| /* |
| * Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * 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 jdk.internal.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. |
| * |
| * <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 { |
| |
| 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); |
| |
| |
| |
| /// helper methods for validating various types of objects/values |
| |
| /** |
| * Create an exception reflecting that some of the input was invalid |
| * |
| * <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! |
| * |
| * @return an exception object |
| */ |
| private RuntimeException invalidInput() { |
| return new IllegalArgumentException(); |
| } |
| |
| /** |
| * Check if a value is 32-bit clean (32 MSB are all zero) |
| * |
| * @param value the 64-bit value to check |
| * |
| * @return true if the value is 32-bit clean |
| */ |
| private boolean is32BitClean(long value) { |
| return value >>> 32 == 0; |
| } |
| |
| /** |
| * Check the validity of a size (the equivalent of a size_t) |
| * |
| * @throws RuntimeException if the size is invalid |
| * (<em>Note:</em> after optimization, invalid inputs may |
| * go undetected, which will lead to unpredictable |
| * behavior) |
| */ |
| private void checkSize(long size) { |
| if (ADDRESS_SIZE == 4) { |
| // Note: this will also check for negative sizes |
| if (!is32BitClean(size)) { |
| throw invalidInput(); |
| } |
| } else if (size < 0) { |
| throw invalidInput(); |
| } |
| } |
| |
| /** |
| * Check the validity of a native address (the equivalent of void*) |
| * |
| * @throws RuntimeException if the address is invalid |
| * (<em>Note:</em> after optimization, invalid inputs may |
| * go undetected, which will lead to unpredictable |
| * behavior) |
| */ |
| private void checkNativeAddress(long address) { |
| if (ADDRESS_SIZE == 4) { |
| // Accept both zero and sign extended pointers. A valid |
| // pointer will, after the +1 below, either have produced |
| // the value 0x0 or 0x1. Masking off the low bit allows |
| // for testing against 0. |
| if ((((address >> 32) + 1) & ~1) != 0) { |
| throw invalidInput(); |
| } |
| } |
| } |
| |
| /** |
| * Check the validity of an offset, relative to a base object |
| * |
| * @param o the base object |
| * @param offset the offset to check |
| * |
| * @throws RuntimeException if the size is invalid |
| * (<em>Note:</em> after optimization, invalid inputs may |
| * go undetected, which will lead to unpredictable |
| * behavior) |
| */ |
| private void checkOffset(Object o, long offset) { |
| if (ADDRESS_SIZE == 4) { |
| // Note: this will also check for negative offsets |
| if (!is32BitClean(offset)) { |
| throw invalidInput(); |
| } |
| } else if (offset < 0) { |
| throw invalidInput(); |
| } |
| } |
| |
| /** |
| * Check the validity of a double-register pointer |
| * |
| * Note: This code deliberately does *not* check for NPE for (at |
| * least) three reasons: |
| * |
| * 1) NPE is not just NULL/0 - there is a range of values all |
| * resulting in an NPE, which is not trivial to check for |
| * |
| * 2) It is the responsibility of the callers of Unsafe methods |
| * to verify the input, so throwing an exception here is not really |
| * useful - passing in a NULL pointer is a critical error and the |
| * must not expect an exception to be thrown anyway. |
| * |
| * 3) the actual operations will detect NULL pointers anyway by |
| * means of traps and signals (like SIGSEGV). |
| * |
| * @param o Java heap object, or null |
| * @param offset indication of where the variable resides in a Java heap |
| * object, if any, else a memory address locating the variable |
| * statically |
| * |
| * @throws RuntimeException if the pointer is invalid |
| * (<em>Note:</em> after optimization, invalid inputs may |
| * go undetected, which will lead to unpredictable |
| * behavior) |
| */ |
| private void checkPointer(Object o, long offset) { |
| if (o == null) { |
| checkNativeAddress(offset); |
| } else { |
| checkOffset(o, offset); |
| } |
| } |
| |
| /** |
| * Check if a type is a primitive array type |
| * |
| * @param c the type to check |
| * |
| * @return true if the type is a primitive array type |
| */ |
| private void checkPrimitiveArray(Class<?> c) { |
| Class<?> componentType = c.getComponentType(); |
| if (componentType == null || !componentType.isPrimitive()) { |
| throw invalidInput(); |
| } |
| } |
| |
| /** |
| * Check that a pointer is a valid primitive array type pointer |
| * |
| * Note: pointers off-heap are considered to be primitive arrays |
| * |
| * @throws RuntimeException if the pointer is invalid |
| * (<em>Note:</em> after optimization, invalid inputs may |
| * go undetected, which will lead to unpredictable |
| * behavior) |
| */ |
| private void checkPrimitivePointer(Object o, long offset) { |
| checkPointer(o, offset); |
| |
| if (o != null) { |
| // If on heap, it it must be a primitive array |
| checkPrimitiveArray(o.getClass()); |
| } |
| } |
| |
| |
| /// 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}. |
| * |
| * <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) |
| */ |
| public long allocateMemory(long bytes) { |
| allocateMemoryChecks(bytes); |
| |
| if (bytes == 0) { |
| return 0; |
| } |
| |
| long p = allocateMemory0(bytes); |
| if (p == 0) { |
| throw new OutOfMemoryError(); |
| } |
| |
| return p; |
| } |
| |
| /** |
| * Validate the arguments to allocateMemory |
| * |
| * @throws RuntimeException if the arguments are invalid |
| * (<em>Note:</em> after optimization, invalid inputs may |
| * go undetected, which will lead to unpredictable |
| * behavior) |
| */ |
| private void allocateMemoryChecks(long bytes) { |
| checkSize(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. |
| * |
| * <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 |
| */ |
| public long reallocateMemory(long address, long bytes) { |
| reallocateMemoryChecks(address, bytes); |
| |
| if (bytes == 0) { |
| freeMemory(address); |
| return 0; |
| } |
| |
| long p = (address == 0) ? allocateMemory0(bytes) : reallocateMemory0(address, bytes); |
| if (p == 0) { |
| throw new OutOfMemoryError(); |
| } |
| |
| return p; |
| } |
| |
| /** |
| * Validate the arguments to reallocateMemory |
| * |
| * @throws RuntimeException if the arguments are invalid |
| * (<em>Note:</em> after optimization, invalid inputs may |
| * go undetected, which will lead to unpredictable |
| * behavior) |
| */ |
| private void reallocateMemoryChecks(long address, long bytes) { |
| checkPointer(null, address); |
| checkSize(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'. |
| * |
| * <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 |
| */ |
| public void setMemory(Object o, long offset, long bytes, byte value) { |
| setMemoryChecks(o, offset, bytes, value); |
| |
| if (bytes == 0) { |
| return; |
| } |
| |
| setMemory0(o, offset, 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)}. |
| */ |
| public void setMemory(long address, long bytes, byte value) { |
| setMemory(null, address, bytes, value); |
| } |
| |
| /** |
| * Validate the arguments to setMemory |
| * |
| * @throws RuntimeException if the arguments are invalid |
| * (<em>Note:</em> after optimization, invalid inputs may |
| * go undetected, which will lead to unpredictable |
| * behavior) |
| */ |
| private void setMemoryChecks(Object o, long offset, long bytes, byte value) { |
| checkPrimitivePointer(o, offset); |
| checkSize(bytes); |
| } |
| |
| /** |
| * 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 |
| */ |
| public void copyMemory(Object srcBase, long srcOffset, |
| Object destBase, long destOffset, |
| long bytes) { |
| copyMemoryChecks(srcBase, srcOffset, destBase, destOffset, bytes); |
| |
| if (bytes == 0) { |
| return; |
| } |
| |
| copyMemory0(srcBase, srcOffset, destBase, destOffset, 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); |
| } |
| |
| /** |
| * Validate the arguments to copyMemory |
| * |
| * @throws RuntimeException if any of the arguments is invalid |
| * (<em>Note:</em> after optimization, invalid inputs may |
| * go undetected, which will lead to unpredictable |
| * behavior) |
| */ |
| private void copyMemoryChecks(Object srcBase, long srcOffset, |
| Object destBase, long destOffset, |
| long bytes) { |
| checkSize(bytes); |
| checkPrimitivePointer(srcBase, srcOffset); |
| checkPrimitivePointer(destBase, destOffset); |
| } |
| |
| /** |
| * Copies all elements from one block of memory to another block, |
| * *unconditionally* byte swapping the elements on the fly. |
| * |
| * <p>This method determines each block's base address by means of two parameters, |
| * and so it provides (in effect) a <em>double-register</em> addressing mode, |
| * as discussed in {@link #getInt(Object,long)}. When the object reference is null, |
| * the offset supplies an absolute base address. |
| * |
| * <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 9 |
| */ |
| public void copySwapMemory(Object srcBase, long srcOffset, |
| Object destBase, long destOffset, |
| long bytes, long elemSize) { |
| copySwapMemoryChecks(srcBase, srcOffset, destBase, destOffset, bytes, elemSize); |
| |
| if (bytes == 0) { |
| return; |
| } |
| |
| copySwapMemory0(srcBase, srcOffset, destBase, destOffset, bytes, elemSize); |
| } |
| |
| private void copySwapMemoryChecks(Object srcBase, long srcOffset, |
| Object destBase, long destOffset, |
| long bytes, long elemSize) { |
| checkSize(bytes); |
| |
| if (elemSize != 2 && elemSize != 4 && elemSize != 8) { |
| throw invalidInput(); |
| } |
| if (bytes % elemSize != 0) { |
| throw invalidInput(); |
| } |
| |
| checkPrimitivePointer(srcBase, srcOffset); |
| checkPrimitivePointer(destBase, destOffset); |
| } |
| |
| /** |
| * Copies all elements from one block of memory to another block, byte swapping the |
| * elements on the fly. |
| * |
| * This provides a <em>single-register</em> addressing mode, as |
| * discussed in {@link #getInt(Object,long)}. |
| * |
| * Equivalent to {@code copySwapMemory(null, srcAddress, null, destAddress, bytes, elemSize)}. |
| */ |
| public void copySwapMemory(long srcAddress, long destAddress, long bytes, long elemSize) { |
| copySwapMemory(null, srcAddress, null, destAddress, bytes, elemSize); |
| } |
| |
| /** |
| * Disposes of a block of native memory, as obtained from {@link |
| * #allocateMemory} or {@link #reallocateMemory}. The address passed to |
| * 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 |
| */ |
| public void freeMemory(long address) { |
| freeMemoryChecks(address); |
| |
| if (address == 0) { |
| return; |
| } |
| |
| freeMemory0(address); |
| } |
| |
| /** |
| * Validate the arguments to freeMemory |
| * |
| * @throws RuntimeException if the arguments are invalid |
| * (<em>Note:</em> after optimization, invalid inputs may |
| * go undetected, which will lead to unpredictable |
| * behavior) |
| */ |
| private void freeMemoryChecks(long address) { |
| checkPointer(null, 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 long objectFieldOffset(Field f) { |
| if (f == null) { |
| throw new NullPointerException(); |
| } |
| |
| return objectFieldOffset0(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 long staticFieldOffset(Field f) { |
| if (f == null) { |
| throw new NullPointerException(); |
| } |
| |
| return staticFieldOffset0(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 Object staticFieldBase(Field f) { |
| if (f == null) { |
| throw new NullPointerException(); |
| } |
| |
| return staticFieldBase0(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 boolean shouldBeInitialized(Class<?> c) { |
| if (c == null) { |
| throw new NullPointerException(); |
| } |
| |
| return shouldBeInitialized0(c); |
| } |
| |
| /** |
| * Ensures the given class has been initialized. This is often |
| * needed in conjunction with obtaining the static field base of a |
| * class. |
| */ |
| public void ensureClassInitialized(Class<?> c) { |
| if (c == null) { |
| throw new NullPointerException(); |
| } |
| |
| ensureClassInitialized0(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 int arrayBaseOffset(Class<?> arrayClass) { |
| if (arrayClass == null) { |
| throw new NullPointerException(); |
| } |
| |
| return arrayBaseOffset0(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 int arrayIndexScale(Class<?> arrayClass) { |
| if (arrayClass == null) { |
| throw new NullPointerException(); |
| } |
| |
| return arrayIndexScale0(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 int addressSize() { |
| return ADDRESS_SIZE; |
| } |
| |
| /** The value of {@code addressSize()} */ |
| public static final int ADDRESS_SIZE = theUnsafe.addressSize0(); |
| |
| /** |
| * 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 Class<?> defineClass(String name, byte[] b, int off, int len, |
| ClassLoader loader, |
| ProtectionDomain protectionDomain) { |
| if (b == null) { |
| throw new NullPointerException(); |
| } |
| if (len < 0) { |
| throw new ArrayIndexOutOfBoundsException(); |
| } |
| |
| return defineClass0(name, b, off, len, loader, protectionDomain); |
| } |
| |
| public native Class<?> defineClass0(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 Class<?> defineAnonymousClass(Class<?> hostClass, byte[] data, Object[] cpPatches) { |
| if (hostClass == null || data == null) { |
| throw new NullPointerException(); |
| } |
| |
| return defineAnonymousClass0(hostClass, data, 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; |
| |
| /** |
| * Allocates an array of a given type, but does not do zeroing. |
| * <p> |
| * This method should only be used in the very rare cases where a high-performance code |
| * overwrites the destination array completely, and compilers cannot assist in zeroing elimination. |
| * In an overwhelming majority of cases, a normal Java allocation should be used instead. |
| * <p> |
| * Users of this method are <b>required</b> to overwrite the initial (garbage) array contents |
| * before allowing untrusted code, or code in other threads, to observe the reference |
| * to the newly allocated array. In addition, the publication of the array reference must be |
| * safe according to the Java Memory Model requirements. |
| * <p> |
| * The safest approach to deal with an uninitialized array is to keep the reference to it in local |
| * variable at least until the initialization is complete, and then publish it <b>once</b>, either |
| * by writing it to a <em>volatile</em> field, or storing it into a <em>final</em> field in constructor, |
| * or issuing a {@link #storeFence} before publishing the reference. |
| * <p> |
| * @implnote This method can only allocate primitive arrays, to avoid garbage reference |
| * elements that could break heap integrity. |
| * |
| * @param componentType array component type to allocate |
| * @param length array size to allocate |
| * @throws IllegalArgumentException if component type is null, or not a primitive class; |
| * or the length is negative |
| */ |
| public Object allocateUninitializedArray(Class<?> componentType, int length) { |
| if (componentType == null) { |
| throw new IllegalArgumentException("Component type is null"); |
| } |
| if (!componentType.isPrimitive()) { |
| throw new IllegalArgumentException("Component type is not primitive"); |
| } |
| if (length < 0) { |
| throw new IllegalArgumentException("Negative length"); |
| } |
| return allocateUninitializedArray0(componentType, length); |
| } |
| |
| @HotSpotIntrinsicCandidate |
| private Object allocateUninitializedArray0(Class<?> componentType, int length) { |
| // These fallbacks provide zeroed arrays, but intrinsic is not required to |
| // return the zeroed arrays. |
| if (componentType == byte.class) return new byte[length]; |
| if (componentType == boolean.class) return new boolean[length]; |
| if (componentType == short.class) return new short[length]; |
| if (componentType == char.class) return new char[length]; |
| if (componentType == int.class) return new int[length]; |
| if (componentType == float.class) return new float[length]; |
| if (componentType == long.class) return new long[length]; |
| if (componentType == double.class) return new double[length]; |
| return null; |
| } |
| |
| /** 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); |
| |
| @HotSpotIntrinsicCandidate |
| public final native Object compareAndExchangeObjectVolatile(Object o, long offset, |
| Object expected, |
| Object x); |
| |
| @HotSpotIntrinsicCandidate |
| public final Object compareAndExchangeObjectAcquire(Object o, long offset, |
| Object expected, |
| Object x) { |
| return compareAndExchangeObjectVolatile(o, offset, expected, x); |
| } |
| |
| @HotSpotIntrinsicCandidate |
| public final Object compareAndExchangeObjectRelease(Object o, long offset, |
| Object expected, |
| Object x) { |
| return compareAndExchangeObjectVolatile(o, offset, expected, x); |
| } |
| |
| @HotSpotIntrinsicCandidate |
| public final boolean weakCompareAndSwapObject(Object o, long offset, |
| Object expected, |
| Object x) { |
| return compareAndSwapObject(o, offset, expected, x); |
| } |
| |
| @HotSpotIntrinsicCandidate |
| public final boolean weakCompareAndSwapObjectAcquire(Object o, long offset, |
| Object expected, |
| Object x) { |
| return compareAndSwapObject(o, offset, expected, x); |
| } |
| |
| @HotSpotIntrinsicCandidate |
| public final boolean weakCompareAndSwapObjectRelease(Object o, long offset, |
| Object expected, |
| Object x) { |
| return compareAndSwapObject(o, offset, expected, 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); |
| |
| @HotSpotIntrinsicCandidate |
| public final native int compareAndExchangeIntVolatile(Object o, long offset, |
| int expected, |
| int x); |
| |
| @HotSpotIntrinsicCandidate |
| public final int compareAndExchangeIntAcquire(Object o, long offset, |
| int expected, |
| int x) { |
| return compareAndExchangeIntVolatile(o, offset, expected, x); |
| } |
| |
| @HotSpotIntrinsicCandidate |
| public final int compareAndExchangeIntRelease(Object o, long offset, |
| int expected, |
| int x) { |
| return compareAndExchangeIntVolatile(o, offset, expected, x); |
| } |
| |
| @HotSpotIntrinsicCandidate |
| public final boolean weakCompareAndSwapInt(Object o, long offset, |
| int expected, |
| int x) { |
| return compareAndSwapInt(o, offset, expected, x); |
| } |
| |
| @HotSpotIntrinsicCandidate |
| public final boolean weakCompareAndSwapIntAcquire(Object o, long offset, |
| int expected, |
| int x) { |
| return compareAndSwapInt(o, offset, expected, x); |
| } |
| |
| @HotSpotIntrinsicCandidate |
| public final boolean weakCompareAndSwapIntRelease(Object o, long offset, |
| int expected, |
| int x) { |
| return compareAndSwapInt(o, offset, expected, 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); |
| |
| @HotSpotIntrinsicCandidate |
| public final native long compareAndExchangeLongVolatile(Object o, long offset, |
| long expected, |
| long x); |
| |
| @HotSpotIntrinsicCandidate |
| public final long compareAndExchangeLongAcquire(Object o, long offset, |
| long expected, |
| long x) { |
| return compareAndExchangeLongVolatile(o, offset, expected, x); |
| } |
| |
| @HotSpotIntrinsicCandidate |
| public final long compareAndExchangeLongRelease(Object o, long offset, |
| long expected, |
| long x) { |
| return compareAndExchangeLongVolatile(o, offset, expected, x); |
| } |
| |
| @HotSpotIntrinsicCandidate |
| public final boolean weakCompareAndSwapLong(Object o, long offset, |
| long expected, |
| long x) { |
| return compareAndSwapLong(o, offset, expected, x); |
| } |
| |
| @HotSpotIntrinsicCandidate |
| public final boolean weakCompareAndSwapLongAcquire(Object o, long offset, |
| long expected, |
| long x) { |
| return compareAndSwapLong(o, offset, expected, x); |
| } |
| |
| @HotSpotIntrinsicCandidate |
| public final boolean weakCompareAndSwapLongRelease(Object o, long offset, |
| long expected, |
| long x) { |
| return compareAndSwapLong(o, offset, expected, 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); |
| |
| |
| |
| /** Acquire version of {@link #getObjectVolatile(Object, long)} */ |
| @HotSpotIntrinsicCandidate |
| public final Object getObjectAcquire(Object o, long offset) { |
| return getObjectVolatile(o, offset); |
| } |
| |
| /** Acquire version of {@link #getBooleanVolatile(Object, long)} */ |
| @HotSpotIntrinsicCandidate |
| public final boolean getBooleanAcquire(Object o, long offset) { |
| return getBooleanVolatile(o, offset); |
| } |
| |
| /** Acquire version of {@link #getByteVolatile(Object, long)} */ |
| @HotSpotIntrinsicCandidate |
| public final byte getByteAcquire(Object o, long offset) { |
| return getByteVolatile(o, offset); |
| } |
| |
| /** Acquire version of {@link #getShortVolatile(Object, long)} */ |
| @HotSpotIntrinsicCandidate |
| public final short getShortAcquire(Object o, long offset) { |
| return getShortVolatile(o, offset); |
| } |
| |
| /** Acquire version of {@link #getCharVolatile(Object, long)} */ |
| @HotSpotIntrinsicCandidate |
| public final char getCharAcquire(Object o, long offset) { |
| return getCharVolatile(o, offset); |
| } |
| |
| /** Acquire version of {@link #getIntVolatile(Object, long)} */ |
| @HotSpotIntrinsicCandidate |
| public final int getIntAcquire(Object o, long offset) { |
| return getIntVolatile(o, offset); |
| } |
| |
| /** Acquire version of {@link #getFloatVolatile(Object, long)} */ |
| @HotSpotIntrinsicCandidate |
| public final float getFloatAcquire(Object o, long offset) { |
| return getFloatVolatile(o, offset); |
| } |
| |
| /** Acquire version of {@link #getLongVolatile(Object, long)} */ |
| @HotSpotIntrinsicCandidate |
| public final long getLongAcquire(Object o, long offset) { |
| return getLongVolatile(o, offset); |
| } |
| |
| /** Acquire version of {@link #getDoubleVolatile(Object, long)} */ |
| @HotSpotIntrinsicCandidate |
| public final double getDoubleAcquire(Object o, long offset) { |
| return getDoubleVolatile(o, offset); |
| } |
| |
| /* |
| * Versions of {@link #putObjectVolatile(Object, long, Object)} |
| * that do 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). |
| */ |
| |
| /** Release version of {@link #putObjectVolatile(Object, long, Object)} */ |
| @HotSpotIntrinsicCandidate |
| public final void putObjectRelease(Object o, long offset, Object x) { |
| putObjectVolatile(o, offset, x); |
| } |
| |
| /** Release version of {@link #putBooleanVolatile(Object, long, boolean)} */ |
| @HotSpotIntrinsicCandidate |
| public final void putBooleanRelease(Object o, long offset, boolean x) { |
| putBooleanVolatile(o, offset, x); |
| } |
| |
| /** Release version of {@link #putByteVolatile(Object, long, byte)} */ |
| @HotSpotIntrinsicCandidate |
| public final void putByteRelease(Object o, long offset, byte x) { |
| putByteVolatile(o, offset, x); |
| } |
| |
| /** Release version of {@link #putShortVolatile(Object, long, short)} */ |
| @HotSpotIntrinsicCandidate |
| public final void putShortRelease(Object o, long offset, short x) { |
| putShortVolatile(o, offset, x); |
| } |
| |
| /** Release version of {@link #putCharVolatile(Object, long, char)} */ |
| @HotSpotIntrinsicCandidate |
| public final void putCharRelease(Object o, long offset, char x) { |
| putCharVolatile(o, offset, x); |
| } |
| |
| /** Release version of {@link #putIntVolatile(Object, long, int)} */ |
| @HotSpotIntrinsicCandidate |
| public final void putIntRelease(Object o, long offset, int x) { |
| putIntVolatile(o, offset, x); |
| } |
| |
| /** Release version of {@link #putFloatVolatile(Object, long, float)} */ |
| @HotSpotIntrinsicCandidate |
| public final void putFloatRelease(Object o, long offset, float x) { |
| putFloatVolatile(o, offset, x); |
| } |
| |
| /** Release version of {@link #putLongVolatile(Object, long, long)} */ |
| @HotSpotIntrinsicCandidate |
| public final void putLongRelease(Object o, long offset, long x) { |
| putLongVolatile(o, offset, x); |
| } |
| |
| /** Release version of {@link #putDoubleVolatile(Object, long, double)} */ |
| @HotSpotIntrinsicCandidate |
| public final void putDoubleRelease(Object o, long offset, double x) { |
| putDoubleVolatile(o, offset, x); |
| } |
| |
| // ------------------------------ Opaque -------------------------------------- |
| |
| /** Opaque version of {@link #getObjectVolatile(Object, long)} */ |
| @HotSpotIntrinsicCandidate |
| public final Object getObjectOpaque(Object o, long offset) { |
| return getObjectVolatile(o, offset); |
| } |
| |
| /** Opaque version of {@link #getBooleanVolatile(Object, long)} */ |
| @HotSpotIntrinsicCandidate |
| public final boolean getBooleanOpaque(Object o, long offset) { |
| return getBooleanVolatile(o, offset); |
| } |
| |
| /** Opaque version of {@link #getByteVolatile(Object, long)} */ |
| @HotSpotIntrinsicCandidate |
| public final byte getByteOpaque(Object o, long offset) { |
| return getByteVolatile(o, offset); |
| } |
| |
| /** Opaque version of {@link #getShortVolatile(Object, long)} */ |
| @HotSpotIntrinsicCandidate |
| public final short getShortOpaque(Object o, long offset) { |
| return getShortVolatile(o, offset); |
| } |
| |
| /** Opaque version of {@link #getCharVolatile(Object, long)} */ |
| @HotSpotIntrinsicCandidate |
| public final char getCharOpaque(Object o, long offset) { |
| return getCharVolatile(o, offset); |
| } |
| |
| /** Opaque version of {@link #getIntVolatile(Object, long)} */ |
| @HotSpotIntrinsicCandidate |
| public final int getIntOpaque(Object o, long offset) { |
| return getIntVolatile(o, offset); |
| } |
| |
| /** Opaque version of {@link #getFloatVolatile(Object, long)} */ |
| @HotSpotIntrinsicCandidate |
| public final float getFloatOpaque(Object o, long offset) { |
| return getFloatVolatile(o, offset); |
| } |
| |
| /** Opaque version of {@link #getLongVolatile(Object, long)} */ |
| @HotSpotIntrinsicCandidate |
| public final long getLongOpaque(Object o, long offset) { |
| return getLongVolatile(o, offset); |
| } |
| |
| /** Opaque version of {@link #getDoubleVolatile(Object, long)} */ |
| @HotSpotIntrinsicCandidate |
| public final double getDoubleOpaque(Object o, long offset) { |
| return getDoubleVolatile(o, offset); |
| } |
| |
| /** Opaque version of {@link #putObjectVolatile(Object, long, Object)} */ |
| @HotSpotIntrinsicCandidate |
| public final void putObjectOpaque(Object o, long offset, Object x) { |
| putObjectVolatile(o, offset, x); |
| } |
| |
| /** Opaque version of {@link #putBooleanVolatile(Object, long, boolean)} */ |
| @HotSpotIntrinsicCandidate |
| public final void putBooleanOpaque(Object o, long offset, boolean x) { |
| putBooleanVolatile(o, offset, x); |
| } |
| |
| /** Opaque version of {@link #putByteVolatile(Object, long, byte)} */ |
| @HotSpotIntrinsicCandidate |
| public final void putByteOpaque(Object o, long offset, byte x) { |
| putByteVolatile(o, offset, x); |
| } |
| |
| /** Opaque version of {@link #putShortVolatile(Object, long, short)} */ |
| @HotSpotIntrinsicCandidate |
| public final void putShortOpaque(Object o, long offset, short x) { |
| putShortVolatile(o, offset, x); |
| } |
| |
| /** Opaque version of {@link #putCharVolatile(Object, long, char)} */ |
| @HotSpotIntrinsicCandidate |
| public final void putCharOpaque(Object o, long offset, char x) { |
| putCharVolatile(o, offset, x); |
| } |
| |
| /** Opaque version of {@link #putIntVolatile(Object, long, int)} */ |
| @HotSpotIntrinsicCandidate |
| public final void putIntOpaque(Object o, long offset, int x) { |
| putIntVolatile(o, offset, x); |
| } |
| |
| /** Opaque version of {@link #putFloatVolatile(Object, long, float)} */ |
| @HotSpotIntrinsicCandidate |
| public final void putFloatOpaque(Object o, long offset, float x) { |
| putFloatVolatile(o, offset, x); |
| } |
| |
| /** Opaque version of {@link #putLongVolatile(Object, long, long)} */ |
| @HotSpotIntrinsicCandidate |
| public final void putLongOpaque(Object o, long offset, long x) { |
| putLongVolatile(o, offset, x); |
| } |
| |
| /** Opaque version of {@link #putDoubleVolatile(Object, long, double)} */ |
| @HotSpotIntrinsicCandidate |
| public final void putDoubleOpaque(Object o, long offset, double x) { |
| putDoubleVolatile(o, offset, 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 int getLoadAverage(double[] loadavg, int nelems) { |
| if (nelems < 0 || nelems > 3 || nelems > loadavg.length) { |
| throw new ArrayIndexOutOfBoundsException(); |
| } |
| |
| return getLoadAverage0(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 {@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(); |
| |
| /** |
| * Ensures that loads before the fence will not be reordered with |
| * loads after the fence. |
| */ |
| public final void loadLoadFence() { |
| loadFence(); |
| } |
| |
| /** |
| * Ensures that stores before the fence will not be reordered with |
| * stores after the fence. |
| */ |
| public final void storeStoreFence() { |
| storeFence(); |
| } |
| |
| |
| /** |
| * 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 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 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) { |
| if ((offset & 1) == 0) { |
| return getChar(o, offset); |
| } else { |
| return (char)makeShort(getByte(o, offset), |
| getByte(o, offset + 1)); |
| } |
| } |
| |
| /** @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 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 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 |
| // 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) ; } |
| |
| |
| |
| private native long allocateMemory0(long bytes); |
| private native long reallocateMemory0(long address, long bytes); |
| private native void freeMemory0(long address); |
| private native void setMemory0(Object o, long offset, long bytes, byte value); |
| @HotSpotIntrinsicCandidate |
| private native void copyMemory0(Object srcBase, long srcOffset, Object destBase, long destOffset, long bytes); |
| private native void copySwapMemory0(Object srcBase, long srcOffset, Object destBase, long destOffset, long bytes, long elemSize); |
| private native long objectFieldOffset0(Field f); |
| private native long staticFieldOffset0(Field f); |
| private native Object staticFieldBase0(Field f); |
| private native boolean shouldBeInitialized0(Class<?> c); |
| private native void ensureClassInitialized0(Class<?> c); |
| private native int arrayBaseOffset0(Class<?> arrayClass); |
| private native int arrayIndexScale0(Class<?> arrayClass); |
| private native int addressSize0(); |
| private native Class<?> defineAnonymousClass0(Class<?> hostClass, byte[] data, Object[] cpPatches); |
| private native int getLoadAverage0(double[] loadavg, int nelems); |
| private native boolean unalignedAccess0(); |
| private native boolean isBigEndian0(); |
| } |