 7));
- }
-
- static long getLongB(long a) {
- return makeLong(_get(a + 0),
- _get(a + 1),
- _get(a + 2),
- _get(a + 3),
- _get(a + 4),
- _get(a + 5),
- _get(a + 6),
- _get(a + 7));
- }
-
- static long getLong(ByteBuffer bb, int bi, boolean bigEndian) {
- return (bigEndian ? getLongB(bb, bi) : getLongL(bb, bi));
- }
-
- static long getLong(long a, boolean bigEndian) {
- return (bigEndian ? getLongB(a) : getLongL(a));
- }
-
- private static byte long7(long x) { return (byte)(x >> 56); }
- private static byte long6(long x) { return (byte)(x >> 48); }
- private static byte long5(long x) { return (byte)(x >> 40); }
- private static byte long4(long x) { return (byte)(x >> 32); }
- private static byte long3(long x) { return (byte)(x >> 24); }
- private static byte long2(long x) { return (byte)(x >> 16); }
- private static byte long1(long x) { return (byte)(x >> 8); }
- private static byte long0(long x) { return (byte)(x >> 0); }
-
- static void putLongL(ByteBuffer bb, int bi, long x) {
- bb._put(bi + 7, long7(x));
- bb._put(bi + 6, long6(x));
- bb._put(bi + 5, long5(x));
- bb._put(bi + 4, long4(x));
- bb._put(bi + 3, long3(x));
- bb._put(bi + 2, long2(x));
- bb._put(bi + 1, long1(x));
- bb._put(bi + 0, long0(x));
- }
-
- static void putLongL(long a, long x) {
- _put(a + 7, long7(x));
- _put(a + 6, long6(x));
- _put(a + 5, long5(x));
- _put(a + 4, long4(x));
- _put(a + 3, long3(x));
- _put(a + 2, long2(x));
- _put(a + 1, long1(x));
- _put(a + 0, long0(x));
- }
-
- static void putLongB(ByteBuffer bb, int bi, long x) {
- bb._put(bi + 0, long7(x));
- bb._put(bi + 1, long6(x));
- bb._put(bi + 2, long5(x));
- bb._put(bi + 3, long4(x));
- bb._put(bi + 4, long3(x));
- bb._put(bi + 5, long2(x));
- bb._put(bi + 6, long1(x));
- bb._put(bi + 7, long0(x));
- }
-
- static void putLongB(long a, long x) {
- _put(a + 0, long7(x));
- _put(a + 1, long6(x));
- _put(a + 2, long5(x));
- _put(a + 3, long4(x));
- _put(a + 4, long3(x));
- _put(a + 5, long2(x));
- _put(a + 6, long1(x));
- _put(a + 7, long0(x));
- }
-
- static void putLong(ByteBuffer bb, int bi, long x, boolean bigEndian) {
- if (bigEndian)
- putLongB(bb, bi, x);
- else
- putLongL(bb, bi, x);
- }
-
- static void putLong(long a, long x, boolean bigEndian) {
- if (bigEndian)
- putLongB(a, x);
- else
- putLongL(a, x);
- }
-
-
- // -- get/put float --
-
- static float getFloatL(ByteBuffer bb, int bi) {
- return Float.intBitsToFloat(getIntL(bb, bi));
- }
-
- static float getFloatL(long a) {
- return Float.intBitsToFloat(getIntL(a));
- }
-
- static float getFloatB(ByteBuffer bb, int bi) {
- return Float.intBitsToFloat(getIntB(bb, bi));
- }
-
- static float getFloatB(long a) {
- return Float.intBitsToFloat(getIntB(a));
- }
-
- static float getFloat(ByteBuffer bb, int bi, boolean bigEndian) {
- return (bigEndian ? getFloatB(bb, bi) : getFloatL(bb, bi));
- }
-
- static float getFloat(long a, boolean bigEndian) {
- return (bigEndian ? getFloatB(a) : getFloatL(a));
- }
-
- static void putFloatL(ByteBuffer bb, int bi, float x) {
- putIntL(bb, bi, Float.floatToRawIntBits(x));
- }
-
- static void putFloatL(long a, float x) {
- putIntL(a, Float.floatToRawIntBits(x));
- }
-
- static void putFloatB(ByteBuffer bb, int bi, float x) {
- putIntB(bb, bi, Float.floatToRawIntBits(x));
- }
-
- static void putFloatB(long a, float x) {
- putIntB(a, Float.floatToRawIntBits(x));
- }
-
- static void putFloat(ByteBuffer bb, int bi, float x, boolean bigEndian) {
- if (bigEndian)
- putFloatB(bb, bi, x);
- else
- putFloatL(bb, bi, x);
- }
-
- static void putFloat(long a, float x, boolean bigEndian) {
- if (bigEndian)
- putFloatB(a, x);
- else
- putFloatL(a, x);
- }
-
-
- // -- get/put double --
-
- static double getDoubleL(ByteBuffer bb, int bi) {
- return Double.longBitsToDouble(getLongL(bb, bi));
- }
-
- static double getDoubleL(long a) {
- return Double.longBitsToDouble(getLongL(a));
- }
-
- static double getDoubleB(ByteBuffer bb, int bi) {
- return Double.longBitsToDouble(getLongB(bb, bi));
- }
-
- static double getDoubleB(long a) {
- return Double.longBitsToDouble(getLongB(a));
- }
-
- static double getDouble(ByteBuffer bb, int bi, boolean bigEndian) {
- return (bigEndian ? getDoubleB(bb, bi) : getDoubleL(bb, bi));
- }
-
- static double getDouble(long a, boolean bigEndian) {
- return (bigEndian ? getDoubleB(a) : getDoubleL(a));
- }
-
- static void putDoubleL(ByteBuffer bb, int bi, double x) {
- putLongL(bb, bi, Double.doubleToRawLongBits(x));
- }
-
- static void putDoubleL(long a, double x) {
- putLongL(a, Double.doubleToRawLongBits(x));
- }
-
- static void putDoubleB(ByteBuffer bb, int bi, double x) {
- putLongB(bb, bi, Double.doubleToRawLongBits(x));
- }
-
- static void putDoubleB(long a, double x) {
- putLongB(a, Double.doubleToRawLongBits(x));
- }
-
- static void putDouble(ByteBuffer bb, int bi, double x, boolean bigEndian) {
- if (bigEndian)
- putDoubleB(bb, bi, x);
- else
- putDoubleL(bb, bi, x);
- }
-
- static void putDouble(long a, double x, boolean bigEndian) {
- if (bigEndian)
- putDoubleB(a, x);
- else
- putDoubleL(a, x);
- }
-
-
- // -- Unsafe access --
-
- private static final Unsafe unsafe = Unsafe.getUnsafe();
-
- private static byte _get(long a) {
- return unsafe.getByte(a);
- }
-
- private static void _put(long a, byte b) {
- unsafe.putByte(a, b);
- }
-
- static Unsafe unsafe() {
- return unsafe;
- }
-
-
- // -- Processor and memory-system properties --
-
- private static ByteOrder byteOrder = null;
-
- static ByteOrder byteOrder() {
- if (byteOrder != null)
- return byteOrder;
- long a = unsafe.allocateMemory(8);
- try {
- unsafe.putLong(a, 0x0102030405060708L);
- byte b = unsafe.getByte(a);
- switch (b) {
- case 0x01: byteOrder = ByteOrder.BIG_ENDIAN; break;
- case 0x08: byteOrder = ByteOrder.LITTLE_ENDIAN; break;
- default:
- throw new Error("Unknown byte order");
- }
- } finally {
- unsafe.freeMemory(a);
- }
- return byteOrder;
- }
-
-
- private static int pageSize = -1;
-
- static int pageSize() {
- if (pageSize == -1)
- pageSize = unsafe().pageSize();
- return pageSize;
- }
-
-
- private static boolean unaligned;
- private static boolean unalignedKnown = false;
-
- static boolean unaligned() {
- if (unalignedKnown)
- return unaligned;
- PrivilegedAction pa
- = new sun.security.action.GetPropertyAction("os.arch");
- String arch = (String)AccessController.doPrivileged(pa);
- unaligned = arch.equals("i386");
- unalignedKnown = true;
- return unaligned;
- }
-
-
- // -- Direct memory management --
-
- // A user-settable upper limit on the maximum amount of allocatable
- // direct buffer memory. This value may be changed during VM
- // initialization if it is launched with "-XX:MaxDirectMemorySize=<size>".
- private static long maxMemory = VM.maxDirectMemory();
- private static long reservedMemory = 0;
- private static boolean memoryLimitSet = false;
-
- // These methods should be called whenever direct memory is allocated or
- // freed. They allow the user to control the amount of direct memory
- // which a process may access. All sizes are specified in bytes.
- static synchronized void reserveMemory(long size) {
- if (!memoryLimitSet && VM.isBooted()) {
- maxMemory = VM.maxDirectMemory();
- memoryLimitSet = true;
- }
- if (reservedMemory + size > maxMemory) {
- System.gc();
- if (reservedMemory + size > maxMemory)
- throw new OutOfMemoryError();
- }
- reservedMemory += size;
- }
-
- static synchronized void unreserveMemory(long size) {
- if (reservedMemory > 0) {
- reservedMemory -= size;
- assert (reservedMemory > -1);
- }
- }
-
-
- // -- Bulk get/put acceleration --
-
- // These numbers represent the point at which we have empirically
- // determined that the average cost of a JNI call exceeds the expense
- // of an element by element copy. These numbers may change over time.
- static final int JNI_COPY_TO_ARRAY_THRESHOLD = 6;
- static final int JNI_COPY_FROM_ARRAY_THRESHOLD = 6;
-
- // These methods do no bounds checking. Verification that the copy will not
- // result in memory corruption should be done prior to invocation.
- // All positions and lengths are specified in bytes.
-
- static native void copyFromByteArray(Object src, long srcPos, long dstAddr,
- long length);
- static native void copyToByteArray(long srcAddr, Object dst, long dstPos,
- long length);
-
- static void copyFromCharArray(Object src, long srcPos, long dstAddr,
- long length)
- {
- copyFromShortArray(src, srcPos, dstAddr, length);
- }
-
- static void copyToCharArray(long srcAddr, Object dst, long dstPos,
- long length)
- {
- copyToShortArray(srcAddr, dst, dstPos, length);
- }
-
- static native void copyFromShortArray(Object src, long srcPos, long dstAddr,
- long length);
- static native void copyToShortArray(long srcAddr, Object dst, long dstPos,
- long length);
-
- static native void copyFromIntArray(Object src, long srcPos, long dstAddr,
- long length);
- static native void copyToIntArray(long srcAddr, Object dst, long dstPos,
- long length);
-
- static native void copyFromLongArray(Object src, long srcPos, long dstAddr,
- long length);
- static native void copyToLongArray(long srcAddr, Object dst, long dstPos,
- long length);
-
- }