1 /* 2 * Copyright (c) 2000, 2019, 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.HotSpotIntrinsicCandidate; 29 import jdk.internal.ref.Cleaner; 30 import jdk.internal.vm.annotation.ForceInline; 31 import sun.nio.ch.DirectBuffer; 32 33 import java.lang.reflect.Field; 34 import java.security.ProtectionDomain; 35 36 37 /** 38 * A collection of methods for performing low-level, unsafe operations. 39 * Although the class and all methods are public, use of this class is 40 * limited because only trusted code can obtain instances of it. 41 * 42 * <em>Note:</em> It is the resposibility of the caller to make sure 43 * arguments are checked before methods of this class are 44 * called. While some rudimentary checks are performed on the input, 45 * the checks are best effort and when performance is an overriding 46 * priority, as when methods of this class are optimized by the 47 * runtime compiler, some or all checks (if any) may be elided. Hence, 48 * the caller must not rely on the checks and corresponding 49 * exceptions! 50 * 51 * @author John R. Rose 52 * @see #getUnsafe 53 */ 54 55 public final class Unsafe { 56 57 private static native void registerNatives(); 58 static { 59 registerNatives(); 60 } 61 62 private Unsafe() {} 63 64 private static final Unsafe theUnsafe = new Unsafe(); 65 66 /** 67 * Provides the caller with the capability of performing unsafe 68 * operations. 69 * 70 * <p>The returned {@code Unsafe} object should be carefully guarded 71 * by the caller, since it can be used to read and write data at arbitrary 72 * memory addresses. It must never be passed to untrusted code. 73 * 74 * <p>Most methods in this class are very low-level, and correspond to a 75 * small number of hardware instructions (on typical machines). Compilers 76 * are encouraged to optimize these methods accordingly. 77 * 78 * <p>Here is a suggested idiom for using unsafe operations: 79 * 80 * <pre> {@code 81 * class MyTrustedClass { 82 * private static final Unsafe unsafe = Unsafe.getUnsafe(); 83 * ... 84 * private long myCountAddress = ...; 85 * public int getCount() { return unsafe.getByte(myCountAddress); } 86 * }}</pre> 87 * 88 * (It may assist compilers to make the local variable {@code final}.) 89 */ 90 public static Unsafe getUnsafe() { 91 return theUnsafe; 92 } 93 94 /// peek and poke operations 95 /// (compilers should optimize these to memory ops) 96 97 // These work on object fields in the Java heap. 98 // They will not work on elements of packed arrays. 99 100 /** 101 * Fetches a value from a given Java variable. 102 * More specifically, fetches a field or array element within the given 103 * object {@code o} at the given offset, or (if {@code o} is null) 104 * from the memory address whose numerical value is the given offset. 105 * <p> 106 * The results are undefined unless one of the following cases is true: 107 * <ul> 108 * <li>The offset was obtained from {@link #objectFieldOffset} on 109 * the {@link java.lang.reflect.Field} of some Java field and the object 110 * referred to by {@code o} is of a class compatible with that 111 * field's class. 112 * 113 * <li>The offset and object reference {@code o} (either null or 114 * non-null) were both obtained via {@link #staticFieldOffset} 115 * and {@link #staticFieldBase} (respectively) from the 116 * reflective {@link Field} representation of some Java field. 117 * 118 * <li>The object referred to by {@code o} is an array, and the offset 119 * is an integer of the form {@code B+N*S}, where {@code N} is 120 * a valid index into the array, and {@code B} and {@code S} are 121 * the values obtained by {@link #arrayBaseOffset} and {@link 122 * #arrayIndexScale} (respectively) from the array's class. The value 123 * referred to is the {@code N}<em>th</em> element of the array. 124 * 125 * </ul> 126 * <p> 127 * If one of the above cases is true, the call references a specific Java 128 * variable (field or array element). However, the results are undefined 129 * if that variable is not in fact of the type returned by this method. 130 * <p> 131 * This method refers to a variable by means of two parameters, and so 132 * it provides (in effect) a <em>double-register</em> addressing mode 133 * for Java variables. When the object reference is null, this method 134 * uses its offset as an absolute address. This is similar in operation 135 * to methods such as {@link #getInt(long)}, which provide (in effect) a 136 * <em>single-register</em> addressing mode for non-Java variables. 137 * However, because Java variables may have a different layout in memory 138 * from non-Java variables, programmers should not assume that these 139 * two addressing modes are ever equivalent. Also, programmers should 140 * remember that offsets from the double-register addressing mode cannot 141 * be portably confused with longs used in the single-register addressing 142 * mode. 143 * 144 * @param o Java heap object in which the variable resides, if any, else 145 * null 146 * @param offset indication of where the variable resides in a Java heap 147 * object, if any, else a memory address locating the variable 148 * statically 149 * @return the value fetched from the indicated Java variable 150 * @throws RuntimeException No defined exceptions are thrown, not even 151 * {@link NullPointerException} 152 */ 153 @HotSpotIntrinsicCandidate 154 public native int getInt(Object o, long offset); 155 156 /** 157 * Stores a value into a given Java variable. 158 * <p> 159 * The first two parameters are interpreted exactly as with 160 * {@link #getInt(Object, long)} to refer to a specific 161 * Java variable (field or array element). The given value 162 * is stored into that variable. 163 * <p> 164 * The variable must be of the same type as the method 165 * parameter {@code x}. 166 * 167 * @param o Java heap object in which the variable resides, if any, else 168 * null 169 * @param offset indication of where the variable resides in a Java heap 170 * object, if any, else a memory address locating the variable 171 * statically 172 * @param x the value to store into the indicated Java variable 173 * @throws RuntimeException No defined exceptions are thrown, not even 174 * {@link NullPointerException} 175 */ 176 @HotSpotIntrinsicCandidate 177 public native void putInt(Object o, long offset, int x); 178 179 /** 180 * Fetches a reference value from a given Java variable. 181 * @see #getInt(Object, long) 182 */ 183 @HotSpotIntrinsicCandidate 184 public native Object getObject(Object o, long offset); 185 186 /** 187 * Stores a reference value into a given Java variable. 188 * <p> 189 * Unless the reference {@code x} being stored is either null 190 * or matches the field type, the results are undefined. 191 * If the reference {@code o} is non-null, card marks or 192 * other store barriers for that object (if the VM requires them) 193 * are updated. 194 * @see #putInt(Object, long, int) 195 */ 196 @HotSpotIntrinsicCandidate 197 public native void putObject(Object o, long offset, Object x); 198 199 /** @see #getInt(Object, long) */ 200 @HotSpotIntrinsicCandidate 201 public native boolean getBoolean(Object o, long offset); 202 203 /** @see #putInt(Object, long, int) */ 204 @HotSpotIntrinsicCandidate 205 public native void putBoolean(Object o, long offset, boolean x); 206 207 /** @see #getInt(Object, long) */ 208 @HotSpotIntrinsicCandidate 209 public native byte getByte(Object o, long offset); 210 211 /** @see #putInt(Object, long, int) */ 212 @HotSpotIntrinsicCandidate 213 public native void putByte(Object o, long offset, byte x); 214 215 /** @see #getInt(Object, long) */ 216 @HotSpotIntrinsicCandidate 217 public native short getShort(Object o, long offset); 218 219 /** @see #putInt(Object, long, int) */ 220 @HotSpotIntrinsicCandidate 221 public native void putShort(Object o, long offset, short x); 222 223 /** @see #getInt(Object, long) */ 224 @HotSpotIntrinsicCandidate 225 public native char getChar(Object o, long offset); 226 227 /** @see #putInt(Object, long, int) */ 228 @HotSpotIntrinsicCandidate 229 public native void putChar(Object o, long offset, char x); 230 231 /** @see #getInt(Object, long) */ 232 @HotSpotIntrinsicCandidate 233 public native long getLong(Object o, long offset); 234 235 /** @see #putInt(Object, long, int) */ 236 @HotSpotIntrinsicCandidate 237 public native void putLong(Object o, long offset, long x); 238 239 /** @see #getInt(Object, long) */ 240 @HotSpotIntrinsicCandidate 241 public native float getFloat(Object o, long offset); 242 243 /** @see #putInt(Object, long, int) */ 244 @HotSpotIntrinsicCandidate 245 public native void putFloat(Object o, long offset, float x); 246 247 /** @see #getInt(Object, long) */ 248 @HotSpotIntrinsicCandidate 249 public native double getDouble(Object o, long offset); 250 251 /** @see #putInt(Object, long, int) */ 252 @HotSpotIntrinsicCandidate 253 public native void putDouble(Object o, long offset, double x); 254 255 /** 256 * Fetches a native pointer from a given memory address. If the address is 257 * zero, or does not point into a block obtained from {@link 258 * #allocateMemory}, the results are undefined. 259 * 260 * <p>If the native pointer is less than 64 bits wide, it is extended as 261 * an unsigned number to a Java long. The pointer may be indexed by any 262 * given byte offset, simply by adding that offset (as a simple integer) to 263 * the long representing the pointer. The number of bytes actually read 264 * from the target address may be determined by consulting {@link 265 * #addressSize}. 266 * 267 * @see #allocateMemory 268 * @see #getInt(Object, long) 269 */ 270 @ForceInline 271 public long getAddress(Object o, long offset) { 272 if (ADDRESS_SIZE == 4) { 273 return Integer.toUnsignedLong(getInt(o, offset)); 274 } else { 275 return getLong(o, offset); 276 } 277 } 278 279 /** 280 * Stores a native pointer into a given memory address. If the address is 281 * zero, or does not point into a block obtained from {@link 282 * #allocateMemory}, the results are undefined. 283 * 284 * <p>The number of bytes actually written at the target address may be 285 * determined by consulting {@link #addressSize}. 286 * 287 * @see #allocateMemory 288 * @see #putInt(Object, long, int) 289 */ 290 @ForceInline 291 public void putAddress(Object o, long offset, long x) { 292 if (ADDRESS_SIZE == 4) { 293 putInt(o, offset, (int)x); 294 } else { 295 putLong(o, offset, x); 296 } 297 } 298 299 // These read VM internal data. 300 301 /** 302 * Fetches an uncompressed reference value from a given native variable 303 * ignoring the VM's compressed references mode. 304 * 305 * @param address a memory address locating the variable 306 * @return the value fetched from the indicated native variable 307 */ 308 public native Object getUncompressedObject(long address); 309 310 // These work on values in the C heap. 311 312 /** 313 * Fetches a value from a given memory address. If the address is zero, or 314 * does not point into a block obtained from {@link #allocateMemory}, the 315 * results are undefined. 316 * 317 * @see #allocateMemory 318 */ 319 @ForceInline 320 public byte getByte(long address) { 321 return getByte(null, address); 322 } 323 324 /** 325 * Stores a value into a given memory address. If the address is zero, or 326 * does not point into a block obtained from {@link #allocateMemory}, the 327 * results are undefined. 328 * 329 * @see #getByte(long) 330 */ 331 @ForceInline 332 public void putByte(long address, byte x) { 333 putByte(null, address, x); 334 } 335 336 /** @see #getByte(long) */ 337 @ForceInline 338 public short getShort(long address) { 339 return getShort(null, address); 340 } 341 342 /** @see #putByte(long, byte) */ 343 @ForceInline 344 public void putShort(long address, short x) { 345 putShort(null, address, x); 346 } 347 348 /** @see #getByte(long) */ 349 @ForceInline 350 public char getChar(long address) { 351 return getChar(null, address); 352 } 353 354 /** @see #putByte(long, byte) */ 355 @ForceInline 356 public void putChar(long address, char x) { 357 putChar(null, address, x); 358 } 359 360 /** @see #getByte(long) */ 361 @ForceInline 362 public int getInt(long address) { 363 return getInt(null, address); 364 } 365 366 /** @see #putByte(long, byte) */ 367 @ForceInline 368 public void putInt(long address, int x) { 369 putInt(null, address, x); 370 } 371 372 /** @see #getByte(long) */ 373 @ForceInline 374 public long getLong(long address) { 375 return getLong(null, address); 376 } 377 378 /** @see #putByte(long, byte) */ 379 @ForceInline 380 public void putLong(long address, long x) { 381 putLong(null, address, x); 382 } 383 384 /** @see #getByte(long) */ 385 @ForceInline 386 public float getFloat(long address) { 387 return getFloat(null, address); 388 } 389 390 /** @see #putByte(long, byte) */ 391 @ForceInline 392 public void putFloat(long address, float x) { 393 putFloat(null, address, x); 394 } 395 396 /** @see #getByte(long) */ 397 @ForceInline 398 public double getDouble(long address) { 399 return getDouble(null, address); 400 } 401 402 /** @see #putByte(long, byte) */ 403 @ForceInline 404 public void putDouble(long address, double x) { 405 putDouble(null, address, x); 406 } 407 408 /** @see #getAddress(Object, long) */ 409 @ForceInline 410 public long getAddress(long address) { 411 return getAddress(null, address); 412 } 413 414 /** @see #putAddress(Object, long, long) */ 415 @ForceInline 416 public void putAddress(long address, long x) { 417 putAddress(null, address, x); 418 } 419 420 421 422 /// helper methods for validating various types of objects/values 423 424 /** 425 * Create an exception reflecting that some of the input was invalid 426 * 427 * <em>Note:</em> It is the resposibility of the caller to make 428 * sure arguments are checked before the methods are called. While 429 * some rudimentary checks are performed on the input, the checks 430 * are best effort and when performance is an overriding priority, 431 * as when methods of this class are optimized by the runtime 432 * compiler, some or all checks (if any) may be elided. Hence, the 433 * caller must not rely on the checks and corresponding 434 * exceptions! 435 * 436 * @return an exception object 437 */ 438 private RuntimeException invalidInput() { 439 return new IllegalArgumentException(); 440 } 441 442 /** 443 * Check if a value is 32-bit clean (32 MSB are all zero) 444 * 445 * @param value the 64-bit value to check 446 * 447 * @return true if the value is 32-bit clean 448 */ 449 private boolean is32BitClean(long value) { 450 return value >>> 32 == 0; 451 } 452 453 /** 454 * Check the validity of a size (the equivalent of a size_t) 455 * 456 * @throws RuntimeException if the size is invalid 457 * (<em>Note:</em> after optimization, invalid inputs may 458 * go undetected, which will lead to unpredictable 459 * behavior) 460 */ 461 private void checkSize(long size) { 462 if (ADDRESS_SIZE == 4) { 463 // Note: this will also check for negative sizes 464 if (!is32BitClean(size)) { 465 throw invalidInput(); 466 } 467 } else if (size < 0) { 468 throw invalidInput(); 469 } 470 } 471 472 /** 473 * Check the validity of a native address (the equivalent of void*) 474 * 475 * @throws RuntimeException if the address is invalid 476 * (<em>Note:</em> after optimization, invalid inputs may 477 * go undetected, which will lead to unpredictable 478 * behavior) 479 */ 480 private void checkNativeAddress(long address) { 481 if (ADDRESS_SIZE == 4) { 482 // Accept both zero and sign extended pointers. A valid 483 // pointer will, after the +1 below, either have produced 484 // the value 0x0 or 0x1. Masking off the low bit allows 485 // for testing against 0. 486 if ((((address >> 32) + 1) & ~1) != 0) { 487 throw invalidInput(); 488 } 489 } 490 } 491 492 /** 493 * Check the validity of an offset, relative to a base object 494 * 495 * @param o the base object 496 * @param offset the offset to check 497 * 498 * @throws RuntimeException if the size is invalid 499 * (<em>Note:</em> after optimization, invalid inputs may 500 * go undetected, which will lead to unpredictable 501 * behavior) 502 */ 503 private void checkOffset(Object o, long offset) { 504 if (ADDRESS_SIZE == 4) { 505 // Note: this will also check for negative offsets 506 if (!is32BitClean(offset)) { 507 throw invalidInput(); 508 } 509 } else if (offset < 0) { 510 throw invalidInput(); 511 } 512 } 513 514 /** 515 * Check the validity of a double-register pointer 516 * 517 * Note: This code deliberately does *not* check for NPE for (at 518 * least) three reasons: 519 * 520 * 1) NPE is not just NULL/0 - there is a range of values all 521 * resulting in an NPE, which is not trivial to check for 522 * 523 * 2) It is the responsibility of the callers of Unsafe methods 524 * to verify the input, so throwing an exception here is not really 525 * useful - passing in a NULL pointer is a critical error and the 526 * must not expect an exception to be thrown anyway. 527 * 528 * 3) the actual operations will detect NULL pointers anyway by 529 * means of traps and signals (like SIGSEGV). 530 * 531 * @param o Java heap object, or null 532 * @param offset indication of where the variable resides in a Java heap 533 * object, if any, else a memory address locating the variable 534 * statically 535 * 536 * @throws RuntimeException if the pointer is invalid 537 * (<em>Note:</em> after optimization, invalid inputs may 538 * go undetected, which will lead to unpredictable 539 * behavior) 540 */ 541 private void checkPointer(Object o, long offset) { 542 if (o == null) { 543 checkNativeAddress(offset); 544 } else { 545 checkOffset(o, offset); 546 } 547 } 548 549 /** 550 * Check if a type is a primitive array type 551 * 552 * @param c the type to check 553 * 554 * @return true if the type is a primitive array type 555 */ 556 private void checkPrimitiveArray(Class<?> c) { 557 Class<?> componentType = c.getComponentType(); 558 if (componentType == null || !componentType.isPrimitive()) { 559 throw invalidInput(); 560 } 561 } 562 563 /** 564 * Check that a pointer is a valid primitive array type pointer 565 * 566 * Note: pointers off-heap are considered to be primitive arrays 567 * 568 * @throws RuntimeException if the pointer is invalid 569 * (<em>Note:</em> after optimization, invalid inputs may 570 * go undetected, which will lead to unpredictable 571 * behavior) 572 */ 573 private void checkPrimitivePointer(Object o, long offset) { 574 checkPointer(o, offset); 575 576 if (o != null) { 577 // If on heap, it must be a primitive array 578 checkPrimitiveArray(o.getClass()); 579 } 580 } 581 582 583 /// wrappers for malloc, realloc, free: 584 585 /** 586 * Allocates a new block of native memory, of the given size in bytes. The 587 * contents of the memory are uninitialized; they will generally be 588 * garbage. The resulting native pointer will never be zero, and will be 589 * aligned for all value types. Dispose of this memory by calling {@link 590 * #freeMemory}, or resize it with {@link #reallocateMemory}. 591 * 592 * <em>Note:</em> It is the resposibility of the caller to make 593 * sure arguments are checked before the methods are called. While 594 * some rudimentary checks are performed on the input, the checks 595 * are best effort and when performance is an overriding priority, 596 * as when methods of this class are optimized by the runtime 597 * compiler, some or all checks (if any) may be elided. Hence, the 598 * caller must not rely on the checks and corresponding 599 * exceptions! 600 * 601 * @throws RuntimeException if the size is negative or too large 602 * for the native size_t type 603 * 604 * @throws OutOfMemoryError if the allocation is refused by the system 605 * 606 * @see #getByte(long) 607 * @see #putByte(long, byte) 608 */ 609 public long allocateMemory(long bytes) { 610 allocateMemoryChecks(bytes); 611 612 if (bytes == 0) { 613 return 0; 614 } 615 616 long p = allocateMemory0(bytes); 617 if (p == 0) { 618 throw new OutOfMemoryError(); 619 } 620 621 return p; 622 } 623 624 /** 625 * Validate the arguments to allocateMemory 626 * 627 * @throws RuntimeException if the arguments are invalid 628 * (<em>Note:</em> after optimization, invalid inputs may 629 * go undetected, which will lead to unpredictable 630 * behavior) 631 */ 632 private void allocateMemoryChecks(long bytes) { 633 checkSize(bytes); 634 } 635 636 /** 637 * Resizes a new block of native memory, to the given size in bytes. The 638 * contents of the new block past the size of the old block are 639 * uninitialized; they will generally be garbage. The resulting native 640 * pointer will be zero if and only if the requested size is zero. The 641 * resulting native pointer will be aligned for all value types. Dispose 642 * of this memory by calling {@link #freeMemory}, or resize it with {@link 643 * #reallocateMemory}. The address passed to this method may be null, in 644 * which case an allocation will be performed. 645 * 646 * <em>Note:</em> It is the resposibility of the caller to make 647 * sure arguments are checked before the methods are called. While 648 * some rudimentary checks are performed on the input, the checks 649 * are best effort and when performance is an overriding priority, 650 * as when methods of this class are optimized by the runtime 651 * compiler, some or all checks (if any) may be elided. Hence, the 652 * caller must not rely on the checks and corresponding 653 * exceptions! 654 * 655 * @throws RuntimeException if the size is negative or too large 656 * for the native size_t type 657 * 658 * @throws OutOfMemoryError if the allocation is refused by the system 659 * 660 * @see #allocateMemory 661 */ 662 public long reallocateMemory(long address, long bytes) { 663 reallocateMemoryChecks(address, bytes); 664 665 if (bytes == 0) { 666 freeMemory(address); 667 return 0; 668 } 669 670 long p = (address == 0) ? allocateMemory0(bytes) : reallocateMemory0(address, bytes); 671 if (p == 0) { 672 throw new OutOfMemoryError(); 673 } 674 675 return p; 676 } 677 678 /** 679 * Validate the arguments to reallocateMemory 680 * 681 * @throws RuntimeException if the arguments are invalid 682 * (<em>Note:</em> after optimization, invalid inputs may 683 * go undetected, which will lead to unpredictable 684 * behavior) 685 */ 686 private void reallocateMemoryChecks(long address, long bytes) { 687 checkPointer(null, address); 688 checkSize(bytes); 689 } 690 691 /** 692 * Sets all bytes in a given block of memory to a fixed value 693 * (usually zero). 694 * 695 * <p>This method determines a block's base address by means of two parameters, 696 * and so it provides (in effect) a <em>double-register</em> addressing mode, 697 * as discussed in {@link #getInt(Object,long)}. When the object reference is null, 698 * the offset supplies an absolute base address. 699 * 700 * <p>The stores are in coherent (atomic) units of a size determined 701 * by the address and length parameters. If the effective address and 702 * length are all even modulo 8, the stores take place in 'long' units. 703 * If the effective address and length are (resp.) even modulo 4 or 2, 704 * the stores take place in units of 'int' or 'short'. 705 * 706 * <em>Note:</em> It is the resposibility of the caller to make 707 * sure arguments are checked before the methods are called. While 708 * some rudimentary checks are performed on the input, the checks 709 * are best effort and when performance is an overriding priority, 710 * as when methods of this class are optimized by the runtime 711 * compiler, some or all checks (if any) may be elided. Hence, the 712 * caller must not rely on the checks and corresponding 713 * exceptions! 714 * 715 * @throws RuntimeException if any of the arguments is invalid 716 * 717 * @since 1.7 718 */ 719 public void setMemory(Object o, long offset, long bytes, byte value) { 720 setMemoryChecks(o, offset, bytes, value); 721 722 if (bytes == 0) { 723 return; 724 } 725 726 setMemory0(o, offset, bytes, value); 727 } 728 729 /** 730 * Sets all bytes in a given block of memory to a fixed value 731 * (usually zero). This provides a <em>single-register</em> addressing mode, 732 * as discussed in {@link #getInt(Object,long)}. 733 * 734 * <p>Equivalent to {@code setMemory(null, address, bytes, value)}. 735 */ 736 public void setMemory(long address, long bytes, byte value) { 737 setMemory(null, address, bytes, value); 738 } 739 740 /** 741 * Validate the arguments to setMemory 742 * 743 * @throws RuntimeException if the arguments are invalid 744 * (<em>Note:</em> after optimization, invalid inputs may 745 * go undetected, which will lead to unpredictable 746 * behavior) 747 */ 748 private void setMemoryChecks(Object o, long offset, long bytes, byte value) { 749 checkPrimitivePointer(o, offset); 750 checkSize(bytes); 751 } 752 753 /** 754 * Sets all bytes in a given block of memory to a copy of another 755 * block. 756 * 757 * <p>This method determines each block's base address by means of two parameters, 758 * and so it provides (in effect) a <em>double-register</em> addressing mode, 759 * as discussed in {@link #getInt(Object,long)}. When the object reference is null, 760 * the offset supplies an absolute base address. 761 * 762 * <p>The transfers are in coherent (atomic) units of a size determined 763 * by the address and length parameters. If the effective addresses and 764 * length are all even modulo 8, the transfer takes place in 'long' units. 765 * If the effective addresses and length are (resp.) even modulo 4 or 2, 766 * the transfer takes place in units of 'int' or 'short'. 767 * 768 * <em>Note:</em> It is the resposibility of the caller to make 769 * sure arguments are checked before the methods are called. While 770 * some rudimentary checks are performed on the input, the checks 771 * are best effort and when performance is an overriding priority, 772 * as when methods of this class are optimized by the runtime 773 * compiler, some or all checks (if any) may be elided. Hence, the 774 * caller must not rely on the checks and corresponding 775 * exceptions! 776 * 777 * @throws RuntimeException if any of the arguments is invalid 778 * 779 * @since 1.7 780 */ 781 public void copyMemory(Object srcBase, long srcOffset, 782 Object destBase, long destOffset, 783 long bytes) { 784 copyMemoryChecks(srcBase, srcOffset, destBase, destOffset, bytes); 785 786 if (bytes == 0) { 787 return; 788 } 789 790 copyMemory0(srcBase, srcOffset, destBase, destOffset, bytes); 791 } 792 793 /** 794 * Sets all bytes in a given block of memory to a copy of another 795 * block. This provides a <em>single-register</em> addressing mode, 796 * as discussed in {@link #getInt(Object,long)}. 797 * 798 * Equivalent to {@code copyMemory(null, srcAddress, null, destAddress, bytes)}. 799 */ 800 public void copyMemory(long srcAddress, long destAddress, long bytes) { 801 copyMemory(null, srcAddress, null, destAddress, bytes); 802 } 803 804 /** 805 * Validate the arguments to copyMemory 806 * 807 * @throws RuntimeException if any of the arguments is invalid 808 * (<em>Note:</em> after optimization, invalid inputs may 809 * go undetected, which will lead to unpredictable 810 * behavior) 811 */ 812 private void copyMemoryChecks(Object srcBase, long srcOffset, 813 Object destBase, long destOffset, 814 long bytes) { 815 checkSize(bytes); 816 checkPrimitivePointer(srcBase, srcOffset); 817 checkPrimitivePointer(destBase, destOffset); 818 } 819 820 /** 821 * Copies all elements from one block of memory to another block, 822 * *unconditionally* byte swapping the elements on the fly. 823 * 824 * <p>This method determines each block's base address by means of two parameters, 825 * and so it provides (in effect) a <em>double-register</em> addressing mode, 826 * as discussed in {@link #getInt(Object,long)}. When the object reference is null, 827 * the offset supplies an absolute base address. 828 * 829 * <em>Note:</em> It is the resposibility of the caller to make 830 * sure arguments are checked before the methods are called. While 831 * some rudimentary checks are performed on the input, the checks 832 * are best effort and when performance is an overriding priority, 833 * as when methods of this class are optimized by the runtime 834 * compiler, some or all checks (if any) may be elided. Hence, the 835 * caller must not rely on the checks and corresponding 836 * exceptions! 837 * 838 * @throws RuntimeException if any of the arguments is invalid 839 * 840 * @since 9 841 */ 842 public void copySwapMemory(Object srcBase, long srcOffset, 843 Object destBase, long destOffset, 844 long bytes, long elemSize) { 845 copySwapMemoryChecks(srcBase, srcOffset, destBase, destOffset, bytes, elemSize); 846 847 if (bytes == 0) { 848 return; 849 } 850 851 copySwapMemory0(srcBase, srcOffset, destBase, destOffset, bytes, elemSize); 852 } 853 854 private void copySwapMemoryChecks(Object srcBase, long srcOffset, 855 Object destBase, long destOffset, 856 long bytes, long elemSize) { 857 checkSize(bytes); 858 859 if (elemSize != 2 && elemSize != 4 && elemSize != 8) { 860 throw invalidInput(); 861 } 862 if (bytes % elemSize != 0) { 863 throw invalidInput(); 864 } 865 866 checkPrimitivePointer(srcBase, srcOffset); 867 checkPrimitivePointer(destBase, destOffset); 868 } 869 870 /** 871 * Copies all elements from one block of memory to another block, byte swapping the 872 * elements on the fly. 873 * 874 * This provides a <em>single-register</em> addressing mode, as 875 * discussed in {@link #getInt(Object,long)}. 876 * 877 * Equivalent to {@code copySwapMemory(null, srcAddress, null, destAddress, bytes, elemSize)}. 878 */ 879 public void copySwapMemory(long srcAddress, long destAddress, long bytes, long elemSize) { 880 copySwapMemory(null, srcAddress, null, destAddress, bytes, elemSize); 881 } 882 883 /** 884 * Disposes of a block of native memory, as obtained from {@link 885 * #allocateMemory} or {@link #reallocateMemory}. The address passed to 886 * this method may be null, in which case no action is taken. 887 * 888 * <em>Note:</em> It is the resposibility of the caller to make 889 * sure arguments are checked before the methods are called. While 890 * some rudimentary checks are performed on the input, the checks 891 * are best effort and when performance is an overriding priority, 892 * as when methods of this class are optimized by the runtime 893 * compiler, some or all checks (if any) may be elided. Hence, the 894 * caller must not rely on the checks and corresponding 895 * exceptions! 896 * 897 * @throws RuntimeException if any of the arguments is invalid 898 * 899 * @see #allocateMemory 900 */ 901 public void freeMemory(long address) { 902 freeMemoryChecks(address); 903 904 if (address == 0) { 905 return; 906 } 907 908 freeMemory0(address); 909 } 910 911 /** 912 * Validate the arguments to freeMemory 913 * 914 * @throws RuntimeException if the arguments are invalid 915 * (<em>Note:</em> after optimization, invalid inputs may 916 * go undetected, which will lead to unpredictable 917 * behavior) 918 */ 919 private void freeMemoryChecks(long address) { 920 checkPointer(null, address); 921 } 922 923 /// random queries 924 925 /** 926 * This constant differs from all results that will ever be returned from 927 * {@link #staticFieldOffset}, {@link #objectFieldOffset}, 928 * or {@link #arrayBaseOffset}. 929 */ 930 public static final int INVALID_FIELD_OFFSET = -1; 931 932 /** 933 * Reports the location of a given field in the storage allocation of its 934 * class. Do not expect to perform any sort of arithmetic on this offset; 935 * it is just a cookie which is passed to the unsafe heap memory accessors. 936 * 937 * <p>Any given field will always have the same offset and base, and no 938 * two distinct fields of the same class will ever have the same offset 939 * and base. 940 * 941 * <p>As of 1.4.1, offsets for fields are represented as long values, 942 * although the Sun JVM does not use the most significant 32 bits. 943 * However, JVM implementations which store static fields at absolute 944 * addresses can use long offsets and null base pointers to express 945 * the field locations in a form usable by {@link #getInt(Object,long)}. 946 * Therefore, code which will be ported to such JVMs on 64-bit platforms 947 * must preserve all bits of static field offsets. 948 * @see #getInt(Object, long) 949 */ 950 public long objectFieldOffset(Field f) { 951 if (f == null) { 952 throw new NullPointerException(); 953 } 954 955 return objectFieldOffset0(f); 956 } 957 958 /** 959 * Reports the location of the field with a given name in the storage 960 * allocation of its class. 961 * 962 * @throws NullPointerException if any parameter is {@code null}. 963 * @throws InternalError if there is no field named {@code name} declared 964 * in class {@code c}, i.e., if {@code c.getDeclaredField(name)} 965 * would throw {@code java.lang.NoSuchFieldException}. 966 * 967 * @see #objectFieldOffset(Field) 968 */ 969 public long objectFieldOffset(Class<?> c, String name) { 970 if (c == null || name == null) { 971 throw new NullPointerException(); 972 } 973 974 return objectFieldOffset1(c, name); 975 } 976 977 /** 978 * Reports the location of a given static field, in conjunction with {@link 979 * #staticFieldBase}. 980 * <p>Do not expect to perform any sort of arithmetic on this offset; 981 * it is just a cookie which is passed to the unsafe heap memory accessors. 982 * 983 * <p>Any given field will always have the same offset, and no two distinct 984 * fields of the same class will ever have the same offset. 985 * 986 * <p>As of 1.4.1, offsets for fields are represented as long values, 987 * although the Sun JVM does not use the most significant 32 bits. 988 * It is hard to imagine a JVM technology which needs more than 989 * a few bits to encode an offset within a non-array object, 990 * However, for consistency with other methods in this class, 991 * this method reports its result as a long value. 992 * @see #getInt(Object, long) 993 */ 994 public long staticFieldOffset(Field f) { 995 if (f == null) { 996 throw new NullPointerException(); 997 } 998 999 return staticFieldOffset0(f); 1000 } 1001 1002 /** 1003 * Reports the location of a given static field, in conjunction with {@link 1004 * #staticFieldOffset}. 1005 * <p>Fetch the base "Object", if any, with which static fields of the 1006 * given class can be accessed via methods like {@link #getInt(Object, 1007 * long)}. This value may be null. This value may refer to an object 1008 * which is a "cookie", not guaranteed to be a real Object, and it should 1009 * not be used in any way except as argument to the get and put routines in 1010 * this class. 1011 */ 1012 public Object staticFieldBase(Field f) { 1013 if (f == null) { 1014 throw new NullPointerException(); 1015 } 1016 1017 return staticFieldBase0(f); 1018 } 1019 1020 /** 1021 * Detects if the given class may need to be initialized. This is often 1022 * needed in conjunction with obtaining the static field base of a 1023 * class. 1024 * @return false only if a call to {@code ensureClassInitialized} would have no effect 1025 */ 1026 public boolean shouldBeInitialized(Class<?> c) { 1027 if (c == null) { 1028 throw new NullPointerException(); 1029 } 1030 1031 return shouldBeInitialized0(c); 1032 } 1033 1034 /** 1035 * Ensures the given class has been initialized. This is often 1036 * needed in conjunction with obtaining the static field base of a 1037 * class. 1038 */ 1039 public void ensureClassInitialized(Class<?> c) { 1040 if (c == null) { 1041 throw new NullPointerException(); 1042 } 1043 1044 ensureClassInitialized0(c); 1045 } 1046 1047 /** 1048 * Reports the offset of the first element in the storage allocation of a 1049 * given array class. If {@link #arrayIndexScale} returns a non-zero value 1050 * for the same class, you may use that scale factor, together with this 1051 * base offset, to form new offsets to access elements of arrays of the 1052 * given class. 1053 * 1054 * @see #getInt(Object, long) 1055 * @see #putInt(Object, long, int) 1056 */ 1057 public int arrayBaseOffset(Class<?> arrayClass) { 1058 if (arrayClass == null) { 1059 throw new NullPointerException(); 1060 } 1061 1062 return arrayBaseOffset0(arrayClass); 1063 } 1064 1065 1066 /** The value of {@code arrayBaseOffset(boolean[].class)} */ 1067 public static final int ARRAY_BOOLEAN_BASE_OFFSET 1068 = theUnsafe.arrayBaseOffset(boolean[].class); 1069 1070 /** The value of {@code arrayBaseOffset(byte[].class)} */ 1071 public static final int ARRAY_BYTE_BASE_OFFSET 1072 = theUnsafe.arrayBaseOffset(byte[].class); 1073 1074 /** The value of {@code arrayBaseOffset(short[].class)} */ 1075 public static final int ARRAY_SHORT_BASE_OFFSET 1076 = theUnsafe.arrayBaseOffset(short[].class); 1077 1078 /** The value of {@code arrayBaseOffset(char[].class)} */ 1079 public static final int ARRAY_CHAR_BASE_OFFSET 1080 = theUnsafe.arrayBaseOffset(char[].class); 1081 1082 /** The value of {@code arrayBaseOffset(int[].class)} */ 1083 public static final int ARRAY_INT_BASE_OFFSET 1084 = theUnsafe.arrayBaseOffset(int[].class); 1085 1086 /** The value of {@code arrayBaseOffset(long[].class)} */ 1087 public static final int ARRAY_LONG_BASE_OFFSET 1088 = theUnsafe.arrayBaseOffset(long[].class); 1089 1090 /** The value of {@code arrayBaseOffset(float[].class)} */ 1091 public static final int ARRAY_FLOAT_BASE_OFFSET 1092 = theUnsafe.arrayBaseOffset(float[].class); 1093 1094 /** The value of {@code arrayBaseOffset(double[].class)} */ 1095 public static final int ARRAY_DOUBLE_BASE_OFFSET 1096 = theUnsafe.arrayBaseOffset(double[].class); 1097 1098 /** The value of {@code arrayBaseOffset(Object[].class)} */ 1099 public static final int ARRAY_OBJECT_BASE_OFFSET 1100 = theUnsafe.arrayBaseOffset(Object[].class); 1101 1102 /** 1103 * Reports the scale factor for addressing elements in the storage 1104 * allocation of a given array class. However, arrays of "narrow" types 1105 * will generally not work properly with accessors like {@link 1106 * #getByte(Object, long)}, so the scale factor for such classes is reported 1107 * as zero. 1108 * 1109 * @see #arrayBaseOffset 1110 * @see #getInt(Object, long) 1111 * @see #putInt(Object, long, int) 1112 */ 1113 public int arrayIndexScale(Class<?> arrayClass) { 1114 if (arrayClass == null) { 1115 throw new NullPointerException(); 1116 } 1117 1118 return arrayIndexScale0(arrayClass); 1119 } 1120 1121 1122 /** The value of {@code arrayIndexScale(boolean[].class)} */ 1123 public static final int ARRAY_BOOLEAN_INDEX_SCALE 1124 = theUnsafe.arrayIndexScale(boolean[].class); 1125 1126 /** The value of {@code arrayIndexScale(byte[].class)} */ 1127 public static final int ARRAY_BYTE_INDEX_SCALE 1128 = theUnsafe.arrayIndexScale(byte[].class); 1129 1130 /** The value of {@code arrayIndexScale(short[].class)} */ 1131 public static final int ARRAY_SHORT_INDEX_SCALE 1132 = theUnsafe.arrayIndexScale(short[].class); 1133 1134 /** The value of {@code arrayIndexScale(char[].class)} */ 1135 public static final int ARRAY_CHAR_INDEX_SCALE 1136 = theUnsafe.arrayIndexScale(char[].class); 1137 1138 /** The value of {@code arrayIndexScale(int[].class)} */ 1139 public static final int ARRAY_INT_INDEX_SCALE 1140 = theUnsafe.arrayIndexScale(int[].class); 1141 1142 /** The value of {@code arrayIndexScale(long[].class)} */ 1143 public static final int ARRAY_LONG_INDEX_SCALE 1144 = theUnsafe.arrayIndexScale(long[].class); 1145 1146 /** The value of {@code arrayIndexScale(float[].class)} */ 1147 public static final int ARRAY_FLOAT_INDEX_SCALE 1148 = theUnsafe.arrayIndexScale(float[].class); 1149 1150 /** The value of {@code arrayIndexScale(double[].class)} */ 1151 public static final int ARRAY_DOUBLE_INDEX_SCALE 1152 = theUnsafe.arrayIndexScale(double[].class); 1153 1154 /** The value of {@code arrayIndexScale(Object[].class)} */ 1155 public static final int ARRAY_OBJECT_INDEX_SCALE 1156 = theUnsafe.arrayIndexScale(Object[].class); 1157 1158 /** 1159 * Reports the size in bytes of a native pointer, as stored via {@link 1160 * #putAddress}. This value will be either 4 or 8. Note that the sizes of 1161 * other primitive types (as stored in native memory blocks) is determined 1162 * fully by their information content. 1163 */ 1164 public int addressSize() { 1165 return ADDRESS_SIZE; 1166 } 1167 1168 /** The value of {@code addressSize()} */ 1169 public static final int ADDRESS_SIZE = theUnsafe.addressSize0(); 1170 1171 /** 1172 * Reports the size in bytes of a native memory page (whatever that is). 1173 * This value will always be a power of two. 1174 */ 1175 public native int pageSize(); 1176 1177 1178 /// random trusted operations from JNI: 1179 1180 /** 1181 * Tells the VM to define a class, without security checks. By default, the 1182 * class loader and protection domain come from the caller's class. 1183 */ 1184 public Class<?> defineClass(String name, byte[] b, int off, int len, 1185 ClassLoader loader, 1186 ProtectionDomain protectionDomain) { 1187 if (b == null) { 1188 throw new NullPointerException(); 1189 } 1190 if (len < 0) { 1191 throw new ArrayIndexOutOfBoundsException(); 1192 } 1193 1194 return defineClass0(name, b, off, len, loader, protectionDomain); 1195 } 1196 1197 public native Class<?> defineClass0(String name, byte[] b, int off, int len, 1198 ClassLoader loader, 1199 ProtectionDomain protectionDomain); 1200 1201 /** 1202 * Defines a class but does not make it known to the class loader or system dictionary. 1203 * <p> 1204 * For each CP entry, the corresponding CP patch must either be null or have 1205 * the a format that matches its tag: 1206 * <ul> 1207 * <li>Integer, Long, Float, Double: the corresponding wrapper object type from java.lang 1208 * <li>Utf8: a string (must have suitable syntax if used as signature or name) 1209 * <li>Class: any java.lang.Class object 1210 * <li>String: any object (not just a java.lang.String) 1211 * <li>InterfaceMethodRef: (NYI) a method handle to invoke on that call site's arguments 1212 * </ul> 1213 * @param hostClass context for linkage, access control, protection domain, and class loader 1214 * @param data bytes of a class file 1215 * @param cpPatches where non-null entries exist, they replace corresponding CP entries in data 1216 */ 1217 public Class<?> defineAnonymousClass(Class<?> hostClass, byte[] data, Object[] cpPatches) { 1218 if (hostClass == null || data == null) { 1219 throw new NullPointerException(); 1220 } 1221 if (hostClass.isArray() || hostClass.isPrimitive()) { 1222 throw new IllegalArgumentException(); 1223 } 1224 1225 return defineAnonymousClass0(hostClass, data, cpPatches); 1226 } 1227 1228 /** 1229 * Allocates an instance but does not run any constructor. 1230 * Initializes the class if it has not yet been. 1231 */ 1232 @HotSpotIntrinsicCandidate 1233 public native Object allocateInstance(Class<?> cls) 1234 throws InstantiationException; 1235 1236 /** 1237 * Allocates an array of a given type, but does not do zeroing. 1238 * <p> 1239 * This method should only be used in the very rare cases where a high-performance code 1240 * overwrites the destination array completely, and compilers cannot assist in zeroing elimination. 1241 * In an overwhelming majority of cases, a normal Java allocation should be used instead. 1242 * <p> 1243 * Users of this method are <b>required</b> to overwrite the initial (garbage) array contents 1244 * before allowing untrusted code, or code in other threads, to observe the reference 1245 * to the newly allocated array. In addition, the publication of the array reference must be 1246 * safe according to the Java Memory Model requirements. 1247 * <p> 1248 * The safest approach to deal with an uninitialized array is to keep the reference to it in local 1249 * variable at least until the initialization is complete, and then publish it <b>once</b>, either 1250 * by writing it to a <em>volatile</em> field, or storing it into a <em>final</em> field in constructor, 1251 * or issuing a {@link #storeFence} before publishing the reference. 1252 * <p> 1253 * @implnote This method can only allocate primitive arrays, to avoid garbage reference 1254 * elements that could break heap integrity. 1255 * 1256 * @param componentType array component type to allocate 1257 * @param length array size to allocate 1258 * @throws IllegalArgumentException if component type is null, or not a primitive class; 1259 * or the length is negative 1260 */ 1261 public Object allocateUninitializedArray(Class<?> componentType, int length) { 1262 if (componentType == null) { 1263 throw new IllegalArgumentException("Component type is null"); 1264 } 1265 if (!componentType.isPrimitive()) { 1266 throw new IllegalArgumentException("Component type is not primitive"); 1267 } 1268 if (length < 0) { 1269 throw new IllegalArgumentException("Negative length"); 1270 } 1271 return allocateUninitializedArray0(componentType, length); 1272 } 1273 1274 @HotSpotIntrinsicCandidate 1275 private Object allocateUninitializedArray0(Class<?> componentType, int length) { 1276 // These fallbacks provide zeroed arrays, but intrinsic is not required to 1277 // return the zeroed arrays. 1278 if (componentType == byte.class) return new byte[length]; 1279 if (componentType == boolean.class) return new boolean[length]; 1280 if (componentType == short.class) return new short[length]; 1281 if (componentType == char.class) return new char[length]; 1282 if (componentType == int.class) return new int[length]; 1283 if (componentType == float.class) return new float[length]; 1284 if (componentType == long.class) return new long[length]; 1285 if (componentType == double.class) return new double[length]; 1286 return null; 1287 } 1288 1289 /** Throws the exception without telling the verifier. */ 1290 public native void throwException(Throwable ee); 1291 1292 /** 1293 * Atomically updates Java variable to {@code x} if it is currently 1294 * holding {@code expected}. 1295 * 1296 * <p>This operation has memory semantics of a {@code volatile} read 1297 * and write. Corresponds to C11 atomic_compare_exchange_strong. 1298 * 1299 * @return {@code true} if successful 1300 */ 1301 @HotSpotIntrinsicCandidate 1302 public final native boolean compareAndSetObject(Object o, long offset, 1303 Object expected, 1304 Object x); 1305 1306 @HotSpotIntrinsicCandidate 1307 public final native Object compareAndExchangeObject(Object o, long offset, 1308 Object expected, 1309 Object x); 1310 1311 @HotSpotIntrinsicCandidate 1312 public final Object compareAndExchangeObjectAcquire(Object o, long offset, 1313 Object expected, 1314 Object x) { 1315 return compareAndExchangeObject(o, offset, expected, x); 1316 } 1317 1318 @HotSpotIntrinsicCandidate 1319 public final Object compareAndExchangeObjectRelease(Object o, long offset, 1320 Object expected, 1321 Object x) { 1322 return compareAndExchangeObject(o, offset, expected, x); 1323 } 1324 1325 @HotSpotIntrinsicCandidate 1326 public final boolean weakCompareAndSetObjectPlain(Object o, long offset, 1327 Object expected, 1328 Object x) { 1329 return compareAndSetObject(o, offset, expected, x); 1330 } 1331 1332 @HotSpotIntrinsicCandidate 1333 public final boolean weakCompareAndSetObjectAcquire(Object o, long offset, 1334 Object expected, 1335 Object x) { 1336 return compareAndSetObject(o, offset, expected, x); 1337 } 1338 1339 @HotSpotIntrinsicCandidate 1340 public final boolean weakCompareAndSetObjectRelease(Object o, long offset, 1341 Object expected, 1342 Object x) { 1343 return compareAndSetObject(o, offset, expected, x); 1344 } 1345 1346 @HotSpotIntrinsicCandidate 1347 public final boolean weakCompareAndSetObject(Object o, long offset, 1348 Object expected, 1349 Object x) { 1350 return compareAndSetObject(o, offset, expected, x); 1351 } 1352 1353 /** 1354 * Atomically updates Java variable to {@code x} if it is currently 1355 * holding {@code expected}. 1356 * 1357 * <p>This operation has memory semantics of a {@code volatile} read 1358 * and write. Corresponds to C11 atomic_compare_exchange_strong. 1359 * 1360 * @return {@code true} if successful 1361 */ 1362 @HotSpotIntrinsicCandidate 1363 public final native boolean compareAndSetInt(Object o, long offset, 1364 int expected, 1365 int x); 1366 1367 @HotSpotIntrinsicCandidate 1368 public final native int compareAndExchangeInt(Object o, long offset, 1369 int expected, 1370 int x); 1371 1372 @HotSpotIntrinsicCandidate 1373 public final int compareAndExchangeIntAcquire(Object o, long offset, 1374 int expected, 1375 int x) { 1376 return compareAndExchangeInt(o, offset, expected, x); 1377 } 1378 1379 @HotSpotIntrinsicCandidate 1380 public final int compareAndExchangeIntRelease(Object o, long offset, 1381 int expected, 1382 int x) { 1383 return compareAndExchangeInt(o, offset, expected, x); 1384 } 1385 1386 @HotSpotIntrinsicCandidate 1387 public final boolean weakCompareAndSetIntPlain(Object o, long offset, 1388 int expected, 1389 int x) { 1390 return compareAndSetInt(o, offset, expected, x); 1391 } 1392 1393 @HotSpotIntrinsicCandidate 1394 public final boolean weakCompareAndSetIntAcquire(Object o, long offset, 1395 int expected, 1396 int x) { 1397 return compareAndSetInt(o, offset, expected, x); 1398 } 1399 1400 @HotSpotIntrinsicCandidate 1401 public final boolean weakCompareAndSetIntRelease(Object o, long offset, 1402 int expected, 1403 int x) { 1404 return compareAndSetInt(o, offset, expected, x); 1405 } 1406 1407 @HotSpotIntrinsicCandidate 1408 public final boolean weakCompareAndSetInt(Object o, long offset, 1409 int expected, 1410 int x) { 1411 return compareAndSetInt(o, offset, expected, x); 1412 } 1413 1414 @HotSpotIntrinsicCandidate 1415 public final byte compareAndExchangeByte(Object o, long offset, 1416 byte expected, 1417 byte x) { 1418 long wordOffset = offset & ~3; 1419 int shift = (int) (offset & 3) << 3; 1420 if (BE) { 1421 shift = 24 - shift; 1422 } 1423 int mask = 0xFF << shift; 1424 int maskedExpected = (expected & 0xFF) << shift; 1425 int maskedX = (x & 0xFF) << shift; 1426 int fullWord; 1427 do { 1428 fullWord = getIntVolatile(o, wordOffset); 1429 if ((fullWord & mask) != maskedExpected) 1430 return (byte) ((fullWord & mask) >> shift); 1431 } while (!weakCompareAndSetInt(o, wordOffset, 1432 fullWord, (fullWord & ~mask) | maskedX)); 1433 return expected; 1434 } 1435 1436 @HotSpotIntrinsicCandidate 1437 public final boolean compareAndSetByte(Object o, long offset, 1438 byte expected, 1439 byte x) { 1440 return compareAndExchangeByte(o, offset, expected, x) == expected; 1441 } 1442 1443 @HotSpotIntrinsicCandidate 1444 public final boolean weakCompareAndSetByte(Object o, long offset, 1445 byte expected, 1446 byte x) { 1447 return compareAndSetByte(o, offset, expected, x); 1448 } 1449 1450 @HotSpotIntrinsicCandidate 1451 public final boolean weakCompareAndSetByteAcquire(Object o, long offset, 1452 byte expected, 1453 byte x) { 1454 return weakCompareAndSetByte(o, offset, expected, x); 1455 } 1456 1457 @HotSpotIntrinsicCandidate 1458 public final boolean weakCompareAndSetByteRelease(Object o, long offset, 1459 byte expected, 1460 byte x) { 1461 return weakCompareAndSetByte(o, offset, expected, x); 1462 } 1463 1464 @HotSpotIntrinsicCandidate 1465 public final boolean weakCompareAndSetBytePlain(Object o, long offset, 1466 byte expected, 1467 byte x) { 1468 return weakCompareAndSetByte(o, offset, expected, x); 1469 } 1470 1471 @HotSpotIntrinsicCandidate 1472 public final byte compareAndExchangeByteAcquire(Object o, long offset, 1473 byte expected, 1474 byte x) { 1475 return compareAndExchangeByte(o, offset, expected, x); 1476 } 1477 1478 @HotSpotIntrinsicCandidate 1479 public final byte compareAndExchangeByteRelease(Object o, long offset, 1480 byte expected, 1481 byte x) { 1482 return compareAndExchangeByte(o, offset, expected, x); 1483 } 1484 1485 @HotSpotIntrinsicCandidate 1486 public final short compareAndExchangeShort(Object o, long offset, 1487 short expected, 1488 short x) { 1489 if ((offset & 3) == 3) { 1490 throw new IllegalArgumentException("Update spans the word, not supported"); 1491 } 1492 long wordOffset = offset & ~3; 1493 int shift = (int) (offset & 3) << 3; 1494 if (BE) { 1495 shift = 16 - shift; 1496 } 1497 int mask = 0xFFFF << shift; 1498 int maskedExpected = (expected & 0xFFFF) << shift; 1499 int maskedX = (x & 0xFFFF) << shift; 1500 int fullWord; 1501 do { 1502 fullWord = getIntVolatile(o, wordOffset); 1503 if ((fullWord & mask) != maskedExpected) { 1504 return (short) ((fullWord & mask) >> shift); 1505 } 1506 } while (!weakCompareAndSetInt(o, wordOffset, 1507 fullWord, (fullWord & ~mask) | maskedX)); 1508 return expected; 1509 } 1510 1511 @HotSpotIntrinsicCandidate 1512 public final boolean compareAndSetShort(Object o, long offset, 1513 short expected, 1514 short x) { 1515 return compareAndExchangeShort(o, offset, expected, x) == expected; 1516 } 1517 1518 @HotSpotIntrinsicCandidate 1519 public final boolean weakCompareAndSetShort(Object o, long offset, 1520 short expected, 1521 short x) { 1522 return compareAndSetShort(o, offset, expected, x); 1523 } 1524 1525 @HotSpotIntrinsicCandidate 1526 public final boolean weakCompareAndSetShortAcquire(Object o, long offset, 1527 short expected, 1528 short x) { 1529 return weakCompareAndSetShort(o, offset, expected, x); 1530 } 1531 1532 @HotSpotIntrinsicCandidate 1533 public final boolean weakCompareAndSetShortRelease(Object o, long offset, 1534 short expected, 1535 short x) { 1536 return weakCompareAndSetShort(o, offset, expected, x); 1537 } 1538 1539 @HotSpotIntrinsicCandidate 1540 public final boolean weakCompareAndSetShortPlain(Object o, long offset, 1541 short expected, 1542 short x) { 1543 return weakCompareAndSetShort(o, offset, expected, x); 1544 } 1545 1546 1547 @HotSpotIntrinsicCandidate 1548 public final short compareAndExchangeShortAcquire(Object o, long offset, 1549 short expected, 1550 short x) { 1551 return compareAndExchangeShort(o, offset, expected, x); 1552 } 1553 1554 @HotSpotIntrinsicCandidate 1555 public final short compareAndExchangeShortRelease(Object o, long offset, 1556 short expected, 1557 short x) { 1558 return compareAndExchangeShort(o, offset, expected, x); 1559 } 1560 1561 @ForceInline 1562 private char s2c(short s) { 1563 return (char) s; 1564 } 1565 1566 @ForceInline 1567 private short c2s(char s) { 1568 return (short) s; 1569 } 1570 1571 @ForceInline 1572 public final boolean compareAndSetChar(Object o, long offset, 1573 char expected, 1574 char x) { 1575 return compareAndSetShort(o, offset, c2s(expected), c2s(x)); 1576 } 1577 1578 @ForceInline 1579 public final char compareAndExchangeChar(Object o, long offset, 1580 char expected, 1581 char x) { 1582 return s2c(compareAndExchangeShort(o, offset, c2s(expected), c2s(x))); 1583 } 1584 1585 @ForceInline 1586 public final char compareAndExchangeCharAcquire(Object o, long offset, 1587 char expected, 1588 char x) { 1589 return s2c(compareAndExchangeShortAcquire(o, offset, c2s(expected), c2s(x))); 1590 } 1591 1592 @ForceInline 1593 public final char compareAndExchangeCharRelease(Object o, long offset, 1594 char expected, 1595 char x) { 1596 return s2c(compareAndExchangeShortRelease(o, offset, c2s(expected), c2s(x))); 1597 } 1598 1599 @ForceInline 1600 public final boolean weakCompareAndSetChar(Object o, long offset, 1601 char expected, 1602 char x) { 1603 return weakCompareAndSetShort(o, offset, c2s(expected), c2s(x)); 1604 } 1605 1606 @ForceInline 1607 public final boolean weakCompareAndSetCharAcquire(Object o, long offset, 1608 char expected, 1609 char x) { 1610 return weakCompareAndSetShortAcquire(o, offset, c2s(expected), c2s(x)); 1611 } 1612 1613 @ForceInline 1614 public final boolean weakCompareAndSetCharRelease(Object o, long offset, 1615 char expected, 1616 char x) { 1617 return weakCompareAndSetShortRelease(o, offset, c2s(expected), c2s(x)); 1618 } 1619 1620 @ForceInline 1621 public final boolean weakCompareAndSetCharPlain(Object o, long offset, 1622 char expected, 1623 char x) { 1624 return weakCompareAndSetShortPlain(o, offset, c2s(expected), c2s(x)); 1625 } 1626 1627 /** 1628 * The JVM converts integral values to boolean values using two 1629 * different conventions, byte testing against zero and truncation 1630 * to least-significant bit. 1631 * 1632 * <p>The JNI documents specify that, at least for returning 1633 * values from native methods, a Java boolean value is converted 1634 * to the value-set 0..1 by first truncating to a byte (0..255 or 1635 * maybe -128..127) and then testing against zero. Thus, Java 1636 * booleans in non-Java data structures are by convention 1637 * represented as 8-bit containers containing either zero (for 1638 * false) or any non-zero value (for true). 1639 * 1640 * <p>Java booleans in the heap are also stored in bytes, but are 1641 * strongly normalized to the value-set 0..1 (i.e., they are 1642 * truncated to the least-significant bit). 1643 * 1644 * <p>The main reason for having different conventions for 1645 * conversion is performance: Truncation to the least-significant 1646 * bit can be usually implemented with fewer (machine) 1647 * instructions than byte testing against zero. 1648 * 1649 * <p>A number of Unsafe methods load boolean values from the heap 1650 * as bytes. Unsafe converts those values according to the JNI 1651 * rules (i.e, using the "testing against zero" convention). The 1652 * method {@code byte2bool} implements that conversion. 1653 * 1654 * @param b the byte to be converted to boolean 1655 * @return the result of the conversion 1656 */ 1657 @ForceInline 1658 private boolean byte2bool(byte b) { 1659 return b != 0; 1660 } 1661 1662 /** 1663 * Convert a boolean value to a byte. The return value is strongly 1664 * normalized to the value-set 0..1 (i.e., the value is truncated 1665 * to the least-significant bit). See {@link #byte2bool(byte)} for 1666 * more details on conversion conventions. 1667 * 1668 * @param b the boolean to be converted to byte (and then normalized) 1669 * @return the result of the conversion 1670 */ 1671 @ForceInline 1672 private byte bool2byte(boolean b) { 1673 return b ? (byte)1 : (byte)0; 1674 } 1675 1676 @ForceInline 1677 public final boolean compareAndSetBoolean(Object o, long offset, 1678 boolean expected, 1679 boolean x) { 1680 return compareAndSetByte(o, offset, bool2byte(expected), bool2byte(x)); 1681 } 1682 1683 @ForceInline 1684 public final boolean compareAndExchangeBoolean(Object o, long offset, 1685 boolean expected, 1686 boolean x) { 1687 return byte2bool(compareAndExchangeByte(o, offset, bool2byte(expected), bool2byte(x))); 1688 } 1689 1690 @ForceInline 1691 public final boolean compareAndExchangeBooleanAcquire(Object o, long offset, 1692 boolean expected, 1693 boolean x) { 1694 return byte2bool(compareAndExchangeByteAcquire(o, offset, bool2byte(expected), bool2byte(x))); 1695 } 1696 1697 @ForceInline 1698 public final boolean compareAndExchangeBooleanRelease(Object o, long offset, 1699 boolean expected, 1700 boolean x) { 1701 return byte2bool(compareAndExchangeByteRelease(o, offset, bool2byte(expected), bool2byte(x))); 1702 } 1703 1704 @ForceInline 1705 public final boolean weakCompareAndSetBoolean(Object o, long offset, 1706 boolean expected, 1707 boolean x) { 1708 return weakCompareAndSetByte(o, offset, bool2byte(expected), bool2byte(x)); 1709 } 1710 1711 @ForceInline 1712 public final boolean weakCompareAndSetBooleanAcquire(Object o, long offset, 1713 boolean expected, 1714 boolean x) { 1715 return weakCompareAndSetByteAcquire(o, offset, bool2byte(expected), bool2byte(x)); 1716 } 1717 1718 @ForceInline 1719 public final boolean weakCompareAndSetBooleanRelease(Object o, long offset, 1720 boolean expected, 1721 boolean x) { 1722 return weakCompareAndSetByteRelease(o, offset, bool2byte(expected), bool2byte(x)); 1723 } 1724 1725 @ForceInline 1726 public final boolean weakCompareAndSetBooleanPlain(Object o, long offset, 1727 boolean expected, 1728 boolean x) { 1729 return weakCompareAndSetBytePlain(o, offset, bool2byte(expected), bool2byte(x)); 1730 } 1731 1732 /** 1733 * Atomically updates Java variable to {@code x} if it is currently 1734 * holding {@code expected}. 1735 * 1736 * <p>This operation has memory semantics of a {@code volatile} read 1737 * and write. Corresponds to C11 atomic_compare_exchange_strong. 1738 * 1739 * @return {@code true} if successful 1740 */ 1741 @ForceInline 1742 public final boolean compareAndSetFloat(Object o, long offset, 1743 float expected, 1744 float x) { 1745 return compareAndSetInt(o, offset, 1746 Float.floatToRawIntBits(expected), 1747 Float.floatToRawIntBits(x)); 1748 } 1749 1750 @ForceInline 1751 public final float compareAndExchangeFloat(Object o, long offset, 1752 float expected, 1753 float x) { 1754 int w = compareAndExchangeInt(o, offset, 1755 Float.floatToRawIntBits(expected), 1756 Float.floatToRawIntBits(x)); 1757 return Float.intBitsToFloat(w); 1758 } 1759 1760 @ForceInline 1761 public final float compareAndExchangeFloatAcquire(Object o, long offset, 1762 float expected, 1763 float x) { 1764 int w = compareAndExchangeIntAcquire(o, offset, 1765 Float.floatToRawIntBits(expected), 1766 Float.floatToRawIntBits(x)); 1767 return Float.intBitsToFloat(w); 1768 } 1769 1770 @ForceInline 1771 public final float compareAndExchangeFloatRelease(Object o, long offset, 1772 float expected, 1773 float x) { 1774 int w = compareAndExchangeIntRelease(o, offset, 1775 Float.floatToRawIntBits(expected), 1776 Float.floatToRawIntBits(x)); 1777 return Float.intBitsToFloat(w); 1778 } 1779 1780 @ForceInline 1781 public final boolean weakCompareAndSetFloatPlain(Object o, long offset, 1782 float expected, 1783 float x) { 1784 return weakCompareAndSetIntPlain(o, offset, 1785 Float.floatToRawIntBits(expected), 1786 Float.floatToRawIntBits(x)); 1787 } 1788 1789 @ForceInline 1790 public final boolean weakCompareAndSetFloatAcquire(Object o, long offset, 1791 float expected, 1792 float x) { 1793 return weakCompareAndSetIntAcquire(o, offset, 1794 Float.floatToRawIntBits(expected), 1795 Float.floatToRawIntBits(x)); 1796 } 1797 1798 @ForceInline 1799 public final boolean weakCompareAndSetFloatRelease(Object o, long offset, 1800 float expected, 1801 float x) { 1802 return weakCompareAndSetIntRelease(o, offset, 1803 Float.floatToRawIntBits(expected), 1804 Float.floatToRawIntBits(x)); 1805 } 1806 1807 @ForceInline 1808 public final boolean weakCompareAndSetFloat(Object o, long offset, 1809 float expected, 1810 float x) { 1811 return weakCompareAndSetInt(o, offset, 1812 Float.floatToRawIntBits(expected), 1813 Float.floatToRawIntBits(x)); 1814 } 1815 1816 /** 1817 * Atomically updates Java variable to {@code x} if it is currently 1818 * holding {@code expected}. 1819 * 1820 * <p>This operation has memory semantics of a {@code volatile} read 1821 * and write. Corresponds to C11 atomic_compare_exchange_strong. 1822 * 1823 * @return {@code true} if successful 1824 */ 1825 @ForceInline 1826 public final boolean compareAndSetDouble(Object o, long offset, 1827 double expected, 1828 double x) { 1829 return compareAndSetLong(o, offset, 1830 Double.doubleToRawLongBits(expected), 1831 Double.doubleToRawLongBits(x)); 1832 } 1833 1834 @ForceInline 1835 public final double compareAndExchangeDouble(Object o, long offset, 1836 double expected, 1837 double x) { 1838 long w = compareAndExchangeLong(o, offset, 1839 Double.doubleToRawLongBits(expected), 1840 Double.doubleToRawLongBits(x)); 1841 return Double.longBitsToDouble(w); 1842 } 1843 1844 @ForceInline 1845 public final double compareAndExchangeDoubleAcquire(Object o, long offset, 1846 double expected, 1847 double x) { 1848 long w = compareAndExchangeLongAcquire(o, offset, 1849 Double.doubleToRawLongBits(expected), 1850 Double.doubleToRawLongBits(x)); 1851 return Double.longBitsToDouble(w); 1852 } 1853 1854 @ForceInline 1855 public final double compareAndExchangeDoubleRelease(Object o, long offset, 1856 double expected, 1857 double x) { 1858 long w = compareAndExchangeLongRelease(o, offset, 1859 Double.doubleToRawLongBits(expected), 1860 Double.doubleToRawLongBits(x)); 1861 return Double.longBitsToDouble(w); 1862 } 1863 1864 @ForceInline 1865 public final boolean weakCompareAndSetDoublePlain(Object o, long offset, 1866 double expected, 1867 double x) { 1868 return weakCompareAndSetLongPlain(o, offset, 1869 Double.doubleToRawLongBits(expected), 1870 Double.doubleToRawLongBits(x)); 1871 } 1872 1873 @ForceInline 1874 public final boolean weakCompareAndSetDoubleAcquire(Object o, long offset, 1875 double expected, 1876 double x) { 1877 return weakCompareAndSetLongAcquire(o, offset, 1878 Double.doubleToRawLongBits(expected), 1879 Double.doubleToRawLongBits(x)); 1880 } 1881 1882 @ForceInline 1883 public final boolean weakCompareAndSetDoubleRelease(Object o, long offset, 1884 double expected, 1885 double x) { 1886 return weakCompareAndSetLongRelease(o, offset, 1887 Double.doubleToRawLongBits(expected), 1888 Double.doubleToRawLongBits(x)); 1889 } 1890 1891 @ForceInline 1892 public final boolean weakCompareAndSetDouble(Object o, long offset, 1893 double expected, 1894 double x) { 1895 return weakCompareAndSetLong(o, offset, 1896 Double.doubleToRawLongBits(expected), 1897 Double.doubleToRawLongBits(x)); 1898 } 1899 1900 /** 1901 * Atomically updates Java variable to {@code x} if it is currently 1902 * holding {@code expected}. 1903 * 1904 * <p>This operation has memory semantics of a {@code volatile} read 1905 * and write. Corresponds to C11 atomic_compare_exchange_strong. 1906 * 1907 * @return {@code true} if successful 1908 */ 1909 @HotSpotIntrinsicCandidate 1910 public final native boolean compareAndSetLong(Object o, long offset, 1911 long expected, 1912 long x); 1913 1914 @HotSpotIntrinsicCandidate 1915 public final native long compareAndExchangeLong(Object o, long offset, 1916 long expected, 1917 long x); 1918 1919 @HotSpotIntrinsicCandidate 1920 public final long compareAndExchangeLongAcquire(Object o, long offset, 1921 long expected, 1922 long x) { 1923 return compareAndExchangeLong(o, offset, expected, x); 1924 } 1925 1926 @HotSpotIntrinsicCandidate 1927 public final long compareAndExchangeLongRelease(Object o, long offset, 1928 long expected, 1929 long x) { 1930 return compareAndExchangeLong(o, offset, expected, x); 1931 } 1932 1933 @HotSpotIntrinsicCandidate 1934 public final boolean weakCompareAndSetLongPlain(Object o, long offset, 1935 long expected, 1936 long x) { 1937 return compareAndSetLong(o, offset, expected, x); 1938 } 1939 1940 @HotSpotIntrinsicCandidate 1941 public final boolean weakCompareAndSetLongAcquire(Object o, long offset, 1942 long expected, 1943 long x) { 1944 return compareAndSetLong(o, offset, expected, x); 1945 } 1946 1947 @HotSpotIntrinsicCandidate 1948 public final boolean weakCompareAndSetLongRelease(Object o, long offset, 1949 long expected, 1950 long x) { 1951 return compareAndSetLong(o, offset, expected, x); 1952 } 1953 1954 @HotSpotIntrinsicCandidate 1955 public final boolean weakCompareAndSetLong(Object o, long offset, 1956 long expected, 1957 long x) { 1958 return compareAndSetLong(o, offset, expected, x); 1959 } 1960 1961 /** 1962 * Fetches a reference value from a given Java variable, with volatile 1963 * load semantics. Otherwise identical to {@link #getObject(Object, long)} 1964 */ 1965 @HotSpotIntrinsicCandidate 1966 public native Object getObjectVolatile(Object o, long offset); 1967 1968 /** 1969 * Stores a reference value into a given Java variable, with 1970 * volatile store semantics. Otherwise identical to {@link #putObject(Object, long, Object)} 1971 */ 1972 @HotSpotIntrinsicCandidate 1973 public native void putObjectVolatile(Object o, long offset, Object x); 1974 1975 /** Volatile version of {@link #getInt(Object, long)} */ 1976 @HotSpotIntrinsicCandidate 1977 public native int getIntVolatile(Object o, long offset); 1978 1979 /** Volatile version of {@link #putInt(Object, long, int)} */ 1980 @HotSpotIntrinsicCandidate 1981 public native void putIntVolatile(Object o, long offset, int x); 1982 1983 /** Volatile version of {@link #getBoolean(Object, long)} */ 1984 @HotSpotIntrinsicCandidate 1985 public native boolean getBooleanVolatile(Object o, long offset); 1986 1987 /** Volatile version of {@link #putBoolean(Object, long, boolean)} */ 1988 @HotSpotIntrinsicCandidate 1989 public native void putBooleanVolatile(Object o, long offset, boolean x); 1990 1991 /** Volatile version of {@link #getByte(Object, long)} */ 1992 @HotSpotIntrinsicCandidate 1993 public native byte getByteVolatile(Object o, long offset); 1994 1995 /** Volatile version of {@link #putByte(Object, long, byte)} */ 1996 @HotSpotIntrinsicCandidate 1997 public native void putByteVolatile(Object o, long offset, byte x); 1998 1999 /** Volatile version of {@link #getShort(Object, long)} */ 2000 @HotSpotIntrinsicCandidate 2001 public native short getShortVolatile(Object o, long offset); 2002 2003 /** Volatile version of {@link #putShort(Object, long, short)} */ 2004 @HotSpotIntrinsicCandidate 2005 public native void putShortVolatile(Object o, long offset, short x); 2006 2007 /** Volatile version of {@link #getChar(Object, long)} */ 2008 @HotSpotIntrinsicCandidate 2009 public native char getCharVolatile(Object o, long offset); 2010 2011 /** Volatile version of {@link #putChar(Object, long, char)} */ 2012 @HotSpotIntrinsicCandidate 2013 public native void putCharVolatile(Object o, long offset, char x); 2014 2015 /** Volatile version of {@link #getLong(Object, long)} */ 2016 @HotSpotIntrinsicCandidate 2017 public native long getLongVolatile(Object o, long offset); 2018 2019 /** Volatile version of {@link #putLong(Object, long, long)} */ 2020 @HotSpotIntrinsicCandidate 2021 public native void putLongVolatile(Object o, long offset, long x); 2022 2023 /** Volatile version of {@link #getFloat(Object, long)} */ 2024 @HotSpotIntrinsicCandidate 2025 public native float getFloatVolatile(Object o, long offset); 2026 2027 /** Volatile version of {@link #putFloat(Object, long, float)} */ 2028 @HotSpotIntrinsicCandidate 2029 public native void putFloatVolatile(Object o, long offset, float x); 2030 2031 /** Volatile version of {@link #getDouble(Object, long)} */ 2032 @HotSpotIntrinsicCandidate 2033 public native double getDoubleVolatile(Object o, long offset); 2034 2035 /** Volatile version of {@link #putDouble(Object, long, double)} */ 2036 @HotSpotIntrinsicCandidate 2037 public native void putDoubleVolatile(Object o, long offset, double x); 2038 2039 2040 2041 /** Acquire version of {@link #getObjectVolatile(Object, long)} */ 2042 @HotSpotIntrinsicCandidate 2043 public final Object getObjectAcquire(Object o, long offset) { 2044 return getObjectVolatile(o, offset); 2045 } 2046 2047 /** Acquire version of {@link #getBooleanVolatile(Object, long)} */ 2048 @HotSpotIntrinsicCandidate 2049 public final boolean getBooleanAcquire(Object o, long offset) { 2050 return getBooleanVolatile(o, offset); 2051 } 2052 2053 /** Acquire version of {@link #getByteVolatile(Object, long)} */ 2054 @HotSpotIntrinsicCandidate 2055 public final byte getByteAcquire(Object o, long offset) { 2056 return getByteVolatile(o, offset); 2057 } 2058 2059 /** Acquire version of {@link #getShortVolatile(Object, long)} */ 2060 @HotSpotIntrinsicCandidate 2061 public final short getShortAcquire(Object o, long offset) { 2062 return getShortVolatile(o, offset); 2063 } 2064 2065 /** Acquire version of {@link #getCharVolatile(Object, long)} */ 2066 @HotSpotIntrinsicCandidate 2067 public final char getCharAcquire(Object o, long offset) { 2068 return getCharVolatile(o, offset); 2069 } 2070 2071 /** Acquire version of {@link #getIntVolatile(Object, long)} */ 2072 @HotSpotIntrinsicCandidate 2073 public final int getIntAcquire(Object o, long offset) { 2074 return getIntVolatile(o, offset); 2075 } 2076 2077 /** Acquire version of {@link #getFloatVolatile(Object, long)} */ 2078 @HotSpotIntrinsicCandidate 2079 public final float getFloatAcquire(Object o, long offset) { 2080 return getFloatVolatile(o, offset); 2081 } 2082 2083 /** Acquire version of {@link #getLongVolatile(Object, long)} */ 2084 @HotSpotIntrinsicCandidate 2085 public final long getLongAcquire(Object o, long offset) { 2086 return getLongVolatile(o, offset); 2087 } 2088 2089 /** Acquire version of {@link #getDoubleVolatile(Object, long)} */ 2090 @HotSpotIntrinsicCandidate 2091 public final double getDoubleAcquire(Object o, long offset) { 2092 return getDoubleVolatile(o, offset); 2093 } 2094 2095 /* 2096 * Versions of {@link #putObjectVolatile(Object, long, Object)} 2097 * that do not guarantee immediate visibility of the store to 2098 * other threads. This method is generally only useful if the 2099 * underlying field is a Java volatile (or if an array cell, one 2100 * that is otherwise only accessed using volatile accesses). 2101 * 2102 * Corresponds to C11 atomic_store_explicit(..., memory_order_release). 2103 */ 2104 2105 /** Release version of {@link #putObjectVolatile(Object, long, Object)} */ 2106 @HotSpotIntrinsicCandidate 2107 public final void putObjectRelease(Object o, long offset, Object x) { 2108 putObjectVolatile(o, offset, x); 2109 } 2110 2111 /** Release version of {@link #putBooleanVolatile(Object, long, boolean)} */ 2112 @HotSpotIntrinsicCandidate 2113 public final void putBooleanRelease(Object o, long offset, boolean x) { 2114 putBooleanVolatile(o, offset, x); 2115 } 2116 2117 /** Release version of {@link #putByteVolatile(Object, long, byte)} */ 2118 @HotSpotIntrinsicCandidate 2119 public final void putByteRelease(Object o, long offset, byte x) { 2120 putByteVolatile(o, offset, x); 2121 } 2122 2123 /** Release version of {@link #putShortVolatile(Object, long, short)} */ 2124 @HotSpotIntrinsicCandidate 2125 public final void putShortRelease(Object o, long offset, short x) { 2126 putShortVolatile(o, offset, x); 2127 } 2128 2129 /** Release version of {@link #putCharVolatile(Object, long, char)} */ 2130 @HotSpotIntrinsicCandidate 2131 public final void putCharRelease(Object o, long offset, char x) { 2132 putCharVolatile(o, offset, x); 2133 } 2134 2135 /** Release version of {@link #putIntVolatile(Object, long, int)} */ 2136 @HotSpotIntrinsicCandidate 2137 public final void putIntRelease(Object o, long offset, int x) { 2138 putIntVolatile(o, offset, x); 2139 } 2140 2141 /** Release version of {@link #putFloatVolatile(Object, long, float)} */ 2142 @HotSpotIntrinsicCandidate 2143 public final void putFloatRelease(Object o, long offset, float x) { 2144 putFloatVolatile(o, offset, x); 2145 } 2146 2147 /** Release version of {@link #putLongVolatile(Object, long, long)} */ 2148 @HotSpotIntrinsicCandidate 2149 public final void putLongRelease(Object o, long offset, long x) { 2150 putLongVolatile(o, offset, x); 2151 } 2152 2153 /** Release version of {@link #putDoubleVolatile(Object, long, double)} */ 2154 @HotSpotIntrinsicCandidate 2155 public final void putDoubleRelease(Object o, long offset, double x) { 2156 putDoubleVolatile(o, offset, x); 2157 } 2158 2159 // ------------------------------ Opaque -------------------------------------- 2160 2161 /** Opaque version of {@link #getObjectVolatile(Object, long)} */ 2162 @HotSpotIntrinsicCandidate 2163 public final Object getObjectOpaque(Object o, long offset) { 2164 return getObjectVolatile(o, offset); 2165 } 2166 2167 /** Opaque version of {@link #getBooleanVolatile(Object, long)} */ 2168 @HotSpotIntrinsicCandidate 2169 public final boolean getBooleanOpaque(Object o, long offset) { 2170 return getBooleanVolatile(o, offset); 2171 } 2172 2173 /** Opaque version of {@link #getByteVolatile(Object, long)} */ 2174 @HotSpotIntrinsicCandidate 2175 public final byte getByteOpaque(Object o, long offset) { 2176 return getByteVolatile(o, offset); 2177 } 2178 2179 /** Opaque version of {@link #getShortVolatile(Object, long)} */ 2180 @HotSpotIntrinsicCandidate 2181 public final short getShortOpaque(Object o, long offset) { 2182 return getShortVolatile(o, offset); 2183 } 2184 2185 /** Opaque version of {@link #getCharVolatile(Object, long)} */ 2186 @HotSpotIntrinsicCandidate 2187 public final char getCharOpaque(Object o, long offset) { 2188 return getCharVolatile(o, offset); 2189 } 2190 2191 /** Opaque version of {@link #getIntVolatile(Object, long)} */ 2192 @HotSpotIntrinsicCandidate 2193 public final int getIntOpaque(Object o, long offset) { 2194 return getIntVolatile(o, offset); 2195 } 2196 2197 /** Opaque version of {@link #getFloatVolatile(Object, long)} */ 2198 @HotSpotIntrinsicCandidate 2199 public final float getFloatOpaque(Object o, long offset) { 2200 return getFloatVolatile(o, offset); 2201 } 2202 2203 /** Opaque version of {@link #getLongVolatile(Object, long)} */ 2204 @HotSpotIntrinsicCandidate 2205 public final long getLongOpaque(Object o, long offset) { 2206 return getLongVolatile(o, offset); 2207 } 2208 2209 /** Opaque version of {@link #getDoubleVolatile(Object, long)} */ 2210 @HotSpotIntrinsicCandidate 2211 public final double getDoubleOpaque(Object o, long offset) { 2212 return getDoubleVolatile(o, offset); 2213 } 2214 2215 /** Opaque version of {@link #putObjectVolatile(Object, long, Object)} */ 2216 @HotSpotIntrinsicCandidate 2217 public final void putObjectOpaque(Object o, long offset, Object x) { 2218 putObjectVolatile(o, offset, x); 2219 } 2220 2221 /** Opaque version of {@link #putBooleanVolatile(Object, long, boolean)} */ 2222 @HotSpotIntrinsicCandidate 2223 public final void putBooleanOpaque(Object o, long offset, boolean x) { 2224 putBooleanVolatile(o, offset, x); 2225 } 2226 2227 /** Opaque version of {@link #putByteVolatile(Object, long, byte)} */ 2228 @HotSpotIntrinsicCandidate 2229 public final void putByteOpaque(Object o, long offset, byte x) { 2230 putByteVolatile(o, offset, x); 2231 } 2232 2233 /** Opaque version of {@link #putShortVolatile(Object, long, short)} */ 2234 @HotSpotIntrinsicCandidate 2235 public final void putShortOpaque(Object o, long offset, short x) { 2236 putShortVolatile(o, offset, x); 2237 } 2238 2239 /** Opaque version of {@link #putCharVolatile(Object, long, char)} */ 2240 @HotSpotIntrinsicCandidate 2241 public final void putCharOpaque(Object o, long offset, char x) { 2242 putCharVolatile(o, offset, x); 2243 } 2244 2245 /** Opaque version of {@link #putIntVolatile(Object, long, int)} */ 2246 @HotSpotIntrinsicCandidate 2247 public final void putIntOpaque(Object o, long offset, int x) { 2248 putIntVolatile(o, offset, x); 2249 } 2250 2251 /** Opaque version of {@link #putFloatVolatile(Object, long, float)} */ 2252 @HotSpotIntrinsicCandidate 2253 public final void putFloatOpaque(Object o, long offset, float x) { 2254 putFloatVolatile(o, offset, x); 2255 } 2256 2257 /** Opaque version of {@link #putLongVolatile(Object, long, long)} */ 2258 @HotSpotIntrinsicCandidate 2259 public final void putLongOpaque(Object o, long offset, long x) { 2260 putLongVolatile(o, offset, x); 2261 } 2262 2263 /** Opaque version of {@link #putDoubleVolatile(Object, long, double)} */ 2264 @HotSpotIntrinsicCandidate 2265 public final void putDoubleOpaque(Object o, long offset, double x) { 2266 putDoubleVolatile(o, offset, x); 2267 } 2268 2269 /** 2270 * Unblocks the given thread blocked on {@code park}, or, if it is 2271 * not blocked, causes the subsequent call to {@code park} not to 2272 * block. Note: this operation is "unsafe" solely because the 2273 * caller must somehow ensure that the thread has not been 2274 * destroyed. Nothing special is usually required to ensure this 2275 * when called from Java (in which there will ordinarily be a live 2276 * reference to the thread) but this is not nearly-automatically 2277 * so when calling from native code. 2278 * 2279 * @param thread the thread to unpark. 2280 */ 2281 @HotSpotIntrinsicCandidate 2282 public native void unpark(Object thread); 2283 2284 /** 2285 * Blocks current thread, returning when a balancing 2286 * {@code unpark} occurs, or a balancing {@code unpark} has 2287 * already occurred, or the thread is interrupted, or, if not 2288 * absolute and time is not zero, the given time nanoseconds have 2289 * elapsed, or if absolute, the given deadline in milliseconds 2290 * since Epoch has passed, or spuriously (i.e., returning for no 2291 * "reason"). Note: This operation is in the Unsafe class only 2292 * because {@code unpark} is, so it would be strange to place it 2293 * elsewhere. 2294 */ 2295 @HotSpotIntrinsicCandidate 2296 public native void park(boolean isAbsolute, long time); 2297 2298 /** 2299 * Gets the load average in the system run queue assigned 2300 * to the available processors averaged over various periods of time. 2301 * This method retrieves the given {@code nelem} samples and 2302 * assigns to the elements of the given {@code loadavg} array. 2303 * The system imposes a maximum of 3 samples, representing 2304 * averages over the last 1, 5, and 15 minutes, respectively. 2305 * 2306 * @param loadavg an array of double of size nelems 2307 * @param nelems the number of samples to be retrieved and 2308 * must be 1 to 3. 2309 * 2310 * @return the number of samples actually retrieved; or -1 2311 * if the load average is unobtainable. 2312 */ 2313 public int getLoadAverage(double[] loadavg, int nelems) { 2314 if (nelems < 0 || nelems > 3 || nelems > loadavg.length) { 2315 throw new ArrayIndexOutOfBoundsException(); 2316 } 2317 2318 return getLoadAverage0(loadavg, nelems); 2319 } 2320 2321 // The following contain CAS-based Java implementations used on 2322 // platforms not supporting native instructions 2323 2324 /** 2325 * Atomically adds the given value to the current value of a field 2326 * or array element within the given object {@code o} 2327 * at the given {@code offset}. 2328 * 2329 * @param o object/array to update the field/element in 2330 * @param offset field/element offset 2331 * @param delta the value to add 2332 * @return the previous value 2333 * @since 1.8 2334 */ 2335 @HotSpotIntrinsicCandidate 2336 public final int getAndAddInt(Object o, long offset, int delta) { 2337 int v; 2338 do { 2339 v = getIntVolatile(o, offset); 2340 } while (!weakCompareAndSetInt(o, offset, v, v + delta)); 2341 return v; 2342 } 2343 2344 @ForceInline 2345 public final int getAndAddIntRelease(Object o, long offset, int delta) { 2346 int v; 2347 do { 2348 v = getInt(o, offset); 2349 } while (!weakCompareAndSetIntRelease(o, offset, v, v + delta)); 2350 return v; 2351 } 2352 2353 @ForceInline 2354 public final int getAndAddIntAcquire(Object o, long offset, int delta) { 2355 int v; 2356 do { 2357 v = getIntAcquire(o, offset); 2358 } while (!weakCompareAndSetIntAcquire(o, offset, v, v + delta)); 2359 return v; 2360 } 2361 2362 /** 2363 * Atomically adds the given value to the current value of a field 2364 * or array element within the given object {@code o} 2365 * at the given {@code offset}. 2366 * 2367 * @param o object/array to update the field/element in 2368 * @param offset field/element offset 2369 * @param delta the value to add 2370 * @return the previous value 2371 * @since 1.8 2372 */ 2373 @HotSpotIntrinsicCandidate 2374 public final long getAndAddLong(Object o, long offset, long delta) { 2375 long v; 2376 do { 2377 v = getLongVolatile(o, offset); 2378 } while (!weakCompareAndSetLong(o, offset, v, v + delta)); 2379 return v; 2380 } 2381 2382 @ForceInline 2383 public final long getAndAddLongRelease(Object o, long offset, long delta) { 2384 long v; 2385 do { 2386 v = getLong(o, offset); 2387 } while (!weakCompareAndSetLongRelease(o, offset, v, v + delta)); 2388 return v; 2389 } 2390 2391 @ForceInline 2392 public final long getAndAddLongAcquire(Object o, long offset, long delta) { 2393 long v; 2394 do { 2395 v = getLongAcquire(o, offset); 2396 } while (!weakCompareAndSetLongAcquire(o, offset, v, v + delta)); 2397 return v; 2398 } 2399 2400 @HotSpotIntrinsicCandidate 2401 public final byte getAndAddByte(Object o, long offset, byte delta) { 2402 byte v; 2403 do { 2404 v = getByteVolatile(o, offset); 2405 } while (!weakCompareAndSetByte(o, offset, v, (byte) (v + delta))); 2406 return v; 2407 } 2408 2409 @ForceInline 2410 public final byte getAndAddByteRelease(Object o, long offset, byte delta) { 2411 byte v; 2412 do { 2413 v = getByte(o, offset); 2414 } while (!weakCompareAndSetByteRelease(o, offset, v, (byte) (v + delta))); 2415 return v; 2416 } 2417 2418 @ForceInline 2419 public final byte getAndAddByteAcquire(Object o, long offset, byte delta) { 2420 byte v; 2421 do { 2422 v = getByteAcquire(o, offset); 2423 } while (!weakCompareAndSetByteAcquire(o, offset, v, (byte) (v + delta))); 2424 return v; 2425 } 2426 2427 @HotSpotIntrinsicCandidate 2428 public final short getAndAddShort(Object o, long offset, short delta) { 2429 short v; 2430 do { 2431 v = getShortVolatile(o, offset); 2432 } while (!weakCompareAndSetShort(o, offset, v, (short) (v + delta))); 2433 return v; 2434 } 2435 2436 @ForceInline 2437 public final short getAndAddShortRelease(Object o, long offset, short delta) { 2438 short v; 2439 do { 2440 v = getShort(o, offset); 2441 } while (!weakCompareAndSetShortRelease(o, offset, v, (short) (v + delta))); 2442 return v; 2443 } 2444 2445 @ForceInline 2446 public final short getAndAddShortAcquire(Object o, long offset, short delta) { 2447 short v; 2448 do { 2449 v = getShortAcquire(o, offset); 2450 } while (!weakCompareAndSetShortAcquire(o, offset, v, (short) (v + delta))); 2451 return v; 2452 } 2453 2454 @ForceInline 2455 public final char getAndAddChar(Object o, long offset, char delta) { 2456 return (char) getAndAddShort(o, offset, (short) delta); 2457 } 2458 2459 @ForceInline 2460 public final char getAndAddCharRelease(Object o, long offset, char delta) { 2461 return (char) getAndAddShortRelease(o, offset, (short) delta); 2462 } 2463 2464 @ForceInline 2465 public final char getAndAddCharAcquire(Object o, long offset, char delta) { 2466 return (char) getAndAddShortAcquire(o, offset, (short) delta); 2467 } 2468 2469 @ForceInline 2470 public final float getAndAddFloat(Object o, long offset, float delta) { 2471 int expectedBits; 2472 float v; 2473 do { 2474 // Load and CAS with the raw bits to avoid issues with NaNs and 2475 // possible bit conversion from signaling NaNs to quiet NaNs that 2476 // may result in the loop not terminating. 2477 expectedBits = getIntVolatile(o, offset); 2478 v = Float.intBitsToFloat(expectedBits); 2479 } while (!weakCompareAndSetInt(o, offset, 2480 expectedBits, Float.floatToRawIntBits(v + delta))); 2481 return v; 2482 } 2483 2484 @ForceInline 2485 public final float getAndAddFloatRelease(Object o, long offset, float delta) { 2486 int expectedBits; 2487 float v; 2488 do { 2489 // Load and CAS with the raw bits to avoid issues with NaNs and 2490 // possible bit conversion from signaling NaNs to quiet NaNs that 2491 // may result in the loop not terminating. 2492 expectedBits = getInt(o, offset); 2493 v = Float.intBitsToFloat(expectedBits); 2494 } while (!weakCompareAndSetIntRelease(o, offset, 2495 expectedBits, Float.floatToRawIntBits(v + delta))); 2496 return v; 2497 } 2498 2499 @ForceInline 2500 public final float getAndAddFloatAcquire(Object o, long offset, float delta) { 2501 int expectedBits; 2502 float v; 2503 do { 2504 // Load and CAS with the raw bits to avoid issues with NaNs and 2505 // possible bit conversion from signaling NaNs to quiet NaNs that 2506 // may result in the loop not terminating. 2507 expectedBits = getIntAcquire(o, offset); 2508 v = Float.intBitsToFloat(expectedBits); 2509 } while (!weakCompareAndSetIntAcquire(o, offset, 2510 expectedBits, Float.floatToRawIntBits(v + delta))); 2511 return v; 2512 } 2513 2514 @ForceInline 2515 public final double getAndAddDouble(Object o, long offset, double delta) { 2516 long expectedBits; 2517 double v; 2518 do { 2519 // Load and CAS with the raw bits to avoid issues with NaNs and 2520 // possible bit conversion from signaling NaNs to quiet NaNs that 2521 // may result in the loop not terminating. 2522 expectedBits = getLongVolatile(o, offset); 2523 v = Double.longBitsToDouble(expectedBits); 2524 } while (!weakCompareAndSetLong(o, offset, 2525 expectedBits, Double.doubleToRawLongBits(v + delta))); 2526 return v; 2527 } 2528 2529 @ForceInline 2530 public final double getAndAddDoubleRelease(Object o, long offset, double delta) { 2531 long expectedBits; 2532 double v; 2533 do { 2534 // Load and CAS with the raw bits to avoid issues with NaNs and 2535 // possible bit conversion from signaling NaNs to quiet NaNs that 2536 // may result in the loop not terminating. 2537 expectedBits = getLong(o, offset); 2538 v = Double.longBitsToDouble(expectedBits); 2539 } while (!weakCompareAndSetLongRelease(o, offset, 2540 expectedBits, Double.doubleToRawLongBits(v + delta))); 2541 return v; 2542 } 2543 2544 @ForceInline 2545 public final double getAndAddDoubleAcquire(Object o, long offset, double delta) { 2546 long expectedBits; 2547 double v; 2548 do { 2549 // Load and CAS with the raw bits to avoid issues with NaNs and 2550 // possible bit conversion from signaling NaNs to quiet NaNs that 2551 // may result in the loop not terminating. 2552 expectedBits = getLongAcquire(o, offset); 2553 v = Double.longBitsToDouble(expectedBits); 2554 } while (!weakCompareAndSetLongAcquire(o, offset, 2555 expectedBits, Double.doubleToRawLongBits(v + delta))); 2556 return v; 2557 } 2558 2559 /** 2560 * Atomically exchanges the given value with the current value of 2561 * a field or array element within the given object {@code o} 2562 * at the given {@code offset}. 2563 * 2564 * @param o object/array to update the field/element in 2565 * @param offset field/element offset 2566 * @param newValue new value 2567 * @return the previous value 2568 * @since 1.8 2569 */ 2570 @HotSpotIntrinsicCandidate 2571 public final int getAndSetInt(Object o, long offset, int newValue) { 2572 int v; 2573 do { 2574 v = getIntVolatile(o, offset); 2575 } while (!weakCompareAndSetInt(o, offset, v, newValue)); 2576 return v; 2577 } 2578 2579 @ForceInline 2580 public final int getAndSetIntRelease(Object o, long offset, int newValue) { 2581 int v; 2582 do { 2583 v = getInt(o, offset); 2584 } while (!weakCompareAndSetIntRelease(o, offset, v, newValue)); 2585 return v; 2586 } 2587 2588 @ForceInline 2589 public final int getAndSetIntAcquire(Object o, long offset, int newValue) { 2590 int v; 2591 do { 2592 v = getIntAcquire(o, offset); 2593 } while (!weakCompareAndSetIntAcquire(o, offset, v, newValue)); 2594 return v; 2595 } 2596 2597 /** 2598 * Atomically exchanges the given value with the current value of 2599 * a field or array element within the given object {@code o} 2600 * at the given {@code offset}. 2601 * 2602 * @param o object/array to update the field/element in 2603 * @param offset field/element offset 2604 * @param newValue new value 2605 * @return the previous value 2606 * @since 1.8 2607 */ 2608 @HotSpotIntrinsicCandidate 2609 public final long getAndSetLong(Object o, long offset, long newValue) { 2610 long v; 2611 do { 2612 v = getLongVolatile(o, offset); 2613 } while (!weakCompareAndSetLong(o, offset, v, newValue)); 2614 return v; 2615 } 2616 2617 @ForceInline 2618 public final long getAndSetLongRelease(Object o, long offset, long newValue) { 2619 long v; 2620 do { 2621 v = getLong(o, offset); 2622 } while (!weakCompareAndSetLongRelease(o, offset, v, newValue)); 2623 return v; 2624 } 2625 2626 @ForceInline 2627 public final long getAndSetLongAcquire(Object o, long offset, long newValue) { 2628 long v; 2629 do { 2630 v = getLongAcquire(o, offset); 2631 } while (!weakCompareAndSetLongAcquire(o, offset, v, newValue)); 2632 return v; 2633 } 2634 2635 /** 2636 * Atomically exchanges the given reference value with the current 2637 * reference value of a field or array element within the given 2638 * object {@code o} at the given {@code offset}. 2639 * 2640 * @param o object/array to update the field/element in 2641 * @param offset field/element offset 2642 * @param newValue new value 2643 * @return the previous value 2644 * @since 1.8 2645 */ 2646 @HotSpotIntrinsicCandidate 2647 public final Object getAndSetObject(Object o, long offset, Object newValue) { 2648 Object v; 2649 do { 2650 v = getObjectVolatile(o, offset); 2651 } while (!weakCompareAndSetObject(o, offset, v, newValue)); 2652 return v; 2653 } 2654 2655 @ForceInline 2656 public final Object getAndSetObjectRelease(Object o, long offset, Object newValue) { 2657 Object v; 2658 do { 2659 v = getObject(o, offset); 2660 } while (!weakCompareAndSetObjectRelease(o, offset, v, newValue)); 2661 return v; 2662 } 2663 2664 @ForceInline 2665 public final Object getAndSetObjectAcquire(Object o, long offset, Object newValue) { 2666 Object v; 2667 do { 2668 v = getObjectAcquire(o, offset); 2669 } while (!weakCompareAndSetObjectAcquire(o, offset, v, newValue)); 2670 return v; 2671 } 2672 2673 @HotSpotIntrinsicCandidate 2674 public final byte getAndSetByte(Object o, long offset, byte newValue) { 2675 byte v; 2676 do { 2677 v = getByteVolatile(o, offset); 2678 } while (!weakCompareAndSetByte(o, offset, v, newValue)); 2679 return v; 2680 } 2681 2682 @ForceInline 2683 public final byte getAndSetByteRelease(Object o, long offset, byte newValue) { 2684 byte v; 2685 do { 2686 v = getByte(o, offset); 2687 } while (!weakCompareAndSetByteRelease(o, offset, v, newValue)); 2688 return v; 2689 } 2690 2691 @ForceInline 2692 public final byte getAndSetByteAcquire(Object o, long offset, byte newValue) { 2693 byte v; 2694 do { 2695 v = getByteAcquire(o, offset); 2696 } while (!weakCompareAndSetByteAcquire(o, offset, v, newValue)); 2697 return v; 2698 } 2699 2700 @ForceInline 2701 public final boolean getAndSetBoolean(Object o, long offset, boolean newValue) { 2702 return byte2bool(getAndSetByte(o, offset, bool2byte(newValue))); 2703 } 2704 2705 @ForceInline 2706 public final boolean getAndSetBooleanRelease(Object o, long offset, boolean newValue) { 2707 return byte2bool(getAndSetByteRelease(o, offset, bool2byte(newValue))); 2708 } 2709 2710 @ForceInline 2711 public final boolean getAndSetBooleanAcquire(Object o, long offset, boolean newValue) { 2712 return byte2bool(getAndSetByteAcquire(o, offset, bool2byte(newValue))); 2713 } 2714 2715 @HotSpotIntrinsicCandidate 2716 public final short getAndSetShort(Object o, long offset, short newValue) { 2717 short v; 2718 do { 2719 v = getShortVolatile(o, offset); 2720 } while (!weakCompareAndSetShort(o, offset, v, newValue)); 2721 return v; 2722 } 2723 2724 @ForceInline 2725 public final short getAndSetShortRelease(Object o, long offset, short newValue) { 2726 short v; 2727 do { 2728 v = getShort(o, offset); 2729 } while (!weakCompareAndSetShortRelease(o, offset, v, newValue)); 2730 return v; 2731 } 2732 2733 @ForceInline 2734 public final short getAndSetShortAcquire(Object o, long offset, short newValue) { 2735 short v; 2736 do { 2737 v = getShortAcquire(o, offset); 2738 } while (!weakCompareAndSetShortAcquire(o, offset, v, newValue)); 2739 return v; 2740 } 2741 2742 @ForceInline 2743 public final char getAndSetChar(Object o, long offset, char newValue) { 2744 return s2c(getAndSetShort(o, offset, c2s(newValue))); 2745 } 2746 2747 @ForceInline 2748 public final char getAndSetCharRelease(Object o, long offset, char newValue) { 2749 return s2c(getAndSetShortRelease(o, offset, c2s(newValue))); 2750 } 2751 2752 @ForceInline 2753 public final char getAndSetCharAcquire(Object o, long offset, char newValue) { 2754 return s2c(getAndSetShortAcquire(o, offset, c2s(newValue))); 2755 } 2756 2757 @ForceInline 2758 public final float getAndSetFloat(Object o, long offset, float newValue) { 2759 int v = getAndSetInt(o, offset, Float.floatToRawIntBits(newValue)); 2760 return Float.intBitsToFloat(v); 2761 } 2762 2763 @ForceInline 2764 public final float getAndSetFloatRelease(Object o, long offset, float newValue) { 2765 int v = getAndSetIntRelease(o, offset, Float.floatToRawIntBits(newValue)); 2766 return Float.intBitsToFloat(v); 2767 } 2768 2769 @ForceInline 2770 public final float getAndSetFloatAcquire(Object o, long offset, float newValue) { 2771 int v = getAndSetIntAcquire(o, offset, Float.floatToRawIntBits(newValue)); 2772 return Float.intBitsToFloat(v); 2773 } 2774 2775 @ForceInline 2776 public final double getAndSetDouble(Object o, long offset, double newValue) { 2777 long v = getAndSetLong(o, offset, Double.doubleToRawLongBits(newValue)); 2778 return Double.longBitsToDouble(v); 2779 } 2780 2781 @ForceInline 2782 public final double getAndSetDoubleRelease(Object o, long offset, double newValue) { 2783 long v = getAndSetLongRelease(o, offset, Double.doubleToRawLongBits(newValue)); 2784 return Double.longBitsToDouble(v); 2785 } 2786 2787 @ForceInline 2788 public final double getAndSetDoubleAcquire(Object o, long offset, double newValue) { 2789 long v = getAndSetLongAcquire(o, offset, Double.doubleToRawLongBits(newValue)); 2790 return Double.longBitsToDouble(v); 2791 } 2792 2793 2794 // The following contain CAS-based Java implementations used on 2795 // platforms not supporting native instructions 2796 2797 @ForceInline 2798 public final boolean getAndBitwiseOrBoolean(Object o, long offset, boolean mask) { 2799 return byte2bool(getAndBitwiseOrByte(o, offset, bool2byte(mask))); 2800 } 2801 2802 @ForceInline 2803 public final boolean getAndBitwiseOrBooleanRelease(Object o, long offset, boolean mask) { 2804 return byte2bool(getAndBitwiseOrByteRelease(o, offset, bool2byte(mask))); 2805 } 2806 2807 @ForceInline 2808 public final boolean getAndBitwiseOrBooleanAcquire(Object o, long offset, boolean mask) { 2809 return byte2bool(getAndBitwiseOrByteAcquire(o, offset, bool2byte(mask))); 2810 } 2811 2812 @ForceInline 2813 public final boolean getAndBitwiseAndBoolean(Object o, long offset, boolean mask) { 2814 return byte2bool(getAndBitwiseAndByte(o, offset, bool2byte(mask))); 2815 } 2816 2817 @ForceInline 2818 public final boolean getAndBitwiseAndBooleanRelease(Object o, long offset, boolean mask) { 2819 return byte2bool(getAndBitwiseAndByteRelease(o, offset, bool2byte(mask))); 2820 } 2821 2822 @ForceInline 2823 public final boolean getAndBitwiseAndBooleanAcquire(Object o, long offset, boolean mask) { 2824 return byte2bool(getAndBitwiseAndByteAcquire(o, offset, bool2byte(mask))); 2825 } 2826 2827 @ForceInline 2828 public final boolean getAndBitwiseXorBoolean(Object o, long offset, boolean mask) { 2829 return byte2bool(getAndBitwiseXorByte(o, offset, bool2byte(mask))); 2830 } 2831 2832 @ForceInline 2833 public final boolean getAndBitwiseXorBooleanRelease(Object o, long offset, boolean mask) { 2834 return byte2bool(getAndBitwiseXorByteRelease(o, offset, bool2byte(mask))); 2835 } 2836 2837 @ForceInline 2838 public final boolean getAndBitwiseXorBooleanAcquire(Object o, long offset, boolean mask) { 2839 return byte2bool(getAndBitwiseXorByteAcquire(o, offset, bool2byte(mask))); 2840 } 2841 2842 2843 @ForceInline 2844 public final byte getAndBitwiseOrByte(Object o, long offset, byte mask) { 2845 byte current; 2846 do { 2847 current = getByteVolatile(o, offset); 2848 } while (!weakCompareAndSetByte(o, offset, 2849 current, (byte) (current | mask))); 2850 return current; 2851 } 2852 2853 @ForceInline 2854 public final byte getAndBitwiseOrByteRelease(Object o, long offset, byte mask) { 2855 byte current; 2856 do { 2857 current = getByte(o, offset); 2858 } while (!weakCompareAndSetByteRelease(o, offset, 2859 current, (byte) (current | mask))); 2860 return current; 2861 } 2862 2863 @ForceInline 2864 public final byte getAndBitwiseOrByteAcquire(Object o, long offset, byte mask) { 2865 byte current; 2866 do { 2867 // Plain read, the value is a hint, the acquire CAS does the work 2868 current = getByte(o, offset); 2869 } while (!weakCompareAndSetByteAcquire(o, offset, 2870 current, (byte) (current | mask))); 2871 return current; 2872 } 2873 2874 @ForceInline 2875 public final byte getAndBitwiseAndByte(Object o, long offset, byte mask) { 2876 byte current; 2877 do { 2878 current = getByteVolatile(o, offset); 2879 } while (!weakCompareAndSetByte(o, offset, 2880 current, (byte) (current & mask))); 2881 return current; 2882 } 2883 2884 @ForceInline 2885 public final byte getAndBitwiseAndByteRelease(Object o, long offset, byte mask) { 2886 byte current; 2887 do { 2888 current = getByte(o, offset); 2889 } while (!weakCompareAndSetByteRelease(o, offset, 2890 current, (byte) (current & mask))); 2891 return current; 2892 } 2893 2894 @ForceInline 2895 public final byte getAndBitwiseAndByteAcquire(Object o, long offset, byte mask) { 2896 byte current; 2897 do { 2898 // Plain read, the value is a hint, the acquire CAS does the work 2899 current = getByte(o, offset); 2900 } while (!weakCompareAndSetByteAcquire(o, offset, 2901 current, (byte) (current & mask))); 2902 return current; 2903 } 2904 2905 @ForceInline 2906 public final byte getAndBitwiseXorByte(Object o, long offset, byte mask) { 2907 byte current; 2908 do { 2909 current = getByteVolatile(o, offset); 2910 } while (!weakCompareAndSetByte(o, offset, 2911 current, (byte) (current ^ mask))); 2912 return current; 2913 } 2914 2915 @ForceInline 2916 public final byte getAndBitwiseXorByteRelease(Object o, long offset, byte mask) { 2917 byte current; 2918 do { 2919 current = getByte(o, offset); 2920 } while (!weakCompareAndSetByteRelease(o, offset, 2921 current, (byte) (current ^ mask))); 2922 return current; 2923 } 2924 2925 @ForceInline 2926 public final byte getAndBitwiseXorByteAcquire(Object o, long offset, byte mask) { 2927 byte current; 2928 do { 2929 // Plain read, the value is a hint, the acquire CAS does the work 2930 current = getByte(o, offset); 2931 } while (!weakCompareAndSetByteAcquire(o, offset, 2932 current, (byte) (current ^ mask))); 2933 return current; 2934 } 2935 2936 2937 @ForceInline 2938 public final char getAndBitwiseOrChar(Object o, long offset, char mask) { 2939 return s2c(getAndBitwiseOrShort(o, offset, c2s(mask))); 2940 } 2941 2942 @ForceInline 2943 public final char getAndBitwiseOrCharRelease(Object o, long offset, char mask) { 2944 return s2c(getAndBitwiseOrShortRelease(o, offset, c2s(mask))); 2945 } 2946 2947 @ForceInline 2948 public final char getAndBitwiseOrCharAcquire(Object o, long offset, char mask) { 2949 return s2c(getAndBitwiseOrShortAcquire(o, offset, c2s(mask))); 2950 } 2951 2952 @ForceInline 2953 public final char getAndBitwiseAndChar(Object o, long offset, char mask) { 2954 return s2c(getAndBitwiseAndShort(o, offset, c2s(mask))); 2955 } 2956 2957 @ForceInline 2958 public final char getAndBitwiseAndCharRelease(Object o, long offset, char mask) { 2959 return s2c(getAndBitwiseAndShortRelease(o, offset, c2s(mask))); 2960 } 2961 2962 @ForceInline 2963 public final char getAndBitwiseAndCharAcquire(Object o, long offset, char mask) { 2964 return s2c(getAndBitwiseAndShortAcquire(o, offset, c2s(mask))); 2965 } 2966 2967 @ForceInline 2968 public final char getAndBitwiseXorChar(Object o, long offset, char mask) { 2969 return s2c(getAndBitwiseXorShort(o, offset, c2s(mask))); 2970 } 2971 2972 @ForceInline 2973 public final char getAndBitwiseXorCharRelease(Object o, long offset, char mask) { 2974 return s2c(getAndBitwiseXorShortRelease(o, offset, c2s(mask))); 2975 } 2976 2977 @ForceInline 2978 public final char getAndBitwiseXorCharAcquire(Object o, long offset, char mask) { 2979 return s2c(getAndBitwiseXorShortAcquire(o, offset, c2s(mask))); 2980 } 2981 2982 2983 @ForceInline 2984 public final short getAndBitwiseOrShort(Object o, long offset, short mask) { 2985 short current; 2986 do { 2987 current = getShortVolatile(o, offset); 2988 } while (!weakCompareAndSetShort(o, offset, 2989 current, (short) (current | mask))); 2990 return current; 2991 } 2992 2993 @ForceInline 2994 public final short getAndBitwiseOrShortRelease(Object o, long offset, short mask) { 2995 short current; 2996 do { 2997 current = getShort(o, offset); 2998 } while (!weakCompareAndSetShortRelease(o, offset, 2999 current, (short) (current | mask))); 3000 return current; 3001 } 3002 3003 @ForceInline 3004 public final short getAndBitwiseOrShortAcquire(Object o, long offset, short mask) { 3005 short current; 3006 do { 3007 // Plain read, the value is a hint, the acquire CAS does the work 3008 current = getShort(o, offset); 3009 } while (!weakCompareAndSetShortAcquire(o, offset, 3010 current, (short) (current | mask))); 3011 return current; 3012 } 3013 3014 @ForceInline 3015 public final short getAndBitwiseAndShort(Object o, long offset, short mask) { 3016 short current; 3017 do { 3018 current = getShortVolatile(o, offset); 3019 } while (!weakCompareAndSetShort(o, offset, 3020 current, (short) (current & mask))); 3021 return current; 3022 } 3023 3024 @ForceInline 3025 public final short getAndBitwiseAndShortRelease(Object o, long offset, short mask) { 3026 short current; 3027 do { 3028 current = getShort(o, offset); 3029 } while (!weakCompareAndSetShortRelease(o, offset, 3030 current, (short) (current & mask))); 3031 return current; 3032 } 3033 3034 @ForceInline 3035 public final short getAndBitwiseAndShortAcquire(Object o, long offset, short mask) { 3036 short current; 3037 do { 3038 // Plain read, the value is a hint, the acquire CAS does the work 3039 current = getShort(o, offset); 3040 } while (!weakCompareAndSetShortAcquire(o, offset, 3041 current, (short) (current & mask))); 3042 return current; 3043 } 3044 3045 @ForceInline 3046 public final short getAndBitwiseXorShort(Object o, long offset, short mask) { 3047 short current; 3048 do { 3049 current = getShortVolatile(o, offset); 3050 } while (!weakCompareAndSetShort(o, offset, 3051 current, (short) (current ^ mask))); 3052 return current; 3053 } 3054 3055 @ForceInline 3056 public final short getAndBitwiseXorShortRelease(Object o, long offset, short mask) { 3057 short current; 3058 do { 3059 current = getShort(o, offset); 3060 } while (!weakCompareAndSetShortRelease(o, offset, 3061 current, (short) (current ^ mask))); 3062 return current; 3063 } 3064 3065 @ForceInline 3066 public final short getAndBitwiseXorShortAcquire(Object o, long offset, short mask) { 3067 short current; 3068 do { 3069 // Plain read, the value is a hint, the acquire CAS does the work 3070 current = getShort(o, offset); 3071 } while (!weakCompareAndSetShortAcquire(o, offset, 3072 current, (short) (current ^ mask))); 3073 return current; 3074 } 3075 3076 3077 @ForceInline 3078 public final int getAndBitwiseOrInt(Object o, long offset, int mask) { 3079 int current; 3080 do { 3081 current = getIntVolatile(o, offset); 3082 } while (!weakCompareAndSetInt(o, offset, 3083 current, current | mask)); 3084 return current; 3085 } 3086 3087 @ForceInline 3088 public final int getAndBitwiseOrIntRelease(Object o, long offset, int mask) { 3089 int current; 3090 do { 3091 current = getInt(o, offset); 3092 } while (!weakCompareAndSetIntRelease(o, offset, 3093 current, current | mask)); 3094 return current; 3095 } 3096 3097 @ForceInline 3098 public final int getAndBitwiseOrIntAcquire(Object o, long offset, int mask) { 3099 int current; 3100 do { 3101 // Plain read, the value is a hint, the acquire CAS does the work 3102 current = getInt(o, offset); 3103 } while (!weakCompareAndSetIntAcquire(o, offset, 3104 current, current | mask)); 3105 return current; 3106 } 3107 3108 /** 3109 * Atomically replaces the current value of a field or array element within 3110 * the given object with the result of bitwise AND between the current value 3111 * and mask. 3112 * 3113 * @param o object/array to update the field/element in 3114 * @param offset field/element offset 3115 * @param mask the mask value 3116 * @return the previous value 3117 * @since 9 3118 */ 3119 @ForceInline 3120 public final int getAndBitwiseAndInt(Object o, long offset, int mask) { 3121 int current; 3122 do { 3123 current = getIntVolatile(o, offset); 3124 } while (!weakCompareAndSetInt(o, offset, 3125 current, current & mask)); 3126 return current; 3127 } 3128 3129 @ForceInline 3130 public final int getAndBitwiseAndIntRelease(Object o, long offset, int mask) { 3131 int current; 3132 do { 3133 current = getInt(o, offset); 3134 } while (!weakCompareAndSetIntRelease(o, offset, 3135 current, current & mask)); 3136 return current; 3137 } 3138 3139 @ForceInline 3140 public final int getAndBitwiseAndIntAcquire(Object o, long offset, int mask) { 3141 int current; 3142 do { 3143 // Plain read, the value is a hint, the acquire CAS does the work 3144 current = getInt(o, offset); 3145 } while (!weakCompareAndSetIntAcquire(o, offset, 3146 current, current & mask)); 3147 return current; 3148 } 3149 3150 @ForceInline 3151 public final int getAndBitwiseXorInt(Object o, long offset, int mask) { 3152 int current; 3153 do { 3154 current = getIntVolatile(o, offset); 3155 } while (!weakCompareAndSetInt(o, offset, 3156 current, current ^ mask)); 3157 return current; 3158 } 3159 3160 @ForceInline 3161 public final int getAndBitwiseXorIntRelease(Object o, long offset, int mask) { 3162 int current; 3163 do { 3164 current = getInt(o, offset); 3165 } while (!weakCompareAndSetIntRelease(o, offset, 3166 current, current ^ mask)); 3167 return current; 3168 } 3169 3170 @ForceInline 3171 public final int getAndBitwiseXorIntAcquire(Object o, long offset, int mask) { 3172 int current; 3173 do { 3174 // Plain read, the value is a hint, the acquire CAS does the work 3175 current = getInt(o, offset); 3176 } while (!weakCompareAndSetIntAcquire(o, offset, 3177 current, current ^ mask)); 3178 return current; 3179 } 3180 3181 3182 @ForceInline 3183 public final long getAndBitwiseOrLong(Object o, long offset, long mask) { 3184 long current; 3185 do { 3186 current = getLongVolatile(o, offset); 3187 } while (!weakCompareAndSetLong(o, offset, 3188 current, current | mask)); 3189 return current; 3190 } 3191 3192 @ForceInline 3193 public final long getAndBitwiseOrLongRelease(Object o, long offset, long mask) { 3194 long current; 3195 do { 3196 current = getLong(o, offset); 3197 } while (!weakCompareAndSetLongRelease(o, offset, 3198 current, current | mask)); 3199 return current; 3200 } 3201 3202 @ForceInline 3203 public final long getAndBitwiseOrLongAcquire(Object o, long offset, long mask) { 3204 long current; 3205 do { 3206 // Plain read, the value is a hint, the acquire CAS does the work 3207 current = getLong(o, offset); 3208 } while (!weakCompareAndSetLongAcquire(o, offset, 3209 current, current | mask)); 3210 return current; 3211 } 3212 3213 @ForceInline 3214 public final long getAndBitwiseAndLong(Object o, long offset, long mask) { 3215 long current; 3216 do { 3217 current = getLongVolatile(o, offset); 3218 } while (!weakCompareAndSetLong(o, offset, 3219 current, current & mask)); 3220 return current; 3221 } 3222 3223 @ForceInline 3224 public final long getAndBitwiseAndLongRelease(Object o, long offset, long mask) { 3225 long current; 3226 do { 3227 current = getLong(o, offset); 3228 } while (!weakCompareAndSetLongRelease(o, offset, 3229 current, current & mask)); 3230 return current; 3231 } 3232 3233 @ForceInline 3234 public final long getAndBitwiseAndLongAcquire(Object o, long offset, long mask) { 3235 long current; 3236 do { 3237 // Plain read, the value is a hint, the acquire CAS does the work 3238 current = getLong(o, offset); 3239 } while (!weakCompareAndSetLongAcquire(o, offset, 3240 current, current & mask)); 3241 return current; 3242 } 3243 3244 @ForceInline 3245 public final long getAndBitwiseXorLong(Object o, long offset, long mask) { 3246 long current; 3247 do { 3248 current = getLongVolatile(o, offset); 3249 } while (!weakCompareAndSetLong(o, offset, 3250 current, current ^ mask)); 3251 return current; 3252 } 3253 3254 @ForceInline 3255 public final long getAndBitwiseXorLongRelease(Object o, long offset, long mask) { 3256 long current; 3257 do { 3258 current = getLong(o, offset); 3259 } while (!weakCompareAndSetLongRelease(o, offset, 3260 current, current ^ mask)); 3261 return current; 3262 } 3263 3264 @ForceInline 3265 public final long getAndBitwiseXorLongAcquire(Object o, long offset, long mask) { 3266 long current; 3267 do { 3268 // Plain read, the value is a hint, the acquire CAS does the work 3269 current = getLong(o, offset); 3270 } while (!weakCompareAndSetLongAcquire(o, offset, 3271 current, current ^ mask)); 3272 return current; 3273 } 3274 3275 3276 3277 /** 3278 * Ensures that loads before the fence will not be reordered with loads and 3279 * stores after the fence; a "LoadLoad plus LoadStore barrier". 3280 * 3281 * Corresponds to C11 atomic_thread_fence(memory_order_acquire) 3282 * (an "acquire fence"). 3283 * 3284 * A pure LoadLoad fence is not provided, since the addition of LoadStore 3285 * is almost always desired, and most current hardware instructions that 3286 * provide a LoadLoad barrier also provide a LoadStore barrier for free. 3287 * @since 1.8 3288 */ 3289 @HotSpotIntrinsicCandidate 3290 public native void loadFence(); 3291 3292 /** 3293 * Ensures that loads and stores before the fence will not be reordered with 3294 * stores after the fence; a "StoreStore plus LoadStore barrier". 3295 * 3296 * Corresponds to C11 atomic_thread_fence(memory_order_release) 3297 * (a "release fence"). 3298 * 3299 * A pure StoreStore fence is not provided, since the addition of LoadStore 3300 * is almost always desired, and most current hardware instructions that 3301 * provide a StoreStore barrier also provide a LoadStore barrier for free. 3302 * @since 1.8 3303 */ 3304 @HotSpotIntrinsicCandidate 3305 public native void storeFence(); 3306 3307 /** 3308 * Ensures that loads and stores before the fence will not be reordered 3309 * with loads and stores after the fence. Implies the effects of both 3310 * loadFence() and storeFence(), and in addition, the effect of a StoreLoad 3311 * barrier. 3312 * 3313 * Corresponds to C11 atomic_thread_fence(memory_order_seq_cst). 3314 * @since 1.8 3315 */ 3316 @HotSpotIntrinsicCandidate 3317 public native void fullFence(); 3318 3319 /** 3320 * Ensures that loads before the fence will not be reordered with 3321 * loads after the fence. 3322 */ 3323 public final void loadLoadFence() { 3324 loadFence(); 3325 } 3326 3327 /** 3328 * Ensures that stores before the fence will not be reordered with 3329 * stores after the fence. 3330 */ 3331 public final void storeStoreFence() { 3332 storeFence(); 3333 } 3334 3335 3336 /** 3337 * Throws IllegalAccessError; for use by the VM for access control 3338 * error support. 3339 * @since 1.8 3340 */ 3341 private static void throwIllegalAccessError() { 3342 throw new IllegalAccessError(); 3343 } 3344 3345 /** 3346 * Throws NoSuchMethodError; for use by the VM for redefinition support. 3347 * @since 13 3348 */ 3349 private static void throwNoSuchMethodError() { 3350 throw new NoSuchMethodError(); 3351 } 3352 3353 /** 3354 * @return Returns true if the native byte ordering of this 3355 * platform is big-endian, false if it is little-endian. 3356 */ 3357 public final boolean isBigEndian() { return BE; } 3358 3359 /** 3360 * @return Returns true if this platform is capable of performing 3361 * accesses at addresses which are not aligned for the type of the 3362 * primitive type being accessed, false otherwise. 3363 */ 3364 public final boolean unalignedAccess() { return unalignedAccess; } 3365 3366 /** 3367 * Fetches a value at some byte offset into a given Java object. 3368 * More specifically, fetches a value within the given object 3369 * <code>o</code> at the given offset, or (if <code>o</code> is 3370 * null) from the memory address whose numerical value is the 3371 * given offset. <p> 3372 * 3373 * The specification of this method is the same as {@link 3374 * #getLong(Object, long)} except that the offset does not need to 3375 * have been obtained from {@link #objectFieldOffset} on the 3376 * {@link java.lang.reflect.Field} of some Java field. The value 3377 * in memory is raw data, and need not correspond to any Java 3378 * variable. Unless <code>o</code> is null, the value accessed 3379 * must be entirely within the allocated object. The endianness 3380 * of the value in memory is the endianness of the native platform. 3381 * 3382 * <p> The read will be atomic with respect to the largest power 3383 * of two that divides the GCD of the offset and the storage size. 3384 * For example, getLongUnaligned will make atomic reads of 2-, 4-, 3385 * or 8-byte storage units if the offset is zero mod 2, 4, or 8, 3386 * respectively. There are no other guarantees of atomicity. 3387 * <p> 3388 * 8-byte atomicity is only guaranteed on platforms on which 3389 * support atomic accesses to longs. 3390 * 3391 * @param o Java heap object in which the value resides, if any, else 3392 * null 3393 * @param offset The offset in bytes from the start of the object 3394 * @return the value fetched from the indicated object 3395 * @throws RuntimeException No defined exceptions are thrown, not even 3396 * {@link NullPointerException} 3397 * @since 9 3398 */ 3399 @HotSpotIntrinsicCandidate 3400 public final long getLongUnaligned(Object o, long offset) { 3401 if ((offset & 7) == 0) { 3402 return getLong(o, offset); 3403 } else if ((offset & 3) == 0) { 3404 return makeLong(getInt(o, offset), 3405 getInt(o, offset + 4)); 3406 } else if ((offset & 1) == 0) { 3407 return makeLong(getShort(o, offset), 3408 getShort(o, offset + 2), 3409 getShort(o, offset + 4), 3410 getShort(o, offset + 6)); 3411 } else { 3412 return makeLong(getByte(o, offset), 3413 getByte(o, offset + 1), 3414 getByte(o, offset + 2), 3415 getByte(o, offset + 3), 3416 getByte(o, offset + 4), 3417 getByte(o, offset + 5), 3418 getByte(o, offset + 6), 3419 getByte(o, offset + 7)); 3420 } 3421 } 3422 /** 3423 * As {@link #getLongUnaligned(Object, long)} but with an 3424 * additional argument which specifies the endianness of the value 3425 * as stored in memory. 3426 * 3427 * @param o Java heap object in which the variable resides 3428 * @param offset The offset in bytes from the start of the object 3429 * @param bigEndian The endianness of the value 3430 * @return the value fetched from the indicated object 3431 * @since 9 3432 */ 3433 public final long getLongUnaligned(Object o, long offset, boolean bigEndian) { 3434 return convEndian(bigEndian, getLongUnaligned(o, offset)); 3435 } 3436 3437 /** @see #getLongUnaligned(Object, long) */ 3438 @HotSpotIntrinsicCandidate 3439 public final int getIntUnaligned(Object o, long offset) { 3440 if ((offset & 3) == 0) { 3441 return getInt(o, offset); 3442 } else if ((offset & 1) == 0) { 3443 return makeInt(getShort(o, offset), 3444 getShort(o, offset + 2)); 3445 } else { 3446 return makeInt(getByte(o, offset), 3447 getByte(o, offset + 1), 3448 getByte(o, offset + 2), 3449 getByte(o, offset + 3)); 3450 } 3451 } 3452 /** @see #getLongUnaligned(Object, long, boolean) */ 3453 public final int getIntUnaligned(Object o, long offset, boolean bigEndian) { 3454 return convEndian(bigEndian, getIntUnaligned(o, offset)); 3455 } 3456 3457 /** @see #getLongUnaligned(Object, long) */ 3458 @HotSpotIntrinsicCandidate 3459 public final short getShortUnaligned(Object o, long offset) { 3460 if ((offset & 1) == 0) { 3461 return getShort(o, offset); 3462 } else { 3463 return makeShort(getByte(o, offset), 3464 getByte(o, offset + 1)); 3465 } 3466 } 3467 /** @see #getLongUnaligned(Object, long, boolean) */ 3468 public final short getShortUnaligned(Object o, long offset, boolean bigEndian) { 3469 return convEndian(bigEndian, getShortUnaligned(o, offset)); 3470 } 3471 3472 /** @see #getLongUnaligned(Object, long) */ 3473 @HotSpotIntrinsicCandidate 3474 public final char getCharUnaligned(Object o, long offset) { 3475 if ((offset & 1) == 0) { 3476 return getChar(o, offset); 3477 } else { 3478 return (char)makeShort(getByte(o, offset), 3479 getByte(o, offset + 1)); 3480 } 3481 } 3482 3483 /** @see #getLongUnaligned(Object, long, boolean) */ 3484 public final char getCharUnaligned(Object o, long offset, boolean bigEndian) { 3485 return convEndian(bigEndian, getCharUnaligned(o, offset)); 3486 } 3487 3488 /** 3489 * Stores a value at some byte offset into a given Java object. 3490 * <p> 3491 * The specification of this method is the same as {@link 3492 * #getLong(Object, long)} except that the offset does not need to 3493 * have been obtained from {@link #objectFieldOffset} on the 3494 * {@link java.lang.reflect.Field} of some Java field. The value 3495 * in memory is raw data, and need not correspond to any Java 3496 * variable. The endianness of the value in memory is the 3497 * endianness of the native platform. 3498 * <p> 3499 * The write will be atomic with respect to the largest power of 3500 * two that divides the GCD of the offset and the storage size. 3501 * For example, putLongUnaligned will make atomic writes of 2-, 4-, 3502 * or 8-byte storage units if the offset is zero mod 2, 4, or 8, 3503 * respectively. There are no other guarantees of atomicity. 3504 * <p> 3505 * 8-byte atomicity is only guaranteed on platforms on which 3506 * support atomic accesses to longs. 3507 * 3508 * @param o Java heap object in which the value resides, if any, else 3509 * null 3510 * @param offset The offset in bytes from the start of the object 3511 * @param x the value to store 3512 * @throws RuntimeException No defined exceptions are thrown, not even 3513 * {@link NullPointerException} 3514 * @since 9 3515 */ 3516 @HotSpotIntrinsicCandidate 3517 public final void putLongUnaligned(Object o, long offset, long x) { 3518 if ((offset & 7) == 0) { 3519 putLong(o, offset, x); 3520 } else if ((offset & 3) == 0) { 3521 putLongParts(o, offset, 3522 (int)(x >> 0), 3523 (int)(x >>> 32)); 3524 } else if ((offset & 1) == 0) { 3525 putLongParts(o, offset, 3526 (short)(x >>> 0), 3527 (short)(x >>> 16), 3528 (short)(x >>> 32), 3529 (short)(x >>> 48)); 3530 } else { 3531 putLongParts(o, offset, 3532 (byte)(x >>> 0), 3533 (byte)(x >>> 8), 3534 (byte)(x >>> 16), 3535 (byte)(x >>> 24), 3536 (byte)(x >>> 32), 3537 (byte)(x >>> 40), 3538 (byte)(x >>> 48), 3539 (byte)(x >>> 56)); 3540 } 3541 } 3542 3543 /** 3544 * As {@link #putLongUnaligned(Object, long, long)} but with an additional 3545 * argument which specifies the endianness of the value as stored in memory. 3546 * @param o Java heap object in which the value resides 3547 * @param offset The offset in bytes from the start of the object 3548 * @param x the value to store 3549 * @param bigEndian The endianness of the value 3550 * @throws RuntimeException No defined exceptions are thrown, not even 3551 * {@link NullPointerException} 3552 * @since 9 3553 */ 3554 public final void putLongUnaligned(Object o, long offset, long x, boolean bigEndian) { 3555 putLongUnaligned(o, offset, convEndian(bigEndian, x)); 3556 } 3557 3558 /** @see #putLongUnaligned(Object, long, long) */ 3559 @HotSpotIntrinsicCandidate 3560 public final void putIntUnaligned(Object o, long offset, int x) { 3561 if ((offset & 3) == 0) { 3562 putInt(o, offset, x); 3563 } else if ((offset & 1) == 0) { 3564 putIntParts(o, offset, 3565 (short)(x >> 0), 3566 (short)(x >>> 16)); 3567 } else { 3568 putIntParts(o, offset, 3569 (byte)(x >>> 0), 3570 (byte)(x >>> 8), 3571 (byte)(x >>> 16), 3572 (byte)(x >>> 24)); 3573 } 3574 } 3575 /** @see #putLongUnaligned(Object, long, long, boolean) */ 3576 public final void putIntUnaligned(Object o, long offset, int x, boolean bigEndian) { 3577 putIntUnaligned(o, offset, convEndian(bigEndian, x)); 3578 } 3579 3580 /** @see #putLongUnaligned(Object, long, long) */ 3581 @HotSpotIntrinsicCandidate 3582 public final void putShortUnaligned(Object o, long offset, short x) { 3583 if ((offset & 1) == 0) { 3584 putShort(o, offset, x); 3585 } else { 3586 putShortParts(o, offset, 3587 (byte)(x >>> 0), 3588 (byte)(x >>> 8)); 3589 } 3590 } 3591 /** @see #putLongUnaligned(Object, long, long, boolean) */ 3592 public final void putShortUnaligned(Object o, long offset, short x, boolean bigEndian) { 3593 putShortUnaligned(o, offset, convEndian(bigEndian, x)); 3594 } 3595 3596 /** @see #putLongUnaligned(Object, long, long) */ 3597 @HotSpotIntrinsicCandidate 3598 public final void putCharUnaligned(Object o, long offset, char x) { 3599 putShortUnaligned(o, offset, (short)x); 3600 } 3601 /** @see #putLongUnaligned(Object, long, long, boolean) */ 3602 public final void putCharUnaligned(Object o, long offset, char x, boolean bigEndian) { 3603 putCharUnaligned(o, offset, convEndian(bigEndian, x)); 3604 } 3605 3606 // JVM interface methods 3607 // BE is true iff the native endianness of this platform is big. 3608 private static final boolean BE = theUnsafe.isBigEndian0(); 3609 3610 // unalignedAccess is true iff this platform can perform unaligned accesses. 3611 private static final boolean unalignedAccess = theUnsafe.unalignedAccess0(); 3612 3613 private static int pickPos(int top, int pos) { return BE ? top - pos : pos; } 3614 3615 // These methods construct integers from bytes. The byte ordering 3616 // is the native endianness of this platform. 3617 private static long makeLong(byte i0, byte i1, byte i2, byte i3, byte i4, byte i5, byte i6, byte i7) { 3618 return ((toUnsignedLong(i0) << pickPos(56, 0)) 3619 | (toUnsignedLong(i1) << pickPos(56, 8)) 3620 | (toUnsignedLong(i2) << pickPos(56, 16)) 3621 | (toUnsignedLong(i3) << pickPos(56, 24)) 3622 | (toUnsignedLong(i4) << pickPos(56, 32)) 3623 | (toUnsignedLong(i5) << pickPos(56, 40)) 3624 | (toUnsignedLong(i6) << pickPos(56, 48)) 3625 | (toUnsignedLong(i7) << pickPos(56, 56))); 3626 } 3627 private static long makeLong(short i0, short i1, short i2, short i3) { 3628 return ((toUnsignedLong(i0) << pickPos(48, 0)) 3629 | (toUnsignedLong(i1) << pickPos(48, 16)) 3630 | (toUnsignedLong(i2) << pickPos(48, 32)) 3631 | (toUnsignedLong(i3) << pickPos(48, 48))); 3632 } 3633 private static long makeLong(int i0, int i1) { 3634 return (toUnsignedLong(i0) << pickPos(32, 0)) 3635 | (toUnsignedLong(i1) << pickPos(32, 32)); 3636 } 3637 private static int makeInt(short i0, short i1) { 3638 return (toUnsignedInt(i0) << pickPos(16, 0)) 3639 | (toUnsignedInt(i1) << pickPos(16, 16)); 3640 } 3641 private static int makeInt(byte i0, byte i1, byte i2, byte i3) { 3642 return ((toUnsignedInt(i0) << pickPos(24, 0)) 3643 | (toUnsignedInt(i1) << pickPos(24, 8)) 3644 | (toUnsignedInt(i2) << pickPos(24, 16)) 3645 | (toUnsignedInt(i3) << pickPos(24, 24))); 3646 } 3647 private static short makeShort(byte i0, byte i1) { 3648 return (short)((toUnsignedInt(i0) << pickPos(8, 0)) 3649 | (toUnsignedInt(i1) << pickPos(8, 8))); 3650 } 3651 3652 private static byte pick(byte le, byte be) { return BE ? be : le; } 3653 private static short pick(short le, short be) { return BE ? be : le; } 3654 private static int pick(int le, int be) { return BE ? be : le; } 3655 3656 // These methods write integers to memory from smaller parts 3657 // provided by their caller. The ordering in which these parts 3658 // are written is the native endianness of this platform. 3659 private void putLongParts(Object o, long offset, byte i0, byte i1, byte i2, byte i3, byte i4, byte i5, byte i6, byte i7) { 3660 putByte(o, offset + 0, pick(i0, i7)); 3661 putByte(o, offset + 1, pick(i1, i6)); 3662 putByte(o, offset + 2, pick(i2, i5)); 3663 putByte(o, offset + 3, pick(i3, i4)); 3664 putByte(o, offset + 4, pick(i4, i3)); 3665 putByte(o, offset + 5, pick(i5, i2)); 3666 putByte(o, offset + 6, pick(i6, i1)); 3667 putByte(o, offset + 7, pick(i7, i0)); 3668 } 3669 private void putLongParts(Object o, long offset, short i0, short i1, short i2, short i3) { 3670 putShort(o, offset + 0, pick(i0, i3)); 3671 putShort(o, offset + 2, pick(i1, i2)); 3672 putShort(o, offset + 4, pick(i2, i1)); 3673 putShort(o, offset + 6, pick(i3, i0)); 3674 } 3675 private void putLongParts(Object o, long offset, int i0, int i1) { 3676 putInt(o, offset + 0, pick(i0, i1)); 3677 putInt(o, offset + 4, pick(i1, i0)); 3678 } 3679 private void putIntParts(Object o, long offset, short i0, short i1) { 3680 putShort(o, offset + 0, pick(i0, i1)); 3681 putShort(o, offset + 2, pick(i1, i0)); 3682 } 3683 private void putIntParts(Object o, long offset, byte i0, byte i1, byte i2, byte i3) { 3684 putByte(o, offset + 0, pick(i0, i3)); 3685 putByte(o, offset + 1, pick(i1, i2)); 3686 putByte(o, offset + 2, pick(i2, i1)); 3687 putByte(o, offset + 3, pick(i3, i0)); 3688 } 3689 private void putShortParts(Object o, long offset, byte i0, byte i1) { 3690 putByte(o, offset + 0, pick(i0, i1)); 3691 putByte(o, offset + 1, pick(i1, i0)); 3692 } 3693 3694 // Zero-extend an integer 3695 private static int toUnsignedInt(byte n) { return n & 0xff; } 3696 private static int toUnsignedInt(short n) { return n & 0xffff; } 3697 private static long toUnsignedLong(byte n) { return n & 0xffl; } 3698 private static long toUnsignedLong(short n) { return n & 0xffffl; } 3699 private static long toUnsignedLong(int n) { return n & 0xffffffffl; } 3700 3701 // Maybe byte-reverse an integer 3702 private static char convEndian(boolean big, char n) { return big == BE ? n : Character.reverseBytes(n); } 3703 private static short convEndian(boolean big, short n) { return big == BE ? n : Short.reverseBytes(n) ; } 3704 private static int convEndian(boolean big, int n) { return big == BE ? n : Integer.reverseBytes(n) ; } 3705 private static long convEndian(boolean big, long n) { return big == BE ? n : Long.reverseBytes(n) ; } 3706 3707 3708 3709 private native long allocateMemory0(long bytes); 3710 private native long reallocateMemory0(long address, long bytes); 3711 private native void freeMemory0(long address); 3712 private native void setMemory0(Object o, long offset, long bytes, byte value); 3713 @HotSpotIntrinsicCandidate 3714 private native void copyMemory0(Object srcBase, long srcOffset, Object destBase, long destOffset, long bytes); 3715 private native void copySwapMemory0(Object srcBase, long srcOffset, Object destBase, long destOffset, long bytes, long elemSize); 3716 private native long objectFieldOffset0(Field f); 3717 private native long objectFieldOffset1(Class<?> c, String name); 3718 private native long staticFieldOffset0(Field f); 3719 private native Object staticFieldBase0(Field f); 3720 private native boolean shouldBeInitialized0(Class<?> c); 3721 private native void ensureClassInitialized0(Class<?> c); 3722 private native int arrayBaseOffset0(Class<?> arrayClass); 3723 private native int arrayIndexScale0(Class<?> arrayClass); 3724 private native int addressSize0(); 3725 private native Class<?> defineAnonymousClass0(Class<?> hostClass, byte[] data, Object[] cpPatches); 3726 private native int getLoadAverage0(double[] loadavg, int nelems); 3727 private native boolean unalignedAccess0(); 3728 private native boolean isBigEndian0(); 3729 3730 /** 3731 * Invokes the given direct byte buffer's cleaner, if any. 3732 * 3733 * @param directBuffer a direct byte buffer 3734 * @throws NullPointerException if {@code directBuffer} is null 3735 * @throws IllegalArgumentException if {@code directBuffer} is non-direct, 3736 * or is a {@link java.nio.Buffer#slice slice}, or is a 3737 * {@link java.nio.Buffer#duplicate duplicate} 3738 */ 3739 public void invokeCleaner(java.nio.ByteBuffer directBuffer) { 3740 if (!directBuffer.isDirect()) 3741 throw new IllegalArgumentException("buffer is non-direct"); 3742 3743 DirectBuffer db = (DirectBuffer) directBuffer; 3744 if (db.attachment() != null) 3745 throw new IllegalArgumentException("duplicate or slice"); 3746 3747 Cleaner cleaner = db.cleaner(); 3748 if (cleaner != null) { 3749 cleaner.clean(); 3750 } 3751 } 3752 }