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