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