8149469: ByteBuffer API and implementation enhancements for VarHandles
Reviewed-by: chegar, alanb
/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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* 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
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*
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* 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
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#warn This file is preprocessed before being compiled
package java.nio;
import java.io.FileDescriptor;
import jdk.internal.misc.Unsafe;
import jdk.internal.misc.VM;
import jdk.internal.ref.Cleaner;
import sun.nio.ch.DirectBuffer;
class Direct$Type$Buffer$RW$$BO$
#if[rw]
extends {#if[byte]?Mapped$Type$Buffer:$Type$Buffer}
#else[rw]
extends Direct$Type$Buffer$BO$
#end[rw]
implements DirectBuffer
{
#if[rw]
// Cached unsafe-access object
protected static final Unsafe unsafe = Bits.unsafe();
// Cached array base offset
private static final long arrayBaseOffset = (long)unsafe.arrayBaseOffset($type$[].class);
// Cached unaligned-access capability
protected static final boolean unaligned = Bits.unaligned();
// Base address, used in all indexing calculations
// NOTE: moved up to Buffer.java for speed in JNI GetDirectBufferAddress
// protected long address;
// An object attached to this buffer. If this buffer is a view of another
// buffer then we use this field to keep a reference to that buffer to
// ensure that its memory isn't freed before we are done with it.
private final Object att;
public Object attachment() {
return att;
}
#if[byte]
private static class Deallocator
implements Runnable
{
private static Unsafe unsafe = Unsafe.getUnsafe();
private long address;
private long size;
private int capacity;
private Deallocator(long address, long size, int capacity) {
assert (address != 0);
this.address = address;
this.size = size;
this.capacity = capacity;
}
public void run() {
if (address == 0) {
// Paranoia
return;
}
unsafe.freeMemory(address);
address = 0;
Bits.unreserveMemory(size, capacity);
}
}
private final Cleaner cleaner;
public Cleaner cleaner() { return cleaner; }
#else[byte]
public Cleaner cleaner() { return null; }
#end[byte]
#end[rw]
#if[byte]
// Primary constructor
//
Direct$Type$Buffer$RW$(int cap) { // package-private
#if[rw]
super(-1, 0, cap, cap);
boolean pa = VM.isDirectMemoryPageAligned();
int ps = Bits.pageSize();
long size = Math.max(1L, (long)cap + (pa ? ps : 0));
Bits.reserveMemory(size, cap);
long base = 0;
try {
base = unsafe.allocateMemory(size);
} catch (OutOfMemoryError x) {
Bits.unreserveMemory(size, cap);
throw x;
}
unsafe.setMemory(base, size, (byte) 0);
if (pa && (base % ps != 0)) {
// Round up to page boundary
address = base + ps - (base & (ps - 1));
} else {
address = base;
}
cleaner = Cleaner.create(this, new Deallocator(base, size, cap));
att = null;
#else[rw]
super(cap);
this.isReadOnly = true;
#end[rw]
}
#if[rw]
// Invoked to construct a direct ByteBuffer referring to the block of
// memory. A given arbitrary object may also be attached to the buffer.
//
Direct$Type$Buffer(long addr, int cap, Object ob) {
super(-1, 0, cap, cap);
address = addr;
cleaner = null;
att = ob;
}
// Invoked only by JNI: NewDirectByteBuffer(void*, long)
//
private Direct$Type$Buffer(long addr, int cap) {
super(-1, 0, cap, cap);
address = addr;
cleaner = null;
att = null;
}
#end[rw]
// For memory-mapped buffers -- invoked by FileChannelImpl via reflection
//
protected Direct$Type$Buffer$RW$(int cap, long addr,
FileDescriptor fd,
Runnable unmapper)
{
#if[rw]
super(-1, 0, cap, cap, fd);
address = addr;
cleaner = Cleaner.create(this, unmapper);
att = null;
#else[rw]
super(cap, addr, fd, unmapper);
this.isReadOnly = true;
#end[rw]
}
#end[byte]
// For duplicates and slices
//
Direct$Type$Buffer$RW$$BO$(DirectBuffer db, // package-private
int mark, int pos, int lim, int cap,
int off)
{
#if[rw]
super(mark, pos, lim, cap);
address = db.address() + off;
#if[byte]
cleaner = null;
#end[byte]
att = db;
#else[rw]
super(db, mark, pos, lim, cap, off);
this.isReadOnly = true;
#end[rw]
}
public $Type$Buffer slice() {
int pos = this.position();
int lim = this.limit();
assert (pos <= lim);
int rem = (pos <= lim ? lim - pos : 0);
int off = (pos << $LG_BYTES_PER_VALUE$);
assert (off >= 0);
return new Direct$Type$Buffer$RW$$BO$(this, -1, 0, rem, rem, off);
}
#if[byte]
public $Type$Buffer slice(int pos, int lim) {
assert (pos >= 0);
assert (pos <= lim);
int rem = lim - pos;
return new Direct$Type$Buffer$RW$$BO$(this, -1, 0, rem, rem, pos);
}
#end[byte]
public $Type$Buffer duplicate() {
return new Direct$Type$Buffer$RW$$BO$(this,
this.markValue(),
this.position(),
this.limit(),
this.capacity(),
0);
}
public $Type$Buffer asReadOnlyBuffer() {
#if[rw]
return new Direct$Type$BufferR$BO$(this,
this.markValue(),
this.position(),
this.limit(),
this.capacity(),
0);
#else[rw]
return duplicate();
#end[rw]
}
#if[rw]
public long address() {
return address;
}
private long ix(int i) {
return address + ((long)i << $LG_BYTES_PER_VALUE$);
}
public $type$ get() {
return $fromBits$($swap$(unsafe.get$Swaptype$(ix(nextGetIndex()))));
}
public $type$ get(int i) {
return $fromBits$($swap$(unsafe.get$Swaptype$(ix(checkIndex(i)))));
}
#if[streamableType]
$type$ getUnchecked(int i) {
return $fromBits$($swap$(unsafe.get$Swaptype$(ix(i))));
}
#end[streamableType]
public $Type$Buffer get($type$[] dst, int offset, int length) {
#if[rw]
if (((long)length << $LG_BYTES_PER_VALUE$) > Bits.JNI_COPY_TO_ARRAY_THRESHOLD) {
checkBounds(offset, length, dst.length);
int pos = position();
int lim = limit();
assert (pos <= lim);
int rem = (pos <= lim ? lim - pos : 0);
if (length > rem)
throw new BufferUnderflowException();
long dstOffset = arrayBaseOffset + ((long)offset << $LG_BYTES_PER_VALUE$);
#if[!byte]
if (order() != ByteOrder.nativeOrder())
unsafe.copySwapMemory(null,
ix(pos),
dst,
dstOffset,
(long)length << $LG_BYTES_PER_VALUE$,
(long)1 << $LG_BYTES_PER_VALUE$);
else
#end[!byte]
unsafe.copyMemory(null,
ix(pos),
dst,
dstOffset,
(long)length << $LG_BYTES_PER_VALUE$);
position(pos + length);
} else {
super.get(dst, offset, length);
}
return this;
#else[rw]
throw new ReadOnlyBufferException();
#end[rw]
}
#end[rw]
public $Type$Buffer put($type$ x) {
#if[rw]
unsafe.put$Swaptype$(ix(nextPutIndex()), $swap$($toBits$(x)));
return this;
#else[rw]
throw new ReadOnlyBufferException();
#end[rw]
}
public $Type$Buffer put(int i, $type$ x) {
#if[rw]
unsafe.put$Swaptype$(ix(checkIndex(i)), $swap$($toBits$(x)));
return this;
#else[rw]
throw new ReadOnlyBufferException();
#end[rw]
}
public $Type$Buffer put($Type$Buffer src) {
#if[rw]
if (src instanceof Direct$Type$Buffer$BO$) {
if (src == this)
throw createSameBufferException();
Direct$Type$Buffer$RW$$BO$ sb = (Direct$Type$Buffer$RW$$BO$)src;
int spos = sb.position();
int slim = sb.limit();
assert (spos <= slim);
int srem = (spos <= slim ? slim - spos : 0);
int pos = position();
int lim = limit();
assert (pos <= lim);
int rem = (pos <= lim ? lim - pos : 0);
if (srem > rem)
throw new BufferOverflowException();
unsafe.copyMemory(sb.ix(spos), ix(pos), (long)srem << $LG_BYTES_PER_VALUE$);
sb.position(spos + srem);
position(pos + srem);
} else if (src.hb != null) {
int spos = src.position();
int slim = src.limit();
assert (spos <= slim);
int srem = (spos <= slim ? slim - spos : 0);
put(src.hb, src.offset + spos, srem);
src.position(spos + srem);
} else {
super.put(src);
}
return this;
#else[rw]
throw new ReadOnlyBufferException();
#end[rw]
}
public $Type$Buffer put($type$[] src, int offset, int length) {
#if[rw]
if (((long)length << $LG_BYTES_PER_VALUE$) > Bits.JNI_COPY_FROM_ARRAY_THRESHOLD) {
checkBounds(offset, length, src.length);
int pos = position();
int lim = limit();
assert (pos <= lim);
int rem = (pos <= lim ? lim - pos : 0);
if (length > rem)
throw new BufferOverflowException();
long srcOffset = arrayBaseOffset + ((long)offset << $LG_BYTES_PER_VALUE$);
#if[!byte]
if (order() != ByteOrder.nativeOrder())
unsafe.copySwapMemory(src,
srcOffset,
null,
ix(pos),
(long)length << $LG_BYTES_PER_VALUE$,
(long)1 << $LG_BYTES_PER_VALUE$);
else
#end[!byte]
unsafe.copyMemory(src,
srcOffset,
null,
ix(pos),
(long)length << $LG_BYTES_PER_VALUE$);
position(pos + length);
} else {
super.put(src, offset, length);
}
return this;
#else[rw]
throw new ReadOnlyBufferException();
#end[rw]
}
public $Type$Buffer compact() {
#if[rw]
int pos = position();
int lim = limit();
assert (pos <= lim);
int rem = (pos <= lim ? lim - pos : 0);
unsafe.copyMemory(ix(pos), ix(0), (long)rem << $LG_BYTES_PER_VALUE$);
position(rem);
limit(capacity());
discardMark();
return this;
#else[rw]
throw new ReadOnlyBufferException();
#end[rw]
}
public boolean isDirect() {
return true;
}
public boolean isReadOnly() {
return {#if[rw]?false:true};
}
#if[char]
public String toString(int start, int end) {
if ((end > limit()) || (start > end))
throw new IndexOutOfBoundsException();
try {
int len = end - start;
char[] ca = new char[len];
CharBuffer cb = CharBuffer.wrap(ca);
CharBuffer db = this.duplicate();
db.position(start);
db.limit(end);
cb.put(db);
return new String(ca);
} catch (StringIndexOutOfBoundsException x) {
throw new IndexOutOfBoundsException();
}
}
// --- Methods to support CharSequence ---
public CharBuffer subSequence(int start, int end) {
int pos = position();
int lim = limit();
assert (pos <= lim);
pos = (pos <= lim ? pos : lim);
int len = lim - pos;
if ((start < 0) || (end > len) || (start > end))
throw new IndexOutOfBoundsException();
return new DirectCharBuffer$RW$$BO$(this,
-1,
pos + start,
pos + end,
capacity(),
offset);
}
#end[char]
#if[!byte]
public ByteOrder order() {
#if[boS]
return ((ByteOrder.nativeOrder() == ByteOrder.BIG_ENDIAN)
? ByteOrder.LITTLE_ENDIAN : ByteOrder.BIG_ENDIAN);
#end[boS]
#if[boU]
return ((ByteOrder.nativeOrder() != ByteOrder.BIG_ENDIAN)
? ByteOrder.LITTLE_ENDIAN : ByteOrder.BIG_ENDIAN);
#end[boU]
}
#end[!byte]
#if[byte]
byte _get(int i) { // package-private
return unsafe.getByte(address + i);
}
void _put(int i, byte b) { // package-private
#if[rw]
unsafe.putByte(address + i, b);
#else[rw]
throw new ReadOnlyBufferException();
#end[rw]
}
// #BIN
//
// Binary-data access methods for short, char, int, long, float,
// and double will be inserted here
#end[byte]
}