https://openjdk.java.net/ 
/*
 * Copyright (c) 2000, 2017, 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.
 */

package sun.misc;

import jdk.internal.vm.annotation.ForceInline;
import jdk.internal.misc.VM;
import jdk.internal.ref.Cleaner;
import jdk.internal.reflect.CallerSensitive;
import jdk.internal.reflect.Reflection;
import sun.nio.ch.DirectBuffer;

import java.lang.reflect.Field;
import java.security.ProtectionDomain;



A collection of methods for performing low-level, unsafe operations.
Although the class and all methods are public, use of this class is
limited because only trusted code can obtain instances of it.
Note: It is the resposibility of the caller to make sure
arguments are checked before methods of this class are
called. While some rudimentary checks are performed on the input,
the checks are best effort and when performance is an overriding
priority, as when methods of this class are optimized by the
runtime compiler, some or all checks (if any) may be elided. Hence,
the caller must not rely on the checks and corresponding
exceptions!

Author:John R. Rose
See Also:
/**
 * A collection of methods for performing low-level, unsafe operations.
 * Although the class and all methods are public, use of this class is
 * limited because only trusted code can obtain instances of it.
 *
 * <em>Note:</em> It is the resposibility of the caller to make sure
 * arguments are checked before methods of this class are
 * called. While some rudimentary checks are performed on the input,
 * the checks are best effort and when performance is an overriding
 * priority, as when methods of this class are optimized by the
 * runtime compiler, some or all checks (if any) may be elided. Hence,
 * the caller must not rely on the checks and corresponding
 * exceptions!
 *
 * @author John R. Rose
 * @see #getUnsafe
 */

public final class Unsafe {

    static {
        Reflection.registerMethodsToFilter(Unsafe.class, "getUnsafe");
    }

    private Unsafe() {}

    private static final Unsafe theUnsafe = new Unsafe();
    private static final jdk.internal.misc.Unsafe theInternalUnsafe = jdk.internal.misc.Unsafe.getUnsafe();

    
Provides the caller with the capability of performing unsafe
operations.

The returned Unsafe object should be carefully guarded by the caller, since it can be used to read and write data at arbitrary memory addresses. It must never be passed to untrusted code. 
Most methods in this class are very low-level, and correspond to a
small number of hardware instructions (on typical machines).  Compilers
are encouraged to optimize these methods accordingly.

Here is a suggested idiom for using unsafe operations:

 
class MyTrustedClass {
  private static final Unsafe unsafe = Unsafe.getUnsafe();
  ...
  private long myCountAddress = ...;
  public int getCount() { return unsafe.getByte(myCountAddress); }
 }
 (It may assist compilers to make the local variable final.) 
Throws:
  • SecurityException – if the class loader of the caller
         class is not in the system domain in which all permissions
         are granted.
/**
     * Provides the caller with the capability of performing unsafe
     * operations.
     *
     * <p>The returned {@code Unsafe} object should be carefully guarded
     * by the caller, since it can be used to read and write data at arbitrary
     * memory addresses.  It must never be passed to untrusted code.
     *
     * <p>Most methods in this class are very low-level, and correspond to a
     * small number of hardware instructions (on typical machines).  Compilers
     * are encouraged to optimize these methods accordingly.
     *
     * <p>Here is a suggested idiom for using unsafe operations:
     *
     * <pre> {@code
     * class MyTrustedClass {
     *   private static final Unsafe unsafe = Unsafe.getUnsafe();
     *   ...
     *   private long myCountAddress = ...;
     *   public int getCount() { return unsafe.getByte(myCountAddress); }
     * }}</pre>
     *
     * (It may assist compilers to make the local variable {@code final}.)
     *
     * @throws  SecurityException if the class loader of the caller
     *          class is not in the system domain in which all permissions
     *          are granted.
     */
    @CallerSensitive
    public static Unsafe getUnsafe() {
        Class<?> caller = Reflection.getCallerClass();
        if (!VM.isSystemDomainLoader(caller.getClassLoader()))
            throw new SecurityException("Unsafe");
        return theUnsafe;
    }

    /// peek and poke operations
    /// (compilers should optimize these to memory ops)

    // These work on object fields in the Java heap.
    // They will not work on elements of packed arrays.

    
Fetches a value from a given Java variable. More specifically, fetches a field or array element within the given object o at the given offset, or (if o is null) from the memory address whose numerical value is the given offset. 

The results are undefined unless one of the following cases is true:

    

  • The offset was obtained from objectFieldOffset on the Field of some Java field and the object referred to by o is of a class compatible with that field's class. 
  • The offset and object reference o (either null or non-null) were both obtained via staticFieldOffset and staticFieldBase (respectively) from the reflective Field representation of some Java field. 
  • The object referred to by o is an array, and the offset is an integer of the form B+N*S, where N is a valid index into the array, and B and S are the values obtained by arrayBaseOffset and arrayIndexScale (respectively) from the array's class. The value referred to is the Nth element of the array.




If one of the above cases is true, the call references a specific Java
variable (field or array element).  However, the results are undefined
if that variable is not in fact of the type returned by this method.


This method refers to a variable by means of two parameters, and so
it provides (in effect) a double-register addressing mode for Java variables. When the object reference is null, this method uses its offset as an absolute address. This is similar in operation to methods such as getInt(long), which provide (in effect) a single-register addressing mode for non-Java variables.
However, because Java variables may have a different layout in memory
from non-Java variables, programmers should not assume that these
two addressing modes are ever equivalent.  Also, programmers should
remember that offsets from the double-register addressing mode cannot
be portably confused with longs used in the single-register addressing
mode.

Params:
  • o – Java heap object in which the variable resides, if any, else
       null
  • offset – indication of where the variable resides in a Java heap
       object, if any, else a memory address locating the variable
       statically
Throws:
Returns:the value fetched from the indicated Java variable
/**
     * Fetches a value from a given Java variable.
     * More specifically, fetches a field or array element within the given
     * object {@code o} at the given offset, or (if {@code o} is null)
     * from the memory address whose numerical value is the given offset.
     * <p>
     * The results are undefined unless one of the following cases is true:
     * <ul>
     * <li>The offset was obtained from {@link #objectFieldOffset} on
     * the {@link java.lang.reflect.Field} of some Java field and the object
     * referred to by {@code o} is of a class compatible with that
     * field's class.
     *
     * <li>The offset and object reference {@code o} (either null or
     * non-null) were both obtained via {@link #staticFieldOffset}
     * and {@link #staticFieldBase} (respectively) from the
     * reflective {@link Field} representation of some Java field.
     *
     * <li>The object referred to by {@code o} is an array, and the offset
     * is an integer of the form {@code B+N*S}, where {@code N} is
     * a valid index into the array, and {@code B} and {@code S} are
     * the values obtained by {@link #arrayBaseOffset} and {@link
     * #arrayIndexScale} (respectively) from the array's class.  The value
     * referred to is the {@code N}<em>th</em> element of the array.
     *
     * </ul>
     * <p>
     * If one of the above cases is true, the call references a specific Java
     * variable (field or array element).  However, the results are undefined
     * if that variable is not in fact of the type returned by this method.
     * <p>
     * This method refers to a variable by means of two parameters, and so
     * it provides (in effect) a <em>double-register</em> addressing mode
     * for Java variables.  When the object reference is null, this method
     * uses its offset as an absolute address.  This is similar in operation
     * to methods such as {@link #getInt(long)}, which provide (in effect) a
     * <em>single-register</em> addressing mode for non-Java variables.
     * However, because Java variables may have a different layout in memory
     * from non-Java variables, programmers should not assume that these
     * two addressing modes are ever equivalent.  Also, programmers should
     * remember that offsets from the double-register addressing mode cannot
     * be portably confused with longs used in the single-register addressing
     * mode.
     *
     * @param o Java heap object in which the variable resides, if any, else
     *        null
     * @param offset indication of where the variable resides in a Java heap
     *        object, if any, else a memory address locating the variable
     *        statically
     * @return the value fetched from the indicated Java variable
     * @throws RuntimeException No defined exceptions are thrown, not even
     *         {@link NullPointerException}
     */
    @ForceInline
    public int getInt(Object o, long offset) {
        return theInternalUnsafe.getInt(o, offset);
    }

    
Stores a value into a given Java variable.

 The first two parameters are interpreted exactly as with getInt(Object, long) to refer to a specific Java variable (field or array element). The given value is stored into that variable. 
 The variable must be of the same type as the method parameter x. 
Params:
  • o – Java heap object in which the variable resides, if any, else
       null
  • offset – indication of where the variable resides in a Java heap
       object, if any, else a memory address locating the variable
       statically
  • x – the value to store into the indicated Java variable
Throws:
/**
     * Stores a value into a given Java variable.
     * <p>
     * The first two parameters are interpreted exactly as with
     * {@link #getInt(Object, long)} to refer to a specific
     * Java variable (field or array element).  The given value
     * is stored into that variable.
     * <p>
     * The variable must be of the same type as the method
     * parameter {@code x}.
     *
     * @param o Java heap object in which the variable resides, if any, else
     *        null
     * @param offset indication of where the variable resides in a Java heap
     *        object, if any, else a memory address locating the variable
     *        statically
     * @param x the value to store into the indicated Java variable
     * @throws RuntimeException No defined exceptions are thrown, not even
     *         {@link NullPointerException}
     */
    @ForceInline
    public void putInt(Object o, long offset, int x) {
        theInternalUnsafe.putInt(o, offset, x);
    }

    
Fetches a reference value from a given Java variable.

See Also:
  • getInt(Object, long)
/**
     * Fetches a reference value from a given Java variable.
     * @see #getInt(Object, long)
     */
    @ForceInline
    public Object getObject(Object o, long offset) {
        return theInternalUnsafe.getObject(o, offset);
    }

    
Stores a reference value into a given Java variable.

 Unless the reference x being stored is either null or matches the field type, the results are undefined. If the reference o is non-null, card marks or other store barriers for that object (if the VM requires them) are updated. 
See Also:
/**
     * Stores a reference value into a given Java variable.
     * <p>
     * Unless the reference {@code x} being stored is either null
     * or matches the field type, the results are undefined.
     * If the reference {@code o} is non-null, card marks or
     * other store barriers for that object (if the VM requires them)
     * are updated.
     * @see #putInt(Object, long, int)
     */
    @ForceInline
    public void putObject(Object o, long offset, Object x) {
        theInternalUnsafe.putObject(o, offset, x);
    }

    
See Also:
/** @see #getInt(Object, long) */
    @ForceInline
    public boolean getBoolean(Object o, long offset) {
        return theInternalUnsafe.getBoolean(o, offset);
    }

    
See Also:
/** @see #putInt(Object, long, int) */
    @ForceInline
    public void putBoolean(Object o, long offset, boolean x) {
        theInternalUnsafe.putBoolean(o, offset, x);
    }

    
See Also:
/** @see #getInt(Object, long) */
    @ForceInline
    public byte getByte(Object o, long offset) {
        return theInternalUnsafe.getByte(o, offset);
    }

    
See Also:
/** @see #putInt(Object, long, int) */
    @ForceInline
    public void putByte(Object o, long offset, byte x) {
        theInternalUnsafe.putByte(o, offset, x);
    }

    
See Also:
/** @see #getInt(Object, long) */
    @ForceInline
    public short getShort(Object o, long offset) {
        return theInternalUnsafe.getShort(o, offset);
    }

    
See Also:
/** @see #putInt(Object, long, int) */
    @ForceInline
    public void putShort(Object o, long offset, short x) {
        theInternalUnsafe.putShort(o, offset, x);
    }

    
See Also:
/** @see #getInt(Object, long) */
    @ForceInline
    public char getChar(Object o, long offset) {
        return theInternalUnsafe.getChar(o, offset);
    }

    
See Also:
/** @see #putInt(Object, long, int) */
    @ForceInline
    public void putChar(Object o, long offset, char x) {
        theInternalUnsafe.putChar(o, offset, x);
    }

    
See Also:
/** @see #getInt(Object, long) */
    @ForceInline
    public long getLong(Object o, long offset) {
        return theInternalUnsafe.getLong(o, offset);
    }

    
See Also:
/** @see #putInt(Object, long, int) */
    @ForceInline
    public void putLong(Object o, long offset, long x) {
        theInternalUnsafe.putLong(o, offset, x);
    }

    
See Also:
/** @see #getInt(Object, long) */
    @ForceInline
    public float getFloat(Object o, long offset) {
        return theInternalUnsafe.getFloat(o, offset);
    }

    
See Also:
/** @see #putInt(Object, long, int) */
    @ForceInline
    public void putFloat(Object o, long offset, float x) {
        theInternalUnsafe.putFloat(o, offset, x);
    }

    
See Also:
/** @see #getInt(Object, long) */
    @ForceInline
    public double getDouble(Object o, long offset) {
        return theInternalUnsafe.getDouble(o, offset);
    }

    
See Also:
/** @see #putInt(Object, long, int) */
    @ForceInline
    public void putDouble(Object o, long offset, double x) {
        theInternalUnsafe.putDouble(o, offset, x);
    }

    // These work on values in the C heap.

    
Fetches a value from a given memory address. If the address is zero, or does not point into a block obtained from allocateMemory, the results are undefined. 
See Also:
/**
     * Fetches a value from a given memory address.  If the address is zero, or
     * does not point into a block obtained from {@link #allocateMemory}, the
     * results are undefined.
     *
     * @see #allocateMemory
     */
    @ForceInline
    public byte getByte(long address) {
        return theInternalUnsafe.getByte(address);
    }

    
Stores a value into a given memory address. If the address is zero, or does not point into a block obtained from allocateMemory, the results are undefined. 
See Also:
/**
     * Stores a value into a given memory address.  If the address is zero, or
     * does not point into a block obtained from {@link #allocateMemory}, the
     * results are undefined.
     *
     * @see #getByte(long)
     */
    @ForceInline
    public void putByte(long address, byte x) {
        theInternalUnsafe.putByte(address, x);
    }

    
See Also:
/** @see #getByte(long) */
    @ForceInline
    public short getShort(long address) {
        return theInternalUnsafe.getShort(address);
    }

    
See Also:
/** @see #putByte(long, byte) */
    @ForceInline
    public void putShort(long address, short x) {
        theInternalUnsafe.putShort(address, x);
    }

    
See Also:
/** @see #getByte(long) */
    @ForceInline
    public char getChar(long address) {
        return theInternalUnsafe.getChar(address);
    }

    
See Also:
/** @see #putByte(long, byte) */
    @ForceInline
    public void putChar(long address, char x) {
        theInternalUnsafe.putChar(address, x);
    }

    
See Also:
/** @see #getByte(long) */
    @ForceInline
    public int getInt(long address) {
        return theInternalUnsafe.getInt(address);
    }

    
See Also:
/** @see #putByte(long, byte) */
    @ForceInline
    public void putInt(long address, int x) {
        theInternalUnsafe.putInt(address, x);
    }

    
See Also:
/** @see #getByte(long) */
    @ForceInline
    public long getLong(long address) {
        return theInternalUnsafe.getLong(address);
    }

    
See Also:
/** @see #putByte(long, byte) */
    @ForceInline
    public void putLong(long address, long x) {
        theInternalUnsafe.putLong(address, x);
    }

    
See Also:
/** @see #getByte(long) */
    @ForceInline
    public float getFloat(long address) {
        return theInternalUnsafe.getFloat(address);
    }

    
See Also:
/** @see #putByte(long, byte) */
    @ForceInline
    public void putFloat(long address, float x) {
        theInternalUnsafe.putFloat(address, x);
    }

    
See Also:
/** @see #getByte(long) */
    @ForceInline
    public double getDouble(long address) {
        return theInternalUnsafe.getDouble(address);
    }

    
See Also:
/** @see #putByte(long, byte) */
    @ForceInline
    public void putDouble(long address, double x) {
        theInternalUnsafe.putDouble(address, x);
    }


    
Fetches a native pointer from a given memory address. If the address is zero, or does not point into a block obtained from allocateMemory, the results are undefined. 
If the native pointer is less than 64 bits wide, it is extended as an unsigned number to a Java long. The pointer may be indexed by any given byte offset, simply by adding that offset (as a simple integer) to the long representing the pointer. The number of bytes actually read from the target address may be determined by consulting addressSize. 
See Also:
/**
     * Fetches a native pointer from a given memory address.  If the address is
     * zero, or does not point into a block obtained from {@link
     * #allocateMemory}, the results are undefined.
     *
     * <p>If the native pointer is less than 64 bits wide, it is extended as
     * an unsigned number to a Java long.  The pointer may be indexed by any
     * given byte offset, simply by adding that offset (as a simple integer) to
     * the long representing the pointer.  The number of bytes actually read
     * from the target address may be determined by consulting {@link
     * #addressSize}.
     *
     * @see #allocateMemory
     */
    @ForceInline
    public long getAddress(long address) {
        return theInternalUnsafe.getAddress(address);
    }

    
Stores a native pointer into a given memory address. If the address is zero, or does not point into a block obtained from allocateMemory, the results are undefined. 
The number of bytes actually written at the target address may be determined by consulting addressSize. 
See Also:
/**
     * Stores a native pointer into a given memory address.  If the address is
     * zero, or does not point into a block obtained from {@link
     * #allocateMemory}, the results are undefined.
     *
     * <p>The number of bytes actually written at the target address may be
     * determined by consulting {@link #addressSize}.
     *
     * @see #getAddress(long)
     */
    @ForceInline
    public void putAddress(long address, long x) {
        theInternalUnsafe.putAddress(address, x);
    }


    /// wrappers for malloc, realloc, free:

    
Allocates a new block of native memory, of the given size in bytes. The contents of the memory are uninitialized; they will generally be garbage. The resulting native pointer will never be zero, and will be aligned for all value types. Dispose of this memory by calling freeMemory, or resize it with reallocateMemory. Note: It is the resposibility of the caller to make
sure arguments are checked before the methods are called. While
some rudimentary checks are performed on the input, the checks
are best effort and when performance is an overriding priority,
as when methods of this class are optimized by the runtime
compiler, some or all checks (if any) may be elided. Hence, the
caller must not rely on the checks and corresponding
exceptions!

Throws:
See Also:
/**
     * Allocates a new block of native memory, of the given size in bytes.  The
     * contents of the memory are uninitialized; they will generally be
     * garbage.  The resulting native pointer will never be zero, and will be
     * aligned for all value types.  Dispose of this memory by calling {@link
     * #freeMemory}, or resize it with {@link #reallocateMemory}.
     *
     * <em>Note:</em> It is the resposibility of the caller to make
     * sure arguments are checked before the methods are called. While
     * some rudimentary checks are performed on the input, the checks
     * are best effort and when performance is an overriding priority,
     * as when methods of this class are optimized by the runtime
     * compiler, some or all checks (if any) may be elided. Hence, the
     * caller must not rely on the checks and corresponding
     * exceptions!
     *
     * @throws RuntimeException if the size is negative or too large
     *         for the native size_t type
     *
     * @throws OutOfMemoryError if the allocation is refused by the system
     *
     * @see #getByte(long)
     * @see #putByte(long, byte)
     */
    @ForceInline
    public long allocateMemory(long bytes) {
        return theInternalUnsafe.allocateMemory(bytes);
    }

    
Resizes a new block of native memory, to the given size in bytes. The contents of the new block past the size of the old block are uninitialized; they will generally be garbage. The resulting native pointer will be zero if and only if the requested size is zero. The resulting native pointer will be aligned for all value types. Dispose of this memory by calling freeMemory, or resize it with reallocateMemory. The address passed to this method may be null, in which case an allocation will be performed. Note: It is the resposibility of the caller to make
sure arguments are checked before the methods are called. While
some rudimentary checks are performed on the input, the checks
are best effort and when performance is an overriding priority,
as when methods of this class are optimized by the runtime
compiler, some or all checks (if any) may be elided. Hence, the
caller must not rely on the checks and corresponding
exceptions!

Throws:
See Also:
/**
     * Resizes a new block of native memory, to the given size in bytes.  The
     * contents of the new block past the size of the old block are
     * uninitialized; they will generally be garbage.  The resulting native
     * pointer will be zero if and only if the requested size is zero.  The
     * resulting native pointer will be aligned for all value types.  Dispose
     * of this memory by calling {@link #freeMemory}, or resize it with {@link
     * #reallocateMemory}.  The address passed to this method may be null, in
     * which case an allocation will be performed.
     *
     * <em>Note:</em> It is the resposibility of the caller to make
     * sure arguments are checked before the methods are called. While
     * some rudimentary checks are performed on the input, the checks
     * are best effort and when performance is an overriding priority,
     * as when methods of this class are optimized by the runtime
     * compiler, some or all checks (if any) may be elided. Hence, the
     * caller must not rely on the checks and corresponding
     * exceptions!
     *
     * @throws RuntimeException if the size is negative or too large
     *         for the native size_t type
     *
     * @throws OutOfMemoryError if the allocation is refused by the system
     *
     * @see #allocateMemory
     */
    @ForceInline
    public long reallocateMemory(long address, long bytes) {
        return theInternalUnsafe.reallocateMemory(address, bytes);
    }

    
Sets all bytes in a given block of memory to a fixed value
(usually zero).

This method determines a block's base address by means of two parameters,
and so it provides (in effect) a double-register addressing mode, as discussed in getInt(Object, long). When the object reference is null, the offset supplies an absolute base address. 
The stores are in coherent (atomic) units of a size determined
by the address and length parameters.  If the effective address and
length are all even modulo 8, the stores take place in 'long' units.
If the effective address and length are (resp.) even modulo 4 or 2,
the stores take place in units of 'int' or 'short'.
Note: It is the resposibility of the caller to make
sure arguments are checked before the methods are called. While
some rudimentary checks are performed on the input, the checks
are best effort and when performance is an overriding priority,
as when methods of this class are optimized by the runtime
compiler, some or all checks (if any) may be elided. Hence, the
caller must not rely on the checks and corresponding
exceptions!

Throws:
Since:1.7
/**
     * Sets all bytes in a given block of memory to a fixed value
     * (usually zero).
     *
     * <p>This method determines a 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.
     *
     * <p>The stores are in coherent (atomic) units of a size determined
     * by the address and length parameters.  If the effective address and
     * length are all even modulo 8, the stores take place in 'long' units.
     * If the effective address and length are (resp.) even modulo 4 or 2,
     * the stores take place in units of 'int' or 'short'.
     *
     * <em>Note:</em> It is the resposibility of the caller to make
     * sure arguments are checked before the methods are called. While
     * some rudimentary checks are performed on the input, the checks
     * are best effort and when performance is an overriding priority,
     * as when methods of this class are optimized by the runtime
     * compiler, some or all checks (if any) may be elided. Hence, the
     * caller must not rely on the checks and corresponding
     * exceptions!
     *
     * @throws RuntimeException if any of the arguments is invalid
     *
     * @since 1.7
     */
    @ForceInline
    public void setMemory(Object o, long offset, long bytes, byte value) {
        theInternalUnsafe.setMemory(o, offset, bytes, value);
    }

    
Sets all bytes in a given block of memory to a fixed value
(usually zero).  This provides a single-register addressing mode, as discussed in getInt(Object, long). 
Equivalent to setMemory(null, address, bytes, value). 
/**
     * Sets all bytes in a given block of memory to a fixed value
     * (usually zero).  This provides a <em>single-register</em> addressing mode,
     * as discussed in {@link #getInt(Object,long)}.
     *
     * <p>Equivalent to {@code setMemory(null, address, bytes, value)}.
     */
    @ForceInline
    public void setMemory(long address, long bytes, byte value) {
        theInternalUnsafe.setMemory(address, bytes, value);
    }

    
Sets all bytes in a given block of memory to a copy of another
block.

This method determines each block's base address by means of two parameters,
and so it provides (in effect) a double-register addressing mode, as discussed in getInt(Object, long). When the object reference is null, the offset supplies an absolute base address. 
The transfers are in coherent (atomic) units of a size determined
by the address and length parameters.  If the effective addresses and
length are all even modulo 8, the transfer takes place in 'long' units.
If the effective addresses and length are (resp.) even modulo 4 or 2,
the transfer takes place in units of 'int' or 'short'.
Note: It is the resposibility of the caller to make
sure arguments are checked before the methods are called. While
some rudimentary checks are performed on the input, the checks
are best effort and when performance is an overriding priority,
as when methods of this class are optimized by the runtime
compiler, some or all checks (if any) may be elided. Hence, the
caller must not rely on the checks and corresponding
exceptions!

Throws:
Since:1.7
/**
     * Sets all bytes in a given block of memory to a copy of another
     * block.
     *
     * <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.
     *
     * <p>The transfers are in coherent (atomic) units of a size determined
     * by the address and length parameters.  If the effective addresses and
     * length are all even modulo 8, the transfer takes place in 'long' units.
     * If the effective addresses and length are (resp.) even modulo 4 or 2,
     * the transfer takes place in units of 'int' or 'short'.
     *
     * <em>Note:</em> It is the resposibility of the caller to make
     * sure arguments are checked before the methods are called. While
     * some rudimentary checks are performed on the input, the checks
     * are best effort and when performance is an overriding priority,
     * as when methods of this class are optimized by the runtime
     * compiler, some or all checks (if any) may be elided. Hence, the
     * caller must not rely on the checks and corresponding
     * exceptions!
     *
     * @throws RuntimeException if any of the arguments is invalid
     *
     * @since 1.7
     */
    @ForceInline
    public void copyMemory(Object srcBase, long srcOffset,
                           Object destBase, long destOffset,
                           long bytes) {
        theInternalUnsafe.copyMemory(srcBase, srcOffset, destBase, destOffset, bytes);
    }

    
Sets all bytes in a given block of memory to a copy of another
block.  This provides a single-register addressing mode, as discussed in getInt(Object, long). Equivalent to copyMemory(null, srcAddress, null, destAddress, bytes). 
/**
     * Sets all bytes in a given block of memory to a copy of another
     * block.  This provides a <em>single-register</em> addressing mode,
     * as discussed in {@link #getInt(Object,long)}.
     *
     * Equivalent to {@code copyMemory(null, srcAddress, null, destAddress, bytes)}.
     */
    @ForceInline
    public void copyMemory(long srcAddress, long destAddress, long bytes) {
        theInternalUnsafe.copyMemory(srcAddress, destAddress, bytes);
    }

    
Disposes of a block of native memory, as obtained from allocateMemory or reallocateMemory. The address passed to this method may be null, in which case no action is taken. Note: It is the resposibility of the caller to make
sure arguments are checked before the methods are called. While
some rudimentary checks are performed on the input, the checks
are best effort and when performance is an overriding priority,
as when methods of this class are optimized by the runtime
compiler, some or all checks (if any) may be elided. Hence, the
caller must not rely on the checks and corresponding
exceptions!

Throws:
See Also:
/**
     * Disposes of a block of native memory, as obtained from {@link
     * #allocateMemory} or {@link #reallocateMemory}.  The address passed to
     * this method may be null, in which case no action is taken.
     *
     * <em>Note:</em> It is the resposibility of the caller to make
     * sure arguments are checked before the methods are called. While
     * some rudimentary checks are performed on the input, the checks
     * are best effort and when performance is an overriding priority,
     * as when methods of this class are optimized by the runtime
     * compiler, some or all checks (if any) may be elided. Hence, the
     * caller must not rely on the checks and corresponding
     * exceptions!
     *
     * @throws RuntimeException if any of the arguments is invalid
     *
     * @see #allocateMemory
     */
    @ForceInline
    public void freeMemory(long address) {
        theInternalUnsafe.freeMemory(address);
    }

    /// random queries

    
This constant differs from all results that will ever be returned from staticFieldOffset, objectFieldOffset, or arrayBaseOffset. 
/**
     * This constant differs from all results that will ever be returned from
     * {@link #staticFieldOffset}, {@link #objectFieldOffset},
     * or {@link #arrayBaseOffset}.
     */
    public static final int INVALID_FIELD_OFFSET = jdk.internal.misc.Unsafe.INVALID_FIELD_OFFSET;

    
Reports the location of a given field in the storage allocation of its
class.  Do not expect to perform any sort of arithmetic on this offset;
it is just a cookie which is passed to the unsafe heap memory accessors.

Any given field will always have the same offset and base, and no
two distinct fields of the same class will ever have the same offset
and base.

As of 1.4.1, offsets for fields are represented as long values, although the Sun JVM does not use the most significant 32 bits. However, JVM implementations which store static fields at absolute addresses can use long offsets and null base pointers to express the field locations in a form usable by getInt(Object, long). Therefore, code which will be ported to such JVMs on 64-bit platforms must preserve all bits of static field offsets. 
See Also:
/**
     * Reports the location of a given field in the storage allocation of its
     * class.  Do not expect to perform any sort of arithmetic on this offset;
     * it is just a cookie which is passed to the unsafe heap memory accessors.
     *
     * <p>Any given field will always have the same offset and base, and no
     * two distinct fields of the same class will ever have the same offset
     * and base.
     *
     * <p>As of 1.4.1, offsets for fields are represented as long values,
     * although the Sun JVM does not use the most significant 32 bits.
     * However, JVM implementations which store static fields at absolute
     * addresses can use long offsets and null base pointers to express
     * the field locations in a form usable by {@link #getInt(Object,long)}.
     * Therefore, code which will be ported to such JVMs on 64-bit platforms
     * must preserve all bits of static field offsets.
     * @see #getInt(Object, long)
     */
    @ForceInline
    public long objectFieldOffset(Field f) {
        return theInternalUnsafe.objectFieldOffset(f);
    }

    
Reports the location of a given static field, in conjunction with staticFieldBase. 
Do not expect to perform any sort of arithmetic on this offset;
it is just a cookie which is passed to the unsafe heap memory accessors.

Any given field will always have the same offset, and no two distinct
fields of the same class will ever have the same offset.

As of 1.4.1, offsets for fields are represented as long values,
although the Sun JVM does not use the most significant 32 bits.
It is hard to imagine a JVM technology which needs more than
a few bits to encode an offset within a non-array object,
However, for consistency with other methods in this class,
this method reports its result as a long value.

See Also:
/**
     * Reports the location of a given static field, in conjunction with {@link
     * #staticFieldBase}.
     * <p>Do not expect to perform any sort of arithmetic on this offset;
     * it is just a cookie which is passed to the unsafe heap memory accessors.
     *
     * <p>Any given field will always have the same offset, and no two distinct
     * fields of the same class will ever have the same offset.
     *
     * <p>As of 1.4.1, offsets for fields are represented as long values,
     * although the Sun JVM does not use the most significant 32 bits.
     * It is hard to imagine a JVM technology which needs more than
     * a few bits to encode an offset within a non-array object,
     * However, for consistency with other methods in this class,
     * this method reports its result as a long value.
     * @see #getInt(Object, long)
     */
    @ForceInline
    public long staticFieldOffset(Field f) {
        return theInternalUnsafe.staticFieldOffset(f);
    }

    
Reports the location of a given static field, in conjunction with staticFieldOffset. 
Fetch the base "Object", if any, with which static fields of the given class can be accessed via methods like getInt(Object, long). This value may be null. This value may refer to an object which is a "cookie", not guaranteed to be a real Object, and it should not be used in any way except as argument to the get and put routines in this class. 
/**
     * Reports the location of a given static field, in conjunction with {@link
     * #staticFieldOffset}.
     * <p>Fetch the base "Object", if any, with which static fields of the
     * given class can be accessed via methods like {@link #getInt(Object,
     * long)}.  This value may be null.  This value may refer to an object
     * which is a "cookie", not guaranteed to be a real Object, and it should
     * not be used in any way except as argument to the get and put routines in
     * this class.
     */
    @ForceInline
    public Object staticFieldBase(Field f) {
        return theInternalUnsafe.staticFieldBase(f);
    }

    
Detects if the given class may need to be initialized. This is often
needed in conjunction with obtaining the static field base of a
class.

Returns:false only if a call to ensureClassInitialized would have no effect
/**
     * Detects if the given class may need to be initialized. This is often
     * needed in conjunction with obtaining the static field base of a
     * class.
     * @return false only if a call to {@code ensureClassInitialized} would have no effect
     */
    @ForceInline
    public boolean shouldBeInitialized(Class<?> c) {
        return theInternalUnsafe.shouldBeInitialized(c);
    }

    
Ensures the given class has been initialized. This is often
needed in conjunction with obtaining the static field base of a
class.

/**
     * Ensures the given class has been initialized. This is often
     * needed in conjunction with obtaining the static field base of a
     * class.
     */
    @ForceInline
    public void ensureClassInitialized(Class<?> c) {
        theInternalUnsafe.ensureClassInitialized(c);
    }

    
Reports the offset of the first element in the storage allocation of a given array class. If arrayIndexScale returns a non-zero value for the same class, you may use that scale factor, together with this base offset, to form new offsets to access elements of arrays of the given class. 
See Also:
/**
     * Reports the offset of the first element in the storage allocation of a
     * given array class.  If {@link #arrayIndexScale} returns a non-zero value
     * for the same class, you may use that scale factor, together with this
     * base offset, to form new offsets to access elements of arrays of the
     * given class.
     *
     * @see #getInt(Object, long)
     * @see #putInt(Object, long, int)
     */
    @ForceInline
    public int arrayBaseOffset(Class<?> arrayClass) {
        return theInternalUnsafe.arrayBaseOffset(arrayClass);
    }

    
The value of arrayBaseOffset(boolean[].class) 
/** The value of {@code arrayBaseOffset(boolean[].class)} */
    public static final int ARRAY_BOOLEAN_BASE_OFFSET = jdk.internal.misc.Unsafe.ARRAY_BOOLEAN_BASE_OFFSET;

    
The value of arrayBaseOffset(byte[].class) 
/** The value of {@code arrayBaseOffset(byte[].class)} */
    public static final int ARRAY_BYTE_BASE_OFFSET = jdk.internal.misc.Unsafe.ARRAY_BYTE_BASE_OFFSET;

    
The value of arrayBaseOffset(short[].class) 
/** The value of {@code arrayBaseOffset(short[].class)} */
    public static final int ARRAY_SHORT_BASE_OFFSET = jdk.internal.misc.Unsafe.ARRAY_SHORT_BASE_OFFSET;

    
The value of arrayBaseOffset(char[].class) 
/** The value of {@code arrayBaseOffset(char[].class)} */
    public static final int ARRAY_CHAR_BASE_OFFSET = jdk.internal.misc.Unsafe.ARRAY_CHAR_BASE_OFFSET;

    
The value of arrayBaseOffset(int[].class) 
/** The value of {@code arrayBaseOffset(int[].class)} */
    public static final int ARRAY_INT_BASE_OFFSET = jdk.internal.misc.Unsafe.ARRAY_INT_BASE_OFFSET;

    
The value of arrayBaseOffset(long[].class) 
/** The value of {@code arrayBaseOffset(long[].class)} */
    public static final int ARRAY_LONG_BASE_OFFSET = jdk.internal.misc.Unsafe.ARRAY_LONG_BASE_OFFSET;

    
The value of arrayBaseOffset(float[].class) 
/** The value of {@code arrayBaseOffset(float[].class)} */
    public static final int ARRAY_FLOAT_BASE_OFFSET = jdk.internal.misc.Unsafe.ARRAY_FLOAT_BASE_OFFSET;

    
The value of arrayBaseOffset(double[].class) 
/** The value of {@code arrayBaseOffset(double[].class)} */
    public static final int ARRAY_DOUBLE_BASE_OFFSET = jdk.internal.misc.Unsafe.ARRAY_DOUBLE_BASE_OFFSET;

    
The value of arrayBaseOffset(Object[].class) 
/** The value of {@code arrayBaseOffset(Object[].class)} */
    public static final int ARRAY_OBJECT_BASE_OFFSET = jdk.internal.misc.Unsafe.ARRAY_OBJECT_BASE_OFFSET;

    
Reports the scale factor for addressing elements in the storage allocation of a given array class. However, arrays of "narrow" types will generally not work properly with accessors like getByte(Object, long), so the scale factor for such classes is reported as zero. 
See Also:
/**
     * Reports the scale factor for addressing elements in the storage
     * allocation of a given array class.  However, arrays of "narrow" types
     * will generally not work properly with accessors like {@link
     * #getByte(Object, long)}, so the scale factor for such classes is reported
     * as zero.
     *
     * @see #arrayBaseOffset
     * @see #getInt(Object, long)
     * @see #putInt(Object, long, int)
     */
    @ForceInline
    public int arrayIndexScale(Class<?> arrayClass) {
        return theInternalUnsafe.arrayIndexScale(arrayClass);
    }

    
The value of arrayIndexScale(boolean[].class) 
/** The value of {@code arrayIndexScale(boolean[].class)} */
    public static final int ARRAY_BOOLEAN_INDEX_SCALE = jdk.internal.misc.Unsafe.ARRAY_BOOLEAN_INDEX_SCALE;

    
The value of arrayIndexScale(byte[].class) 
/** The value of {@code arrayIndexScale(byte[].class)} */
    public static final int ARRAY_BYTE_INDEX_SCALE = jdk.internal.misc.Unsafe.ARRAY_BYTE_INDEX_SCALE;

    
The value of arrayIndexScale(short[].class) 
/** The value of {@code arrayIndexScale(short[].class)} */
    public static final int ARRAY_SHORT_INDEX_SCALE = jdk.internal.misc.Unsafe.ARRAY_SHORT_INDEX_SCALE;

    
The value of arrayIndexScale(char[].class) 
/** The value of {@code arrayIndexScale(char[].class)} */
    public static final int ARRAY_CHAR_INDEX_SCALE = jdk.internal.misc.Unsafe.ARRAY_CHAR_INDEX_SCALE;

    
The value of arrayIndexScale(int[].class) 
/** The value of {@code arrayIndexScale(int[].class)} */
    public static final int ARRAY_INT_INDEX_SCALE = jdk.internal.misc.Unsafe.ARRAY_INT_INDEX_SCALE;

    
The value of arrayIndexScale(long[].class) 
/** The value of {@code arrayIndexScale(long[].class)} */
    public static final int ARRAY_LONG_INDEX_SCALE = jdk.internal.misc.Unsafe.ARRAY_LONG_INDEX_SCALE;

    
The value of arrayIndexScale(float[].class) 
/** The value of {@code arrayIndexScale(float[].class)} */
    public static final int ARRAY_FLOAT_INDEX_SCALE = jdk.internal.misc.Unsafe.ARRAY_FLOAT_INDEX_SCALE;

    
The value of arrayIndexScale(double[].class) 
/** The value of {@code arrayIndexScale(double[].class)} */
    public static final int ARRAY_DOUBLE_INDEX_SCALE = jdk.internal.misc.Unsafe.ARRAY_DOUBLE_INDEX_SCALE;

    
The value of arrayIndexScale(Object[].class) 
/** The value of {@code arrayIndexScale(Object[].class)} */
    public static final int ARRAY_OBJECT_INDEX_SCALE = jdk.internal.misc.Unsafe.ARRAY_OBJECT_INDEX_SCALE;

    
Reports the size in bytes of a native pointer, as stored via putAddress. This value will be either 4 or 8. Note that the sizes of other primitive types (as stored in native memory blocks) is determined fully by their information content. 
/**
     * Reports the size in bytes of a native pointer, as stored via {@link
     * #putAddress}.  This value will be either 4 or 8.  Note that the sizes of
     * other primitive types (as stored in native memory blocks) is determined
     * fully by their information content.
     */
    @ForceInline
    public int addressSize() {
        return theInternalUnsafe.addressSize();
    }

    
The value of addressSize() 
/** The value of {@code addressSize()} */
    public static final int ADDRESS_SIZE = theInternalUnsafe.addressSize();

    
Reports the size in bytes of a native memory page (whatever that is).
This value will always be a power of two.

/**
     * Reports the size in bytes of a native memory page (whatever that is).
     * This value will always be a power of two.
     */
    @ForceInline
    public int pageSize() {
        return theInternalUnsafe.pageSize();
    }


    /// random trusted operations from JNI:

    
Tells the VM to define a class, without security checks.  By default, the
class loader and protection domain come from the caller's class.

See Also:
Deprecated:Use MethodHandles.Lookup#defineClass to define a class to the same class loader and in the same runtime package and protection domain of a given Lookup's lookup class.
/**
     * Tells the VM to define a class, without security checks.  By default, the
     * class loader and protection domain come from the caller's class.
     *
     * @deprecated Use {@link java.lang.invoke.MethodHandles.Lookup#defineClass MethodHandles.Lookup#defineClass}
     * to define a class to the same class loader and in the same runtime package
     * and {@linkplain java.security.ProtectionDomain protection domain} of a
     * given {@code Lookup}'s {@linkplain java.lang.invoke.MethodHandles.Lookup#lookupClass() lookup class}.
     *
     * @see java.lang.invoke.MethodHandles.Lookup#defineClass(byte[])
     */
    @Deprecated(since="9", forRemoval=true)
    @ForceInline
    public Class<?> defineClass(String name, byte[] b, int off, int len,
                                ClassLoader loader,
                                ProtectionDomain protectionDomain) {
        return theInternalUnsafe.defineClass(name, b, off, len, loader, protectionDomain);
    }

    
Defines a class but does not make it known to the class loader or system dictionary.


For each CP entry, the corresponding CP patch must either be null or have
the a format that matches its tag:

    

  • Integer, Long, Float, Double: the corresponding wrapper object type from java.lang

  • Utf8: a string (must have suitable syntax if used as signature or name)

  • Class: any java.lang.Class object

  • String: any object (not just a java.lang.String)

  • InterfaceMethodRef: (NYI) a method handle to invoke on that call site's arguments



Params:
  • hostClass – context for linkage, access control, protection domain, and class loader
  • data –      bytes of a class file
  • cpPatches – where non-null entries exist, they replace corresponding CP entries in data
/**
     * Defines a class but does not make it known to the class loader or system dictionary.
     * <p>
     * For each CP entry, the corresponding CP patch must either be null or have
     * the a format that matches its tag:
     * <ul>
     * <li>Integer, Long, Float, Double: the corresponding wrapper object type from java.lang
     * <li>Utf8: a string (must have suitable syntax if used as signature or name)
     * <li>Class: any java.lang.Class object
     * <li>String: any object (not just a java.lang.String)
     * <li>InterfaceMethodRef: (NYI) a method handle to invoke on that call site's arguments
     * </ul>
     * @param hostClass context for linkage, access control, protection domain, and class loader
     * @param data      bytes of a class file
     * @param cpPatches where non-null entries exist, they replace corresponding CP entries in data
     */
    @ForceInline
    public Class<?> defineAnonymousClass(Class<?> hostClass, byte[] data, Object[] cpPatches) {
        return theInternalUnsafe.defineAnonymousClass(hostClass, data, cpPatches);
    }

    
Allocates an instance but does not run any constructor.
Initializes the class if it has not yet been.

/**
     * Allocates an instance but does not run any constructor.
     * Initializes the class if it has not yet been.
     */
    @ForceInline
    public Object allocateInstance(Class<?> cls)
        throws InstantiationException {
        return theInternalUnsafe.allocateInstance(cls);
    }

    
Throws the exception without telling the verifier. 
/** Throws the exception without telling the verifier. */
    @ForceInline
    public void throwException(Throwable ee) {
        theInternalUnsafe.throwException(ee);
    }

    
Atomically updates Java variable to x if it is currently holding expected. 
This operation has memory semantics of a volatile read and write. Corresponds to C11 atomic_compare_exchange_strong. 
Returns:true if successful
/**
     * Atomically updates Java variable to {@code x} if it is currently
     * holding {@code expected}.
     *
     * <p>This operation has memory semantics of a {@code volatile} read
     * and write.  Corresponds to C11 atomic_compare_exchange_strong.
     *
     * @return {@code true} if successful
     */
    @ForceInline
    public final boolean compareAndSwapObject(Object o, long offset,
                                              Object expected,
                                              Object x) {
        return theInternalUnsafe.compareAndSetObject(o, offset, expected, x);
    }

    
Atomically updates Java variable to x if it is currently holding expected. 
This operation has memory semantics of a volatile read and write. Corresponds to C11 atomic_compare_exchange_strong. 
Returns:true if successful
/**
     * Atomically updates Java variable to {@code x} if it is currently
     * holding {@code expected}.
     *
     * <p>This operation has memory semantics of a {@code volatile} read
     * and write.  Corresponds to C11 atomic_compare_exchange_strong.
     *
     * @return {@code true} if successful
     */
    @ForceInline
    public final boolean compareAndSwapInt(Object o, long offset,
                                           int expected,
                                           int x) {
        return theInternalUnsafe.compareAndSetInt(o, offset, expected, x);
    }

    
Atomically updates Java variable to x if it is currently holding expected. 
This operation has memory semantics of a volatile read and write. Corresponds to C11 atomic_compare_exchange_strong. 
Returns:true if successful
/**
     * Atomically updates Java variable to {@code x} if it is currently
     * holding {@code expected}.
     *
     * <p>This operation has memory semantics of a {@code volatile} read
     * and write.  Corresponds to C11 atomic_compare_exchange_strong.
     *
     * @return {@code true} if successful
     */
    @ForceInline
    public final boolean compareAndSwapLong(Object o, long offset,
                                            long expected,
                                            long x) {
        return theInternalUnsafe.compareAndSetLong(o, offset, expected, x);
    }

    
Fetches a reference value from a given Java variable, with volatile load semantics. Otherwise identical to getObject(Object, long) 
/**
     * Fetches a reference value from a given Java variable, with volatile
     * load semantics. Otherwise identical to {@link #getObject(Object, long)}
     */
    @ForceInline
    public Object getObjectVolatile(Object o, long offset) {
        return theInternalUnsafe.getObjectVolatile(o, offset);
    }

    
Stores a reference value into a given Java variable, with volatile store semantics. Otherwise identical to putObject(Object, long, Object) 
/**
     * Stores a reference value into a given Java variable, with
     * volatile store semantics. Otherwise identical to {@link #putObject(Object, long, Object)}
     */
    @ForceInline
    public void putObjectVolatile(Object o, long offset, Object x) {
        theInternalUnsafe.putObjectVolatile(o, offset, x);
    }

    
Volatile version of getInt(Object, long) 
/** Volatile version of {@link #getInt(Object, long)}  */
    @ForceInline
    public int getIntVolatile(Object o, long offset) {
        return theInternalUnsafe.getIntVolatile(o, offset);
    }

    
Volatile version of putInt(Object, long, int) 
/** Volatile version of {@link #putInt(Object, long, int)}  */
    @ForceInline
    public void putIntVolatile(Object o, long offset, int x) {
        theInternalUnsafe.putIntVolatile(o, offset, x);
    }

    
Volatile version of getBoolean(Object, long) 
/** Volatile version of {@link #getBoolean(Object, long)}  */
    @ForceInline
    public boolean getBooleanVolatile(Object o, long offset) {
        return theInternalUnsafe.getBooleanVolatile(o, offset);
    }

    /** Volatile version of {@link #putBoolean(Object, long, boolean)}  */
    @ForceInline
    public void putBooleanVolatile(Object o, long offset, boolean x) {
        theInternalUnsafe.putBooleanVolatile(o, offset, x);
    }

    
Volatile version of getByte(Object, long) 
/** Volatile version of {@link #getByte(Object, long)}  */
    @ForceInline
    public byte getByteVolatile(Object o, long offset) {
        return theInternalUnsafe.getByteVolatile(o, offset);
    }

    
Volatile version of putByte(Object, long, byte) 
/** Volatile version of {@link #putByte(Object, long, byte)}  */
    @ForceInline
    public void putByteVolatile(Object o, long offset, byte x) {
        theInternalUnsafe.putByteVolatile(o, offset, x);
    }

    
Volatile version of getShort(Object, long) 
/** Volatile version of {@link #getShort(Object, long)}  */
    @ForceInline
    public short getShortVolatile(Object o, long offset) {
        return theInternalUnsafe.getShortVolatile(o, offset);
    }

    
Volatile version of putShort(Object, long, short) 
/** Volatile version of {@link #putShort(Object, long, short)}  */
    @ForceInline
    public void putShortVolatile(Object o, long offset, short x) {
        theInternalUnsafe.putShortVolatile(o, offset, x);
    }

    
Volatile version of getChar(Object, long) 
/** Volatile version of {@link #getChar(Object, long)}  */
    @ForceInline
    public char getCharVolatile(Object o, long offset) {
        return theInternalUnsafe.getCharVolatile(o, offset);
    }

    
Volatile version of putChar(Object, long, char) 
/** Volatile version of {@link #putChar(Object, long, char)}  */
    @ForceInline
    public void putCharVolatile(Object o, long offset, char x) {
        theInternalUnsafe.putCharVolatile(o, offset, x);
    }

    
Volatile version of getLong(Object, long) 
/** Volatile version of {@link #getLong(Object, long)}  */
    @ForceInline
    public long getLongVolatile(Object o, long offset) {
        return theInternalUnsafe.getLongVolatile(o, offset);
    }

    
Volatile version of putLong(Object, long, long) 
/** Volatile version of {@link #putLong(Object, long, long)}  */
    @ForceInline
    public void putLongVolatile(Object o, long offset, long x) {
        theInternalUnsafe.putLongVolatile(o, offset, x);
    }

    
Volatile version of getFloat(Object, long) 
/** Volatile version of {@link #getFloat(Object, long)}  */
    @ForceInline
    public float getFloatVolatile(Object o, long offset) {
        return theInternalUnsafe.getFloatVolatile(o, offset);
    }

    
Volatile version of putFloat(Object, long, float) 
/** Volatile version of {@link #putFloat(Object, long, float)}  */
    @ForceInline
    public void putFloatVolatile(Object o, long offset, float x) {
        theInternalUnsafe.putFloatVolatile(o, offset, x);
    }

    
Volatile version of getDouble(Object, long) 
/** Volatile version of {@link #getDouble(Object, long)}  */
    @ForceInline
    public double getDoubleVolatile(Object o, long offset) {
        return theInternalUnsafe.getDoubleVolatile(o, offset);
    }

    
Volatile version of putDouble(Object, long, double) 
/** Volatile version of {@link #putDouble(Object, long, double)}  */
    @ForceInline
    public void putDoubleVolatile(Object o, long offset, double x) {
        theInternalUnsafe.putDoubleVolatile(o, offset, x);
    }

    
Version of putObjectVolatile(Object, long, Object) that does not guarantee immediate visibility of the store to other threads. This method is generally only useful if the underlying field is a Java volatile (or if an array cell, one that is otherwise only accessed using volatile accesses). Corresponds to C11 atomic_store_explicit(..., memory_order_release). 
/**
     * Version of {@link #putObjectVolatile(Object, long, Object)}
     * that does not guarantee immediate visibility of the store to
     * other threads. This method is generally only useful if the
     * underlying field is a Java volatile (or if an array cell, one
     * that is otherwise only accessed using volatile accesses).
     *
     * Corresponds to C11 atomic_store_explicit(..., memory_order_release).
     */
    @ForceInline
    public void putOrderedObject(Object o, long offset, Object x) {
        theInternalUnsafe.putObjectRelease(o, offset, x);
    }

    
Ordered/Lazy version of putIntVolatile(Object, long, int) 
/** Ordered/Lazy version of {@link #putIntVolatile(Object, long, int)}  */
    @ForceInline
    public void putOrderedInt(Object o, long offset, int x) {
        theInternalUnsafe.putIntRelease(o, offset, x);
    }

    
Ordered/Lazy version of putLongVolatile(Object, long, long) 
/** Ordered/Lazy version of {@link #putLongVolatile(Object, long, long)} */
    @ForceInline
    public void putOrderedLong(Object o, long offset, long x) {
        theInternalUnsafe.putLongRelease(o, offset, x);
    }

    
Unblocks the given thread blocked on park, or, if it is not blocked, causes the subsequent call to park not to block. Note: this operation is "unsafe" solely because the caller must somehow ensure that the thread has not been destroyed. Nothing special is usually required to ensure this when called from Java (in which there will ordinarily be a live reference to the thread) but this is not nearly-automatically so when calling from native code. 
Params:
  • thread – the thread to unpark.
/**
     * Unblocks the given thread blocked on {@code park}, or, if it is
     * not blocked, causes the subsequent call to {@code park} not to
     * block.  Note: this operation is "unsafe" solely because the
     * caller must somehow ensure that the thread has not been
     * destroyed. Nothing special is usually required to ensure this
     * when called from Java (in which there will ordinarily be a live
     * reference to the thread) but this is not nearly-automatically
     * so when calling from native code.
     *
     * @param thread the thread to unpark.
     */
    @ForceInline
    public void unpark(Object thread) {
        theInternalUnsafe.unpark(thread);
    }

    
Blocks current thread, returning when a balancing unpark occurs, or a balancing unpark has already occurred, or the thread is interrupted, or, if not absolute and time is not zero, the given time nanoseconds have elapsed, or if absolute, the given deadline in milliseconds since Epoch has passed, or spuriously (i.e., returning for no "reason"). Note: This operation is in the Unsafe class only because unpark is, so it would be strange to place it elsewhere. 
/**
     * Blocks current thread, returning when a balancing
     * {@code unpark} occurs, or a balancing {@code unpark} has
     * already occurred, or the thread is interrupted, or, if not
     * absolute and time is not zero, the given time nanoseconds have
     * elapsed, or if absolute, the given deadline in milliseconds
     * since Epoch has passed, or spuriously (i.e., returning for no
     * "reason"). Note: This operation is in the Unsafe class only
     * because {@code unpark} is, so it would be strange to place it
     * elsewhere.
     */
    @ForceInline
    public void park(boolean isAbsolute, long time) {
        theInternalUnsafe.park(isAbsolute, time);
    }

    
Gets the load average in the system run queue assigned to the available processors averaged over various periods of time. This method retrieves the given nelem samples and assigns to the elements of the given loadavg array. The system imposes a maximum of 3 samples, representing averages over the last 1, 5, and 15 minutes, respectively. 
Params:
  • loadavg – an array of double of size nelems
  • nelems – the number of samples to be retrieved and
       must be 1 to 3.
Returns:the number of samples actually retrieved; or -1
        if the load average is unobtainable.
/**
     * Gets the load average in the system run queue assigned
     * to the available processors averaged over various periods of time.
     * This method retrieves the given {@code nelem} samples and
     * assigns to the elements of the given {@code loadavg} array.
     * The system imposes a maximum of 3 samples, representing
     * averages over the last 1,  5,  and  15 minutes, respectively.
     *
     * @param loadavg an array of double of size nelems
     * @param nelems the number of samples to be retrieved and
     *        must be 1 to 3.
     *
     * @return the number of samples actually retrieved; or -1
     *         if the load average is unobtainable.
     */
    @ForceInline
    public int getLoadAverage(double[] loadavg, int nelems) {
        return theInternalUnsafe.getLoadAverage(loadavg, nelems);
    }

    // The following contain CAS-based Java implementations used on
    // platforms not supporting native instructions

    
Atomically adds the given value to the current value of a field or array element within the given object o at the given offset. 
Params:
  • o – object/array to update the field/element in
  • offset – field/element offset
  • delta – the value to add
Returns:the previous value
Since:1.8
/**
     * Atomically adds the given value to the current value of a field
     * or array element within the given object {@code o}
     * at the given {@code offset}.
     *
     * @param o object/array to update the field/element in
     * @param offset field/element offset
     * @param delta the value to add
     * @return the previous value
     * @since 1.8
     */
    @ForceInline
    public final int getAndAddInt(Object o, long offset, int delta) {
        return theInternalUnsafe.getAndAddInt(o, offset, delta);
    }

    
Atomically adds the given value to the current value of a field or array element within the given object o at the given offset. 
Params:
  • o – object/array to update the field/element in
  • offset – field/element offset
  • delta – the value to add
Returns:the previous value
Since:1.8
/**
     * Atomically adds the given value to the current value of a field
     * or array element within the given object {@code o}
     * at the given {@code offset}.
     *
     * @param o object/array to update the field/element in
     * @param offset field/element offset
     * @param delta the value to add
     * @return the previous value
     * @since 1.8
     */
    @ForceInline
    public final long getAndAddLong(Object o, long offset, long delta) {
        return theInternalUnsafe.getAndAddLong(o, offset, delta);
    }

    
Atomically exchanges the given value with the current value of a field or array element within the given object o at the given offset. 
Params:
  • o – object/array to update the field/element in
  • offset – field/element offset
  • newValue – new value
Returns:the previous value
Since:1.8
/**
     * Atomically exchanges the given value with the current value of
     * a field or array element within the given object {@code o}
     * at the given {@code offset}.
     *
     * @param o object/array to update the field/element in
     * @param offset field/element offset
     * @param newValue new value
     * @return the previous value
     * @since 1.8
     */
    @ForceInline
    public final int getAndSetInt(Object o, long offset, int newValue) {
        return theInternalUnsafe.getAndSetInt(o, offset, newValue);
    }

    
Atomically exchanges the given value with the current value of a field or array element within the given object o at the given offset. 
Params:
  • o – object/array to update the field/element in
  • offset – field/element offset
  • newValue – new value
Returns:the previous value
Since:1.8
/**
     * Atomically exchanges the given value with the current value of
     * a field or array element within the given object {@code o}
     * at the given {@code offset}.
     *
     * @param o object/array to update the field/element in
     * @param offset field/element offset
     * @param newValue new value
     * @return the previous value
     * @since 1.8
     */
    @ForceInline
    public final long getAndSetLong(Object o, long offset, long newValue) {
        return theInternalUnsafe.getAndSetLong(o, offset, newValue);
    }

    
Atomically exchanges the given reference value with the current reference value of a field or array element within the given object o at the given offset. 
Params:
  • o – object/array to update the field/element in
  • offset – field/element offset
  • newValue – new value
Returns:the previous value
Since:1.8
/**
     * Atomically exchanges the given reference value with the current
     * reference value of a field or array element within the given
     * object {@code o} at the given {@code offset}.
     *
     * @param o object/array to update the field/element in
     * @param offset field/element offset
     * @param newValue new value
     * @return the previous value
     * @since 1.8
     */
    @ForceInline
    public final Object getAndSetObject(Object o, long offset, Object newValue) {
        return theInternalUnsafe.getAndSetObject(o, offset, newValue);
    }


    
Ensures that loads before the fence will not be reordered with loads and
stores after the fence; a "LoadLoad plus LoadStore barrier".
Corresponds to C11 atomic_thread_fence(memory_order_acquire)
(an "acquire fence").
A pure LoadLoad fence is not provided, since the addition of LoadStore
is almost always desired, and most current hardware instructions that
provide a LoadLoad barrier also provide a LoadStore barrier for free.

Since:1.8
/**
     * Ensures that loads before the fence will not be reordered with loads and
     * stores after the fence; a "LoadLoad plus LoadStore barrier".
     *
     * Corresponds to C11 atomic_thread_fence(memory_order_acquire)
     * (an "acquire fence").
     *
     * A pure LoadLoad fence is not provided, since the addition of LoadStore
     * is almost always desired, and most current hardware instructions that
     * provide a LoadLoad barrier also provide a LoadStore barrier for free.
     * @since 1.8
     */
    @ForceInline
    public void loadFence() {
        theInternalUnsafe.loadFence();
    }

    
Ensures that loads and stores before the fence will not be reordered with
stores after the fence; a "StoreStore plus LoadStore barrier".
Corresponds to C11 atomic_thread_fence(memory_order_release)
(a "release fence").
A pure StoreStore fence is not provided, since the addition of LoadStore
is almost always desired, and most current hardware instructions that
provide a StoreStore barrier also provide a LoadStore barrier for free.

Since:1.8
/**
     * Ensures that loads and stores before the fence will not be reordered with
     * stores after the fence; a "StoreStore plus LoadStore barrier".
     *
     * Corresponds to C11 atomic_thread_fence(memory_order_release)
     * (a "release fence").
     *
     * A pure StoreStore fence is not provided, since the addition of LoadStore
     * is almost always desired, and most current hardware instructions that
     * provide a StoreStore barrier also provide a LoadStore barrier for free.
     * @since 1.8
     */
    @ForceInline
    public void storeFence() {
        theInternalUnsafe.storeFence();
    }

    
Ensures that loads and stores before the fence will not be reordered
with loads and stores after the fence.  Implies the effects of both
loadFence() and storeFence(), and in addition, the effect of a StoreLoad
barrier.
Corresponds to C11 atomic_thread_fence(memory_order_seq_cst).

Since:1.8
/**
     * Ensures that loads and stores before the fence will not be reordered
     * with loads and stores after the fence.  Implies the effects of both
     * loadFence() and storeFence(), and in addition, the effect of a StoreLoad
     * barrier.
     *
     * Corresponds to C11 atomic_thread_fence(memory_order_seq_cst).
     * @since 1.8
     */
    @ForceInline
    public void fullFence() {
        theInternalUnsafe.fullFence();
    }

    
Invokes the given direct byte buffer's cleaner, if any.

Params:
  • directBuffer – a direct byte buffer
Throws:
Since:9
/**
     * Invokes the given direct byte buffer's cleaner, if any.
     *
     * @param directBuffer a direct byte buffer
     * @throws NullPointerException if {@code directBuffer} is null
     * @throws IllegalArgumentException if {@code directBuffer} is non-direct,
     * or is a {@link java.nio.Buffer#slice slice}, or is a
     * {@link java.nio.Buffer#duplicate duplicate}
     * @since 9
     */
    public void invokeCleaner(java.nio.ByteBuffer directBuffer) {
        if (!directBuffer.isDirect())
            throw new IllegalArgumentException("buffer is non-direct");

        DirectBuffer db = (DirectBuffer)directBuffer;
        if (db.attachment() != null)
            throw new IllegalArgumentException("duplicate or slice");

        Cleaner cleaner = db.cleaner();
        if (cleaner != null) {
            cleaner.clean();
        }
    }
}