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