--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.base/share/classes/jdk/internal/misc/Unsafe.java Tue Oct 27 14:19:55 2015 +0000
@@ -0,0 +1,1391 @@
+/*
+ * Copyright (c) 2000, 2015, 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 jdk.internal.misc;
+
+import java.lang.reflect.Field;
+import java.security.ProtectionDomain;
+
+import sun.reflect.CallerSensitive;
+import sun.reflect.Reflection;
+import sun.misc.VM;
+
+import jdk.internal.HotSpotIntrinsicCandidate;
+
+
+/**
+ * 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.
+ *
+ * @author John R. Rose
+ * @see #getUnsafe
+ */
+
+public final class Unsafe {
+
+ private static native void registerNatives();
+ static {
+ registerNatives();
+ sun.reflect.Reflection.registerMethodsToFilter(Unsafe.class, "getUnsafe");
+ }
+
+ private Unsafe() {}
+
+ private static final Unsafe theUnsafe = new Unsafe();
+
+ /**
+ * 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 a security manager exists and its
+ * {@code checkPropertiesAccess} method doesn't allow
+ * access to the system properties.
+ */
+ @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 {@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}
+ */
+ @HotSpotIntrinsicCandidate
+ public native int getInt(Object o, long offset);
+
+ /**
+ * 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}
+ */
+ @HotSpotIntrinsicCandidate
+ public native void putInt(Object o, long offset, int x);
+
+ /**
+ * Fetches a reference value from a given Java variable.
+ * @see #getInt(Object, long)
+ */
+ @HotSpotIntrinsicCandidate
+ public native Object getObject(Object o, long offset);
+
+ /**
+ * 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)
+ */
+ @HotSpotIntrinsicCandidate
+ public native void putObject(Object o, long offset, Object x);
+
+ /** @see #getInt(Object, long) */
+ @HotSpotIntrinsicCandidate
+ public native boolean getBoolean(Object o, long offset);
+ /** @see #putInt(Object, long, int) */
+ @HotSpotIntrinsicCandidate
+ public native void putBoolean(Object o, long offset, boolean x);
+ /** @see #getInt(Object, long) */
+ @HotSpotIntrinsicCandidate
+ public native byte getByte(Object o, long offset);
+ /** @see #putInt(Object, long, int) */
+ @HotSpotIntrinsicCandidate
+ public native void putByte(Object o, long offset, byte x);
+ /** @see #getInt(Object, long) */
+ @HotSpotIntrinsicCandidate
+ public native short getShort(Object o, long offset);
+ /** @see #putInt(Object, long, int) */
+ @HotSpotIntrinsicCandidate
+ public native void putShort(Object o, long offset, short x);
+ /** @see #getInt(Object, long) */
+ @HotSpotIntrinsicCandidate
+ public native char getChar(Object o, long offset);
+ /** @see #putInt(Object, long, int) */
+ @HotSpotIntrinsicCandidate
+ public native void putChar(Object o, long offset, char x);
+ /** @see #getInt(Object, long) */
+ @HotSpotIntrinsicCandidate
+ public native long getLong(Object o, long offset);
+ /** @see #putInt(Object, long, int) */
+ @HotSpotIntrinsicCandidate
+ public native void putLong(Object o, long offset, long x);
+ /** @see #getInt(Object, long) */
+ @HotSpotIntrinsicCandidate
+ public native float getFloat(Object o, long offset);
+ /** @see #putInt(Object, long, int) */
+ @HotSpotIntrinsicCandidate
+ public native void putFloat(Object o, long offset, float x);
+ /** @see #getInt(Object, long) */
+ @HotSpotIntrinsicCandidate
+ public native double getDouble(Object o, long offset);
+ /** @see #putInt(Object, long, int) */
+ @HotSpotIntrinsicCandidate
+ public native void putDouble(Object o, long offset, double x);
+
+ // These read VM internal data.
+
+ /**
+ * Fetches an uncompressed reference value from a given native variable
+ * ignoring the VM's compressed references mode.
+ *
+ * @param address a memory address locating the variable
+ * @return the value fetched from the indicated native variable
+ */
+ public native Object getUncompressedObject(long address);
+
+ /**
+ * Fetches the {@link java.lang.Class} Java mirror for the given native
+ * metaspace {@code Klass} pointer.
+ *
+ * @param metaspaceKlass a native metaspace {@code Klass} pointer
+ * @return the {@link java.lang.Class} Java mirror
+ */
+ public native Class<?> getJavaMirror(long metaspaceKlass);
+
+ /**
+ * Fetches a native metaspace {@code Klass} pointer for the given Java
+ * object.
+ *
+ * @param o Java heap object for which to fetch the class pointer
+ * @return a native metaspace {@code Klass} pointer
+ */
+ public native long getKlassPointer(Object o);
+
+ // 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 {@link #allocateMemory}, the
+ * results are undefined.
+ *
+ * @see #allocateMemory
+ */
+ @HotSpotIntrinsicCandidate
+ public native byte getByte(long address);
+
+ /**
+ * 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)
+ */
+ @HotSpotIntrinsicCandidate
+ public native void putByte(long address, byte x);
+
+ /** @see #getByte(long) */
+ @HotSpotIntrinsicCandidate
+ public native short getShort(long address);
+ /** @see #putByte(long, byte) */
+ @HotSpotIntrinsicCandidate
+ public native void putShort(long address, short x);
+ /** @see #getByte(long) */
+ @HotSpotIntrinsicCandidate
+ public native char getChar(long address);
+ /** @see #putByte(long, byte) */
+ @HotSpotIntrinsicCandidate
+ public native void putChar(long address, char x);
+ /** @see #getByte(long) */
+ @HotSpotIntrinsicCandidate
+ public native int getInt(long address);
+ /** @see #putByte(long, byte) */
+ @HotSpotIntrinsicCandidate
+ public native void putInt(long address, int x);
+ /** @see #getByte(long) */
+ @HotSpotIntrinsicCandidate
+ public native long getLong(long address);
+ /** @see #putByte(long, byte) */
+ @HotSpotIntrinsicCandidate
+ public native void putLong(long address, long x);
+ /** @see #getByte(long) */
+ @HotSpotIntrinsicCandidate
+ public native float getFloat(long address);
+ /** @see #putByte(long, byte) */
+ @HotSpotIntrinsicCandidate
+ public native void putFloat(long address, float x);
+ /** @see #getByte(long) */
+ @HotSpotIntrinsicCandidate
+ public native double getDouble(long address);
+ /** @see #putByte(long, byte) */
+ @HotSpotIntrinsicCandidate
+ public native void putDouble(long address, double x);
+
+ /**
+ * 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
+ */
+ @HotSpotIntrinsicCandidate
+ public native long getAddress(long address);
+
+ /**
+ * 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)
+ */
+ @HotSpotIntrinsicCandidate
+ public native void putAddress(long address, long 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 {@link
+ * #freeMemory}, or resize it with {@link #reallocateMemory}.
+ *
+ * @throws IllegalArgumentException 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)
+ */
+ public native long allocateMemory(long 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 {@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.
+ *
+ * @throws IllegalArgumentException 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
+ */
+ public native long reallocateMemory(long address, long bytes);
+
+ /**
+ * 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'.
+ *
+ * @since 1.7
+ */
+ public native void setMemory(Object o, long offset, long bytes, byte 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)}.
+ */
+ public void setMemory(long address, long bytes, byte value) {
+ setMemory(null, address, bytes, value);
+ }
+
+ /**
+ * 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'.
+ *
+ * @since 1.7
+ */
+ @HotSpotIntrinsicCandidate
+ public native void copyMemory(Object srcBase, long srcOffset,
+ Object destBase, long destOffset,
+ long 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)}.
+ */
+ public void copyMemory(long srcAddress, long destAddress, long bytes) {
+ copyMemory(null, srcAddress, null, destAddress, bytes);
+ }
+
+ /**
+ * 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.
+ *
+ * @see #allocateMemory
+ */
+ public native void freeMemory(long address);
+
+ /// random queries
+
+ /**
+ * 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 = -1;
+
+ /**
+ * 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)
+ */
+ public native long objectFieldOffset(Field f);
+
+ /**
+ * 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)
+ */
+ public native long staticFieldOffset(Field f);
+
+ /**
+ * 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.
+ */
+ public native Object staticFieldBase(Field 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.
+ * @return false only if a call to {@code ensureClassInitialized} would have no effect
+ */
+ public native boolean shouldBeInitialized(Class<?> c);
+
+ /**
+ * Ensures the given class has been initialized. This is often
+ * needed in conjunction with obtaining the static field base of a
+ * class.
+ */
+ public native void ensureClassInitialized(Class<?> c);
+
+ /**
+ * 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)
+ */
+ public native int arrayBaseOffset(Class<?> arrayClass);
+
+ /** The value of {@code arrayBaseOffset(boolean[].class)} */
+ public static final int ARRAY_BOOLEAN_BASE_OFFSET
+ = theUnsafe.arrayBaseOffset(boolean[].class);
+
+ /** The value of {@code arrayBaseOffset(byte[].class)} */
+ public static final int ARRAY_BYTE_BASE_OFFSET
+ = theUnsafe.arrayBaseOffset(byte[].class);
+
+ /** The value of {@code arrayBaseOffset(short[].class)} */
+ public static final int ARRAY_SHORT_BASE_OFFSET
+ = theUnsafe.arrayBaseOffset(short[].class);
+
+ /** The value of {@code arrayBaseOffset(char[].class)} */
+ public static final int ARRAY_CHAR_BASE_OFFSET
+ = theUnsafe.arrayBaseOffset(char[].class);
+
+ /** The value of {@code arrayBaseOffset(int[].class)} */
+ public static final int ARRAY_INT_BASE_OFFSET
+ = theUnsafe.arrayBaseOffset(int[].class);
+
+ /** The value of {@code arrayBaseOffset(long[].class)} */
+ public static final int ARRAY_LONG_BASE_OFFSET
+ = theUnsafe.arrayBaseOffset(long[].class);
+
+ /** The value of {@code arrayBaseOffset(float[].class)} */
+ public static final int ARRAY_FLOAT_BASE_OFFSET
+ = theUnsafe.arrayBaseOffset(float[].class);
+
+ /** The value of {@code arrayBaseOffset(double[].class)} */
+ public static final int ARRAY_DOUBLE_BASE_OFFSET
+ = theUnsafe.arrayBaseOffset(double[].class);
+
+ /** The value of {@code arrayBaseOffset(Object[].class)} */
+ public static final int ARRAY_OBJECT_BASE_OFFSET
+ = theUnsafe.arrayBaseOffset(Object[].class);
+
+ /**
+ * 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)
+ */
+ public native int arrayIndexScale(Class<?> arrayClass);
+
+ /** The value of {@code arrayIndexScale(boolean[].class)} */
+ public static final int ARRAY_BOOLEAN_INDEX_SCALE
+ = theUnsafe.arrayIndexScale(boolean[].class);
+
+ /** The value of {@code arrayIndexScale(byte[].class)} */
+ public static final int ARRAY_BYTE_INDEX_SCALE
+ = theUnsafe.arrayIndexScale(byte[].class);
+
+ /** The value of {@code arrayIndexScale(short[].class)} */
+ public static final int ARRAY_SHORT_INDEX_SCALE
+ = theUnsafe.arrayIndexScale(short[].class);
+
+ /** The value of {@code arrayIndexScale(char[].class)} */
+ public static final int ARRAY_CHAR_INDEX_SCALE
+ = theUnsafe.arrayIndexScale(char[].class);
+
+ /** The value of {@code arrayIndexScale(int[].class)} */
+ public static final int ARRAY_INT_INDEX_SCALE
+ = theUnsafe.arrayIndexScale(int[].class);
+
+ /** The value of {@code arrayIndexScale(long[].class)} */
+ public static final int ARRAY_LONG_INDEX_SCALE
+ = theUnsafe.arrayIndexScale(long[].class);
+
+ /** The value of {@code arrayIndexScale(float[].class)} */
+ public static final int ARRAY_FLOAT_INDEX_SCALE
+ = theUnsafe.arrayIndexScale(float[].class);
+
+ /** The value of {@code arrayIndexScale(double[].class)} */
+ public static final int ARRAY_DOUBLE_INDEX_SCALE
+ = theUnsafe.arrayIndexScale(double[].class);
+
+ /** The value of {@code arrayIndexScale(Object[].class)} */
+ public static final int ARRAY_OBJECT_INDEX_SCALE
+ = theUnsafe.arrayIndexScale(Object[].class);
+
+ /**
+ * 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.
+ */
+ public native int addressSize();
+
+ /** The value of {@code addressSize()} */
+ public static final int ADDRESS_SIZE = theUnsafe.addressSize();
+
+ /**
+ * Reports the size in bytes of a native memory page (whatever that is).
+ * This value will always be a power of two.
+ */
+ public native int 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.
+ */
+ public native Class<?> defineClass(String name, byte[] b, int off, int len,
+ ClassLoader loader,
+ ProtectionDomain protectionDomain);
+
+ /**
+ * 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
+ */
+ public native Class<?> defineAnonymousClass(Class<?> hostClass, byte[] data, Object[] cpPatches);
+
+ /**
+ * Allocates an instance but does not run any constructor.
+ * Initializes the class if it has not yet been.
+ */
+ @HotSpotIntrinsicCandidate
+ public native Object allocateInstance(Class<?> cls)
+ throws InstantiationException;
+
+ /** Throws the exception without telling the verifier. */
+ public native void throwException(Throwable ee);
+
+ /**
+ * 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
+ */
+ @HotSpotIntrinsicCandidate
+ public final native boolean compareAndSwapObject(Object o, long offset,
+ Object expected,
+ Object x);
+
+ /**
+ * 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
+ */
+ @HotSpotIntrinsicCandidate
+ public final native boolean compareAndSwapInt(Object o, long offset,
+ int expected,
+ int x);
+
+ /**
+ * 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
+ */
+ @HotSpotIntrinsicCandidate
+ public final native boolean compareAndSwapLong(Object o, long offset,
+ long expected,
+ long x);
+
+ /**
+ * Fetches a reference value from a given Java variable, with volatile
+ * load semantics. Otherwise identical to {@link #getObject(Object, long)}
+ */
+ @HotSpotIntrinsicCandidate
+ public native Object getObjectVolatile(Object o, long offset);
+
+ /**
+ * Stores a reference value into a given Java variable, with
+ * volatile store semantics. Otherwise identical to {@link #putObject(Object, long, Object)}
+ */
+ @HotSpotIntrinsicCandidate
+ public native void putObjectVolatile(Object o, long offset, Object x);
+
+ /** Volatile version of {@link #getInt(Object, long)} */
+ @HotSpotIntrinsicCandidate
+ public native int getIntVolatile(Object o, long offset);
+
+ /** Volatile version of {@link #putInt(Object, long, int)} */
+ @HotSpotIntrinsicCandidate
+ public native void putIntVolatile(Object o, long offset, int x);
+
+ /** Volatile version of {@link #getBoolean(Object, long)} */
+ @HotSpotIntrinsicCandidate
+ public native boolean getBooleanVolatile(Object o, long offset);
+
+ /** Volatile version of {@link #putBoolean(Object, long, boolean)} */
+ @HotSpotIntrinsicCandidate
+ public native void putBooleanVolatile(Object o, long offset, boolean x);
+
+ /** Volatile version of {@link #getByte(Object, long)} */
+ @HotSpotIntrinsicCandidate
+ public native byte getByteVolatile(Object o, long offset);
+
+ /** Volatile version of {@link #putByte(Object, long, byte)} */
+ @HotSpotIntrinsicCandidate
+ public native void putByteVolatile(Object o, long offset, byte x);
+
+ /** Volatile version of {@link #getShort(Object, long)} */
+ @HotSpotIntrinsicCandidate
+ public native short getShortVolatile(Object o, long offset);
+
+ /** Volatile version of {@link #putShort(Object, long, short)} */
+ @HotSpotIntrinsicCandidate
+ public native void putShortVolatile(Object o, long offset, short x);
+
+ /** Volatile version of {@link #getChar(Object, long)} */
+ @HotSpotIntrinsicCandidate
+ public native char getCharVolatile(Object o, long offset);
+
+ /** Volatile version of {@link #putChar(Object, long, char)} */
+ @HotSpotIntrinsicCandidate
+ public native void putCharVolatile(Object o, long offset, char x);
+
+ /** Volatile version of {@link #getLong(Object, long)} */
+ @HotSpotIntrinsicCandidate
+ public native long getLongVolatile(Object o, long offset);
+
+ /** Volatile version of {@link #putLong(Object, long, long)} */
+ @HotSpotIntrinsicCandidate
+ public native void putLongVolatile(Object o, long offset, long x);
+
+ /** Volatile version of {@link #getFloat(Object, long)} */
+ @HotSpotIntrinsicCandidate
+ public native float getFloatVolatile(Object o, long offset);
+
+ /** Volatile version of {@link #putFloat(Object, long, float)} */
+ @HotSpotIntrinsicCandidate
+ public native void putFloatVolatile(Object o, long offset, float x);
+
+ /** Volatile version of {@link #getDouble(Object, long)} */
+ @HotSpotIntrinsicCandidate
+ public native double getDoubleVolatile(Object o, long offset);
+
+ /** Volatile version of {@link #putDouble(Object, long, double)} */
+ @HotSpotIntrinsicCandidate
+ public native void putDoubleVolatile(Object o, long offset, double x);
+
+ /**
+ * 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).
+ */
+ @HotSpotIntrinsicCandidate
+ public native void putOrderedObject(Object o, long offset, Object x);
+
+ /** Ordered/Lazy version of {@link #putIntVolatile(Object, long, int)} */
+ @HotSpotIntrinsicCandidate
+ public native void putOrderedInt(Object o, long offset, int x);
+
+ /** Ordered/Lazy version of {@link #putLongVolatile(Object, long, long)} */
+ @HotSpotIntrinsicCandidate
+ public native void putOrderedLong(Object o, long offset, long x);
+
+ /**
+ * 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.
+ */
+ @HotSpotIntrinsicCandidate
+ public native void unpark(Object thread);
+
+ /**
+ * 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.
+ */
+ @HotSpotIntrinsicCandidate
+ public native void park(boolean isAbsolute, long 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 {@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.
+ */
+ public native int getLoadAverage(double[] loadavg, int 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 {@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
+ */
+ @HotSpotIntrinsicCandidate
+ public final int getAndAddInt(Object o, long offset, int delta) {
+ int v;
+ do {
+ v = getIntVolatile(o, offset);
+ } while (!compareAndSwapInt(o, offset, v, v + delta));
+ return v;
+ }
+
+ /**
+ * 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
+ */
+ @HotSpotIntrinsicCandidate
+ public final long getAndAddLong(Object o, long offset, long delta) {
+ long v;
+ do {
+ v = getLongVolatile(o, offset);
+ } while (!compareAndSwapLong(o, offset, v, v + delta));
+ return v;
+ }
+
+ /**
+ * 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
+ */
+ @HotSpotIntrinsicCandidate
+ public final int getAndSetInt(Object o, long offset, int newValue) {
+ int v;
+ do {
+ v = getIntVolatile(o, offset);
+ } while (!compareAndSwapInt(o, offset, v, newValue));
+ return v;
+ }
+
+ /**
+ * 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
+ */
+ @HotSpotIntrinsicCandidate
+ public final long getAndSetLong(Object o, long offset, long newValue) {
+ long v;
+ do {
+ v = getLongVolatile(o, offset);
+ } while (!compareAndSwapLong(o, offset, v, newValue));
+ return v;
+ }
+
+ /**
+ * 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
+ */
+ @HotSpotIntrinsicCandidate
+ public final Object getAndSetObject(Object o, long offset, Object newValue) {
+ Object v;
+ do {
+ v = getObjectVolatile(o, offset);
+ } while (!compareAndSwapObject(o, offset, v, newValue));
+ return v;
+ }
+
+
+ /**
+ * 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
+ */
+ @HotSpotIntrinsicCandidate
+ public native void 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
+ */
+ @HotSpotIntrinsicCandidate
+ public native void 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
+ */
+ @HotSpotIntrinsicCandidate
+ public native void fullFence();
+
+ /**
+ * Throws IllegalAccessError; for use by the VM for access control
+ * error support.
+ * @since 1.8
+ */
+ private static void throwIllegalAccessError() {
+ throw new IllegalAccessError();
+ }
+
+ /**
+ * @return Returns true if the native byte ordering of this
+ * platform is big-endian, false if it is little-endian.
+ */
+ public final boolean isBigEndian() { return BE; }
+
+ /**
+ * @return Returns true if this platform is capable of performing
+ * accesses at addresses which are not aligned for the type of the
+ * primitive type being accessed, false otherwise.
+ */
+ public final boolean unalignedAccess() { return unalignedAccess; }
+
+ /**
+ * Fetches a value at some byte offset into a given Java object.
+ * More specifically, fetches a value within the given object
+ * <code>o</code> at the given offset, or (if <code>o</code> is
+ * null) from the memory address whose numerical value is the
+ * given offset. <p>
+ *
+ * The specification of this method is the same as {@link
+ * #getLong(Object, long)} except that the offset does not need to
+ * have been obtained from {@link #objectFieldOffset} on the
+ * {@link java.lang.reflect.Field} of some Java field. The value
+ * in memory is raw data, and need not correspond to any Java
+ * variable. Unless <code>o</code> is null, the value accessed
+ * must be entirely within the allocated object. The endianness
+ * of the value in memory is the endianness of the native platform.
+ *
+ * <p> The read will be atomic with respect to the largest power
+ * of two that divides the GCD of the offset and the storage size.
+ * For example, getLongUnaligned will make atomic reads of 2-, 4-,
+ * or 8-byte storage units if the offset is zero mod 2, 4, or 8,
+ * respectively. There are no other guarantees of atomicity.
+ * <p>
+ * 8-byte atomicity is only guaranteed on platforms on which
+ * support atomic accesses to longs.
+ *
+ * @param o Java heap object in which the value resides, if any, else
+ * null
+ * @param offset The offset in bytes from the start of the object
+ * @return the value fetched from the indicated object
+ * @throws RuntimeException No defined exceptions are thrown, not even
+ * {@link NullPointerException}
+ * @since 1.9
+ */
+ @HotSpotIntrinsicCandidate
+ public final long getLongUnaligned(Object o, long offset) {
+ if ((offset & 7) == 0) {
+ return getLong(o, offset);
+ } else if ((offset & 3) == 0) {
+ return makeLong(getInt(o, offset),
+ getInt(o, offset + 4));
+ } else if ((offset & 1) == 0) {
+ return makeLong(getShort(o, offset),
+ getShort(o, offset + 2),
+ getShort(o, offset + 4),
+ getShort(o, offset + 6));
+ } else {
+ return makeLong(getByte(o, offset),
+ getByte(o, offset + 1),
+ getByte(o, offset + 2),
+ getByte(o, offset + 3),
+ getByte(o, offset + 4),
+ getByte(o, offset + 5),
+ getByte(o, offset + 6),
+ getByte(o, offset + 7));
+ }
+ }
+ /**
+ * As {@link #getLongUnaligned(Object, long)} but with an
+ * additional argument which specifies the endianness of the value
+ * as stored in memory.
+ *
+ * @param o Java heap object in which the variable resides
+ * @param offset The offset in bytes from the start of the object
+ * @param bigEndian The endianness of the value
+ * @return the value fetched from the indicated object
+ * @since 1.9
+ */
+ public final long getLongUnaligned(Object o, long offset, boolean bigEndian) {
+ return convEndian(bigEndian, getLongUnaligned(o, offset));
+ }
+
+ /** @see #getLongUnaligned(Object, long) */
+ @HotSpotIntrinsicCandidate
+ public final int getIntUnaligned(Object o, long offset) {
+ if ((offset & 3) == 0) {
+ return getInt(o, offset);
+ } else if ((offset & 1) == 0) {
+ return makeInt(getShort(o, offset),
+ getShort(o, offset + 2));
+ } else {
+ return makeInt(getByte(o, offset),
+ getByte(o, offset + 1),
+ getByte(o, offset + 2),
+ getByte(o, offset + 3));
+ }
+ }
+ /** @see #getLongUnaligned(Object, long, boolean) */
+ public final int getIntUnaligned(Object o, long offset, boolean bigEndian) {
+ return convEndian(bigEndian, getIntUnaligned(o, offset));
+ }
+
+ /** @see #getLongUnaligned(Object, long) */
+ @HotSpotIntrinsicCandidate
+ public final short getShortUnaligned(Object o, long offset) {
+ if ((offset & 1) == 0) {
+ return getShort(o, offset);
+ } else {
+ return makeShort(getByte(o, offset),
+ getByte(o, offset + 1));
+ }
+ }
+ /** @see #getLongUnaligned(Object, long, boolean) */
+ public final short getShortUnaligned(Object o, long offset, boolean bigEndian) {
+ return convEndian(bigEndian, getShortUnaligned(o, offset));
+ }
+
+ /** @see #getLongUnaligned(Object, long) */
+ @HotSpotIntrinsicCandidate
+ public final char getCharUnaligned(Object o, long offset) {
+ return (char)getShortUnaligned(o, offset);
+ }
+
+ /** @see #getLongUnaligned(Object, long, boolean) */
+ public final char getCharUnaligned(Object o, long offset, boolean bigEndian) {
+ return convEndian(bigEndian, getCharUnaligned(o, offset));
+ }
+
+ /**
+ * Stores a value at some byte offset into a given Java object.
+ * <p>
+ * The specification of this method is the same as {@link
+ * #getLong(Object, long)} except that the offset does not need to
+ * have been obtained from {@link #objectFieldOffset} on the
+ * {@link java.lang.reflect.Field} of some Java field. The value
+ * in memory is raw data, and need not correspond to any Java
+ * variable. The endianness of the value in memory is the
+ * endianness of the native platform.
+ * <p>
+ * The write will be atomic with respect to the largest power of
+ * two that divides the GCD of the offset and the storage size.
+ * For example, putLongUnaligned will make atomic writes of 2-, 4-,
+ * or 8-byte storage units if the offset is zero mod 2, 4, or 8,
+ * respectively. There are no other guarantees of atomicity.
+ * <p>
+ * 8-byte atomicity is only guaranteed on platforms on which
+ * support atomic accesses to longs.
+ *
+ * @param o Java heap object in which the value resides, if any, else
+ * null
+ * @param offset The offset in bytes from the start of the object
+ * @param x the value to store
+ * @throws RuntimeException No defined exceptions are thrown, not even
+ * {@link NullPointerException}
+ * @since 1.9
+ */
+ @HotSpotIntrinsicCandidate
+ public final void putLongUnaligned(Object o, long offset, long x) {
+ if ((offset & 7) == 0) {
+ putLong(o, offset, x);
+ } else if ((offset & 3) == 0) {
+ putLongParts(o, offset,
+ (int)(x >> 0),
+ (int)(x >>> 32));
+ } else if ((offset & 1) == 0) {
+ putLongParts(o, offset,
+ (short)(x >>> 0),
+ (short)(x >>> 16),
+ (short)(x >>> 32),
+ (short)(x >>> 48));
+ } else {
+ putLongParts(o, offset,
+ (byte)(x >>> 0),
+ (byte)(x >>> 8),
+ (byte)(x >>> 16),
+ (byte)(x >>> 24),
+ (byte)(x >>> 32),
+ (byte)(x >>> 40),
+ (byte)(x >>> 48),
+ (byte)(x >>> 56));
+ }
+ }
+
+ /**
+ * As {@link #putLongUnaligned(Object, long, long)} but with an additional
+ * argument which specifies the endianness of the value as stored in memory.
+ * @param o Java heap object in which the value resides
+ * @param offset The offset in bytes from the start of the object
+ * @param x the value to store
+ * @param bigEndian The endianness of the value
+ * @throws RuntimeException No defined exceptions are thrown, not even
+ * {@link NullPointerException}
+ * @since 1.9
+ */
+ public final void putLongUnaligned(Object o, long offset, long x, boolean bigEndian) {
+ putLongUnaligned(o, offset, convEndian(bigEndian, x));
+ }
+
+ /** @see #putLongUnaligned(Object, long, long) */
+ @HotSpotIntrinsicCandidate
+ public final void putIntUnaligned(Object o, long offset, int x) {
+ if ((offset & 3) == 0) {
+ putInt(o, offset, x);
+ } else if ((offset & 1) == 0) {
+ putIntParts(o, offset,
+ (short)(x >> 0),
+ (short)(x >>> 16));
+ } else {
+ putIntParts(o, offset,
+ (byte)(x >>> 0),
+ (byte)(x >>> 8),
+ (byte)(x >>> 16),
+ (byte)(x >>> 24));
+ }
+ }
+ /** @see #putLongUnaligned(Object, long, long, boolean) */
+ public final void putIntUnaligned(Object o, long offset, int x, boolean bigEndian) {
+ putIntUnaligned(o, offset, convEndian(bigEndian, x));
+ }
+
+ /** @see #putLongUnaligned(Object, long, long) */
+ @HotSpotIntrinsicCandidate
+ public final void putShortUnaligned(Object o, long offset, short x) {
+ if ((offset & 1) == 0) {
+ putShort(o, offset, x);
+ } else {
+ putShortParts(o, offset,
+ (byte)(x >>> 0),
+ (byte)(x >>> 8));
+ }
+ }
+ /** @see #putLongUnaligned(Object, long, long, boolean) */
+ public final void putShortUnaligned(Object o, long offset, short x, boolean bigEndian) {
+ putShortUnaligned(o, offset, convEndian(bigEndian, x));
+ }
+
+ /** @see #putLongUnaligned(Object, long, long) */
+ @HotSpotIntrinsicCandidate
+ public final void putCharUnaligned(Object o, long offset, char x) {
+ putShortUnaligned(o, offset, (short)x);
+ }
+ /** @see #putLongUnaligned(Object, long, long, boolean) */
+ public final void putCharUnaligned(Object o, long offset, char x, boolean bigEndian) {
+ putCharUnaligned(o, offset, convEndian(bigEndian, x));
+ }
+
+ // JVM interface methods
+ private native boolean unalignedAccess0();
+ private native boolean isBigEndian0();
+
+ // BE is true iff the native endianness of this platform is big.
+ private static final boolean BE = theUnsafe.isBigEndian0();
+
+ // unalignedAccess is true iff this platform can perform unaligned accesses.
+ private static final boolean unalignedAccess = theUnsafe.unalignedAccess0();
+
+ private static int pickPos(int top, int pos) { return BE ? top - pos : pos; }
+
+ // These methods construct integers from bytes. The byte ordering
+ // is the native endianness of this platform.
+ private static long makeLong(byte i0, byte i1, byte i2, byte i3, byte i4, byte i5, byte i6, byte i7) {
+ return ((toUnsignedLong(i0) << pickPos(56, 0))
+ | (toUnsignedLong(i1) << pickPos(56, 8))
+ | (toUnsignedLong(i2) << pickPos(56, 16))
+ | (toUnsignedLong(i3) << pickPos(56, 24))
+ | (toUnsignedLong(i4) << pickPos(56, 32))
+ | (toUnsignedLong(i5) << pickPos(56, 40))
+ | (toUnsignedLong(i6) << pickPos(56, 48))
+ | (toUnsignedLong(i7) << pickPos(56, 56)));
+ }
+ private static long makeLong(short i0, short i1, short i2, short i3) {
+ return ((toUnsignedLong(i0) << pickPos(48, 0))
+ | (toUnsignedLong(i1) << pickPos(48, 16))
+ | (toUnsignedLong(i2) << pickPos(48, 32))
+ | (toUnsignedLong(i3) << pickPos(48, 48)));
+ }
+ private static long makeLong(int i0, int i1) {
+ return (toUnsignedLong(i0) << pickPos(32, 0))
+ | (toUnsignedLong(i1) << pickPos(32, 32));
+ }
+ private static int makeInt(short i0, short i1) {
+ return (toUnsignedInt(i0) << pickPos(16, 0))
+ | (toUnsignedInt(i1) << pickPos(16, 16));
+ }
+ private static int makeInt(byte i0, byte i1, byte i2, byte i3) {
+ return ((toUnsignedInt(i0) << pickPos(24, 0))
+ | (toUnsignedInt(i1) << pickPos(24, 8))
+ | (toUnsignedInt(i2) << pickPos(24, 16))
+ | (toUnsignedInt(i3) << pickPos(24, 24)));
+ }
+ private static short makeShort(byte i0, byte i1) {
+ return (short)((toUnsignedInt(i0) << pickPos(8, 0))
+ | (toUnsignedInt(i1) << pickPos(8, 8)));
+ }
+
+ private static byte pick(byte le, byte be) { return BE ? be : le; }
+ private static short pick(short le, short be) { return BE ? be : le; }
+ private static int pick(int le, int be) { return BE ? be : le; }
+
+ // These methods write integers to memory from smaller parts
+ // provided by their caller. The ordering in which these parts
+ // are written is the native endianness of this platform.
+ private void putLongParts(Object o, long offset, byte i0, byte i1, byte i2, byte i3, byte i4, byte i5, byte i6, byte i7) {
+ putByte(o, offset + 0, pick(i0, i7));
+ putByte(o, offset + 1, pick(i1, i6));
+ putByte(o, offset + 2, pick(i2, i5));
+ putByte(o, offset + 3, pick(i3, i4));
+ putByte(o, offset + 4, pick(i4, i3));
+ putByte(o, offset + 5, pick(i5, i2));
+ putByte(o, offset + 6, pick(i6, i1));
+ putByte(o, offset + 7, pick(i7, i0));
+ }
+ private void putLongParts(Object o, long offset, short i0, short i1, short i2, short i3) {
+ putShort(o, offset + 0, pick(i0, i3));
+ putShort(o, offset + 2, pick(i1, i2));
+ putShort(o, offset + 4, pick(i2, i1));
+ putShort(o, offset + 6, pick(i3, i0));
+ }
+ private void putLongParts(Object o, long offset, int i0, int i1) {
+ putInt(o, offset + 0, pick(i0, i1));
+ putInt(o, offset + 4, pick(i1, i0));
+ }
+ private void putIntParts(Object o, long offset, short i0, short i1) {
+ putShort(o, offset + 0, pick(i0, i1));
+ putShort(o, offset + 2, pick(i1, i0));
+ }
+ private void putIntParts(Object o, long offset, byte i0, byte i1, byte i2, byte i3) {
+ putByte(o, offset + 0, pick(i0, i3));
+ putByte(o, offset + 1, pick(i1, i2));
+ putByte(o, offset + 2, pick(i2, i1));
+ putByte(o, offset + 3, pick(i3, i0));
+ }
+ private void putShortParts(Object o, long offset, byte i0, byte i1) {
+ putByte(o, offset + 0, pick(i0, i1));
+ putByte(o, offset + 1, pick(i1, i0));
+ }
+
+ // Zero-extend an integer
+ private static int toUnsignedInt(byte n) { return n & 0xff; }
+ private static int toUnsignedInt(short n) { return n & 0xffff; }
+ private static long toUnsignedLong(byte n) { return n & 0xffl; }
+ private static long toUnsignedLong(short n) { return n & 0xffffl; }
+ private static long toUnsignedLong(int n) { return n & 0xffffffffl; }
+
+ // Maybe byte-reverse an integer
+ private static char convEndian(boolean big, char n) { return big == BE ? n : Character.reverseBytes(n); }
+ private static short convEndian(boolean big, short n) { return big == BE ? n : Short.reverseBytes(n) ; }
+ private static int convEndian(boolean big, int n) { return big == BE ? n : Integer.reverseBytes(n) ; }
+ private static long convEndian(boolean big, long n) { return big == BE ? n : Long.reverseBytes(n) ; }
+}
--- a/jdk/src/java.base/share/classes/sun/misc/Unsafe.java Wed Oct 21 16:39:02 2015 -0400
+++ b/jdk/src/java.base/share/classes/sun/misc/Unsafe.java Tue Oct 27 14:19:55 2015 +0000
@@ -1036,355 +1036,8 @@
throw new IllegalAccessError();
}
- /**
- * @return Returns true if the native byte ordering of this
- * platform is big-endian, false if it is little-endian.
- */
- public final boolean isBigEndian() { return BE; }
-
- /**
- * @return Returns true if this platform is capable of performing
- * accesses at addresses which are not aligned for the type of the
- * primitive type being accessed, false otherwise.
- */
- public final boolean unalignedAccess() { return unalignedAccess; }
-
- /**
- * Fetches a value at some byte offset into a given Java object.
- * More specifically, fetches a value within the given object
- * <code>o</code> at the given offset, or (if <code>o</code> is
- * null) from the memory address whose numerical value is the
- * given offset. <p>
- *
- * The specification of this method is the same as {@link
- * #getLong(Object, long)} except that the offset does not need to
- * have been obtained from {@link #objectFieldOffset} on the
- * {@link java.lang.reflect.Field} of some Java field. The value
- * in memory is raw data, and need not correspond to any Java
- * variable. Unless <code>o</code> is null, the value accessed
- * must be entirely within the allocated object. The endianness
- * of the value in memory is the endianness of the native platform.
- *
- * <p> The read will be atomic with respect to the largest power
- * of two that divides the GCD of the offset and the storage size.
- * For example, getLongUnaligned will make atomic reads of 2-, 4-,
- * or 8-byte storage units if the offset is zero mod 2, 4, or 8,
- * respectively. There are no other guarantees of atomicity.
- * <p>
- * 8-byte atomicity is only guaranteed on platforms on which
- * support atomic accesses to longs.
- *
- * @param o Java heap object in which the value resides, if any, else
- * null
- * @param offset The offset in bytes from the start of the object
- * @return the value fetched from the indicated object
- * @throws RuntimeException No defined exceptions are thrown, not even
- * {@link NullPointerException}
- * @since 1.9
- */
- @HotSpotIntrinsicCandidate
- public final long getLongUnaligned(Object o, long offset) {
- if ((offset & 7) == 0) {
- return getLong(o, offset);
- } else if ((offset & 3) == 0) {
- return makeLong(getInt(o, offset),
- getInt(o, offset + 4));
- } else if ((offset & 1) == 0) {
- return makeLong(getShort(o, offset),
- getShort(o, offset + 2),
- getShort(o, offset + 4),
- getShort(o, offset + 6));
- } else {
- return makeLong(getByte(o, offset),
- getByte(o, offset + 1),
- getByte(o, offset + 2),
- getByte(o, offset + 3),
- getByte(o, offset + 4),
- getByte(o, offset + 5),
- getByte(o, offset + 6),
- getByte(o, offset + 7));
- }
- }
- /**
- * As {@link #getLongUnaligned(Object, long)} but with an
- * additional argument which specifies the endianness of the value
- * as stored in memory.
- *
- * @param o Java heap object in which the variable resides
- * @param offset The offset in bytes from the start of the object
- * @param bigEndian The endianness of the value
- * @return the value fetched from the indicated object
- * @since 1.9
- */
- public final long getLongUnaligned(Object o, long offset, boolean bigEndian) {
- return convEndian(bigEndian, getLongUnaligned(o, offset));
- }
-
- /** @see #getLongUnaligned(Object, long) */
- @HotSpotIntrinsicCandidate
- public final int getIntUnaligned(Object o, long offset) {
- if ((offset & 3) == 0) {
- return getInt(o, offset);
- } else if ((offset & 1) == 0) {
- return makeInt(getShort(o, offset),
- getShort(o, offset + 2));
- } else {
- return makeInt(getByte(o, offset),
- getByte(o, offset + 1),
- getByte(o, offset + 2),
- getByte(o, offset + 3));
- }
- }
- /** @see #getLongUnaligned(Object, long, boolean) */
- public final int getIntUnaligned(Object o, long offset, boolean bigEndian) {
- return convEndian(bigEndian, getIntUnaligned(o, offset));
- }
-
- /** @see #getLongUnaligned(Object, long) */
- @HotSpotIntrinsicCandidate
- public final short getShortUnaligned(Object o, long offset) {
- if ((offset & 1) == 0) {
- return getShort(o, offset);
- } else {
- return makeShort(getByte(o, offset),
- getByte(o, offset + 1));
- }
- }
- /** @see #getLongUnaligned(Object, long, boolean) */
- public final short getShortUnaligned(Object o, long offset, boolean bigEndian) {
- return convEndian(bigEndian, getShortUnaligned(o, offset));
- }
-
- /** @see #getLongUnaligned(Object, long) */
- @HotSpotIntrinsicCandidate
- public final char getCharUnaligned(Object o, long offset) {
- return (char)getShortUnaligned(o, offset);
- }
-
- /** @see #getLongUnaligned(Object, long, boolean) */
- public final char getCharUnaligned(Object o, long offset, boolean bigEndian) {
- return convEndian(bigEndian, getCharUnaligned(o, offset));
- }
-
- /**
- * Stores a value at some byte offset into a given Java object.
- * <p>
- * The specification of this method is the same as {@link
- * #getLong(Object, long)} except that the offset does not need to
- * have been obtained from {@link #objectFieldOffset} on the
- * {@link java.lang.reflect.Field} of some Java field. The value
- * in memory is raw data, and need not correspond to any Java
- * variable. The endianness of the value in memory is the
- * endianness of the native platform.
- * <p>
- * The write will be atomic with respect to the largest power of
- * two that divides the GCD of the offset and the storage size.
- * For example, putLongUnaligned will make atomic writes of 2-, 4-,
- * or 8-byte storage units if the offset is zero mod 2, 4, or 8,
- * respectively. There are no other guarantees of atomicity.
- * <p>
- * 8-byte atomicity is only guaranteed on platforms on which
- * support atomic accesses to longs.
- *
- * @param o Java heap object in which the value resides, if any, else
- * null
- * @param offset The offset in bytes from the start of the object
- * @param x the value to store
- * @throws RuntimeException No defined exceptions are thrown, not even
- * {@link NullPointerException}
- * @since 1.9
- */
- @HotSpotIntrinsicCandidate
- public final void putLongUnaligned(Object o, long offset, long x) {
- if ((offset & 7) == 0) {
- putLong(o, offset, x);
- } else if ((offset & 3) == 0) {
- putLongParts(o, offset,
- (int)(x >> 0),
- (int)(x >>> 32));
- } else if ((offset & 1) == 0) {
- putLongParts(o, offset,
- (short)(x >>> 0),
- (short)(x >>> 16),
- (short)(x >>> 32),
- (short)(x >>> 48));
- } else {
- putLongParts(o, offset,
- (byte)(x >>> 0),
- (byte)(x >>> 8),
- (byte)(x >>> 16),
- (byte)(x >>> 24),
- (byte)(x >>> 32),
- (byte)(x >>> 40),
- (byte)(x >>> 48),
- (byte)(x >>> 56));
- }
- }
-
- /**
- * As {@link #putLongUnaligned(Object, long, long)} but with an additional
- * argument which specifies the endianness of the value as stored in memory.
- * @param o Java heap object in which the value resides
- * @param offset The offset in bytes from the start of the object
- * @param x the value to store
- * @param bigEndian The endianness of the value
- * @throws RuntimeException No defined exceptions are thrown, not even
- * {@link NullPointerException}
- * @since 1.9
- */
- public final void putLongUnaligned(Object o, long offset, long x, boolean bigEndian) {
- putLongUnaligned(o, offset, convEndian(bigEndian, x));
- }
-
- /** @see #putLongUnaligned(Object, long, long) */
- @HotSpotIntrinsicCandidate
- public final void putIntUnaligned(Object o, long offset, int x) {
- if ((offset & 3) == 0) {
- putInt(o, offset, x);
- } else if ((offset & 1) == 0) {
- putIntParts(o, offset,
- (short)(x >> 0),
- (short)(x >>> 16));
- } else {
- putIntParts(o, offset,
- (byte)(x >>> 0),
- (byte)(x >>> 8),
- (byte)(x >>> 16),
- (byte)(x >>> 24));
- }
- }
- /** @see #putLongUnaligned(Object, long, long, boolean) */
- public final void putIntUnaligned(Object o, long offset, int x, boolean bigEndian) {
- putIntUnaligned(o, offset, convEndian(bigEndian, x));
- }
-
- /** @see #putLongUnaligned(Object, long, long) */
- @HotSpotIntrinsicCandidate
- public final void putShortUnaligned(Object o, long offset, short x) {
- if ((offset & 1) == 0) {
- putShort(o, offset, x);
- } else {
- putShortParts(o, offset,
- (byte)(x >>> 0),
- (byte)(x >>> 8));
- }
- }
- /** @see #putLongUnaligned(Object, long, long, boolean) */
- public final void putShortUnaligned(Object o, long offset, short x, boolean bigEndian) {
- putShortUnaligned(o, offset, convEndian(bigEndian, x));
- }
-
- /** @see #putLongUnaligned(Object, long, long) */
- @HotSpotIntrinsicCandidate
- public final void putCharUnaligned(Object o, long offset, char x) {
- putShortUnaligned(o, offset, (short)x);
- }
- /** @see #putLongUnaligned(Object, long, long, boolean) */
- public final void putCharUnaligned(Object o, long offset, char x, boolean bigEndian) {
- putCharUnaligned(o, offset, convEndian(bigEndian, x));
- }
-
// JVM interface methods
private native boolean unalignedAccess0();
private native boolean isBigEndian0();
- // BE is true iff the native endianness of this platform is big.
- private static final boolean BE = theUnsafe.isBigEndian0();
-
- // unalignedAccess is true iff this platform can perform unaligned accesses.
- private static final boolean unalignedAccess = theUnsafe.unalignedAccess0();
-
- private static int pickPos(int top, int pos) { return BE ? top - pos : pos; }
-
- // These methods construct integers from bytes. The byte ordering
- // is the native endianness of this platform.
- private static long makeLong(byte i0, byte i1, byte i2, byte i3, byte i4, byte i5, byte i6, byte i7) {
- return ((toUnsignedLong(i0) << pickPos(56, 0))
- | (toUnsignedLong(i1) << pickPos(56, 8))
- | (toUnsignedLong(i2) << pickPos(56, 16))
- | (toUnsignedLong(i3) << pickPos(56, 24))
- | (toUnsignedLong(i4) << pickPos(56, 32))
- | (toUnsignedLong(i5) << pickPos(56, 40))
- | (toUnsignedLong(i6) << pickPos(56, 48))
- | (toUnsignedLong(i7) << pickPos(56, 56)));
- }
- private static long makeLong(short i0, short i1, short i2, short i3) {
- return ((toUnsignedLong(i0) << pickPos(48, 0))
- | (toUnsignedLong(i1) << pickPos(48, 16))
- | (toUnsignedLong(i2) << pickPos(48, 32))
- | (toUnsignedLong(i3) << pickPos(48, 48)));
- }
- private static long makeLong(int i0, int i1) {
- return (toUnsignedLong(i0) << pickPos(32, 0))
- | (toUnsignedLong(i1) << pickPos(32, 32));
- }
- private static int makeInt(short i0, short i1) {
- return (toUnsignedInt(i0) << pickPos(16, 0))
- | (toUnsignedInt(i1) << pickPos(16, 16));
- }
- private static int makeInt(byte i0, byte i1, byte i2, byte i3) {
- return ((toUnsignedInt(i0) << pickPos(24, 0))
- | (toUnsignedInt(i1) << pickPos(24, 8))
- | (toUnsignedInt(i2) << pickPos(24, 16))
- | (toUnsignedInt(i3) << pickPos(24, 24)));
- }
- private static short makeShort(byte i0, byte i1) {
- return (short)((toUnsignedInt(i0) << pickPos(8, 0))
- | (toUnsignedInt(i1) << pickPos(8, 8)));
- }
-
- private static byte pick(byte le, byte be) { return BE ? be : le; }
- private static short pick(short le, short be) { return BE ? be : le; }
- private static int pick(int le, int be) { return BE ? be : le; }
-
- // These methods write integers to memory from smaller parts
- // provided by their caller. The ordering in which these parts
- // are written is the native endianness of this platform.
- private void putLongParts(Object o, long offset, byte i0, byte i1, byte i2, byte i3, byte i4, byte i5, byte i6, byte i7) {
- putByte(o, offset + 0, pick(i0, i7));
- putByte(o, offset + 1, pick(i1, i6));
- putByte(o, offset + 2, pick(i2, i5));
- putByte(o, offset + 3, pick(i3, i4));
- putByte(o, offset + 4, pick(i4, i3));
- putByte(o, offset + 5, pick(i5, i2));
- putByte(o, offset + 6, pick(i6, i1));
- putByte(o, offset + 7, pick(i7, i0));
- }
- private void putLongParts(Object o, long offset, short i0, short i1, short i2, short i3) {
- putShort(o, offset + 0, pick(i0, i3));
- putShort(o, offset + 2, pick(i1, i2));
- putShort(o, offset + 4, pick(i2, i1));
- putShort(o, offset + 6, pick(i3, i0));
- }
- private void putLongParts(Object o, long offset, int i0, int i1) {
- putInt(o, offset + 0, pick(i0, i1));
- putInt(o, offset + 4, pick(i1, i0));
- }
- private void putIntParts(Object o, long offset, short i0, short i1) {
- putShort(o, offset + 0, pick(i0, i1));
- putShort(o, offset + 2, pick(i1, i0));
- }
- private void putIntParts(Object o, long offset, byte i0, byte i1, byte i2, byte i3) {
- putByte(o, offset + 0, pick(i0, i3));
- putByte(o, offset + 1, pick(i1, i2));
- putByte(o, offset + 2, pick(i2, i1));
- putByte(o, offset + 3, pick(i3, i0));
- }
- private void putShortParts(Object o, long offset, byte i0, byte i1) {
- putByte(o, offset + 0, pick(i0, i1));
- putByte(o, offset + 1, pick(i1, i0));
- }
-
- // Zero-extend an integer
- private static int toUnsignedInt(byte n) { return n & 0xff; }
- private static int toUnsignedInt(short n) { return n & 0xffff; }
- private static long toUnsignedLong(byte n) { return n & 0xffl; }
- private static long toUnsignedLong(short n) { return n & 0xffffl; }
- private static long toUnsignedLong(int n) { return n & 0xffffffffl; }
-
- // Maybe byte-reverse an integer
- private static char convEndian(boolean big, char n) { return big == BE ? n : Character.reverseBytes(n); }
- private static short convEndian(boolean big, short n) { return big == BE ? n : Short.reverseBytes(n) ; }
- private static int convEndian(boolean big, int n) { return big == BE ? n : Integer.reverseBytes(n) ; }
- private static long convEndian(boolean big, long n) { return big == BE ? n : Long.reverseBytes(n) ; }
}