1 /*
2 * Copyright (c) 2000, 2022, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package jdk.internal.misc;
27
28 import jdk.internal.ref.Cleaner;
29 import jdk.internal.value.PrimitiveClass;
30 import jdk.internal.vm.annotation.ForceInline;
31 import jdk.internal.vm.annotation.IntrinsicCandidate;
32 import sun.nio.ch.DirectBuffer;
33
34 import java.lang.reflect.Field;
35 import java.security.ProtectionDomain;
36
37 import static jdk.internal.misc.UnsafeConstants.*;
38
39 /**
40 * A collection of methods for performing low-level, unsafe operations.
41 * Although the class and all methods are public, use of this class is
42 * limited because only trusted code can obtain instances of it.
43 *
44 * <em>Note:</em> It is the responsibility of the caller to make sure
45 * arguments are checked before methods of this class are
46 * called. While some rudimentary checks are performed on the input,
47 * the checks are best effort and when performance is an overriding
48 * priority, as when methods of this class are optimized by the
49 * runtime compiler, some or all checks (if any) may be elided. Hence,
50 * the caller must not rely on the checks and corresponding
51 * exceptions!
52 *
53 * @author John R. Rose
54 * @see #getUnsafe
55 */
56
57 public final class Unsafe {
58
59 private static native void registerNatives();
60 static {
61 registerNatives();
62 }
63
64 private Unsafe() {}
65
66 private static final Unsafe theUnsafe = new Unsafe();
67
68 /**
69 * Provides the caller with the capability of performing unsafe
70 * operations.
71 *
72 * <p>The returned {@code Unsafe} object should be carefully guarded
73 * by the caller, since it can be used to read and write data at arbitrary
74 * memory addresses. It must never be passed to untrusted code.
75 *
76 * <p>Most methods in this class are very low-level, and correspond to a
77 * small number of hardware instructions (on typical machines). Compilers
78 * are encouraged to optimize these methods accordingly.
79 *
80 * <p>Here is a suggested idiom for using unsafe operations:
81 *
82 * <pre> {@code
83 * class MyTrustedClass {
84 * private static final Unsafe unsafe = Unsafe.getUnsafe();
85 * ...
86 * private long myCountAddress = ...;
87 * public int getCount() { return unsafe.getByte(myCountAddress); }
88 * }}</pre>
89 *
90 * (It may assist compilers to make the local variable {@code final}.)
91 */
92 public static Unsafe getUnsafe() {
93 return theUnsafe;
94 }
95
96 /// peek and poke operations
97 /// (compilers should optimize these to memory ops)
98
99 // These work on object fields in the Java heap.
100 // They will not work on elements of packed arrays.
101
102 /**
103 * Fetches a value from a given Java variable.
104 * More specifically, fetches a field or array element within the given
105 * object {@code o} at the given offset, or (if {@code o} is null)
106 * from the memory address whose numerical value is the given offset.
107 * <p>
108 * The results are undefined unless one of the following cases is true:
109 * <ul>
110 * <li>The offset was obtained from {@link #objectFieldOffset} on
111 * the {@link java.lang.reflect.Field} of some Java field and the object
112 * referred to by {@code o} is of a class compatible with that
113 * field's class.
114 *
115 * <li>The offset and object reference {@code o} (either null or
116 * non-null) were both obtained via {@link #staticFieldOffset}
117 * and {@link #staticFieldBase} (respectively) from the
118 * reflective {@link Field} representation of some Java field.
119 *
120 * <li>The object referred to by {@code o} is an array, and the offset
121 * is an integer of the form {@code B+N*S}, where {@code N} is
122 * a valid index into the array, and {@code B} and {@code S} are
123 * the values obtained by {@link #arrayBaseOffset} and {@link
124 * #arrayIndexScale} (respectively) from the array's class. The value
125 * referred to is the {@code N}<em>th</em> element of the array.
126 *
127 * </ul>
128 * <p>
129 * If one of the above cases is true, the call references a specific Java
130 * variable (field or array element). However, the results are undefined
131 * if that variable is not in fact of the type returned by this method.
132 * <p>
133 * This method refers to a variable by means of two parameters, and so
134 * it provides (in effect) a <em>double-register</em> addressing mode
135 * for Java variables. When the object reference is null, this method
136 * uses its offset as an absolute address. This is similar in operation
137 * to methods such as {@link #getInt(long)}, which provide (in effect) a
138 * <em>single-register</em> addressing mode for non-Java variables.
139 * However, because Java variables may have a different layout in memory
140 * from non-Java variables, programmers should not assume that these
141 * two addressing modes are ever equivalent. Also, programmers should
142 * remember that offsets from the double-register addressing mode cannot
143 * be portably confused with longs used in the single-register addressing
144 * mode.
145 *
146 * @param o Java heap object in which the variable resides, if any, else
147 * null
148 * @param offset indication of where the variable resides in a Java heap
149 * object, if any, else a memory address locating the variable
150 * statically
151 * @return the value fetched from the indicated Java variable
152 * @throws RuntimeException No defined exceptions are thrown, not even
153 * {@link NullPointerException}
154 */
155 @IntrinsicCandidate
156 public native int getInt(Object o, long offset);
157
158 /**
159 * Stores a value into a given Java variable.
160 * <p>
161 * The first two parameters are interpreted exactly as with
162 * {@link #getInt(Object, long)} to refer to a specific
163 * Java variable (field or array element). The given value
164 * is stored into that variable.
165 * <p>
166 * The variable must be of the same type as the method
167 * parameter {@code x}.
168 *
169 * @param o Java heap object in which the variable resides, if any, else
170 * null
171 * @param offset indication of where the variable resides in a Java heap
172 * object, if any, else a memory address locating the variable
173 * statically
174 * @param x the value to store into the indicated Java variable
175 * @throws RuntimeException No defined exceptions are thrown, not even
176 * {@link NullPointerException}
177 */
178 @IntrinsicCandidate
179 public native void putInt(Object o, long offset, int x);
180
181
182 /**
183 * Returns true if the given field is flattened.
184 */
185 public boolean isFlattened(Field f) {
186 if (f == null) {
187 throw new NullPointerException();
188 }
189 return isFlattenedField0(f);
190 }
191
192 private native boolean isFlattenedField0(Object o);
193
194 /**
195 * Returns true if the given class is a flattened array.
196 */
197 public native boolean isFlattenedArray(Class<?> arrayClass);
198
199 /**
200 * Fetches a reference value from a given Java variable.
201 * This method can return a reference to either an object or value
202 * or a null reference.
203 *
204 * @see #getInt(Object, long)
205 */
206 @IntrinsicCandidate
207 public native Object getReference(Object o, long offset);
208
209 /**
210 * Stores a reference value into a given Java variable.
211 * This method can store a reference to either an object or value
212 * or a null reference.
213 * <p>
214 * Unless the reference {@code x} being stored is either null
215 * or matches the field type, the results are undefined.
216 * If the reference {@code o} is non-null, card marks or
217 * other store barriers for that object (if the VM requires them)
218 * are updated.
219 * @see #putInt(Object, long, int)
220 */
221 @IntrinsicCandidate
222 public native void putReference(Object o, long offset, Object x);
223
224 /**
225 * Fetches a value of type {@code <V>} from a given Java variable.
226 * More specifically, fetches a field or array element within the given
227 * {@code o} object at the given offset, or (if {@code o} is null)
228 * from the memory address whose numerical value is the given offset.
229 *
230 * @param o Java heap object in which the variable resides, if any, else
231 * null
232 * @param offset indication of where the variable resides in a Java heap
233 * object, if any, else a memory address locating the variable
234 * statically
235 * @param valueType value type
236 * @param <V> the type of a value
237 * @return the value fetched from the indicated Java variable
238 * @throws RuntimeException No defined exceptions are thrown, not even
239 * {@link NullPointerException}
240 */
241 @IntrinsicCandidate
242 public native <V> V getValue(Object o, long offset, Class<?> valueType);
243
244 /**
245 * Stores the given value into a given Java variable.
246 *
247 * Unless the reference {@code o} being stored is either null
248 * or matches the field type, the results are undefined.
249 *
250 * @param o Java heap object in which the variable resides, if any, else
251 * null
252 * @param offset indication of where the variable resides in a Java heap
253 * object, if any, else a memory address locating the variable
254 * statically
255 * @param valueType value type
256 * @param v the value to store into the indicated Java variable
257 * @param <V> the type of a value
258 * @throws RuntimeException No defined exceptions are thrown, not even
259 * {@link NullPointerException}
260 */
261 @IntrinsicCandidate
262 public native <V> void putValue(Object o, long offset, Class<?> valueType, V v);
263
264 /**
265 * Fetches a reference value of the given type from a given Java variable.
266 * This method can return a reference to a value if it is non-null.
267 * If the value is null, this method returns a default value for
268 * primitive value types or null for identity classes and value classes.
269 *
270 * @param type type
271 */
272 public Object getReference(Object o, long offset, Class<?> type) {
273 Object ref = getReference(o, offset);
274 if (ref == null && PrimitiveClass.isPrimitiveValueType(type)) {
275 // If the type of the returned reference is a primitive value type,
276 // return an uninitialized default value if null
277 ref = uninitializedDefaultValue(type);
278 }
279 return ref;
280 }
281
282 public Object getReferenceVolatile(Object o, long offset, Class<?> type) {
283 Object ref = getReferenceVolatile(o, offset);
284 if (ref == null && PrimitiveClass.isPrimitiveValueType(type)) {
285 // If the type of the returned reference is a primitive value type,
286 // return an uninitialized default value if null
287 ref = uninitializedDefaultValue(type);
288 }
289 return ref;
290 }
291
292 /**
293 * Returns an uninitialized default value of the given value type.
294 */
295 public native <V> V uninitializedDefaultValue(Class<?> type);
296
297 /**
298 * Returns an object instance with a private buffered value whose layout
299 * and contents is exactly the given value instance. The return object
300 * is in the larval state that can be updated using the unsafe put operation.
301 *
302 * @param value a value instance
303 * @param <V> the type of the given value instance
304 */
305 @IntrinsicCandidate
306 public native <V> V makePrivateBuffer(V value);
307
308 /**
309 * Exits the larval state and returns a value instance.
310 *
311 * @param value a value instance
312 * @param <V> the type of the given value instance
313 */
314 @IntrinsicCandidate
315 public native <V> V finishPrivateBuffer(V value);
316
317 /**
318 * Returns the header size of the given value type.
319 *
320 * @param valueType value type
321 * @return the header size of the value type
322 */
323 public native <V> long valueHeaderSize(Class<V> valueType);
324
325 /** @see #getInt(Object, long) */
326 @IntrinsicCandidate
327 public native boolean getBoolean(Object o, long offset);
328
329 /** @see #putInt(Object, long, int) */
330 @IntrinsicCandidate
331 public native void putBoolean(Object o, long offset, boolean x);
332
333 /** @see #getInt(Object, long) */
334 @IntrinsicCandidate
335 public native byte getByte(Object o, long offset);
336
337 /** @see #putInt(Object, long, int) */
338 @IntrinsicCandidate
339 public native void putByte(Object o, long offset, byte x);
340
341 /** @see #getInt(Object, long) */
342 @IntrinsicCandidate
343 public native short getShort(Object o, long offset);
344
345 /** @see #putInt(Object, long, int) */
346 @IntrinsicCandidate
347 public native void putShort(Object o, long offset, short x);
348
349 /** @see #getInt(Object, long) */
350 @IntrinsicCandidate
351 public native char getChar(Object o, long offset);
352
353 /** @see #putInt(Object, long, int) */
354 @IntrinsicCandidate
355 public native void putChar(Object o, long offset, char x);
356
357 /** @see #getInt(Object, long) */
358 @IntrinsicCandidate
359 public native long getLong(Object o, long offset);
360
361 /** @see #putInt(Object, long, int) */
362 @IntrinsicCandidate
363 public native void putLong(Object o, long offset, long x);
364
365 /** @see #getInt(Object, long) */
366 @IntrinsicCandidate
367 public native float getFloat(Object o, long offset);
368
369 /** @see #putInt(Object, long, int) */
370 @IntrinsicCandidate
371 public native void putFloat(Object o, long offset, float x);
372
373 /** @see #getInt(Object, long) */
374 @IntrinsicCandidate
375 public native double getDouble(Object o, long offset);
376
377 /** @see #putInt(Object, long, int) */
378 @IntrinsicCandidate
379 public native void putDouble(Object o, long offset, double x);
380
381 /**
382 * Fetches a native pointer from a given memory address. If the address is
383 * zero, or does not point into a block obtained from {@link
384 * #allocateMemory}, the results are undefined.
385 *
386 * <p>If the native pointer is less than 64 bits wide, it is extended as
387 * an unsigned number to a Java long. The pointer may be indexed by any
388 * given byte offset, simply by adding that offset (as a simple integer) to
389 * the long representing the pointer. The number of bytes actually read
390 * from the target address may be determined by consulting {@link
391 * #addressSize}.
392 *
393 * @see #allocateMemory
394 * @see #getInt(Object, long)
395 */
396 @ForceInline
397 public long getAddress(Object o, long offset) {
398 if (ADDRESS_SIZE == 4) {
399 return Integer.toUnsignedLong(getInt(o, offset));
400 } else {
401 return getLong(o, offset);
402 }
403 }
404
405 /**
406 * Stores a native pointer into a given memory address. If the address is
407 * zero, or does not point into a block obtained from {@link
408 * #allocateMemory}, the results are undefined.
409 *
410 * <p>The number of bytes actually written at the target address may be
411 * determined by consulting {@link #addressSize}.
412 *
413 * @see #allocateMemory
414 * @see #putInt(Object, long, int)
415 */
416 @ForceInline
417 public void putAddress(Object o, long offset, long x) {
418 if (ADDRESS_SIZE == 4) {
419 putInt(o, offset, (int)x);
420 } else {
421 putLong(o, offset, x);
422 }
423 }
424
425 // These read VM internal data.
426
427 /**
428 * Fetches an uncompressed reference value from a given native variable
429 * ignoring the VM's compressed references mode.
430 *
431 * @param address a memory address locating the variable
432 * @return the value fetched from the indicated native variable
433 */
434 public native Object getUncompressedObject(long address);
435
436 // These work on values in the C heap.
437
438 /**
439 * Fetches a value from a given memory address. If the address is zero, or
440 * does not point into a block obtained from {@link #allocateMemory}, the
441 * results are undefined.
442 *
443 * @see #allocateMemory
444 */
445 @ForceInline
446 public byte getByte(long address) {
447 return getByte(null, address);
448 }
449
450 /**
451 * Stores a value into a given memory address. If the address is zero, or
452 * does not point into a block obtained from {@link #allocateMemory}, the
453 * results are undefined.
454 *
455 * @see #getByte(long)
456 */
457 @ForceInline
458 public void putByte(long address, byte x) {
459 putByte(null, address, x);
460 }
461
462 /** @see #getByte(long) */
463 @ForceInline
464 public short getShort(long address) {
465 return getShort(null, address);
466 }
467
468 /** @see #putByte(long, byte) */
469 @ForceInline
470 public void putShort(long address, short x) {
471 putShort(null, address, x);
472 }
473
474 /** @see #getByte(long) */
475 @ForceInline
476 public char getChar(long address) {
477 return getChar(null, address);
478 }
479
480 /** @see #putByte(long, byte) */
481 @ForceInline
482 public void putChar(long address, char x) {
483 putChar(null, address, x);
484 }
485
486 /** @see #getByte(long) */
487 @ForceInline
488 public int getInt(long address) {
489 return getInt(null, address);
490 }
491
492 /** @see #putByte(long, byte) */
493 @ForceInline
494 public void putInt(long address, int x) {
495 putInt(null, address, x);
496 }
497
498 /** @see #getByte(long) */
499 @ForceInline
500 public long getLong(long address) {
501 return getLong(null, address);
502 }
503
504 /** @see #putByte(long, byte) */
505 @ForceInline
506 public void putLong(long address, long x) {
507 putLong(null, address, x);
508 }
509
510 /** @see #getByte(long) */
511 @ForceInline
512 public float getFloat(long address) {
513 return getFloat(null, address);
514 }
515
516 /** @see #putByte(long, byte) */
517 @ForceInline
518 public void putFloat(long address, float x) {
519 putFloat(null, address, x);
520 }
521
522 /** @see #getByte(long) */
523 @ForceInline
524 public double getDouble(long address) {
525 return getDouble(null, address);
526 }
527
528 /** @see #putByte(long, byte) */
529 @ForceInline
530 public void putDouble(long address, double x) {
531 putDouble(null, address, x);
532 }
533
534 /** @see #getAddress(Object, long) */
535 @ForceInline
536 public long getAddress(long address) {
537 return getAddress(null, address);
538 }
539
540 /** @see #putAddress(Object, long, long) */
541 @ForceInline
542 public void putAddress(long address, long x) {
543 putAddress(null, address, x);
544 }
545
546
547
548 /// helper methods for validating various types of objects/values
549
550 /**
551 * Create an exception reflecting that some of the input was invalid
552 *
553 * <em>Note:</em> It is the responsibility of the caller to make
554 * sure arguments are checked before the methods are called. While
555 * some rudimentary checks are performed on the input, the checks
556 * are best effort and when performance is an overriding priority,
557 * as when methods of this class are optimized by the runtime
558 * compiler, some or all checks (if any) may be elided. Hence, the
559 * caller must not rely on the checks and corresponding
560 * exceptions!
561 *
562 * @return an exception object
563 */
564 private RuntimeException invalidInput() {
565 return new IllegalArgumentException();
566 }
567
568 /**
569 * Check if a value is 32-bit clean (32 MSB are all zero)
570 *
571 * @param value the 64-bit value to check
572 *
573 * @return true if the value is 32-bit clean
574 */
575 private boolean is32BitClean(long value) {
576 return value >>> 32 == 0;
577 }
578
579 /**
580 * Check the validity of a size (the equivalent of a size_t)
581 *
582 * @throws RuntimeException if the size is invalid
583 * (<em>Note:</em> after optimization, invalid inputs may
584 * go undetected, which will lead to unpredictable
585 * behavior)
586 */
587 private void checkSize(long size) {
588 if (ADDRESS_SIZE == 4) {
589 // Note: this will also check for negative sizes
590 if (!is32BitClean(size)) {
591 throw invalidInput();
592 }
593 } else if (size < 0) {
594 throw invalidInput();
595 }
596 }
597
598 /**
599 * Check the validity of a native address (the equivalent of void*)
600 *
601 * @throws RuntimeException if the address is invalid
602 * (<em>Note:</em> after optimization, invalid inputs may
603 * go undetected, which will lead to unpredictable
604 * behavior)
605 */
606 private void checkNativeAddress(long address) {
607 if (ADDRESS_SIZE == 4) {
608 // Accept both zero and sign extended pointers. A valid
609 // pointer will, after the +1 below, either have produced
610 // the value 0x0 or 0x1. Masking off the low bit allows
611 // for testing against 0.
612 if ((((address >> 32) + 1) & ~1) != 0) {
613 throw invalidInput();
614 }
615 }
616 }
617
618 /**
619 * Check the validity of an offset, relative to a base object
620 *
621 * @param o the base object
622 * @param offset the offset to check
623 *
624 * @throws RuntimeException if the size is invalid
625 * (<em>Note:</em> after optimization, invalid inputs may
626 * go undetected, which will lead to unpredictable
627 * behavior)
628 */
629 private void checkOffset(Object o, long offset) {
630 if (ADDRESS_SIZE == 4) {
631 // Note: this will also check for negative offsets
632 if (!is32BitClean(offset)) {
633 throw invalidInput();
634 }
635 } else if (offset < 0) {
636 throw invalidInput();
637 }
638 }
639
640 /**
641 * Check the validity of a double-register pointer
642 *
643 * Note: This code deliberately does *not* check for NPE for (at
644 * least) three reasons:
645 *
646 * 1) NPE is not just NULL/0 - there is a range of values all
647 * resulting in an NPE, which is not trivial to check for
648 *
649 * 2) It is the responsibility of the callers of Unsafe methods
650 * to verify the input, so throwing an exception here is not really
651 * useful - passing in a NULL pointer is a critical error and the
652 * must not expect an exception to be thrown anyway.
653 *
654 * 3) the actual operations will detect NULL pointers anyway by
655 * means of traps and signals (like SIGSEGV).
656 *
657 * @param o Java heap object, or null
658 * @param offset indication of where the variable resides in a Java heap
659 * object, if any, else a memory address locating the variable
660 * statically
661 *
662 * @throws RuntimeException if the pointer is invalid
663 * (<em>Note:</em> after optimization, invalid inputs may
664 * go undetected, which will lead to unpredictable
665 * behavior)
666 */
667 private void checkPointer(Object o, long offset) {
668 if (o == null) {
669 checkNativeAddress(offset);
670 } else {
671 checkOffset(o, offset);
672 }
673 }
674
675 /**
676 * Check if a type is a primitive array type
677 *
678 * @param c the type to check
679 *
680 * @return true if the type is a primitive array type
681 */
682 private void checkPrimitiveArray(Class<?> c) {
683 Class<?> componentType = c.getComponentType();
684 if (componentType == null || !componentType.isPrimitive()) {
685 throw invalidInput();
686 }
687 }
688
689 /**
690 * Check that a pointer is a valid primitive array type pointer
691 *
692 * Note: pointers off-heap are considered to be primitive arrays
693 *
694 * @throws RuntimeException if the pointer is invalid
695 * (<em>Note:</em> after optimization, invalid inputs may
696 * go undetected, which will lead to unpredictable
697 * behavior)
698 */
699 private void checkPrimitivePointer(Object o, long offset) {
700 checkPointer(o, offset);
701
702 if (o != null) {
703 // If on heap, it must be a primitive array
704 checkPrimitiveArray(o.getClass());
705 }
706 }
707
708
709 /// wrappers for malloc, realloc, free:
710
711 /**
712 * Round up allocation size to a multiple of HeapWordSize.
713 */
714 private long alignToHeapWordSize(long bytes) {
715 if (bytes >= 0) {
716 return (bytes + ADDRESS_SIZE - 1) & ~(ADDRESS_SIZE - 1);
717 } else {
718 throw invalidInput();
719 }
720 }
721
722 /**
723 * Allocates a new block of native memory, of the given size in bytes. The
724 * contents of the memory are uninitialized; they will generally be
725 * garbage. The resulting native pointer will never be zero, and will be
726 * aligned for all value types. Dispose of this memory by calling {@link
727 * #freeMemory}, or resize it with {@link #reallocateMemory}.
728 *
729 * <em>Note:</em> It is the responsibility of the caller to make
730 * sure arguments are checked before the methods are called. While
731 * some rudimentary checks are performed on the input, the checks
732 * are best effort and when performance is an overriding priority,
733 * as when methods of this class are optimized by the runtime
734 * compiler, some or all checks (if any) may be elided. Hence, the
735 * caller must not rely on the checks and corresponding
736 * exceptions!
737 *
738 * @throws RuntimeException if the size is negative or too large
739 * for the native size_t type
740 *
741 * @throws OutOfMemoryError if the allocation is refused by the system
742 *
743 * @see #getByte(long)
744 * @see #putByte(long, byte)
745 */
746 public long allocateMemory(long bytes) {
747 bytes = alignToHeapWordSize(bytes);
748
749 allocateMemoryChecks(bytes);
750
751 if (bytes == 0) {
752 return 0;
753 }
754
755 long p = allocateMemory0(bytes);
756 if (p == 0) {
757 throw new OutOfMemoryError("Unable to allocate " + bytes + " bytes");
758 }
759
760 return p;
761 }
762
763 /**
764 * Validate the arguments to allocateMemory
765 *
766 * @throws RuntimeException if the arguments are invalid
767 * (<em>Note:</em> after optimization, invalid inputs may
768 * go undetected, which will lead to unpredictable
769 * behavior)
770 */
771 private void allocateMemoryChecks(long bytes) {
772 checkSize(bytes);
773 }
774
775 /**
776 * Resizes a new block of native memory, to the given size in bytes. The
777 * contents of the new block past the size of the old block are
778 * uninitialized; they will generally be garbage. The resulting native
779 * pointer will be zero if and only if the requested size is zero. The
780 * resulting native pointer will be aligned for all value types. Dispose
781 * of this memory by calling {@link #freeMemory}, or resize it with {@link
782 * #reallocateMemory}. The address passed to this method may be null, in
783 * which case an allocation will be performed.
784 *
785 * <em>Note:</em> It is the responsibility of the caller to make
786 * sure arguments are checked before the methods are called. While
787 * some rudimentary checks are performed on the input, the checks
788 * are best effort and when performance is an overriding priority,
789 * as when methods of this class are optimized by the runtime
790 * compiler, some or all checks (if any) may be elided. Hence, the
791 * caller must not rely on the checks and corresponding
792 * exceptions!
793 *
794 * @throws RuntimeException if the size is negative or too large
795 * for the native size_t type
796 *
797 * @throws OutOfMemoryError if the allocation is refused by the system
798 *
799 * @see #allocateMemory
800 */
801 public long reallocateMemory(long address, long bytes) {
802 bytes = alignToHeapWordSize(bytes);
803
804 reallocateMemoryChecks(address, bytes);
805
806 if (bytes == 0) {
807 freeMemory(address);
808 return 0;
809 }
810
811 long p = (address == 0) ? allocateMemory0(bytes) : reallocateMemory0(address, bytes);
812 if (p == 0) {
813 throw new OutOfMemoryError("Unable to allocate " + bytes + " bytes");
814 }
815
816 return p;
817 }
818
819 /**
820 * Validate the arguments to reallocateMemory
821 *
822 * @throws RuntimeException if the arguments are invalid
823 * (<em>Note:</em> after optimization, invalid inputs may
824 * go undetected, which will lead to unpredictable
825 * behavior)
826 */
827 private void reallocateMemoryChecks(long address, long bytes) {
828 checkPointer(null, address);
829 checkSize(bytes);
830 }
831
832 /**
833 * Sets all bytes in a given block of memory to a fixed value
834 * (usually zero).
835 *
836 * <p>This method determines a block's base address by means of two parameters,
837 * and so it provides (in effect) a <em>double-register</em> addressing mode,
838 * as discussed in {@link #getInt(Object,long)}. When the object reference is null,
839 * the offset supplies an absolute base address.
840 *
841 * <p>The stores are in coherent (atomic) units of a size determined
842 * by the address and length parameters. If the effective address and
843 * length are all even modulo 8, the stores take place in 'long' units.
844 * If the effective address and length are (resp.) even modulo 4 or 2,
845 * the stores take place in units of 'int' or 'short'.
846 *
847 * <em>Note:</em> It is the responsibility of the caller to make
848 * sure arguments are checked before the methods are called. While
849 * some rudimentary checks are performed on the input, the checks
850 * are best effort and when performance is an overriding priority,
851 * as when methods of this class are optimized by the runtime
852 * compiler, some or all checks (if any) may be elided. Hence, the
853 * caller must not rely on the checks and corresponding
854 * exceptions!
855 *
856 * @throws RuntimeException if any of the arguments is invalid
857 *
858 * @since 1.7
859 */
860 public void setMemory(Object o, long offset, long bytes, byte value) {
861 setMemoryChecks(o, offset, bytes, value);
862
863 if (bytes == 0) {
864 return;
865 }
866
867 setMemory0(o, offset, bytes, value);
868 }
869
870 /**
871 * Sets all bytes in a given block of memory to a fixed value
872 * (usually zero). This provides a <em>single-register</em> addressing mode,
873 * as discussed in {@link #getInt(Object,long)}.
874 *
875 * <p>Equivalent to {@code setMemory(null, address, bytes, value)}.
876 */
877 public void setMemory(long address, long bytes, byte value) {
878 setMemory(null, address, bytes, value);
879 }
880
881 /**
882 * Validate the arguments to setMemory
883 *
884 * @throws RuntimeException if the arguments are invalid
885 * (<em>Note:</em> after optimization, invalid inputs may
886 * go undetected, which will lead to unpredictable
887 * behavior)
888 */
889 private void setMemoryChecks(Object o, long offset, long bytes, byte value) {
890 checkPrimitivePointer(o, offset);
891 checkSize(bytes);
892 }
893
894 /**
895 * Sets all bytes in a given block of memory to a copy of another
896 * block.
897 *
898 * <p>This method determines each block's base address by means of two parameters,
899 * and so it provides (in effect) a <em>double-register</em> addressing mode,
900 * as discussed in {@link #getInt(Object,long)}. When the object reference is null,
901 * the offset supplies an absolute base address.
902 *
903 * <p>The transfers are in coherent (atomic) units of a size determined
904 * by the address and length parameters. If the effective addresses and
905 * length are all even modulo 8, the transfer takes place in 'long' units.
906 * If the effective addresses and length are (resp.) even modulo 4 or 2,
907 * the transfer takes place in units of 'int' or 'short'.
908 *
909 * <em>Note:</em> It is the responsibility of the caller to make
910 * sure arguments are checked before the methods are called. While
911 * some rudimentary checks are performed on the input, the checks
912 * are best effort and when performance is an overriding priority,
913 * as when methods of this class are optimized by the runtime
914 * compiler, some or all checks (if any) may be elided. Hence, the
915 * caller must not rely on the checks and corresponding
916 * exceptions!
917 *
918 * @throws RuntimeException if any of the arguments is invalid
919 *
920 * @since 1.7
921 */
922 public void copyMemory(Object srcBase, long srcOffset,
923 Object destBase, long destOffset,
924 long bytes) {
925 copyMemoryChecks(srcBase, srcOffset, destBase, destOffset, bytes);
926
927 if (bytes == 0) {
928 return;
929 }
930
931 copyMemory0(srcBase, srcOffset, destBase, destOffset, bytes);
932 }
933
934 /**
935 * Sets all bytes in a given block of memory to a copy of another
936 * block. This provides a <em>single-register</em> addressing mode,
937 * as discussed in {@link #getInt(Object,long)}.
938 *
939 * Equivalent to {@code copyMemory(null, srcAddress, null, destAddress, bytes)}.
940 */
941 public void copyMemory(long srcAddress, long destAddress, long bytes) {
942 copyMemory(null, srcAddress, null, destAddress, bytes);
943 }
944
945 /**
946 * Validate the arguments to copyMemory
947 *
948 * @throws RuntimeException if any of the arguments is invalid
949 * (<em>Note:</em> after optimization, invalid inputs may
950 * go undetected, which will lead to unpredictable
951 * behavior)
952 */
953 private void copyMemoryChecks(Object srcBase, long srcOffset,
954 Object destBase, long destOffset,
955 long bytes) {
956 checkSize(bytes);
957 checkPrimitivePointer(srcBase, srcOffset);
958 checkPrimitivePointer(destBase, destOffset);
959 }
960
961 /**
962 * Copies all elements from one block of memory to another block,
963 * *unconditionally* byte swapping the elements on the fly.
964 *
965 * <p>This method determines each block's base address by means of two parameters,
966 * and so it provides (in effect) a <em>double-register</em> addressing mode,
967 * as discussed in {@link #getInt(Object,long)}. When the object reference is null,
968 * the offset supplies an absolute base address.
969 *
970 * <em>Note:</em> It is the responsibility of the caller to make
971 * sure arguments are checked before the methods are called. While
972 * some rudimentary checks are performed on the input, the checks
973 * are best effort and when performance is an overriding priority,
974 * as when methods of this class are optimized by the runtime
975 * compiler, some or all checks (if any) may be elided. Hence, the
976 * caller must not rely on the checks and corresponding
977 * exceptions!
978 *
979 * @throws RuntimeException if any of the arguments is invalid
980 *
981 * @since 9
982 */
983 public void copySwapMemory(Object srcBase, long srcOffset,
984 Object destBase, long destOffset,
985 long bytes, long elemSize) {
986 copySwapMemoryChecks(srcBase, srcOffset, destBase, destOffset, bytes, elemSize);
987
988 if (bytes == 0) {
989 return;
990 }
991
992 copySwapMemory0(srcBase, srcOffset, destBase, destOffset, bytes, elemSize);
993 }
994
995 private void copySwapMemoryChecks(Object srcBase, long srcOffset,
996 Object destBase, long destOffset,
997 long bytes, long elemSize) {
998 checkSize(bytes);
999
1000 if (elemSize != 2 && elemSize != 4 && elemSize != 8) {
1001 throw invalidInput();
1002 }
1003 if (bytes % elemSize != 0) {
1004 throw invalidInput();
1005 }
1006
1007 checkPrimitivePointer(srcBase, srcOffset);
1008 checkPrimitivePointer(destBase, destOffset);
1009 }
1010
1011 /**
1012 * Copies all elements from one block of memory to another block, byte swapping the
1013 * elements on the fly.
1014 *
1015 * This provides a <em>single-register</em> addressing mode, as
1016 * discussed in {@link #getInt(Object,long)}.
1017 *
1018 * Equivalent to {@code copySwapMemory(null, srcAddress, null, destAddress, bytes, elemSize)}.
1019 */
1020 public void copySwapMemory(long srcAddress, long destAddress, long bytes, long elemSize) {
1021 copySwapMemory(null, srcAddress, null, destAddress, bytes, elemSize);
1022 }
1023
1024 /**
1025 * Disposes of a block of native memory, as obtained from {@link
1026 * #allocateMemory} or {@link #reallocateMemory}. The address passed to
1027 * this method may be null, in which case no action is taken.
1028 *
1029 * <em>Note:</em> It is the responsibility of the caller to make
1030 * sure arguments are checked before the methods are called. While
1031 * some rudimentary checks are performed on the input, the checks
1032 * are best effort and when performance is an overriding priority,
1033 * as when methods of this class are optimized by the runtime
1034 * compiler, some or all checks (if any) may be elided. Hence, the
1035 * caller must not rely on the checks and corresponding
1036 * exceptions!
1037 *
1038 * @throws RuntimeException if any of the arguments is invalid
1039 *
1040 * @see #allocateMemory
1041 */
1042 public void freeMemory(long address) {
1043 freeMemoryChecks(address);
1044
1045 if (address == 0) {
1046 return;
1047 }
1048
1049 freeMemory0(address);
1050 }
1051
1052 /**
1053 * Validate the arguments to freeMemory
1054 *
1055 * @throws RuntimeException if the arguments are invalid
1056 * (<em>Note:</em> after optimization, invalid inputs may
1057 * go undetected, which will lead to unpredictable
1058 * behavior)
1059 */
1060 private void freeMemoryChecks(long address) {
1061 checkPointer(null, address);
1062 }
1063
1064 /**
1065 * Ensure writeback of a specified virtual memory address range
1066 * from cache to physical memory. All bytes in the address range
1067 * are guaranteed to have been written back to physical memory on
1068 * return from this call i.e. subsequently executed store
1069 * instructions are guaranteed not to be visible before the
1070 * writeback is completed.
1071 *
1072 * @param address
1073 * the lowest byte address that must be guaranteed written
1074 * back to memory. bytes at lower addresses may also be
1075 * written back.
1076 *
1077 * @param length
1078 * the length in bytes of the region starting at address
1079 * that must be guaranteed written back to memory.
1080 *
1081 * @throws RuntimeException if memory writeback is not supported
1082 * on the current hardware of if the arguments are invalid.
1083 * (<em>Note:</em> after optimization, invalid inputs may
1084 * go undetected, which will lead to unpredictable
1085 * behavior)
1086 *
1087 * @since 14
1088 */
1089
1090 public void writebackMemory(long address, long length) {
1091 checkWritebackEnabled();
1092 checkWritebackMemory(address, length);
1093
1094 // perform any required pre-writeback barrier
1095 writebackPreSync0();
1096
1097 // write back one cache line at a time
1098 long line = dataCacheLineAlignDown(address);
1099 long end = address + length;
1100 while (line < end) {
1101 writeback0(line);
1102 line += dataCacheLineFlushSize();
1103 }
1104
1105 // perform any required post-writeback barrier
1106 writebackPostSync0();
1107 }
1108
1109 /**
1110 * Validate the arguments to writebackMemory
1111 *
1112 * @throws RuntimeException if the arguments are invalid
1113 * (<em>Note:</em> after optimization, invalid inputs may
1114 * go undetected, which will lead to unpredictable
1115 * behavior)
1116 */
1117 private void checkWritebackMemory(long address, long length) {
1118 checkNativeAddress(address);
1119 checkSize(length);
1120 }
1121
1122 /**
1123 * Validate that the current hardware supports memory writeback.
1124 * (<em>Note:</em> this is a belt and braces check. Clients are
1125 * expected to test whether writeback is enabled by calling
1126 * ({@link isWritebackEnabled #isWritebackEnabled} and avoid
1127 * calling method {@link writeback #writeback} if it is disabled).
1128 *
1129 *
1130 * @throws RuntimeException if memory writeback is not supported
1131 */
1132 private void checkWritebackEnabled() {
1133 if (!isWritebackEnabled()) {
1134 throw new RuntimeException("writebackMemory not enabled!");
1135 }
1136 }
1137
1138 /**
1139 * force writeback of an individual cache line.
1140 *
1141 * @param address
1142 * the start address of the cache line to be written back
1143 */
1144 @IntrinsicCandidate
1145 private native void writeback0(long address);
1146
1147 /**
1148 * Serialize writeback operations relative to preceding memory writes.
1149 */
1150 @IntrinsicCandidate
1151 private native void writebackPreSync0();
1152
1153 /**
1154 * Serialize writeback operations relative to following memory writes.
1155 */
1156 @IntrinsicCandidate
1157 private native void writebackPostSync0();
1158
1159 /// random queries
1160
1161 /**
1162 * This constant differs from all results that will ever be returned from
1163 * {@link #staticFieldOffset}, {@link #objectFieldOffset},
1164 * or {@link #arrayBaseOffset}.
1165 */
1166 public static final int INVALID_FIELD_OFFSET = -1;
1167
1168 /**
1169 * Reports the location of a given field in the storage allocation of its
1170 * class. Do not expect to perform any sort of arithmetic on this offset;
1171 * it is just a cookie which is passed to the unsafe heap memory accessors.
1172 *
1173 * <p>Any given field will always have the same offset and base, and no
1174 * two distinct fields of the same class will ever have the same offset
1175 * and base.
1176 *
1177 * <p>As of 1.4.1, offsets for fields are represented as long values,
1178 * although the Sun JVM does not use the most significant 32 bits.
1179 * However, JVM implementations which store static fields at absolute
1180 * addresses can use long offsets and null base pointers to express
1181 * the field locations in a form usable by {@link #getInt(Object,long)}.
1182 * Therefore, code which will be ported to such JVMs on 64-bit platforms
1183 * must preserve all bits of static field offsets.
1184 * @see #getInt(Object, long)
1185 */
1186 public long objectFieldOffset(Field f) {
1187 if (f == null) {
1188 throw new NullPointerException();
1189 }
1190
1191 return objectFieldOffset0(f);
1192 }
1193
1194 /**
1195 * Reports the location of the field with a given name in the storage
1196 * allocation of its class.
1197 *
1198 * @throws NullPointerException if any parameter is {@code null}.
1199 * @throws InternalError if there is no field named {@code name} declared
1200 * in class {@code c}, i.e., if {@code c.getDeclaredField(name)}
1201 * would throw {@code java.lang.NoSuchFieldException}.
1202 *
1203 * @see #objectFieldOffset(Field)
1204 */
1205 public long objectFieldOffset(Class<?> c, String name) {
1206 if (c == null || name == null) {
1207 throw new NullPointerException();
1208 }
1209
1210 return objectFieldOffset1(c, name);
1211 }
1212
1213 /**
1214 * Reports the location of a given static field, in conjunction with {@link
1215 * #staticFieldBase}.
1216 * <p>Do not expect to perform any sort of arithmetic on this offset;
1217 * it is just a cookie which is passed to the unsafe heap memory accessors.
1218 *
1219 * <p>Any given field will always have the same offset, and no two distinct
1220 * fields of the same class will ever have the same offset.
1221 *
1222 * <p>As of 1.4.1, offsets for fields are represented as long values,
1223 * although the Sun JVM does not use the most significant 32 bits.
1224 * It is hard to imagine a JVM technology which needs more than
1225 * a few bits to encode an offset within a non-array object,
1226 * However, for consistency with other methods in this class,
1227 * this method reports its result as a long value.
1228 * @see #getInt(Object, long)
1229 */
1230 public long staticFieldOffset(Field f) {
1231 if (f == null) {
1232 throw new NullPointerException();
1233 }
1234
1235 return staticFieldOffset0(f);
1236 }
1237
1238 /**
1239 * Reports the location of a given static field, in conjunction with {@link
1240 * #staticFieldOffset}.
1241 * <p>Fetch the base "Object", if any, with which static fields of the
1242 * given class can be accessed via methods like {@link #getInt(Object,
1243 * long)}. This value may be null. This value may refer to an object
1244 * which is a "cookie", not guaranteed to be a real Object, and it should
1245 * not be used in any way except as argument to the get and put routines in
1246 * this class.
1247 */
1248 public Object staticFieldBase(Field f) {
1249 if (f == null) {
1250 throw new NullPointerException();
1251 }
1252
1253 return staticFieldBase0(f);
1254 }
1255
1256 /**
1257 * Detects if the given class may need to be initialized. This is often
1258 * needed in conjunction with obtaining the static field base of a
1259 * class.
1260 * @return false only if a call to {@code ensureClassInitialized} would have no effect
1261 */
1262 public boolean shouldBeInitialized(Class<?> c) {
1263 if (c == null) {
1264 throw new NullPointerException();
1265 }
1266
1267 return shouldBeInitialized0(c);
1268 }
1269
1270 /**
1271 * Ensures the given class has been initialized (see JVMS-5.5 for details).
1272 * This is often needed in conjunction with obtaining the static field base
1273 * of a class.
1274 *
1275 * The call returns when either class {@code c} is fully initialized or
1276 * class {@code c} is being initialized and the call is performed from
1277 * the initializing thread. In the latter case a subsequent call to
1278 * {@link #shouldBeInitialized} will return {@code true}.
1279 */
1280 public void ensureClassInitialized(Class<?> c) {
1281 if (c == null) {
1282 throw new NullPointerException();
1283 }
1284
1285 ensureClassInitialized0(c);
1286 }
1287
1288 /**
1289 * Reports the offset of the first element in the storage allocation of a
1290 * given array class. If {@link #arrayIndexScale} returns a non-zero value
1291 * for the same class, you may use that scale factor, together with this
1292 * base offset, to form new offsets to access elements of arrays of the
1293 * given class.
1294 *
1295 * @see #getInt(Object, long)
1296 * @see #putInt(Object, long, int)
1297 */
1298 public int arrayBaseOffset(Class<?> arrayClass) {
1299 if (arrayClass == null) {
1300 throw new NullPointerException();
1301 }
1302
1303 return arrayBaseOffset0(arrayClass);
1304 }
1305
1306
1307 /** The value of {@code arrayBaseOffset(boolean[].class)} */
1308 public static final int ARRAY_BOOLEAN_BASE_OFFSET
1309 = theUnsafe.arrayBaseOffset(boolean[].class);
1310
1311 /** The value of {@code arrayBaseOffset(byte[].class)} */
1312 public static final int ARRAY_BYTE_BASE_OFFSET
1313 = theUnsafe.arrayBaseOffset(byte[].class);
1314
1315 /** The value of {@code arrayBaseOffset(short[].class)} */
1316 public static final int ARRAY_SHORT_BASE_OFFSET
1317 = theUnsafe.arrayBaseOffset(short[].class);
1318
1319 /** The value of {@code arrayBaseOffset(char[].class)} */
1320 public static final int ARRAY_CHAR_BASE_OFFSET
1321 = theUnsafe.arrayBaseOffset(char[].class);
1322
1323 /** The value of {@code arrayBaseOffset(int[].class)} */
1324 public static final int ARRAY_INT_BASE_OFFSET
1325 = theUnsafe.arrayBaseOffset(int[].class);
1326
1327 /** The value of {@code arrayBaseOffset(long[].class)} */
1328 public static final int ARRAY_LONG_BASE_OFFSET
1329 = theUnsafe.arrayBaseOffset(long[].class);
1330
1331 /** The value of {@code arrayBaseOffset(float[].class)} */
1332 public static final int ARRAY_FLOAT_BASE_OFFSET
1333 = theUnsafe.arrayBaseOffset(float[].class);
1334
1335 /** The value of {@code arrayBaseOffset(double[].class)} */
1336 public static final int ARRAY_DOUBLE_BASE_OFFSET
1337 = theUnsafe.arrayBaseOffset(double[].class);
1338
1339 /** The value of {@code arrayBaseOffset(Object[].class)} */
1340 public static final int ARRAY_OBJECT_BASE_OFFSET
1341 = theUnsafe.arrayBaseOffset(Object[].class);
1342
1343 /**
1344 * Reports the scale factor for addressing elements in the storage
1345 * allocation of a given array class. However, arrays of "narrow" types
1346 * will generally not work properly with accessors like {@link
1347 * #getByte(Object, long)}, so the scale factor for such classes is reported
1348 * as zero.
1349 *
1350 * @see #arrayBaseOffset
1351 * @see #getInt(Object, long)
1352 * @see #putInt(Object, long, int)
1353 */
1354 public int arrayIndexScale(Class<?> arrayClass) {
1355 if (arrayClass == null) {
1356 throw new NullPointerException();
1357 }
1358
1359 return arrayIndexScale0(arrayClass);
1360 }
1361
1362 /**
1363 * Return the size of the object in the heap.
1364 * @param o an object
1365 * @return the objects's size
1366 * @since Valhalla
1367 */
1368 public long getObjectSize(Object o) {
1369 if (o == null)
1370 throw new NullPointerException();
1371 return getObjectSize0(o);
1372 }
1373
1374 /** The value of {@code arrayIndexScale(boolean[].class)} */
1375 public static final int ARRAY_BOOLEAN_INDEX_SCALE
1376 = theUnsafe.arrayIndexScale(boolean[].class);
1377
1378 /** The value of {@code arrayIndexScale(byte[].class)} */
1379 public static final int ARRAY_BYTE_INDEX_SCALE
1380 = theUnsafe.arrayIndexScale(byte[].class);
1381
1382 /** The value of {@code arrayIndexScale(short[].class)} */
1383 public static final int ARRAY_SHORT_INDEX_SCALE
1384 = theUnsafe.arrayIndexScale(short[].class);
1385
1386 /** The value of {@code arrayIndexScale(char[].class)} */
1387 public static final int ARRAY_CHAR_INDEX_SCALE
1388 = theUnsafe.arrayIndexScale(char[].class);
1389
1390 /** The value of {@code arrayIndexScale(int[].class)} */
1391 public static final int ARRAY_INT_INDEX_SCALE
1392 = theUnsafe.arrayIndexScale(int[].class);
1393
1394 /** The value of {@code arrayIndexScale(long[].class)} */
1395 public static final int ARRAY_LONG_INDEX_SCALE
1396 = theUnsafe.arrayIndexScale(long[].class);
1397
1398 /** The value of {@code arrayIndexScale(float[].class)} */
1399 public static final int ARRAY_FLOAT_INDEX_SCALE
1400 = theUnsafe.arrayIndexScale(float[].class);
1401
1402 /** The value of {@code arrayIndexScale(double[].class)} */
1403 public static final int ARRAY_DOUBLE_INDEX_SCALE
1404 = theUnsafe.arrayIndexScale(double[].class);
1405
1406 /** The value of {@code arrayIndexScale(Object[].class)} */
1407 public static final int ARRAY_OBJECT_INDEX_SCALE
1408 = theUnsafe.arrayIndexScale(Object[].class);
1409
1410 /**
1411 * Reports the size in bytes of a native pointer, as stored via {@link
1412 * #putAddress}. This value will be either 4 or 8. Note that the sizes of
1413 * other primitive types (as stored in native memory blocks) is determined
1414 * fully by their information content.
1415 */
1416 public int addressSize() {
1417 return ADDRESS_SIZE;
1418 }
1419
1420 /** The value of {@code addressSize()} */
1421 public static final int ADDRESS_SIZE = ADDRESS_SIZE0;
1422
1423 /**
1424 * Reports the size in bytes of a native memory page (whatever that is).
1425 * This value will always be a power of two.
1426 */
1427 public int pageSize() { return PAGE_SIZE; }
1428
1429 /**
1430 * Reports the size in bytes of a data cache line written back by
1431 * the hardware cache line flush operation available to the JVM or
1432 * 0 if data cache line flushing is not enabled.
1433 */
1434 public int dataCacheLineFlushSize() { return DATA_CACHE_LINE_FLUSH_SIZE; }
1435
1436 /**
1437 * Rounds down address to a data cache line boundary as
1438 * determined by {@link #dataCacheLineFlushSize}
1439 * @return the rounded down address
1440 */
1441 public long dataCacheLineAlignDown(long address) {
1442 return (address & ~(DATA_CACHE_LINE_FLUSH_SIZE - 1));
1443 }
1444
1445 /**
1446 * Returns true if data cache line writeback
1447 */
1448 public static boolean isWritebackEnabled() { return DATA_CACHE_LINE_FLUSH_SIZE != 0; }
1449
1450 /// random trusted operations from JNI:
1451
1452 /**
1453 * Tells the VM to define a class, without security checks. By default, the
1454 * class loader and protection domain come from the caller's class.
1455 */
1456 public Class<?> defineClass(String name, byte[] b, int off, int len,
1457 ClassLoader loader,
1458 ProtectionDomain protectionDomain) {
1459 if (b == null) {
1460 throw new NullPointerException();
1461 }
1462 if (len < 0) {
1463 throw new ArrayIndexOutOfBoundsException();
1464 }
1465
1466 return defineClass0(name, b, off, len, loader, protectionDomain);
1467 }
1468
1469 public native Class<?> defineClass0(String name, byte[] b, int off, int len,
1470 ClassLoader loader,
1471 ProtectionDomain protectionDomain);
1472
1473 /**
1474 * Allocates an instance but does not run any constructor.
1475 * Initializes the class if it has not yet been.
1476 */
1477 @IntrinsicCandidate
1478 public native Object allocateInstance(Class<?> cls)
1479 throws InstantiationException;
1480
1481 /**
1482 * Allocates an array of a given type, but does not do zeroing.
1483 * <p>
1484 * This method should only be used in the very rare cases where a high-performance code
1485 * overwrites the destination array completely, and compilers cannot assist in zeroing elimination.
1486 * In an overwhelming majority of cases, a normal Java allocation should be used instead.
1487 * <p>
1488 * Users of this method are <b>required</b> to overwrite the initial (garbage) array contents
1489 * before allowing untrusted code, or code in other threads, to observe the reference
1490 * to the newly allocated array. In addition, the publication of the array reference must be
1491 * safe according to the Java Memory Model requirements.
1492 * <p>
1493 * The safest approach to deal with an uninitialized array is to keep the reference to it in local
1494 * variable at least until the initialization is complete, and then publish it <b>once</b>, either
1495 * by writing it to a <em>volatile</em> field, or storing it into a <em>final</em> field in constructor,
1496 * or issuing a {@link #storeFence} before publishing the reference.
1497 * <p>
1498 * @implnote This method can only allocate primitive arrays, to avoid garbage reference
1499 * elements that could break heap integrity.
1500 *
1501 * @param componentType array component type to allocate
1502 * @param length array size to allocate
1503 * @throws IllegalArgumentException if component type is null, or not a primitive class;
1504 * or the length is negative
1505 */
1506 public Object allocateUninitializedArray(Class<?> componentType, int length) {
1507 if (componentType == null) {
1508 throw new IllegalArgumentException("Component type is null");
1509 }
1510 if (!componentType.isPrimitive()) {
1511 throw new IllegalArgumentException("Component type is not primitive");
1512 }
1513 if (length < 0) {
1514 throw new IllegalArgumentException("Negative length");
1515 }
1516 return allocateUninitializedArray0(componentType, length);
1517 }
1518
1519 @IntrinsicCandidate
1520 private Object allocateUninitializedArray0(Class<?> componentType, int length) {
1521 // These fallbacks provide zeroed arrays, but intrinsic is not required to
1522 // return the zeroed arrays.
1523 if (componentType == byte.class) return new byte[length];
1524 if (componentType == boolean.class) return new boolean[length];
1525 if (componentType == short.class) return new short[length];
1526 if (componentType == char.class) return new char[length];
1527 if (componentType == int.class) return new int[length];
1528 if (componentType == float.class) return new float[length];
1529 if (componentType == long.class) return new long[length];
1530 if (componentType == double.class) return new double[length];
1531 return null;
1532 }
1533
1534 /** Throws the exception without telling the verifier. */
1535 public native void throwException(Throwable ee);
1536
1537 /**
1538 * Atomically updates Java variable to {@code x} if it is currently
1539 * holding {@code expected}.
1540 *
1541 * <p>This operation has memory semantics of a {@code volatile} read
1542 * and write. Corresponds to C11 atomic_compare_exchange_strong.
1543 *
1544 * @return {@code true} if successful
1545 */
1546 @IntrinsicCandidate
1547 public final native boolean compareAndSetReference(Object o, long offset,
1548 Object expected,
1549 Object x);
1550
1551 private final boolean isValueObject(Object o) {
1552 return o != null && o.getClass().isValue();
1553 }
1554
1555 /*
1556 * For primitive type, CAS should do substitutability test as opposed
1557 * to two pointers comparison.
1558 *
1559 * Perhaps we can keep the xxxObject methods for compatibility and
1560 * change the JDK 13 xxxReference method signature freely.
1561 */
1562 public final <V> boolean compareAndSetReference(Object o, long offset,
1563 Class<?> type,
1564 V expected,
1565 V x) {
1566 if (type.isValue() || isValueObject(expected)) {
1567 synchronized (valueLock) {
1568 Object witness = getReference(o, offset);
1569 if (witness == expected) {
1570 putReference(o, offset, x);
1571 return true;
1572 } else {
1573 return false;
1574 }
1575 }
1576 } else {
1577 return compareAndSetReference(o, offset, expected, x);
1578 }
1579 }
1580
1581 @ForceInline
1582 public final <V> boolean compareAndSetValue(Object o, long offset,
1583 Class<?> valueType,
1584 V expected,
1585 V x) {
1586 synchronized (valueLock) {
1587 Object witness = getValue(o, offset, valueType);
1588 if (witness == expected) {
1589 putValue(o, offset, valueType, x);
1590 return true;
1591 }
1592 else {
1593 return false;
1594 }
1595 }
1596 }
1597
1598 @IntrinsicCandidate
1599 public final native Object compareAndExchangeReference(Object o, long offset,
1600 Object expected,
1601 Object x);
1602
1603 public final <V> Object compareAndExchangeReference(Object o, long offset,
1604 Class<?> valueType,
1605 V expected,
1606 V x) {
1607 if (valueType.isValue() || isValueObject(expected)) {
1608 synchronized (valueLock) {
1609 Object witness = getReference(o, offset);
1610 if (witness == expected) {
1611 putReference(o, offset, x);
1612 }
1613 return witness;
1614 }
1615 } else {
1616 return compareAndExchangeReference(o, offset, expected, x);
1617 }
1618 }
1619
1620 @ForceInline
1621 public final <V> Object compareAndExchangeValue(Object o, long offset,
1622 Class<?> valueType,
1623 V expected,
1624 V x) {
1625 synchronized (valueLock) {
1626 Object witness = getValue(o, offset, valueType);
1627 if (witness == expected) {
1628 putValue(o, offset, valueType, x);
1629 }
1630 return witness;
1631 }
1632 }
1633
1634 @IntrinsicCandidate
1635 public final Object compareAndExchangeReferenceAcquire(Object o, long offset,
1636 Object expected,
1637 Object x) {
1638 return compareAndExchangeReference(o, offset, expected, x);
1639 }
1640
1641 public final <V> Object compareAndExchangeReferenceAcquire(Object o, long offset,
1642 Class<?> valueType,
1643 V expected,
1644 V x) {
1645 return compareAndExchangeReference(o, offset, valueType, expected, x);
1646 }
1647
1648 @ForceInline
1649 public final <V> Object compareAndExchangeValueAcquire(Object o, long offset,
1650 Class<?> valueType,
1651 V expected,
1652 V x) {
1653 return compareAndExchangeValue(o, offset, valueType, expected, x);
1654 }
1655
1656 @IntrinsicCandidate
1657 public final Object compareAndExchangeReferenceRelease(Object o, long offset,
1658 Object expected,
1659 Object x) {
1660 return compareAndExchangeReference(o, offset, expected, x);
1661 }
1662
1663 public final <V> Object compareAndExchangeReferenceRelease(Object o, long offset,
1664 Class<?> valueType,
1665 V expected,
1666 V x) {
1667 return compareAndExchangeReference(o, offset, valueType, expected, x);
1668 }
1669
1670 @ForceInline
1671 public final <V> Object compareAndExchangeValueRelease(Object o, long offset,
1672 Class<?> valueType,
1673 V expected,
1674 V x) {
1675 return compareAndExchangeValue(o, offset, valueType, expected, x);
1676 }
1677
1678 @IntrinsicCandidate
1679 public final boolean weakCompareAndSetReferencePlain(Object o, long offset,
1680 Object expected,
1681 Object x) {
1682 return compareAndSetReference(o, offset, expected, x);
1683 }
1684
1685 public final <V> boolean weakCompareAndSetReferencePlain(Object o, long offset,
1686 Class<?> valueType,
1687 V expected,
1688 V x) {
1689 if (valueType.isValue() || isValueObject(expected)) {
1690 return compareAndSetReference(o, offset, valueType, expected, x);
1691 } else {
1692 return weakCompareAndSetReferencePlain(o, offset, expected, x);
1693 }
1694 }
1695
1696 @ForceInline
1697 public final <V> boolean weakCompareAndSetValuePlain(Object o, long offset,
1698 Class<?> valueType,
1699 V expected,
1700 V x) {
1701 return compareAndSetValue(o, offset, valueType, expected, x);
1702 }
1703
1704 @IntrinsicCandidate
1705 public final boolean weakCompareAndSetReferenceAcquire(Object o, long offset,
1706 Object expected,
1707 Object x) {
1708 return compareAndSetReference(o, offset, expected, x);
1709 }
1710
1711 public final <V> boolean weakCompareAndSetReferenceAcquire(Object o, long offset,
1712 Class<?> valueType,
1713 V expected,
1714 V x) {
1715 if (valueType.isValue() || isValueObject(expected)) {
1716 return compareAndSetReference(o, offset, valueType, expected, x);
1717 } else {
1718 return weakCompareAndSetReferencePlain(o, offset, expected, x);
1719 }
1720 }
1721
1722 @ForceInline
1723 public final <V> boolean weakCompareAndSetValueAcquire(Object o, long offset,
1724 Class<?> valueType,
1725 V expected,
1726 V x) {
1727 return compareAndSetValue(o, offset, valueType, expected, x);
1728 }
1729
1730 @IntrinsicCandidate
1731 public final boolean weakCompareAndSetReferenceRelease(Object o, long offset,
1732 Object expected,
1733 Object x) {
1734 return compareAndSetReference(o, offset, expected, x);
1735 }
1736
1737 public final <V> boolean weakCompareAndSetReferenceRelease(Object o, long offset,
1738 Class<?> valueType,
1739 V expected,
1740 V x) {
1741 if (valueType.isValue() || isValueObject(expected)) {
1742 return compareAndSetReference(o, offset, valueType, expected, x);
1743 } else {
1744 return weakCompareAndSetReferencePlain(o, offset, expected, x);
1745 }
1746 }
1747
1748 @ForceInline
1749 public final <V> boolean weakCompareAndSetValueRelease(Object o, long offset,
1750 Class<?> valueType,
1751 V expected,
1752 V x) {
1753 return compareAndSetValue(o, offset, valueType, expected, x);
1754 }
1755
1756 @IntrinsicCandidate
1757 public final boolean weakCompareAndSetReference(Object o, long offset,
1758 Object expected,
1759 Object x) {
1760 return compareAndSetReference(o, offset, expected, x);
1761 }
1762
1763 public final <V> boolean weakCompareAndSetReference(Object o, long offset,
1764 Class<?> valueType,
1765 V expected,
1766 V x) {
1767 if (valueType.isValue() || isValueObject(expected)) {
1768 return compareAndSetReference(o, offset, valueType, expected, x);
1769 } else {
1770 return weakCompareAndSetReferencePlain(o, offset, expected, x);
1771 }
1772 }
1773
1774 @ForceInline
1775 public final <V> boolean weakCompareAndSetValue(Object o, long offset,
1776 Class<?> valueType,
1777 V expected,
1778 V x) {
1779 return compareAndSetValue(o, offset, valueType, expected, x);
1780 }
1781
1782 /**
1783 * Atomically updates Java variable to {@code x} if it is currently
1784 * holding {@code expected}.
1785 *
1786 * <p>This operation has memory semantics of a {@code volatile} read
1787 * and write. Corresponds to C11 atomic_compare_exchange_strong.
1788 *
1789 * @return {@code true} if successful
1790 */
1791 @IntrinsicCandidate
1792 public final native boolean compareAndSetInt(Object o, long offset,
1793 int expected,
1794 int x);
1795
1796 @IntrinsicCandidate
1797 public final native int compareAndExchangeInt(Object o, long offset,
1798 int expected,
1799 int x);
1800
1801 @IntrinsicCandidate
1802 public final int compareAndExchangeIntAcquire(Object o, long offset,
1803 int expected,
1804 int x) {
1805 return compareAndExchangeInt(o, offset, expected, x);
1806 }
1807
1808 @IntrinsicCandidate
1809 public final int compareAndExchangeIntRelease(Object o, long offset,
1810 int expected,
1811 int x) {
1812 return compareAndExchangeInt(o, offset, expected, x);
1813 }
1814
1815 @IntrinsicCandidate
1816 public final boolean weakCompareAndSetIntPlain(Object o, long offset,
1817 int expected,
1818 int x) {
1819 return compareAndSetInt(o, offset, expected, x);
1820 }
1821
1822 @IntrinsicCandidate
1823 public final boolean weakCompareAndSetIntAcquire(Object o, long offset,
1824 int expected,
1825 int x) {
1826 return compareAndSetInt(o, offset, expected, x);
1827 }
1828
1829 @IntrinsicCandidate
1830 public final boolean weakCompareAndSetIntRelease(Object o, long offset,
1831 int expected,
1832 int x) {
1833 return compareAndSetInt(o, offset, expected, x);
1834 }
1835
1836 @IntrinsicCandidate
1837 public final boolean weakCompareAndSetInt(Object o, long offset,
1838 int expected,
1839 int x) {
1840 return compareAndSetInt(o, offset, expected, x);
1841 }
1842
1843 @IntrinsicCandidate
1844 public final byte compareAndExchangeByte(Object o, long offset,
1845 byte expected,
1846 byte x) {
1847 long wordOffset = offset & ~3;
1848 int shift = (int) (offset & 3) << 3;
1849 if (BIG_ENDIAN) {
1850 shift = 24 - shift;
1851 }
1852 int mask = 0xFF << shift;
1853 int maskedExpected = (expected & 0xFF) << shift;
1854 int maskedX = (x & 0xFF) << shift;
1855 int fullWord;
1856 do {
1857 fullWord = getIntVolatile(o, wordOffset);
1858 if ((fullWord & mask) != maskedExpected)
1859 return (byte) ((fullWord & mask) >> shift);
1860 } while (!weakCompareAndSetInt(o, wordOffset,
1861 fullWord, (fullWord & ~mask) | maskedX));
1862 return expected;
1863 }
1864
1865 @IntrinsicCandidate
1866 public final boolean compareAndSetByte(Object o, long offset,
1867 byte expected,
1868 byte x) {
1869 return compareAndExchangeByte(o, offset, expected, x) == expected;
1870 }
1871
1872 @IntrinsicCandidate
1873 public final boolean weakCompareAndSetByte(Object o, long offset,
1874 byte expected,
1875 byte x) {
1876 return compareAndSetByte(o, offset, expected, x);
1877 }
1878
1879 @IntrinsicCandidate
1880 public final boolean weakCompareAndSetByteAcquire(Object o, long offset,
1881 byte expected,
1882 byte x) {
1883 return weakCompareAndSetByte(o, offset, expected, x);
1884 }
1885
1886 @IntrinsicCandidate
1887 public final boolean weakCompareAndSetByteRelease(Object o, long offset,
1888 byte expected,
1889 byte x) {
1890 return weakCompareAndSetByte(o, offset, expected, x);
1891 }
1892
1893 @IntrinsicCandidate
1894 public final boolean weakCompareAndSetBytePlain(Object o, long offset,
1895 byte expected,
1896 byte x) {
1897 return weakCompareAndSetByte(o, offset, expected, x);
1898 }
1899
1900 @IntrinsicCandidate
1901 public final byte compareAndExchangeByteAcquire(Object o, long offset,
1902 byte expected,
1903 byte x) {
1904 return compareAndExchangeByte(o, offset, expected, x);
1905 }
1906
1907 @IntrinsicCandidate
1908 public final byte compareAndExchangeByteRelease(Object o, long offset,
1909 byte expected,
1910 byte x) {
1911 return compareAndExchangeByte(o, offset, expected, x);
1912 }
1913
1914 @IntrinsicCandidate
1915 public final short compareAndExchangeShort(Object o, long offset,
1916 short expected,
1917 short x) {
1918 if ((offset & 3) == 3) {
1919 throw new IllegalArgumentException("Update spans the word, not supported");
1920 }
1921 long wordOffset = offset & ~3;
1922 int shift = (int) (offset & 3) << 3;
1923 if (BIG_ENDIAN) {
1924 shift = 16 - shift;
1925 }
1926 int mask = 0xFFFF << shift;
1927 int maskedExpected = (expected & 0xFFFF) << shift;
1928 int maskedX = (x & 0xFFFF) << shift;
1929 int fullWord;
1930 do {
1931 fullWord = getIntVolatile(o, wordOffset);
1932 if ((fullWord & mask) != maskedExpected) {
1933 return (short) ((fullWord & mask) >> shift);
1934 }
1935 } while (!weakCompareAndSetInt(o, wordOffset,
1936 fullWord, (fullWord & ~mask) | maskedX));
1937 return expected;
1938 }
1939
1940 @IntrinsicCandidate
1941 public final boolean compareAndSetShort(Object o, long offset,
1942 short expected,
1943 short x) {
1944 return compareAndExchangeShort(o, offset, expected, x) == expected;
1945 }
1946
1947 @IntrinsicCandidate
1948 public final boolean weakCompareAndSetShort(Object o, long offset,
1949 short expected,
1950 short x) {
1951 return compareAndSetShort(o, offset, expected, x);
1952 }
1953
1954 @IntrinsicCandidate
1955 public final boolean weakCompareAndSetShortAcquire(Object o, long offset,
1956 short expected,
1957 short x) {
1958 return weakCompareAndSetShort(o, offset, expected, x);
1959 }
1960
1961 @IntrinsicCandidate
1962 public final boolean weakCompareAndSetShortRelease(Object o, long offset,
1963 short expected,
1964 short x) {
1965 return weakCompareAndSetShort(o, offset, expected, x);
1966 }
1967
1968 @IntrinsicCandidate
1969 public final boolean weakCompareAndSetShortPlain(Object o, long offset,
1970 short expected,
1971 short x) {
1972 return weakCompareAndSetShort(o, offset, expected, x);
1973 }
1974
1975
1976 @IntrinsicCandidate
1977 public final short compareAndExchangeShortAcquire(Object o, long offset,
1978 short expected,
1979 short x) {
1980 return compareAndExchangeShort(o, offset, expected, x);
1981 }
1982
1983 @IntrinsicCandidate
1984 public final short compareAndExchangeShortRelease(Object o, long offset,
1985 short expected,
1986 short x) {
1987 return compareAndExchangeShort(o, offset, expected, x);
1988 }
1989
1990 @ForceInline
1991 private char s2c(short s) {
1992 return (char) s;
1993 }
1994
1995 @ForceInline
1996 private short c2s(char s) {
1997 return (short) s;
1998 }
1999
2000 @ForceInline
2001 public final boolean compareAndSetChar(Object o, long offset,
2002 char expected,
2003 char x) {
2004 return compareAndSetShort(o, offset, c2s(expected), c2s(x));
2005 }
2006
2007 @ForceInline
2008 public final char compareAndExchangeChar(Object o, long offset,
2009 char expected,
2010 char x) {
2011 return s2c(compareAndExchangeShort(o, offset, c2s(expected), c2s(x)));
2012 }
2013
2014 @ForceInline
2015 public final char compareAndExchangeCharAcquire(Object o, long offset,
2016 char expected,
2017 char x) {
2018 return s2c(compareAndExchangeShortAcquire(o, offset, c2s(expected), c2s(x)));
2019 }
2020
2021 @ForceInline
2022 public final char compareAndExchangeCharRelease(Object o, long offset,
2023 char expected,
2024 char x) {
2025 return s2c(compareAndExchangeShortRelease(o, offset, c2s(expected), c2s(x)));
2026 }
2027
2028 @ForceInline
2029 public final boolean weakCompareAndSetChar(Object o, long offset,
2030 char expected,
2031 char x) {
2032 return weakCompareAndSetShort(o, offset, c2s(expected), c2s(x));
2033 }
2034
2035 @ForceInline
2036 public final boolean weakCompareAndSetCharAcquire(Object o, long offset,
2037 char expected,
2038 char x) {
2039 return weakCompareAndSetShortAcquire(o, offset, c2s(expected), c2s(x));
2040 }
2041
2042 @ForceInline
2043 public final boolean weakCompareAndSetCharRelease(Object o, long offset,
2044 char expected,
2045 char x) {
2046 return weakCompareAndSetShortRelease(o, offset, c2s(expected), c2s(x));
2047 }
2048
2049 @ForceInline
2050 public final boolean weakCompareAndSetCharPlain(Object o, long offset,
2051 char expected,
2052 char x) {
2053 return weakCompareAndSetShortPlain(o, offset, c2s(expected), c2s(x));
2054 }
2055
2056 /**
2057 * The JVM converts integral values to boolean values using two
2058 * different conventions, byte testing against zero and truncation
2059 * to least-significant bit.
2060 *
2061 * <p>The JNI documents specify that, at least for returning
2062 * values from native methods, a Java boolean value is converted
2063 * to the value-set 0..1 by first truncating to a byte (0..255 or
2064 * maybe -128..127) and then testing against zero. Thus, Java
2065 * booleans in non-Java data structures are by convention
2066 * represented as 8-bit containers containing either zero (for
2067 * false) or any non-zero value (for true).
2068 *
2069 * <p>Java booleans in the heap are also stored in bytes, but are
2070 * strongly normalized to the value-set 0..1 (i.e., they are
2071 * truncated to the least-significant bit).
2072 *
2073 * <p>The main reason for having different conventions for
2074 * conversion is performance: Truncation to the least-significant
2075 * bit can be usually implemented with fewer (machine)
2076 * instructions than byte testing against zero.
2077 *
2078 * <p>A number of Unsafe methods load boolean values from the heap
2079 * as bytes. Unsafe converts those values according to the JNI
2080 * rules (i.e, using the "testing against zero" convention). The
2081 * method {@code byte2bool} implements that conversion.
2082 *
2083 * @param b the byte to be converted to boolean
2084 * @return the result of the conversion
2085 */
2086 @ForceInline
2087 private boolean byte2bool(byte b) {
2088 return b != 0;
2089 }
2090
2091 /**
2092 * Convert a boolean value to a byte. The return value is strongly
2093 * normalized to the value-set 0..1 (i.e., the value is truncated
2094 * to the least-significant bit). See {@link #byte2bool(byte)} for
2095 * more details on conversion conventions.
2096 *
2097 * @param b the boolean to be converted to byte (and then normalized)
2098 * @return the result of the conversion
2099 */
2100 @ForceInline
2101 private byte bool2byte(boolean b) {
2102 return b ? (byte)1 : (byte)0;
2103 }
2104
2105 @ForceInline
2106 public final boolean compareAndSetBoolean(Object o, long offset,
2107 boolean expected,
2108 boolean x) {
2109 return compareAndSetByte(o, offset, bool2byte(expected), bool2byte(x));
2110 }
2111
2112 @ForceInline
2113 public final boolean compareAndExchangeBoolean(Object o, long offset,
2114 boolean expected,
2115 boolean x) {
2116 return byte2bool(compareAndExchangeByte(o, offset, bool2byte(expected), bool2byte(x)));
2117 }
2118
2119 @ForceInline
2120 public final boolean compareAndExchangeBooleanAcquire(Object o, long offset,
2121 boolean expected,
2122 boolean x) {
2123 return byte2bool(compareAndExchangeByteAcquire(o, offset, bool2byte(expected), bool2byte(x)));
2124 }
2125
2126 @ForceInline
2127 public final boolean compareAndExchangeBooleanRelease(Object o, long offset,
2128 boolean expected,
2129 boolean x) {
2130 return byte2bool(compareAndExchangeByteRelease(o, offset, bool2byte(expected), bool2byte(x)));
2131 }
2132
2133 @ForceInline
2134 public final boolean weakCompareAndSetBoolean(Object o, long offset,
2135 boolean expected,
2136 boolean x) {
2137 return weakCompareAndSetByte(o, offset, bool2byte(expected), bool2byte(x));
2138 }
2139
2140 @ForceInline
2141 public final boolean weakCompareAndSetBooleanAcquire(Object o, long offset,
2142 boolean expected,
2143 boolean x) {
2144 return weakCompareAndSetByteAcquire(o, offset, bool2byte(expected), bool2byte(x));
2145 }
2146
2147 @ForceInline
2148 public final boolean weakCompareAndSetBooleanRelease(Object o, long offset,
2149 boolean expected,
2150 boolean x) {
2151 return weakCompareAndSetByteRelease(o, offset, bool2byte(expected), bool2byte(x));
2152 }
2153
2154 @ForceInline
2155 public final boolean weakCompareAndSetBooleanPlain(Object o, long offset,
2156 boolean expected,
2157 boolean x) {
2158 return weakCompareAndSetBytePlain(o, offset, bool2byte(expected), bool2byte(x));
2159 }
2160
2161 /**
2162 * Atomically updates Java variable to {@code x} if it is currently
2163 * holding {@code expected}.
2164 *
2165 * <p>This operation has memory semantics of a {@code volatile} read
2166 * and write. Corresponds to C11 atomic_compare_exchange_strong.
2167 *
2168 * @return {@code true} if successful
2169 */
2170 @ForceInline
2171 public final boolean compareAndSetFloat(Object o, long offset,
2172 float expected,
2173 float x) {
2174 return compareAndSetInt(o, offset,
2175 Float.floatToRawIntBits(expected),
2176 Float.floatToRawIntBits(x));
2177 }
2178
2179 @ForceInline
2180 public final float compareAndExchangeFloat(Object o, long offset,
2181 float expected,
2182 float x) {
2183 int w = compareAndExchangeInt(o, offset,
2184 Float.floatToRawIntBits(expected),
2185 Float.floatToRawIntBits(x));
2186 return Float.intBitsToFloat(w);
2187 }
2188
2189 @ForceInline
2190 public final float compareAndExchangeFloatAcquire(Object o, long offset,
2191 float expected,
2192 float x) {
2193 int w = compareAndExchangeIntAcquire(o, offset,
2194 Float.floatToRawIntBits(expected),
2195 Float.floatToRawIntBits(x));
2196 return Float.intBitsToFloat(w);
2197 }
2198
2199 @ForceInline
2200 public final float compareAndExchangeFloatRelease(Object o, long offset,
2201 float expected,
2202 float x) {
2203 int w = compareAndExchangeIntRelease(o, offset,
2204 Float.floatToRawIntBits(expected),
2205 Float.floatToRawIntBits(x));
2206 return Float.intBitsToFloat(w);
2207 }
2208
2209 @ForceInline
2210 public final boolean weakCompareAndSetFloatPlain(Object o, long offset,
2211 float expected,
2212 float x) {
2213 return weakCompareAndSetIntPlain(o, offset,
2214 Float.floatToRawIntBits(expected),
2215 Float.floatToRawIntBits(x));
2216 }
2217
2218 @ForceInline
2219 public final boolean weakCompareAndSetFloatAcquire(Object o, long offset,
2220 float expected,
2221 float x) {
2222 return weakCompareAndSetIntAcquire(o, offset,
2223 Float.floatToRawIntBits(expected),
2224 Float.floatToRawIntBits(x));
2225 }
2226
2227 @ForceInline
2228 public final boolean weakCompareAndSetFloatRelease(Object o, long offset,
2229 float expected,
2230 float x) {
2231 return weakCompareAndSetIntRelease(o, offset,
2232 Float.floatToRawIntBits(expected),
2233 Float.floatToRawIntBits(x));
2234 }
2235
2236 @ForceInline
2237 public final boolean weakCompareAndSetFloat(Object o, long offset,
2238 float expected,
2239 float x) {
2240 return weakCompareAndSetInt(o, offset,
2241 Float.floatToRawIntBits(expected),
2242 Float.floatToRawIntBits(x));
2243 }
2244
2245 /**
2246 * Atomically updates Java variable to {@code x} if it is currently
2247 * holding {@code expected}.
2248 *
2249 * <p>This operation has memory semantics of a {@code volatile} read
2250 * and write. Corresponds to C11 atomic_compare_exchange_strong.
2251 *
2252 * @return {@code true} if successful
2253 */
2254 @ForceInline
2255 public final boolean compareAndSetDouble(Object o, long offset,
2256 double expected,
2257 double x) {
2258 return compareAndSetLong(o, offset,
2259 Double.doubleToRawLongBits(expected),
2260 Double.doubleToRawLongBits(x));
2261 }
2262
2263 @ForceInline
2264 public final double compareAndExchangeDouble(Object o, long offset,
2265 double expected,
2266 double x) {
2267 long w = compareAndExchangeLong(o, offset,
2268 Double.doubleToRawLongBits(expected),
2269 Double.doubleToRawLongBits(x));
2270 return Double.longBitsToDouble(w);
2271 }
2272
2273 @ForceInline
2274 public final double compareAndExchangeDoubleAcquire(Object o, long offset,
2275 double expected,
2276 double x) {
2277 long w = compareAndExchangeLongAcquire(o, offset,
2278 Double.doubleToRawLongBits(expected),
2279 Double.doubleToRawLongBits(x));
2280 return Double.longBitsToDouble(w);
2281 }
2282
2283 @ForceInline
2284 public final double compareAndExchangeDoubleRelease(Object o, long offset,
2285 double expected,
2286 double x) {
2287 long w = compareAndExchangeLongRelease(o, offset,
2288 Double.doubleToRawLongBits(expected),
2289 Double.doubleToRawLongBits(x));
2290 return Double.longBitsToDouble(w);
2291 }
2292
2293 @ForceInline
2294 public final boolean weakCompareAndSetDoublePlain(Object o, long offset,
2295 double expected,
2296 double x) {
2297 return weakCompareAndSetLongPlain(o, offset,
2298 Double.doubleToRawLongBits(expected),
2299 Double.doubleToRawLongBits(x));
2300 }
2301
2302 @ForceInline
2303 public final boolean weakCompareAndSetDoubleAcquire(Object o, long offset,
2304 double expected,
2305 double x) {
2306 return weakCompareAndSetLongAcquire(o, offset,
2307 Double.doubleToRawLongBits(expected),
2308 Double.doubleToRawLongBits(x));
2309 }
2310
2311 @ForceInline
2312 public final boolean weakCompareAndSetDoubleRelease(Object o, long offset,
2313 double expected,
2314 double x) {
2315 return weakCompareAndSetLongRelease(o, offset,
2316 Double.doubleToRawLongBits(expected),
2317 Double.doubleToRawLongBits(x));
2318 }
2319
2320 @ForceInline
2321 public final boolean weakCompareAndSetDouble(Object o, long offset,
2322 double expected,
2323 double x) {
2324 return weakCompareAndSetLong(o, offset,
2325 Double.doubleToRawLongBits(expected),
2326 Double.doubleToRawLongBits(x));
2327 }
2328
2329 /**
2330 * Atomically updates Java variable to {@code x} if it is currently
2331 * holding {@code expected}.
2332 *
2333 * <p>This operation has memory semantics of a {@code volatile} read
2334 * and write. Corresponds to C11 atomic_compare_exchange_strong.
2335 *
2336 * @return {@code true} if successful
2337 */
2338 @IntrinsicCandidate
2339 public final native boolean compareAndSetLong(Object o, long offset,
2340 long expected,
2341 long x);
2342
2343 @IntrinsicCandidate
2344 public final native long compareAndExchangeLong(Object o, long offset,
2345 long expected,
2346 long x);
2347
2348 @IntrinsicCandidate
2349 public final long compareAndExchangeLongAcquire(Object o, long offset,
2350 long expected,
2351 long x) {
2352 return compareAndExchangeLong(o, offset, expected, x);
2353 }
2354
2355 @IntrinsicCandidate
2356 public final long compareAndExchangeLongRelease(Object o, long offset,
2357 long expected,
2358 long x) {
2359 return compareAndExchangeLong(o, offset, expected, x);
2360 }
2361
2362 @IntrinsicCandidate
2363 public final boolean weakCompareAndSetLongPlain(Object o, long offset,
2364 long expected,
2365 long x) {
2366 return compareAndSetLong(o, offset, expected, x);
2367 }
2368
2369 @IntrinsicCandidate
2370 public final boolean weakCompareAndSetLongAcquire(Object o, long offset,
2371 long expected,
2372 long x) {
2373 return compareAndSetLong(o, offset, expected, x);
2374 }
2375
2376 @IntrinsicCandidate
2377 public final boolean weakCompareAndSetLongRelease(Object o, long offset,
2378 long expected,
2379 long x) {
2380 return compareAndSetLong(o, offset, expected, x);
2381 }
2382
2383 @IntrinsicCandidate
2384 public final boolean weakCompareAndSetLong(Object o, long offset,
2385 long expected,
2386 long x) {
2387 return compareAndSetLong(o, offset, expected, x);
2388 }
2389
2390 /**
2391 * Fetches a reference value from a given Java variable, with volatile
2392 * load semantics. Otherwise identical to {@link #getReference(Object, long)}
2393 */
2394 @IntrinsicCandidate
2395 public native Object getReferenceVolatile(Object o, long offset);
2396
2397 /**
2398 * Global lock for atomic and volatile strength access to any value of
2399 * a value type. This is a temporary workaround until better localized
2400 * atomic access mechanisms are supported for value class and primitive class.
2401 */
2402 private static final Object valueLock = new Object();
2403
2404 public final <V> Object getValueVolatile(Object base, long offset, Class<?> valueType) {
2405 synchronized (valueLock) {
2406 return getValue(base, offset, valueType);
2407 }
2408 }
2409
2410 /**
2411 * Stores a reference value into a given Java variable, with
2412 * volatile store semantics. Otherwise identical to {@link #putReference(Object, long, Object)}
2413 */
2414 @IntrinsicCandidate
2415 public native void putReferenceVolatile(Object o, long offset, Object x);
2416
2417 public final <V> void putValueVolatile(Object o, long offset, Class<?> valueType, V x) {
2418 synchronized (valueLock) {
2419 putValue(o, offset, valueType, x);
2420 }
2421 }
2422
2423 /** Volatile version of {@link #getInt(Object, long)} */
2424 @IntrinsicCandidate
2425 public native int getIntVolatile(Object o, long offset);
2426
2427 /** Volatile version of {@link #putInt(Object, long, int)} */
2428 @IntrinsicCandidate
2429 public native void putIntVolatile(Object o, long offset, int x);
2430
2431 /** Volatile version of {@link #getBoolean(Object, long)} */
2432 @IntrinsicCandidate
2433 public native boolean getBooleanVolatile(Object o, long offset);
2434
2435 /** Volatile version of {@link #putBoolean(Object, long, boolean)} */
2436 @IntrinsicCandidate
2437 public native void putBooleanVolatile(Object o, long offset, boolean x);
2438
2439 /** Volatile version of {@link #getByte(Object, long)} */
2440 @IntrinsicCandidate
2441 public native byte getByteVolatile(Object o, long offset);
2442
2443 /** Volatile version of {@link #putByte(Object, long, byte)} */
2444 @IntrinsicCandidate
2445 public native void putByteVolatile(Object o, long offset, byte x);
2446
2447 /** Volatile version of {@link #getShort(Object, long)} */
2448 @IntrinsicCandidate
2449 public native short getShortVolatile(Object o, long offset);
2450
2451 /** Volatile version of {@link #putShort(Object, long, short)} */
2452 @IntrinsicCandidate
2453 public native void putShortVolatile(Object o, long offset, short x);
2454
2455 /** Volatile version of {@link #getChar(Object, long)} */
2456 @IntrinsicCandidate
2457 public native char getCharVolatile(Object o, long offset);
2458
2459 /** Volatile version of {@link #putChar(Object, long, char)} */
2460 @IntrinsicCandidate
2461 public native void putCharVolatile(Object o, long offset, char x);
2462
2463 /** Volatile version of {@link #getLong(Object, long)} */
2464 @IntrinsicCandidate
2465 public native long getLongVolatile(Object o, long offset);
2466
2467 /** Volatile version of {@link #putLong(Object, long, long)} */
2468 @IntrinsicCandidate
2469 public native void putLongVolatile(Object o, long offset, long x);
2470
2471 /** Volatile version of {@link #getFloat(Object, long)} */
2472 @IntrinsicCandidate
2473 public native float getFloatVolatile(Object o, long offset);
2474
2475 /** Volatile version of {@link #putFloat(Object, long, float)} */
2476 @IntrinsicCandidate
2477 public native void putFloatVolatile(Object o, long offset, float x);
2478
2479 /** Volatile version of {@link #getDouble(Object, long)} */
2480 @IntrinsicCandidate
2481 public native double getDoubleVolatile(Object o, long offset);
2482
2483 /** Volatile version of {@link #putDouble(Object, long, double)} */
2484 @IntrinsicCandidate
2485 public native void putDoubleVolatile(Object o, long offset, double x);
2486
2487
2488
2489 /** Acquire version of {@link #getReferenceVolatile(Object, long)} */
2490 @IntrinsicCandidate
2491 public final Object getReferenceAcquire(Object o, long offset) {
2492 return getReferenceVolatile(o, offset);
2493 }
2494
2495 public final <V> Object getValueAcquire(Object base, long offset, Class<?> valueType) {
2496 return getValueVolatile(base, offset, valueType);
2497 }
2498
2499 /** Acquire version of {@link #getBooleanVolatile(Object, long)} */
2500 @IntrinsicCandidate
2501 public final boolean getBooleanAcquire(Object o, long offset) {
2502 return getBooleanVolatile(o, offset);
2503 }
2504
2505 /** Acquire version of {@link #getByteVolatile(Object, long)} */
2506 @IntrinsicCandidate
2507 public final byte getByteAcquire(Object o, long offset) {
2508 return getByteVolatile(o, offset);
2509 }
2510
2511 /** Acquire version of {@link #getShortVolatile(Object, long)} */
2512 @IntrinsicCandidate
2513 public final short getShortAcquire(Object o, long offset) {
2514 return getShortVolatile(o, offset);
2515 }
2516
2517 /** Acquire version of {@link #getCharVolatile(Object, long)} */
2518 @IntrinsicCandidate
2519 public final char getCharAcquire(Object o, long offset) {
2520 return getCharVolatile(o, offset);
2521 }
2522
2523 /** Acquire version of {@link #getIntVolatile(Object, long)} */
2524 @IntrinsicCandidate
2525 public final int getIntAcquire(Object o, long offset) {
2526 return getIntVolatile(o, offset);
2527 }
2528
2529 /** Acquire version of {@link #getFloatVolatile(Object, long)} */
2530 @IntrinsicCandidate
2531 public final float getFloatAcquire(Object o, long offset) {
2532 return getFloatVolatile(o, offset);
2533 }
2534
2535 /** Acquire version of {@link #getLongVolatile(Object, long)} */
2536 @IntrinsicCandidate
2537 public final long getLongAcquire(Object o, long offset) {
2538 return getLongVolatile(o, offset);
2539 }
2540
2541 /** Acquire version of {@link #getDoubleVolatile(Object, long)} */
2542 @IntrinsicCandidate
2543 public final double getDoubleAcquire(Object o, long offset) {
2544 return getDoubleVolatile(o, offset);
2545 }
2546
2547 /*
2548 * Versions of {@link #putReferenceVolatile(Object, long, Object)}
2549 * that do not guarantee immediate visibility of the store to
2550 * other threads. This method is generally only useful if the
2551 * underlying field is a Java volatile (or if an array cell, one
2552 * that is otherwise only accessed using volatile accesses).
2553 *
2554 * Corresponds to C11 atomic_store_explicit(..., memory_order_release).
2555 */
2556
2557 /** Release version of {@link #putReferenceVolatile(Object, long, Object)} */
2558 @IntrinsicCandidate
2559 public final void putReferenceRelease(Object o, long offset, Object x) {
2560 putReferenceVolatile(o, offset, x);
2561 }
2562
2563 public final <V> void putValueRelease(Object o, long offset, Class<?> valueType, V x) {
2564 putValueVolatile(o, offset, valueType, x);
2565 }
2566
2567 /** Release version of {@link #putBooleanVolatile(Object, long, boolean)} */
2568 @IntrinsicCandidate
2569 public final void putBooleanRelease(Object o, long offset, boolean x) {
2570 putBooleanVolatile(o, offset, x);
2571 }
2572
2573 /** Release version of {@link #putByteVolatile(Object, long, byte)} */
2574 @IntrinsicCandidate
2575 public final void putByteRelease(Object o, long offset, byte x) {
2576 putByteVolatile(o, offset, x);
2577 }
2578
2579 /** Release version of {@link #putShortVolatile(Object, long, short)} */
2580 @IntrinsicCandidate
2581 public final void putShortRelease(Object o, long offset, short x) {
2582 putShortVolatile(o, offset, x);
2583 }
2584
2585 /** Release version of {@link #putCharVolatile(Object, long, char)} */
2586 @IntrinsicCandidate
2587 public final void putCharRelease(Object o, long offset, char x) {
2588 putCharVolatile(o, offset, x);
2589 }
2590
2591 /** Release version of {@link #putIntVolatile(Object, long, int)} */
2592 @IntrinsicCandidate
2593 public final void putIntRelease(Object o, long offset, int x) {
2594 putIntVolatile(o, offset, x);
2595 }
2596
2597 /** Release version of {@link #putFloatVolatile(Object, long, float)} */
2598 @IntrinsicCandidate
2599 public final void putFloatRelease(Object o, long offset, float x) {
2600 putFloatVolatile(o, offset, x);
2601 }
2602
2603 /** Release version of {@link #putLongVolatile(Object, long, long)} */
2604 @IntrinsicCandidate
2605 public final void putLongRelease(Object o, long offset, long x) {
2606 putLongVolatile(o, offset, x);
2607 }
2608
2609 /** Release version of {@link #putDoubleVolatile(Object, long, double)} */
2610 @IntrinsicCandidate
2611 public final void putDoubleRelease(Object o, long offset, double x) {
2612 putDoubleVolatile(o, offset, x);
2613 }
2614
2615 // ------------------------------ Opaque --------------------------------------
2616
2617 /** Opaque version of {@link #getReferenceVolatile(Object, long)} */
2618 @IntrinsicCandidate
2619 public final Object getReferenceOpaque(Object o, long offset) {
2620 return getReferenceVolatile(o, offset);
2621 }
2622
2623 public final <V> Object getValueOpaque(Object base, long offset, Class<?> valueType) {
2624 return getValueVolatile(base, offset, valueType);
2625 }
2626
2627 /** Opaque version of {@link #getBooleanVolatile(Object, long)} */
2628 @IntrinsicCandidate
2629 public final boolean getBooleanOpaque(Object o, long offset) {
2630 return getBooleanVolatile(o, offset);
2631 }
2632
2633 /** Opaque version of {@link #getByteVolatile(Object, long)} */
2634 @IntrinsicCandidate
2635 public final byte getByteOpaque(Object o, long offset) {
2636 return getByteVolatile(o, offset);
2637 }
2638
2639 /** Opaque version of {@link #getShortVolatile(Object, long)} */
2640 @IntrinsicCandidate
2641 public final short getShortOpaque(Object o, long offset) {
2642 return getShortVolatile(o, offset);
2643 }
2644
2645 /** Opaque version of {@link #getCharVolatile(Object, long)} */
2646 @IntrinsicCandidate
2647 public final char getCharOpaque(Object o, long offset) {
2648 return getCharVolatile(o, offset);
2649 }
2650
2651 /** Opaque version of {@link #getIntVolatile(Object, long)} */
2652 @IntrinsicCandidate
2653 public final int getIntOpaque(Object o, long offset) {
2654 return getIntVolatile(o, offset);
2655 }
2656
2657 /** Opaque version of {@link #getFloatVolatile(Object, long)} */
2658 @IntrinsicCandidate
2659 public final float getFloatOpaque(Object o, long offset) {
2660 return getFloatVolatile(o, offset);
2661 }
2662
2663 /** Opaque version of {@link #getLongVolatile(Object, long)} */
2664 @IntrinsicCandidate
2665 public final long getLongOpaque(Object o, long offset) {
2666 return getLongVolatile(o, offset);
2667 }
2668
2669 /** Opaque version of {@link #getDoubleVolatile(Object, long)} */
2670 @IntrinsicCandidate
2671 public final double getDoubleOpaque(Object o, long offset) {
2672 return getDoubleVolatile(o, offset);
2673 }
2674
2675 /** Opaque version of {@link #putReferenceVolatile(Object, long, Object)} */
2676 @IntrinsicCandidate
2677 public final void putReferenceOpaque(Object o, long offset, Object x) {
2678 putReferenceVolatile(o, offset, x);
2679 }
2680
2681 public final <V> void putValueOpaque(Object o, long offset, Class<?> valueType, V x) {
2682 putValueVolatile(o, offset, valueType, x);
2683 }
2684
2685 /** Opaque version of {@link #putBooleanVolatile(Object, long, boolean)} */
2686 @IntrinsicCandidate
2687 public final void putBooleanOpaque(Object o, long offset, boolean x) {
2688 putBooleanVolatile(o, offset, x);
2689 }
2690
2691 /** Opaque version of {@link #putByteVolatile(Object, long, byte)} */
2692 @IntrinsicCandidate
2693 public final void putByteOpaque(Object o, long offset, byte x) {
2694 putByteVolatile(o, offset, x);
2695 }
2696
2697 /** Opaque version of {@link #putShortVolatile(Object, long, short)} */
2698 @IntrinsicCandidate
2699 public final void putShortOpaque(Object o, long offset, short x) {
2700 putShortVolatile(o, offset, x);
2701 }
2702
2703 /** Opaque version of {@link #putCharVolatile(Object, long, char)} */
2704 @IntrinsicCandidate
2705 public final void putCharOpaque(Object o, long offset, char x) {
2706 putCharVolatile(o, offset, x);
2707 }
2708
2709 /** Opaque version of {@link #putIntVolatile(Object, long, int)} */
2710 @IntrinsicCandidate
2711 public final void putIntOpaque(Object o, long offset, int x) {
2712 putIntVolatile(o, offset, x);
2713 }
2714
2715 /** Opaque version of {@link #putFloatVolatile(Object, long, float)} */
2716 @IntrinsicCandidate
2717 public final void putFloatOpaque(Object o, long offset, float x) {
2718 putFloatVolatile(o, offset, x);
2719 }
2720
2721 /** Opaque version of {@link #putLongVolatile(Object, long, long)} */
2722 @IntrinsicCandidate
2723 public final void putLongOpaque(Object o, long offset, long x) {
2724 putLongVolatile(o, offset, x);
2725 }
2726
2727 /** Opaque version of {@link #putDoubleVolatile(Object, long, double)} */
2728 @IntrinsicCandidate
2729 public final void putDoubleOpaque(Object o, long offset, double x) {
2730 putDoubleVolatile(o, offset, x);
2731 }
2732
2733 /**
2734 * Unblocks the given thread blocked on {@code park}, or, if it is
2735 * not blocked, causes the subsequent call to {@code park} not to
2736 * block. Note: this operation is "unsafe" solely because the
2737 * caller must somehow ensure that the thread has not been
2738 * destroyed. Nothing special is usually required to ensure this
2739 * when called from Java (in which there will ordinarily be a live
2740 * reference to the thread) but this is not nearly-automatically
2741 * so when calling from native code.
2742 *
2743 * @param thread the thread to unpark.
2744 */
2745 @IntrinsicCandidate
2746 public native void unpark(Object thread);
2747
2748 /**
2749 * Blocks current thread, returning when a balancing
2750 * {@code unpark} occurs, or a balancing {@code unpark} has
2751 * already occurred, or the thread is interrupted, or, if not
2752 * absolute and time is not zero, the given time nanoseconds have
2753 * elapsed, or if absolute, the given deadline in milliseconds
2754 * since Epoch has passed, or spuriously (i.e., returning for no
2755 * "reason"). Note: This operation is in the Unsafe class only
2756 * because {@code unpark} is, so it would be strange to place it
2757 * elsewhere.
2758 */
2759 @IntrinsicCandidate
2760 public native void park(boolean isAbsolute, long time);
2761
2762 /**
2763 * Gets the load average in the system run queue assigned
2764 * to the available processors averaged over various periods of time.
2765 * This method retrieves the given {@code nelem} samples and
2766 * assigns to the elements of the given {@code loadavg} array.
2767 * The system imposes a maximum of 3 samples, representing
2768 * averages over the last 1, 5, and 15 minutes, respectively.
2769 *
2770 * @param loadavg an array of double of size nelems
2771 * @param nelems the number of samples to be retrieved and
2772 * must be 1 to 3.
2773 *
2774 * @return the number of samples actually retrieved; or -1
2775 * if the load average is unobtainable.
2776 */
2777 public int getLoadAverage(double[] loadavg, int nelems) {
2778 if (nelems < 0 || nelems > 3 || nelems > loadavg.length) {
2779 throw new ArrayIndexOutOfBoundsException();
2780 }
2781
2782 return getLoadAverage0(loadavg, nelems);
2783 }
2784
2785 // The following contain CAS-based Java implementations used on
2786 // platforms not supporting native instructions
2787
2788 /**
2789 * Atomically adds the given value to the current value of a field
2790 * or array element within the given object {@code o}
2791 * at the given {@code offset}.
2792 *
2793 * @param o object/array to update the field/element in
2794 * @param offset field/element offset
2795 * @param delta the value to add
2796 * @return the previous value
2797 * @since 1.8
2798 */
2799 @IntrinsicCandidate
2800 public final int getAndAddInt(Object o, long offset, int delta) {
2801 int v;
2802 do {
2803 v = getIntVolatile(o, offset);
2804 } while (!weakCompareAndSetInt(o, offset, v, v + delta));
2805 return v;
2806 }
2807
2808 @ForceInline
2809 public final int getAndAddIntRelease(Object o, long offset, int delta) {
2810 int v;
2811 do {
2812 v = getInt(o, offset);
2813 } while (!weakCompareAndSetIntRelease(o, offset, v, v + delta));
2814 return v;
2815 }
2816
2817 @ForceInline
2818 public final int getAndAddIntAcquire(Object o, long offset, int delta) {
2819 int v;
2820 do {
2821 v = getIntAcquire(o, offset);
2822 } while (!weakCompareAndSetIntAcquire(o, offset, v, v + delta));
2823 return v;
2824 }
2825
2826 /**
2827 * Atomically adds the given value to the current value of a field
2828 * or array element within the given object {@code o}
2829 * at the given {@code offset}.
2830 *
2831 * @param o object/array to update the field/element in
2832 * @param offset field/element offset
2833 * @param delta the value to add
2834 * @return the previous value
2835 * @since 1.8
2836 */
2837 @IntrinsicCandidate
2838 public final long getAndAddLong(Object o, long offset, long delta) {
2839 long v;
2840 do {
2841 v = getLongVolatile(o, offset);
2842 } while (!weakCompareAndSetLong(o, offset, v, v + delta));
2843 return v;
2844 }
2845
2846 @ForceInline
2847 public final long getAndAddLongRelease(Object o, long offset, long delta) {
2848 long v;
2849 do {
2850 v = getLong(o, offset);
2851 } while (!weakCompareAndSetLongRelease(o, offset, v, v + delta));
2852 return v;
2853 }
2854
2855 @ForceInline
2856 public final long getAndAddLongAcquire(Object o, long offset, long delta) {
2857 long v;
2858 do {
2859 v = getLongAcquire(o, offset);
2860 } while (!weakCompareAndSetLongAcquire(o, offset, v, v + delta));
2861 return v;
2862 }
2863
2864 @IntrinsicCandidate
2865 public final byte getAndAddByte(Object o, long offset, byte delta) {
2866 byte v;
2867 do {
2868 v = getByteVolatile(o, offset);
2869 } while (!weakCompareAndSetByte(o, offset, v, (byte) (v + delta)));
2870 return v;
2871 }
2872
2873 @ForceInline
2874 public final byte getAndAddByteRelease(Object o, long offset, byte delta) {
2875 byte v;
2876 do {
2877 v = getByte(o, offset);
2878 } while (!weakCompareAndSetByteRelease(o, offset, v, (byte) (v + delta)));
2879 return v;
2880 }
2881
2882 @ForceInline
2883 public final byte getAndAddByteAcquire(Object o, long offset, byte delta) {
2884 byte v;
2885 do {
2886 v = getByteAcquire(o, offset);
2887 } while (!weakCompareAndSetByteAcquire(o, offset, v, (byte) (v + delta)));
2888 return v;
2889 }
2890
2891 @IntrinsicCandidate
2892 public final short getAndAddShort(Object o, long offset, short delta) {
2893 short v;
2894 do {
2895 v = getShortVolatile(o, offset);
2896 } while (!weakCompareAndSetShort(o, offset, v, (short) (v + delta)));
2897 return v;
2898 }
2899
2900 @ForceInline
2901 public final short getAndAddShortRelease(Object o, long offset, short delta) {
2902 short v;
2903 do {
2904 v = getShort(o, offset);
2905 } while (!weakCompareAndSetShortRelease(o, offset, v, (short) (v + delta)));
2906 return v;
2907 }
2908
2909 @ForceInline
2910 public final short getAndAddShortAcquire(Object o, long offset, short delta) {
2911 short v;
2912 do {
2913 v = getShortAcquire(o, offset);
2914 } while (!weakCompareAndSetShortAcquire(o, offset, v, (short) (v + delta)));
2915 return v;
2916 }
2917
2918 @ForceInline
2919 public final char getAndAddChar(Object o, long offset, char delta) {
2920 return (char) getAndAddShort(o, offset, (short) delta);
2921 }
2922
2923 @ForceInline
2924 public final char getAndAddCharRelease(Object o, long offset, char delta) {
2925 return (char) getAndAddShortRelease(o, offset, (short) delta);
2926 }
2927
2928 @ForceInline
2929 public final char getAndAddCharAcquire(Object o, long offset, char delta) {
2930 return (char) getAndAddShortAcquire(o, offset, (short) delta);
2931 }
2932
2933 @ForceInline
2934 public final float getAndAddFloat(Object o, long offset, float delta) {
2935 int expectedBits;
2936 float v;
2937 do {
2938 // Load and CAS with the raw bits to avoid issues with NaNs and
2939 // possible bit conversion from signaling NaNs to quiet NaNs that
2940 // may result in the loop not terminating.
2941 expectedBits = getIntVolatile(o, offset);
2942 v = Float.intBitsToFloat(expectedBits);
2943 } while (!weakCompareAndSetInt(o, offset,
2944 expectedBits, Float.floatToRawIntBits(v + delta)));
2945 return v;
2946 }
2947
2948 @ForceInline
2949 public final float getAndAddFloatRelease(Object o, long offset, float delta) {
2950 int expectedBits;
2951 float v;
2952 do {
2953 // Load and CAS with the raw bits to avoid issues with NaNs and
2954 // possible bit conversion from signaling NaNs to quiet NaNs that
2955 // may result in the loop not terminating.
2956 expectedBits = getInt(o, offset);
2957 v = Float.intBitsToFloat(expectedBits);
2958 } while (!weakCompareAndSetIntRelease(o, offset,
2959 expectedBits, Float.floatToRawIntBits(v + delta)));
2960 return v;
2961 }
2962
2963 @ForceInline
2964 public final float getAndAddFloatAcquire(Object o, long offset, float delta) {
2965 int expectedBits;
2966 float v;
2967 do {
2968 // Load and CAS with the raw bits to avoid issues with NaNs and
2969 // possible bit conversion from signaling NaNs to quiet NaNs that
2970 // may result in the loop not terminating.
2971 expectedBits = getIntAcquire(o, offset);
2972 v = Float.intBitsToFloat(expectedBits);
2973 } while (!weakCompareAndSetIntAcquire(o, offset,
2974 expectedBits, Float.floatToRawIntBits(v + delta)));
2975 return v;
2976 }
2977
2978 @ForceInline
2979 public final double getAndAddDouble(Object o, long offset, double delta) {
2980 long expectedBits;
2981 double v;
2982 do {
2983 // Load and CAS with the raw bits to avoid issues with NaNs and
2984 // possible bit conversion from signaling NaNs to quiet NaNs that
2985 // may result in the loop not terminating.
2986 expectedBits = getLongVolatile(o, offset);
2987 v = Double.longBitsToDouble(expectedBits);
2988 } while (!weakCompareAndSetLong(o, offset,
2989 expectedBits, Double.doubleToRawLongBits(v + delta)));
2990 return v;
2991 }
2992
2993 @ForceInline
2994 public final double getAndAddDoubleRelease(Object o, long offset, double delta) {
2995 long expectedBits;
2996 double v;
2997 do {
2998 // Load and CAS with the raw bits to avoid issues with NaNs and
2999 // possible bit conversion from signaling NaNs to quiet NaNs that
3000 // may result in the loop not terminating.
3001 expectedBits = getLong(o, offset);
3002 v = Double.longBitsToDouble(expectedBits);
3003 } while (!weakCompareAndSetLongRelease(o, offset,
3004 expectedBits, Double.doubleToRawLongBits(v + delta)));
3005 return v;
3006 }
3007
3008 @ForceInline
3009 public final double getAndAddDoubleAcquire(Object o, long offset, double delta) {
3010 long expectedBits;
3011 double v;
3012 do {
3013 // Load and CAS with the raw bits to avoid issues with NaNs and
3014 // possible bit conversion from signaling NaNs to quiet NaNs that
3015 // may result in the loop not terminating.
3016 expectedBits = getLongAcquire(o, offset);
3017 v = Double.longBitsToDouble(expectedBits);
3018 } while (!weakCompareAndSetLongAcquire(o, offset,
3019 expectedBits, Double.doubleToRawLongBits(v + delta)));
3020 return v;
3021 }
3022
3023 /**
3024 * Atomically exchanges the given value with the current value of
3025 * a field or array element within the given object {@code o}
3026 * at the given {@code offset}.
3027 *
3028 * @param o object/array to update the field/element in
3029 * @param offset field/element offset
3030 * @param newValue new value
3031 * @return the previous value
3032 * @since 1.8
3033 */
3034 @IntrinsicCandidate
3035 public final int getAndSetInt(Object o, long offset, int newValue) {
3036 int v;
3037 do {
3038 v = getIntVolatile(o, offset);
3039 } while (!weakCompareAndSetInt(o, offset, v, newValue));
3040 return v;
3041 }
3042
3043 @ForceInline
3044 public final int getAndSetIntRelease(Object o, long offset, int newValue) {
3045 int v;
3046 do {
3047 v = getInt(o, offset);
3048 } while (!weakCompareAndSetIntRelease(o, offset, v, newValue));
3049 return v;
3050 }
3051
3052 @ForceInline
3053 public final int getAndSetIntAcquire(Object o, long offset, int newValue) {
3054 int v;
3055 do {
3056 v = getIntAcquire(o, offset);
3057 } while (!weakCompareAndSetIntAcquire(o, offset, v, newValue));
3058 return v;
3059 }
3060
3061 /**
3062 * Atomically exchanges the given value with the current value of
3063 * a field or array element within the given object {@code o}
3064 * at the given {@code offset}.
3065 *
3066 * @param o object/array to update the field/element in
3067 * @param offset field/element offset
3068 * @param newValue new value
3069 * @return the previous value
3070 * @since 1.8
3071 */
3072 @IntrinsicCandidate
3073 public final long getAndSetLong(Object o, long offset, long newValue) {
3074 long v;
3075 do {
3076 v = getLongVolatile(o, offset);
3077 } while (!weakCompareAndSetLong(o, offset, v, newValue));
3078 return v;
3079 }
3080
3081 @ForceInline
3082 public final long getAndSetLongRelease(Object o, long offset, long newValue) {
3083 long v;
3084 do {
3085 v = getLong(o, offset);
3086 } while (!weakCompareAndSetLongRelease(o, offset, v, newValue));
3087 return v;
3088 }
3089
3090 @ForceInline
3091 public final long getAndSetLongAcquire(Object o, long offset, long newValue) {
3092 long v;
3093 do {
3094 v = getLongAcquire(o, offset);
3095 } while (!weakCompareAndSetLongAcquire(o, offset, v, newValue));
3096 return v;
3097 }
3098
3099 /**
3100 * Atomically exchanges the given reference value with the current
3101 * reference value of a field or array element within the given
3102 * object {@code o} at the given {@code offset}.
3103 *
3104 * @param o object/array to update the field/element in
3105 * @param offset field/element offset
3106 * @param newValue new value
3107 * @return the previous value
3108 * @since 1.8
3109 */
3110 @IntrinsicCandidate
3111 public final Object getAndSetReference(Object o, long offset, Object newValue) {
3112 Object v;
3113 do {
3114 v = getReferenceVolatile(o, offset);
3115 } while (!weakCompareAndSetReference(o, offset, v, newValue));
3116 return v;
3117 }
3118
3119 @SuppressWarnings("unchecked")
3120 public final <V> Object getAndSetValue(Object o, long offset, Class<?> valueType, V newValue) {
3121 synchronized (valueLock) {
3122 Object oldValue = getValue(o, offset, valueType);
3123 putValue(o, offset, valueType, newValue);
3124 return oldValue;
3125 }
3126 }
3127
3128 @ForceInline
3129 public final Object getAndSetReferenceRelease(Object o, long offset, Object newValue) {
3130 Object v;
3131 do {
3132 v = getReference(o, offset);
3133 } while (!weakCompareAndSetReferenceRelease(o, offset, v, newValue));
3134 return v;
3135 }
3136
3137 @ForceInline
3138 public final <V> Object getAndSetValueRelease(Object o, long offset, Class<?> valueType, V newValue) {
3139 return getAndSetValue(o, offset, valueType, newValue);
3140 }
3141
3142 @ForceInline
3143 public final Object getAndSetReferenceAcquire(Object o, long offset, Object newValue) {
3144 Object v;
3145 do {
3146 v = getReferenceAcquire(o, offset);
3147 } while (!weakCompareAndSetReferenceAcquire(o, offset, v, newValue));
3148 return v;
3149 }
3150
3151 @ForceInline
3152 public final <V> Object getAndSetValueAcquire(Object o, long offset, Class<?> valueType, V newValue) {
3153 return getAndSetValue(o, offset, valueType, newValue);
3154 }
3155
3156 @IntrinsicCandidate
3157 public final byte getAndSetByte(Object o, long offset, byte newValue) {
3158 byte v;
3159 do {
3160 v = getByteVolatile(o, offset);
3161 } while (!weakCompareAndSetByte(o, offset, v, newValue));
3162 return v;
3163 }
3164
3165 @ForceInline
3166 public final byte getAndSetByteRelease(Object o, long offset, byte newValue) {
3167 byte v;
3168 do {
3169 v = getByte(o, offset);
3170 } while (!weakCompareAndSetByteRelease(o, offset, v, newValue));
3171 return v;
3172 }
3173
3174 @ForceInline
3175 public final byte getAndSetByteAcquire(Object o, long offset, byte newValue) {
3176 byte v;
3177 do {
3178 v = getByteAcquire(o, offset);
3179 } while (!weakCompareAndSetByteAcquire(o, offset, v, newValue));
3180 return v;
3181 }
3182
3183 @ForceInline
3184 public final boolean getAndSetBoolean(Object o, long offset, boolean newValue) {
3185 return byte2bool(getAndSetByte(o, offset, bool2byte(newValue)));
3186 }
3187
3188 @ForceInline
3189 public final boolean getAndSetBooleanRelease(Object o, long offset, boolean newValue) {
3190 return byte2bool(getAndSetByteRelease(o, offset, bool2byte(newValue)));
3191 }
3192
3193 @ForceInline
3194 public final boolean getAndSetBooleanAcquire(Object o, long offset, boolean newValue) {
3195 return byte2bool(getAndSetByteAcquire(o, offset, bool2byte(newValue)));
3196 }
3197
3198 @IntrinsicCandidate
3199 public final short getAndSetShort(Object o, long offset, short newValue) {
3200 short v;
3201 do {
3202 v = getShortVolatile(o, offset);
3203 } while (!weakCompareAndSetShort(o, offset, v, newValue));
3204 return v;
3205 }
3206
3207 @ForceInline
3208 public final short getAndSetShortRelease(Object o, long offset, short newValue) {
3209 short v;
3210 do {
3211 v = getShort(o, offset);
3212 } while (!weakCompareAndSetShortRelease(o, offset, v, newValue));
3213 return v;
3214 }
3215
3216 @ForceInline
3217 public final short getAndSetShortAcquire(Object o, long offset, short newValue) {
3218 short v;
3219 do {
3220 v = getShortAcquire(o, offset);
3221 } while (!weakCompareAndSetShortAcquire(o, offset, v, newValue));
3222 return v;
3223 }
3224
3225 @ForceInline
3226 public final char getAndSetChar(Object o, long offset, char newValue) {
3227 return s2c(getAndSetShort(o, offset, c2s(newValue)));
3228 }
3229
3230 @ForceInline
3231 public final char getAndSetCharRelease(Object o, long offset, char newValue) {
3232 return s2c(getAndSetShortRelease(o, offset, c2s(newValue)));
3233 }
3234
3235 @ForceInline
3236 public final char getAndSetCharAcquire(Object o, long offset, char newValue) {
3237 return s2c(getAndSetShortAcquire(o, offset, c2s(newValue)));
3238 }
3239
3240 @ForceInline
3241 public final float getAndSetFloat(Object o, long offset, float newValue) {
3242 int v = getAndSetInt(o, offset, Float.floatToRawIntBits(newValue));
3243 return Float.intBitsToFloat(v);
3244 }
3245
3246 @ForceInline
3247 public final float getAndSetFloatRelease(Object o, long offset, float newValue) {
3248 int v = getAndSetIntRelease(o, offset, Float.floatToRawIntBits(newValue));
3249 return Float.intBitsToFloat(v);
3250 }
3251
3252 @ForceInline
3253 public final float getAndSetFloatAcquire(Object o, long offset, float newValue) {
3254 int v = getAndSetIntAcquire(o, offset, Float.floatToRawIntBits(newValue));
3255 return Float.intBitsToFloat(v);
3256 }
3257
3258 @ForceInline
3259 public final double getAndSetDouble(Object o, long offset, double newValue) {
3260 long v = getAndSetLong(o, offset, Double.doubleToRawLongBits(newValue));
3261 return Double.longBitsToDouble(v);
3262 }
3263
3264 @ForceInline
3265 public final double getAndSetDoubleRelease(Object o, long offset, double newValue) {
3266 long v = getAndSetLongRelease(o, offset, Double.doubleToRawLongBits(newValue));
3267 return Double.longBitsToDouble(v);
3268 }
3269
3270 @ForceInline
3271 public final double getAndSetDoubleAcquire(Object o, long offset, double newValue) {
3272 long v = getAndSetLongAcquire(o, offset, Double.doubleToRawLongBits(newValue));
3273 return Double.longBitsToDouble(v);
3274 }
3275
3276
3277 // The following contain CAS-based Java implementations used on
3278 // platforms not supporting native instructions
3279
3280 @ForceInline
3281 public final boolean getAndBitwiseOrBoolean(Object o, long offset, boolean mask) {
3282 return byte2bool(getAndBitwiseOrByte(o, offset, bool2byte(mask)));
3283 }
3284
3285 @ForceInline
3286 public final boolean getAndBitwiseOrBooleanRelease(Object o, long offset, boolean mask) {
3287 return byte2bool(getAndBitwiseOrByteRelease(o, offset, bool2byte(mask)));
3288 }
3289
3290 @ForceInline
3291 public final boolean getAndBitwiseOrBooleanAcquire(Object o, long offset, boolean mask) {
3292 return byte2bool(getAndBitwiseOrByteAcquire(o, offset, bool2byte(mask)));
3293 }
3294
3295 @ForceInline
3296 public final boolean getAndBitwiseAndBoolean(Object o, long offset, boolean mask) {
3297 return byte2bool(getAndBitwiseAndByte(o, offset, bool2byte(mask)));
3298 }
3299
3300 @ForceInline
3301 public final boolean getAndBitwiseAndBooleanRelease(Object o, long offset, boolean mask) {
3302 return byte2bool(getAndBitwiseAndByteRelease(o, offset, bool2byte(mask)));
3303 }
3304
3305 @ForceInline
3306 public final boolean getAndBitwiseAndBooleanAcquire(Object o, long offset, boolean mask) {
3307 return byte2bool(getAndBitwiseAndByteAcquire(o, offset, bool2byte(mask)));
3308 }
3309
3310 @ForceInline
3311 public final boolean getAndBitwiseXorBoolean(Object o, long offset, boolean mask) {
3312 return byte2bool(getAndBitwiseXorByte(o, offset, bool2byte(mask)));
3313 }
3314
3315 @ForceInline
3316 public final boolean getAndBitwiseXorBooleanRelease(Object o, long offset, boolean mask) {
3317 return byte2bool(getAndBitwiseXorByteRelease(o, offset, bool2byte(mask)));
3318 }
3319
3320 @ForceInline
3321 public final boolean getAndBitwiseXorBooleanAcquire(Object o, long offset, boolean mask) {
3322 return byte2bool(getAndBitwiseXorByteAcquire(o, offset, bool2byte(mask)));
3323 }
3324
3325
3326 @ForceInline
3327 public final byte getAndBitwiseOrByte(Object o, long offset, byte mask) {
3328 byte current;
3329 do {
3330 current = getByteVolatile(o, offset);
3331 } while (!weakCompareAndSetByte(o, offset,
3332 current, (byte) (current | mask)));
3333 return current;
3334 }
3335
3336 @ForceInline
3337 public final byte getAndBitwiseOrByteRelease(Object o, long offset, byte mask) {
3338 byte current;
3339 do {
3340 current = getByte(o, offset);
3341 } while (!weakCompareAndSetByteRelease(o, offset,
3342 current, (byte) (current | mask)));
3343 return current;
3344 }
3345
3346 @ForceInline
3347 public final byte getAndBitwiseOrByteAcquire(Object o, long offset, byte mask) {
3348 byte current;
3349 do {
3350 // Plain read, the value is a hint, the acquire CAS does the work
3351 current = getByte(o, offset);
3352 } while (!weakCompareAndSetByteAcquire(o, offset,
3353 current, (byte) (current | mask)));
3354 return current;
3355 }
3356
3357 @ForceInline
3358 public final byte getAndBitwiseAndByte(Object o, long offset, byte mask) {
3359 byte current;
3360 do {
3361 current = getByteVolatile(o, offset);
3362 } while (!weakCompareAndSetByte(o, offset,
3363 current, (byte) (current & mask)));
3364 return current;
3365 }
3366
3367 @ForceInline
3368 public final byte getAndBitwiseAndByteRelease(Object o, long offset, byte mask) {
3369 byte current;
3370 do {
3371 current = getByte(o, offset);
3372 } while (!weakCompareAndSetByteRelease(o, offset,
3373 current, (byte) (current & mask)));
3374 return current;
3375 }
3376
3377 @ForceInline
3378 public final byte getAndBitwiseAndByteAcquire(Object o, long offset, byte mask) {
3379 byte current;
3380 do {
3381 // Plain read, the value is a hint, the acquire CAS does the work
3382 current = getByte(o, offset);
3383 } while (!weakCompareAndSetByteAcquire(o, offset,
3384 current, (byte) (current & mask)));
3385 return current;
3386 }
3387
3388 @ForceInline
3389 public final byte getAndBitwiseXorByte(Object o, long offset, byte mask) {
3390 byte current;
3391 do {
3392 current = getByteVolatile(o, offset);
3393 } while (!weakCompareAndSetByte(o, offset,
3394 current, (byte) (current ^ mask)));
3395 return current;
3396 }
3397
3398 @ForceInline
3399 public final byte getAndBitwiseXorByteRelease(Object o, long offset, byte mask) {
3400 byte current;
3401 do {
3402 current = getByte(o, offset);
3403 } while (!weakCompareAndSetByteRelease(o, offset,
3404 current, (byte) (current ^ mask)));
3405 return current;
3406 }
3407
3408 @ForceInline
3409 public final byte getAndBitwiseXorByteAcquire(Object o, long offset, byte mask) {
3410 byte current;
3411 do {
3412 // Plain read, the value is a hint, the acquire CAS does the work
3413 current = getByte(o, offset);
3414 } while (!weakCompareAndSetByteAcquire(o, offset,
3415 current, (byte) (current ^ mask)));
3416 return current;
3417 }
3418
3419
3420 @ForceInline
3421 public final char getAndBitwiseOrChar(Object o, long offset, char mask) {
3422 return s2c(getAndBitwiseOrShort(o, offset, c2s(mask)));
3423 }
3424
3425 @ForceInline
3426 public final char getAndBitwiseOrCharRelease(Object o, long offset, char mask) {
3427 return s2c(getAndBitwiseOrShortRelease(o, offset, c2s(mask)));
3428 }
3429
3430 @ForceInline
3431 public final char getAndBitwiseOrCharAcquire(Object o, long offset, char mask) {
3432 return s2c(getAndBitwiseOrShortAcquire(o, offset, c2s(mask)));
3433 }
3434
3435 @ForceInline
3436 public final char getAndBitwiseAndChar(Object o, long offset, char mask) {
3437 return s2c(getAndBitwiseAndShort(o, offset, c2s(mask)));
3438 }
3439
3440 @ForceInline
3441 public final char getAndBitwiseAndCharRelease(Object o, long offset, char mask) {
3442 return s2c(getAndBitwiseAndShortRelease(o, offset, c2s(mask)));
3443 }
3444
3445 @ForceInline
3446 public final char getAndBitwiseAndCharAcquire(Object o, long offset, char mask) {
3447 return s2c(getAndBitwiseAndShortAcquire(o, offset, c2s(mask)));
3448 }
3449
3450 @ForceInline
3451 public final char getAndBitwiseXorChar(Object o, long offset, char mask) {
3452 return s2c(getAndBitwiseXorShort(o, offset, c2s(mask)));
3453 }
3454
3455 @ForceInline
3456 public final char getAndBitwiseXorCharRelease(Object o, long offset, char mask) {
3457 return s2c(getAndBitwiseXorShortRelease(o, offset, c2s(mask)));
3458 }
3459
3460 @ForceInline
3461 public final char getAndBitwiseXorCharAcquire(Object o, long offset, char mask) {
3462 return s2c(getAndBitwiseXorShortAcquire(o, offset, c2s(mask)));
3463 }
3464
3465
3466 @ForceInline
3467 public final short getAndBitwiseOrShort(Object o, long offset, short mask) {
3468 short current;
3469 do {
3470 current = getShortVolatile(o, offset);
3471 } while (!weakCompareAndSetShort(o, offset,
3472 current, (short) (current | mask)));
3473 return current;
3474 }
3475
3476 @ForceInline
3477 public final short getAndBitwiseOrShortRelease(Object o, long offset, short mask) {
3478 short current;
3479 do {
3480 current = getShort(o, offset);
3481 } while (!weakCompareAndSetShortRelease(o, offset,
3482 current, (short) (current | mask)));
3483 return current;
3484 }
3485
3486 @ForceInline
3487 public final short getAndBitwiseOrShortAcquire(Object o, long offset, short mask) {
3488 short current;
3489 do {
3490 // Plain read, the value is a hint, the acquire CAS does the work
3491 current = getShort(o, offset);
3492 } while (!weakCompareAndSetShortAcquire(o, offset,
3493 current, (short) (current | mask)));
3494 return current;
3495 }
3496
3497 @ForceInline
3498 public final short getAndBitwiseAndShort(Object o, long offset, short mask) {
3499 short current;
3500 do {
3501 current = getShortVolatile(o, offset);
3502 } while (!weakCompareAndSetShort(o, offset,
3503 current, (short) (current & mask)));
3504 return current;
3505 }
3506
3507 @ForceInline
3508 public final short getAndBitwiseAndShortRelease(Object o, long offset, short mask) {
3509 short current;
3510 do {
3511 current = getShort(o, offset);
3512 } while (!weakCompareAndSetShortRelease(o, offset,
3513 current, (short) (current & mask)));
3514 return current;
3515 }
3516
3517 @ForceInline
3518 public final short getAndBitwiseAndShortAcquire(Object o, long offset, short mask) {
3519 short current;
3520 do {
3521 // Plain read, the value is a hint, the acquire CAS does the work
3522 current = getShort(o, offset);
3523 } while (!weakCompareAndSetShortAcquire(o, offset,
3524 current, (short) (current & mask)));
3525 return current;
3526 }
3527
3528 @ForceInline
3529 public final short getAndBitwiseXorShort(Object o, long offset, short mask) {
3530 short current;
3531 do {
3532 current = getShortVolatile(o, offset);
3533 } while (!weakCompareAndSetShort(o, offset,
3534 current, (short) (current ^ mask)));
3535 return current;
3536 }
3537
3538 @ForceInline
3539 public final short getAndBitwiseXorShortRelease(Object o, long offset, short mask) {
3540 short current;
3541 do {
3542 current = getShort(o, offset);
3543 } while (!weakCompareAndSetShortRelease(o, offset,
3544 current, (short) (current ^ mask)));
3545 return current;
3546 }
3547
3548 @ForceInline
3549 public final short getAndBitwiseXorShortAcquire(Object o, long offset, short mask) {
3550 short current;
3551 do {
3552 // Plain read, the value is a hint, the acquire CAS does the work
3553 current = getShort(o, offset);
3554 } while (!weakCompareAndSetShortAcquire(o, offset,
3555 current, (short) (current ^ mask)));
3556 return current;
3557 }
3558
3559
3560 @ForceInline
3561 public final int getAndBitwiseOrInt(Object o, long offset, int mask) {
3562 int current;
3563 do {
3564 current = getIntVolatile(o, offset);
3565 } while (!weakCompareAndSetInt(o, offset,
3566 current, current | mask));
3567 return current;
3568 }
3569
3570 @ForceInline
3571 public final int getAndBitwiseOrIntRelease(Object o, long offset, int mask) {
3572 int current;
3573 do {
3574 current = getInt(o, offset);
3575 } while (!weakCompareAndSetIntRelease(o, offset,
3576 current, current | mask));
3577 return current;
3578 }
3579
3580 @ForceInline
3581 public final int getAndBitwiseOrIntAcquire(Object o, long offset, int mask) {
3582 int current;
3583 do {
3584 // Plain read, the value is a hint, the acquire CAS does the work
3585 current = getInt(o, offset);
3586 } while (!weakCompareAndSetIntAcquire(o, offset,
3587 current, current | mask));
3588 return current;
3589 }
3590
3591 /**
3592 * Atomically replaces the current value of a field or array element within
3593 * the given object with the result of bitwise AND between the current value
3594 * and mask.
3595 *
3596 * @param o object/array to update the field/element in
3597 * @param offset field/element offset
3598 * @param mask the mask value
3599 * @return the previous value
3600 * @since 9
3601 */
3602 @ForceInline
3603 public final int getAndBitwiseAndInt(Object o, long offset, int mask) {
3604 int current;
3605 do {
3606 current = getIntVolatile(o, offset);
3607 } while (!weakCompareAndSetInt(o, offset,
3608 current, current & mask));
3609 return current;
3610 }
3611
3612 @ForceInline
3613 public final int getAndBitwiseAndIntRelease(Object o, long offset, int mask) {
3614 int current;
3615 do {
3616 current = getInt(o, offset);
3617 } while (!weakCompareAndSetIntRelease(o, offset,
3618 current, current & mask));
3619 return current;
3620 }
3621
3622 @ForceInline
3623 public final int getAndBitwiseAndIntAcquire(Object o, long offset, int mask) {
3624 int current;
3625 do {
3626 // Plain read, the value is a hint, the acquire CAS does the work
3627 current = getInt(o, offset);
3628 } while (!weakCompareAndSetIntAcquire(o, offset,
3629 current, current & mask));
3630 return current;
3631 }
3632
3633 @ForceInline
3634 public final int getAndBitwiseXorInt(Object o, long offset, int mask) {
3635 int current;
3636 do {
3637 current = getIntVolatile(o, offset);
3638 } while (!weakCompareAndSetInt(o, offset,
3639 current, current ^ mask));
3640 return current;
3641 }
3642
3643 @ForceInline
3644 public final int getAndBitwiseXorIntRelease(Object o, long offset, int mask) {
3645 int current;
3646 do {
3647 current = getInt(o, offset);
3648 } while (!weakCompareAndSetIntRelease(o, offset,
3649 current, current ^ mask));
3650 return current;
3651 }
3652
3653 @ForceInline
3654 public final int getAndBitwiseXorIntAcquire(Object o, long offset, int mask) {
3655 int current;
3656 do {
3657 // Plain read, the value is a hint, the acquire CAS does the work
3658 current = getInt(o, offset);
3659 } while (!weakCompareAndSetIntAcquire(o, offset,
3660 current, current ^ mask));
3661 return current;
3662 }
3663
3664
3665 @ForceInline
3666 public final long getAndBitwiseOrLong(Object o, long offset, long mask) {
3667 long current;
3668 do {
3669 current = getLongVolatile(o, offset);
3670 } while (!weakCompareAndSetLong(o, offset,
3671 current, current | mask));
3672 return current;
3673 }
3674
3675 @ForceInline
3676 public final long getAndBitwiseOrLongRelease(Object o, long offset, long mask) {
3677 long current;
3678 do {
3679 current = getLong(o, offset);
3680 } while (!weakCompareAndSetLongRelease(o, offset,
3681 current, current | mask));
3682 return current;
3683 }
3684
3685 @ForceInline
3686 public final long getAndBitwiseOrLongAcquire(Object o, long offset, long mask) {
3687 long current;
3688 do {
3689 // Plain read, the value is a hint, the acquire CAS does the work
3690 current = getLong(o, offset);
3691 } while (!weakCompareAndSetLongAcquire(o, offset,
3692 current, current | mask));
3693 return current;
3694 }
3695
3696 @ForceInline
3697 public final long getAndBitwiseAndLong(Object o, long offset, long mask) {
3698 long current;
3699 do {
3700 current = getLongVolatile(o, offset);
3701 } while (!weakCompareAndSetLong(o, offset,
3702 current, current & mask));
3703 return current;
3704 }
3705
3706 @ForceInline
3707 public final long getAndBitwiseAndLongRelease(Object o, long offset, long mask) {
3708 long current;
3709 do {
3710 current = getLong(o, offset);
3711 } while (!weakCompareAndSetLongRelease(o, offset,
3712 current, current & mask));
3713 return current;
3714 }
3715
3716 @ForceInline
3717 public final long getAndBitwiseAndLongAcquire(Object o, long offset, long mask) {
3718 long current;
3719 do {
3720 // Plain read, the value is a hint, the acquire CAS does the work
3721 current = getLong(o, offset);
3722 } while (!weakCompareAndSetLongAcquire(o, offset,
3723 current, current & mask));
3724 return current;
3725 }
3726
3727 @ForceInline
3728 public final long getAndBitwiseXorLong(Object o, long offset, long mask) {
3729 long current;
3730 do {
3731 current = getLongVolatile(o, offset);
3732 } while (!weakCompareAndSetLong(o, offset,
3733 current, current ^ mask));
3734 return current;
3735 }
3736
3737 @ForceInline
3738 public final long getAndBitwiseXorLongRelease(Object o, long offset, long mask) {
3739 long current;
3740 do {
3741 current = getLong(o, offset);
3742 } while (!weakCompareAndSetLongRelease(o, offset,
3743 current, current ^ mask));
3744 return current;
3745 }
3746
3747 @ForceInline
3748 public final long getAndBitwiseXorLongAcquire(Object o, long offset, long mask) {
3749 long current;
3750 do {
3751 // Plain read, the value is a hint, the acquire CAS does the work
3752 current = getLong(o, offset);
3753 } while (!weakCompareAndSetLongAcquire(o, offset,
3754 current, current ^ mask));
3755 return current;
3756 }
3757
3758
3759
3760 /**
3761 * Ensures that loads before the fence will not be reordered with loads and
3762 * stores after the fence; a "LoadLoad plus LoadStore barrier".
3763 *
3764 * Corresponds to C11 atomic_thread_fence(memory_order_acquire)
3765 * (an "acquire fence").
3766 *
3767 * Provides a LoadLoad barrier followed by a LoadStore barrier.
3768 *
3769 * @since 1.8
3770 */
3771 @IntrinsicCandidate
3772 public final void loadFence() {
3773 // If loadFence intrinsic is not available, fall back to full fence.
3774 fullFence();
3775 }
3776
3777 /**
3778 * Ensures that loads and stores before the fence will not be reordered with
3779 * stores after the fence; a "StoreStore plus LoadStore barrier".
3780 *
3781 * Corresponds to C11 atomic_thread_fence(memory_order_release)
3782 * (a "release fence").
3783 *
3784 * Provides a StoreStore barrier followed by a LoadStore barrier.
3785 *
3786 * @since 1.8
3787 */
3788 @IntrinsicCandidate
3789 public final void storeFence() {
3790 // If storeFence intrinsic is not available, fall back to full fence.
3791 fullFence();
3792 }
3793
3794 /**
3795 * Ensures that loads and stores before the fence will not be reordered
3796 * with loads and stores after the fence. Implies the effects of both
3797 * loadFence() and storeFence(), and in addition, the effect of a StoreLoad
3798 * barrier.
3799 *
3800 * Corresponds to C11 atomic_thread_fence(memory_order_seq_cst).
3801 * @since 1.8
3802 */
3803 @IntrinsicCandidate
3804 public native void fullFence();
3805
3806 /**
3807 * Ensures that loads before the fence will not be reordered with
3808 * loads after the fence.
3809 *
3810 * @implNote
3811 * This method is operationally equivalent to {@link #loadFence()}.
3812 *
3813 * @since 9
3814 */
3815 public final void loadLoadFence() {
3816 loadFence();
3817 }
3818
3819 /**
3820 * Ensures that stores before the fence will not be reordered with
3821 * stores after the fence.
3822 *
3823 * @since 9
3824 */
3825 @IntrinsicCandidate
3826 public final void storeStoreFence() {
3827 // If storeStoreFence intrinsic is not available, fall back to storeFence.
3828 storeFence();
3829 }
3830
3831 /**
3832 * Throws IllegalAccessError; for use by the VM for access control
3833 * error support.
3834 * @since 1.8
3835 */
3836 private static void throwIllegalAccessError() {
3837 throw new IllegalAccessError();
3838 }
3839
3840 /**
3841 * Throws NoSuchMethodError; for use by the VM for redefinition support.
3842 * @since 13
3843 */
3844 private static void throwNoSuchMethodError() {
3845 throw new NoSuchMethodError();
3846 }
3847
3848 /**
3849 * @return Returns true if the native byte ordering of this
3850 * platform is big-endian, false if it is little-endian.
3851 */
3852 public final boolean isBigEndian() { return BIG_ENDIAN; }
3853
3854 /**
3855 * @return Returns true if this platform is capable of performing
3856 * accesses at addresses which are not aligned for the type of the
3857 * primitive type being accessed, false otherwise.
3858 */
3859 public final boolean unalignedAccess() { return UNALIGNED_ACCESS; }
3860
3861 /**
3862 * Fetches a value at some byte offset into a given Java object.
3863 * More specifically, fetches a value within the given object
3864 * <code>o</code> at the given offset, or (if <code>o</code> is
3865 * null) from the memory address whose numerical value is the
3866 * given offset. <p>
3867 *
3868 * The specification of this method is the same as {@link
3869 * #getLong(Object, long)} except that the offset does not need to
3870 * have been obtained from {@link #objectFieldOffset} on the
3871 * {@link java.lang.reflect.Field} of some Java field. The value
3872 * in memory is raw data, and need not correspond to any Java
3873 * variable. Unless <code>o</code> is null, the value accessed
3874 * must be entirely within the allocated object. The endianness
3875 * of the value in memory is the endianness of the native platform.
3876 *
3877 * <p> The read will be atomic with respect to the largest power
3878 * of two that divides the GCD of the offset and the storage size.
3879 * For example, getLongUnaligned will make atomic reads of 2-, 4-,
3880 * or 8-byte storage units if the offset is zero mod 2, 4, or 8,
3881 * respectively. There are no other guarantees of atomicity.
3882 * <p>
3883 * 8-byte atomicity is only guaranteed on platforms on which
3884 * support atomic accesses to longs.
3885 *
3886 * @param o Java heap object in which the value resides, if any, else
3887 * null
3888 * @param offset The offset in bytes from the start of the object
3889 * @return the value fetched from the indicated object
3890 * @throws RuntimeException No defined exceptions are thrown, not even
3891 * {@link NullPointerException}
3892 * @since 9
3893 */
3894 @IntrinsicCandidate
3895 public final long getLongUnaligned(Object o, long offset) {
3896 if ((offset & 7) == 0) {
3897 return getLong(o, offset);
3898 } else if ((offset & 3) == 0) {
3899 return makeLong(getInt(o, offset),
3900 getInt(o, offset + 4));
3901 } else if ((offset & 1) == 0) {
3902 return makeLong(getShort(o, offset),
3903 getShort(o, offset + 2),
3904 getShort(o, offset + 4),
3905 getShort(o, offset + 6));
3906 } else {
3907 return makeLong(getByte(o, offset),
3908 getByte(o, offset + 1),
3909 getByte(o, offset + 2),
3910 getByte(o, offset + 3),
3911 getByte(o, offset + 4),
3912 getByte(o, offset + 5),
3913 getByte(o, offset + 6),
3914 getByte(o, offset + 7));
3915 }
3916 }
3917 /**
3918 * As {@link #getLongUnaligned(Object, long)} but with an
3919 * additional argument which specifies the endianness of the value
3920 * as stored in memory.
3921 *
3922 * @param o Java heap object in which the variable resides
3923 * @param offset The offset in bytes from the start of the object
3924 * @param bigEndian The endianness of the value
3925 * @return the value fetched from the indicated object
3926 * @since 9
3927 */
3928 public final long getLongUnaligned(Object o, long offset, boolean bigEndian) {
3929 return convEndian(bigEndian, getLongUnaligned(o, offset));
3930 }
3931
3932 /** @see #getLongUnaligned(Object, long) */
3933 @IntrinsicCandidate
3934 public final int getIntUnaligned(Object o, long offset) {
3935 if ((offset & 3) == 0) {
3936 return getInt(o, offset);
3937 } else if ((offset & 1) == 0) {
3938 return makeInt(getShort(o, offset),
3939 getShort(o, offset + 2));
3940 } else {
3941 return makeInt(getByte(o, offset),
3942 getByte(o, offset + 1),
3943 getByte(o, offset + 2),
3944 getByte(o, offset + 3));
3945 }
3946 }
3947 /** @see #getLongUnaligned(Object, long, boolean) */
3948 public final int getIntUnaligned(Object o, long offset, boolean bigEndian) {
3949 return convEndian(bigEndian, getIntUnaligned(o, offset));
3950 }
3951
3952 /** @see #getLongUnaligned(Object, long) */
3953 @IntrinsicCandidate
3954 public final short getShortUnaligned(Object o, long offset) {
3955 if ((offset & 1) == 0) {
3956 return getShort(o, offset);
3957 } else {
3958 return makeShort(getByte(o, offset),
3959 getByte(o, offset + 1));
3960 }
3961 }
3962 /** @see #getLongUnaligned(Object, long, boolean) */
3963 public final short getShortUnaligned(Object o, long offset, boolean bigEndian) {
3964 return convEndian(bigEndian, getShortUnaligned(o, offset));
3965 }
3966
3967 /** @see #getLongUnaligned(Object, long) */
3968 @IntrinsicCandidate
3969 public final char getCharUnaligned(Object o, long offset) {
3970 if ((offset & 1) == 0) {
3971 return getChar(o, offset);
3972 } else {
3973 return (char)makeShort(getByte(o, offset),
3974 getByte(o, offset + 1));
3975 }
3976 }
3977
3978 /** @see #getLongUnaligned(Object, long, boolean) */
3979 public final char getCharUnaligned(Object o, long offset, boolean bigEndian) {
3980 return convEndian(bigEndian, getCharUnaligned(o, offset));
3981 }
3982
3983 /**
3984 * Stores a value at some byte offset into a given Java object.
3985 * <p>
3986 * The specification of this method is the same as {@link
3987 * #getLong(Object, long)} except that the offset does not need to
3988 * have been obtained from {@link #objectFieldOffset} on the
3989 * {@link java.lang.reflect.Field} of some Java field. The value
3990 * in memory is raw data, and need not correspond to any Java
3991 * variable. The endianness of the value in memory is the
3992 * endianness of the native platform.
3993 * <p>
3994 * The write will be atomic with respect to the largest power of
3995 * two that divides the GCD of the offset and the storage size.
3996 * For example, putLongUnaligned will make atomic writes of 2-, 4-,
3997 * or 8-byte storage units if the offset is zero mod 2, 4, or 8,
3998 * respectively. There are no other guarantees of atomicity.
3999 * <p>
4000 * 8-byte atomicity is only guaranteed on platforms on which
4001 * support atomic accesses to longs.
4002 *
4003 * @param o Java heap object in which the value resides, if any, else
4004 * null
4005 * @param offset The offset in bytes from the start of the object
4006 * @param x the value to store
4007 * @throws RuntimeException No defined exceptions are thrown, not even
4008 * {@link NullPointerException}
4009 * @since 9
4010 */
4011 @IntrinsicCandidate
4012 public final void putLongUnaligned(Object o, long offset, long x) {
4013 if ((offset & 7) == 0) {
4014 putLong(o, offset, x);
4015 } else if ((offset & 3) == 0) {
4016 putLongParts(o, offset,
4017 (int)(x >> 0),
4018 (int)(x >>> 32));
4019 } else if ((offset & 1) == 0) {
4020 putLongParts(o, offset,
4021 (short)(x >>> 0),
4022 (short)(x >>> 16),
4023 (short)(x >>> 32),
4024 (short)(x >>> 48));
4025 } else {
4026 putLongParts(o, offset,
4027 (byte)(x >>> 0),
4028 (byte)(x >>> 8),
4029 (byte)(x >>> 16),
4030 (byte)(x >>> 24),
4031 (byte)(x >>> 32),
4032 (byte)(x >>> 40),
4033 (byte)(x >>> 48),
4034 (byte)(x >>> 56));
4035 }
4036 }
4037
4038 /**
4039 * As {@link #putLongUnaligned(Object, long, long)} but with an additional
4040 * argument which specifies the endianness of the value as stored in memory.
4041 * @param o Java heap object in which the value resides
4042 * @param offset The offset in bytes from the start of the object
4043 * @param x the value to store
4044 * @param bigEndian The endianness of the value
4045 * @throws RuntimeException No defined exceptions are thrown, not even
4046 * {@link NullPointerException}
4047 * @since 9
4048 */
4049 public final void putLongUnaligned(Object o, long offset, long x, boolean bigEndian) {
4050 putLongUnaligned(o, offset, convEndian(bigEndian, x));
4051 }
4052
4053 /** @see #putLongUnaligned(Object, long, long) */
4054 @IntrinsicCandidate
4055 public final void putIntUnaligned(Object o, long offset, int x) {
4056 if ((offset & 3) == 0) {
4057 putInt(o, offset, x);
4058 } else if ((offset & 1) == 0) {
4059 putIntParts(o, offset,
4060 (short)(x >> 0),
4061 (short)(x >>> 16));
4062 } else {
4063 putIntParts(o, offset,
4064 (byte)(x >>> 0),
4065 (byte)(x >>> 8),
4066 (byte)(x >>> 16),
4067 (byte)(x >>> 24));
4068 }
4069 }
4070 /** @see #putLongUnaligned(Object, long, long, boolean) */
4071 public final void putIntUnaligned(Object o, long offset, int x, boolean bigEndian) {
4072 putIntUnaligned(o, offset, convEndian(bigEndian, x));
4073 }
4074
4075 /** @see #putLongUnaligned(Object, long, long) */
4076 @IntrinsicCandidate
4077 public final void putShortUnaligned(Object o, long offset, short x) {
4078 if ((offset & 1) == 0) {
4079 putShort(o, offset, x);
4080 } else {
4081 putShortParts(o, offset,
4082 (byte)(x >>> 0),
4083 (byte)(x >>> 8));
4084 }
4085 }
4086 /** @see #putLongUnaligned(Object, long, long, boolean) */
4087 public final void putShortUnaligned(Object o, long offset, short x, boolean bigEndian) {
4088 putShortUnaligned(o, offset, convEndian(bigEndian, x));
4089 }
4090
4091 /** @see #putLongUnaligned(Object, long, long) */
4092 @IntrinsicCandidate
4093 public final void putCharUnaligned(Object o, long offset, char x) {
4094 putShortUnaligned(o, offset, (short)x);
4095 }
4096 /** @see #putLongUnaligned(Object, long, long, boolean) */
4097 public final void putCharUnaligned(Object o, long offset, char x, boolean bigEndian) {
4098 putCharUnaligned(o, offset, convEndian(bigEndian, x));
4099 }
4100
4101 private static int pickPos(int top, int pos) { return BIG_ENDIAN ? top - pos : pos; }
4102
4103 // These methods construct integers from bytes. The byte ordering
4104 // is the native endianness of this platform.
4105 private static long makeLong(byte i0, byte i1, byte i2, byte i3, byte i4, byte i5, byte i6, byte i7) {
4106 return ((toUnsignedLong(i0) << pickPos(56, 0))
4107 | (toUnsignedLong(i1) << pickPos(56, 8))
4108 | (toUnsignedLong(i2) << pickPos(56, 16))
4109 | (toUnsignedLong(i3) << pickPos(56, 24))
4110 | (toUnsignedLong(i4) << pickPos(56, 32))
4111 | (toUnsignedLong(i5) << pickPos(56, 40))
4112 | (toUnsignedLong(i6) << pickPos(56, 48))
4113 | (toUnsignedLong(i7) << pickPos(56, 56)));
4114 }
4115 private static long makeLong(short i0, short i1, short i2, short i3) {
4116 return ((toUnsignedLong(i0) << pickPos(48, 0))
4117 | (toUnsignedLong(i1) << pickPos(48, 16))
4118 | (toUnsignedLong(i2) << pickPos(48, 32))
4119 | (toUnsignedLong(i3) << pickPos(48, 48)));
4120 }
4121 private static long makeLong(int i0, int i1) {
4122 return (toUnsignedLong(i0) << pickPos(32, 0))
4123 | (toUnsignedLong(i1) << pickPos(32, 32));
4124 }
4125 private static int makeInt(short i0, short i1) {
4126 return (toUnsignedInt(i0) << pickPos(16, 0))
4127 | (toUnsignedInt(i1) << pickPos(16, 16));
4128 }
4129 private static int makeInt(byte i0, byte i1, byte i2, byte i3) {
4130 return ((toUnsignedInt(i0) << pickPos(24, 0))
4131 | (toUnsignedInt(i1) << pickPos(24, 8))
4132 | (toUnsignedInt(i2) << pickPos(24, 16))
4133 | (toUnsignedInt(i3) << pickPos(24, 24)));
4134 }
4135 private static short makeShort(byte i0, byte i1) {
4136 return (short)((toUnsignedInt(i0) << pickPos(8, 0))
4137 | (toUnsignedInt(i1) << pickPos(8, 8)));
4138 }
4139
4140 private static byte pick(byte le, byte be) { return BIG_ENDIAN ? be : le; }
4141 private static short pick(short le, short be) { return BIG_ENDIAN ? be : le; }
4142 private static int pick(int le, int be) { return BIG_ENDIAN ? be : le; }
4143
4144 // These methods write integers to memory from smaller parts
4145 // provided by their caller. The ordering in which these parts
4146 // are written is the native endianness of this platform.
4147 private void putLongParts(Object o, long offset, byte i0, byte i1, byte i2, byte i3, byte i4, byte i5, byte i6, byte i7) {
4148 putByte(o, offset + 0, pick(i0, i7));
4149 putByte(o, offset + 1, pick(i1, i6));
4150 putByte(o, offset + 2, pick(i2, i5));
4151 putByte(o, offset + 3, pick(i3, i4));
4152 putByte(o, offset + 4, pick(i4, i3));
4153 putByte(o, offset + 5, pick(i5, i2));
4154 putByte(o, offset + 6, pick(i6, i1));
4155 putByte(o, offset + 7, pick(i7, i0));
4156 }
4157 private void putLongParts(Object o, long offset, short i0, short i1, short i2, short i3) {
4158 putShort(o, offset + 0, pick(i0, i3));
4159 putShort(o, offset + 2, pick(i1, i2));
4160 putShort(o, offset + 4, pick(i2, i1));
4161 putShort(o, offset + 6, pick(i3, i0));
4162 }
4163 private void putLongParts(Object o, long offset, int i0, int i1) {
4164 putInt(o, offset + 0, pick(i0, i1));
4165 putInt(o, offset + 4, pick(i1, i0));
4166 }
4167 private void putIntParts(Object o, long offset, short i0, short i1) {
4168 putShort(o, offset + 0, pick(i0, i1));
4169 putShort(o, offset + 2, pick(i1, i0));
4170 }
4171 private void putIntParts(Object o, long offset, byte i0, byte i1, byte i2, byte i3) {
4172 putByte(o, offset + 0, pick(i0, i3));
4173 putByte(o, offset + 1, pick(i1, i2));
4174 putByte(o, offset + 2, pick(i2, i1));
4175 putByte(o, offset + 3, pick(i3, i0));
4176 }
4177 private void putShortParts(Object o, long offset, byte i0, byte i1) {
4178 putByte(o, offset + 0, pick(i0, i1));
4179 putByte(o, offset + 1, pick(i1, i0));
4180 }
4181
4182 // Zero-extend an integer
4183 private static int toUnsignedInt(byte n) { return n & 0xff; }
4184 private static int toUnsignedInt(short n) { return n & 0xffff; }
4185 private static long toUnsignedLong(byte n) { return n & 0xffl; }
4186 private static long toUnsignedLong(short n) { return n & 0xffffl; }
4187 private static long toUnsignedLong(int n) { return n & 0xffffffffl; }
4188
4189 // Maybe byte-reverse an integer
4190 private static char convEndian(boolean big, char n) { return big == BIG_ENDIAN ? n : Character.reverseBytes(n); }
4191 private static short convEndian(boolean big, short n) { return big == BIG_ENDIAN ? n : Short.reverseBytes(n) ; }
4192 private static int convEndian(boolean big, int n) { return big == BIG_ENDIAN ? n : Integer.reverseBytes(n) ; }
4193 private static long convEndian(boolean big, long n) { return big == BIG_ENDIAN ? n : Long.reverseBytes(n) ; }
4194
4195
4196
4197 private native long allocateMemory0(long bytes);
4198 private native long reallocateMemory0(long address, long bytes);
4199 private native void freeMemory0(long address);
4200 private native void setMemory0(Object o, long offset, long bytes, byte value);
4201 @IntrinsicCandidate
4202 private native void copyMemory0(Object srcBase, long srcOffset, Object destBase, long destOffset, long bytes);
4203 private native void copySwapMemory0(Object srcBase, long srcOffset, Object destBase, long destOffset, long bytes, long elemSize);
4204 private native long objectFieldOffset0(Field f);
4205 private native long objectFieldOffset1(Class<?> c, String name);
4206 private native long staticFieldOffset0(Field f);
4207 private native Object staticFieldBase0(Field f);
4208 private native boolean shouldBeInitialized0(Class<?> c);
4209 private native void ensureClassInitialized0(Class<?> c);
4210 private native int arrayBaseOffset0(Class<?> arrayClass);
4211 private native int arrayIndexScale0(Class<?> arrayClass);
4212 private native long getObjectSize0(Object o);
4213 private native int getLoadAverage0(double[] loadavg, int nelems);
4214
4215
4216 /**
4217 * Invokes the given direct byte buffer's cleaner, if any.
4218 *
4219 * @param directBuffer a direct byte buffer
4220 * @throws NullPointerException if {@code directBuffer} is null
4221 * @throws IllegalArgumentException if {@code directBuffer} is non-direct,
4222 * or is a {@link java.nio.Buffer#slice slice}, or is a
4223 * {@link java.nio.Buffer#duplicate duplicate}
4224 */
4225 public void invokeCleaner(java.nio.ByteBuffer directBuffer) {
4226 if (!directBuffer.isDirect())
4227 throw new IllegalArgumentException("buffer is non-direct");
4228
4229 DirectBuffer db = (DirectBuffer) directBuffer;
4230 if (db.attachment() != null)
4231 throw new IllegalArgumentException("duplicate or slice");
4232
4233 Cleaner cleaner = db.cleaner();
4234 if (cleaner != null) {
4235 cleaner.clean();
4236 }
4237 }
4238
4239 // The following deprecated methods are used by JSR 166.
4240
4241 @Deprecated(since="12", forRemoval=true)
4242 public final Object getObject(Object o, long offset) {
4243 return getReference(o, offset);
4244 }
4245 @Deprecated(since="12", forRemoval=true)
4246 public final Object getObjectVolatile(Object o, long offset) {
4247 return getReferenceVolatile(o, offset);
4248 }
4249 @Deprecated(since="12", forRemoval=true)
4250 public final Object getObjectAcquire(Object o, long offset) {
4251 return getReferenceAcquire(o, offset);
4252 }
4253 @Deprecated(since="12", forRemoval=true)
4254 public final Object getObjectOpaque(Object o, long offset) {
4255 return getReferenceOpaque(o, offset);
4256 }
4257
4258
4259 @Deprecated(since="12", forRemoval=true)
4260 public final void putObject(Object o, long offset, Object x) {
4261 putReference(o, offset, x);
4262 }
4263 @Deprecated(since="12", forRemoval=true)
4264 public final void putObjectVolatile(Object o, long offset, Object x) {
4265 putReferenceVolatile(o, offset, x);
4266 }
4267 @Deprecated(since="12", forRemoval=true)
4268 public final void putObjectOpaque(Object o, long offset, Object x) {
4269 putReferenceOpaque(o, offset, x);
4270 }
4271 @Deprecated(since="12", forRemoval=true)
4272 public final void putObjectRelease(Object o, long offset, Object x) {
4273 putReferenceRelease(o, offset, x);
4274 }
4275
4276
4277 @Deprecated(since="12", forRemoval=true)
4278 public final Object getAndSetObject(Object o, long offset, Object newValue) {
4279 return getAndSetReference(o, offset, newValue);
4280 }
4281 @Deprecated(since="12", forRemoval=true)
4282 public final Object getAndSetObjectAcquire(Object o, long offset, Object newValue) {
4283 return getAndSetReferenceAcquire(o, offset, newValue);
4284 }
4285 @Deprecated(since="12", forRemoval=true)
4286 public final Object getAndSetObjectRelease(Object o, long offset, Object newValue) {
4287 return getAndSetReferenceRelease(o, offset, newValue);
4288 }
4289
4290
4291 @Deprecated(since="12", forRemoval=true)
4292 public final boolean compareAndSetObject(Object o, long offset, Object expected, Object x) {
4293 return compareAndSetReference(o, offset, expected, x);
4294 }
4295 @Deprecated(since="12", forRemoval=true)
4296 public final Object compareAndExchangeObject(Object o, long offset, Object expected, Object x) {
4297 return compareAndExchangeReference(o, offset, expected, x);
4298 }
4299 @Deprecated(since="12", forRemoval=true)
4300 public final Object compareAndExchangeObjectAcquire(Object o, long offset, Object expected, Object x) {
4301 return compareAndExchangeReferenceAcquire(o, offset, expected, x);
4302 }
4303 @Deprecated(since="12", forRemoval=true)
4304 public final Object compareAndExchangeObjectRelease(Object o, long offset, Object expected, Object x) {
4305 return compareAndExchangeReferenceRelease(o, offset, expected, x);
4306 }
4307
4308
4309 @Deprecated(since="12", forRemoval=true)
4310 public final boolean weakCompareAndSetObject(Object o, long offset, Object expected, Object x) {
4311 return weakCompareAndSetReference(o, offset, expected, x);
4312 }
4313 @Deprecated(since="12", forRemoval=true)
4314 public final boolean weakCompareAndSetObjectAcquire(Object o, long offset, Object expected, Object x) {
4315 return weakCompareAndSetReferenceAcquire(o, offset, expected, x);
4316 }
4317 @Deprecated(since="12", forRemoval=true)
4318 public final boolean weakCompareAndSetObjectPlain(Object o, long offset, Object expected, Object x) {
4319 return weakCompareAndSetReferencePlain(o, offset, expected, x);
4320 }
4321 @Deprecated(since="12", forRemoval=true)
4322 public final boolean weakCompareAndSetObjectRelease(Object o, long offset, Object expected, Object x) {
4323 return weakCompareAndSetReferenceRelease(o, offset, expected, x);
4324 }
4325 }