169 * The first two parameters are interpreted exactly as with
170 * {@link #getInt(Object, long)} to refer to a specific
171 * Java variable (field or array element). The given value
172 * is stored into that variable.
173 * <p>
174 * The variable must be of the same type as the method
175 * parameter {@code x}.
176 *
177 * @param o Java heap object in which the variable resides, if any, else
178 * null
179 * @param offset indication of where the variable resides in a Java heap
180 * object, if any, else a memory address locating the variable
181 * statically
182 * @param x the value to store into the indicated Java variable
183 * @throws RuntimeException No defined exceptions are thrown, not even
184 * {@link NullPointerException}
185 */
186 @IntrinsicCandidate
187 public native void putInt(Object o, long offset, int x);
188
189 /**
190 * Fetches a reference value from a given Java variable.
191 * @see #getInt(Object, long)
192 */
193 @IntrinsicCandidate
194 public native Object getReference(Object o, long offset);
195
196 /**
197 * Stores a reference value into a given Java variable.
198 * <p>
199 * Unless the reference {@code x} being stored is either null
200 * or matches the field type, the results are undefined.
201 * If the reference {@code o} is non-null, card marks or
202 * other store barriers for that object (if the VM requires them)
203 * are updated.
204 * @see #putInt(Object, long, int)
205 */
206 @IntrinsicCandidate
207 public native void putReference(Object o, long offset, Object x);
208
209 /** @see #getInt(Object, long) */
210 @IntrinsicCandidate
211 public native boolean getBoolean(Object o, long offset);
212
213 /** @see #putInt(Object, long, int) */
214 @IntrinsicCandidate
215 public native void putBoolean(Object o, long offset, boolean x);
216
217 /** @see #getInt(Object, long) */
218 @IntrinsicCandidate
219 public native byte getByte(Object o, long offset);
220
221 /** @see #putInt(Object, long, int) */
222 @IntrinsicCandidate
223 public native void putByte(Object o, long offset, byte x);
224
225 /** @see #getInt(Object, long) */
226 @IntrinsicCandidate
227 public native short getShort(Object o, long offset);
228
1178 }
1179
1180 /**
1181 * Ensures the given class has been initialized (see JVMS-5.5 for details).
1182 * This is often needed in conjunction with obtaining the static field base
1183 * of a class.
1184 *
1185 * The call returns when either class {@code c} is fully initialized or
1186 * class {@code c} is being initialized and the call is performed from
1187 * the initializing thread. In the latter case a subsequent call to
1188 * {@link #shouldBeInitialized} will return {@code true}.
1189 */
1190 public void ensureClassInitialized(Class<?> c) {
1191 if (c == null) {
1192 throw new NullPointerException();
1193 }
1194
1195 ensureClassInitialized0(c);
1196 }
1197
1198 /**
1199 * Reports the offset of the first element in the storage allocation of a
1200 * given array class. If {@link #arrayIndexScale} returns a non-zero value
1201 * for the same class, you may use that scale factor, together with this
1202 * base offset, to form new offsets to access elements of arrays of the
1203 * given class.
1204 * <p>
1205 * The return value is in the range of a {@code int}. The return type is
1206 * {@code long} to emphasize that long arithmetic should always be used
1207 * for offset calculations to avoid overflows.
1208 *
1209 * @see #getInt(Object, long)
1210 * @see #putInt(Object, long, int)
1211 */
1212 public long arrayBaseOffset(Class<?> arrayClass) {
1213 if (arrayClass == null) {
1214 throw new NullPointerException();
1215 }
1216
1217 return arrayBaseOffset0(arrayClass);
1218 }
1219
1220
1221 /** The value of {@code arrayBaseOffset(boolean[].class)} */
1222 public static final long ARRAY_BOOLEAN_BASE_OFFSET
1223 = theUnsafe.arrayBaseOffset(boolean[].class);
1224
1225 /** The value of {@code arrayBaseOffset(byte[].class)} */
1226 public static final long ARRAY_BYTE_BASE_OFFSET
1227 = theUnsafe.arrayBaseOffset(byte[].class);
1228
1229 /** The value of {@code arrayBaseOffset(short[].class)} */
1230 public static final long ARRAY_SHORT_BASE_OFFSET
1231 = theUnsafe.arrayBaseOffset(short[].class);
1232
1233 /** The value of {@code arrayBaseOffset(char[].class)} */
1234 public static final long ARRAY_CHAR_BASE_OFFSET
1235 = theUnsafe.arrayBaseOffset(char[].class);
1236
1237 /** The value of {@code arrayBaseOffset(int[].class)} */
1238 public static final long ARRAY_INT_BASE_OFFSET
1239 = theUnsafe.arrayBaseOffset(int[].class);
1246 public static final long ARRAY_FLOAT_BASE_OFFSET
1247 = theUnsafe.arrayBaseOffset(float[].class);
1248
1249 /** The value of {@code arrayBaseOffset(double[].class)} */
1250 public static final long ARRAY_DOUBLE_BASE_OFFSET
1251 = theUnsafe.arrayBaseOffset(double[].class);
1252
1253 /** The value of {@code arrayBaseOffset(Object[].class)} */
1254 public static final long ARRAY_OBJECT_BASE_OFFSET
1255 = theUnsafe.arrayBaseOffset(Object[].class);
1256
1257 /**
1258 * Reports the scale factor for addressing elements in the storage
1259 * allocation of a given array class. However, arrays of "narrow" types
1260 * will generally not work properly with accessors like {@link
1261 * #getByte(Object, long)}, so the scale factor for such classes is reported
1262 * as zero.
1263 * <p>
1264 * The computation of the actual memory offset should always use {@code
1265 * long} arithmetic to avoid overflows.
1266 *
1267 * @see #arrayBaseOffset
1268 * @see #getInt(Object, long)
1269 * @see #putInt(Object, long, int)
1270 */
1271 public int arrayIndexScale(Class<?> arrayClass) {
1272 if (arrayClass == null) {
1273 throw new NullPointerException();
1274 }
1275
1276 return arrayIndexScale0(arrayClass);
1277 }
1278
1279
1280 /** The value of {@code arrayIndexScale(boolean[].class)} */
1281 public static final int ARRAY_BOOLEAN_INDEX_SCALE
1282 = theUnsafe.arrayIndexScale(boolean[].class);
1283
1284 /** The value of {@code arrayIndexScale(byte[].class)} */
1285 public static final int ARRAY_BYTE_INDEX_SCALE
1286 = theUnsafe.arrayIndexScale(byte[].class);
1287
1288 /** The value of {@code arrayIndexScale(short[].class)} */
1289 public static final int ARRAY_SHORT_INDEX_SCALE
1290 = theUnsafe.arrayIndexScale(short[].class);
1291
1292 /** The value of {@code arrayIndexScale(char[].class)} */
1293 public static final int ARRAY_CHAR_INDEX_SCALE
1294 = theUnsafe.arrayIndexScale(char[].class);
1295
1296 /** The value of {@code arrayIndexScale(int[].class)} */
1297 public static final int ARRAY_INT_INDEX_SCALE
1298 = theUnsafe.arrayIndexScale(int[].class);
1437 return null;
1438 }
1439
1440 /** Throws the exception without telling the verifier. */
1441 public native void throwException(Throwable ee);
1442
1443 /**
1444 * Atomically updates Java variable to {@code x} if it is currently
1445 * holding {@code expected}.
1446 *
1447 * <p>This operation has memory semantics of a {@code volatile} read
1448 * and write. Corresponds to C11 atomic_compare_exchange_strong.
1449 *
1450 * @return {@code true} if successful
1451 */
1452 @IntrinsicCandidate
1453 public final native boolean compareAndSetReference(Object o, long offset,
1454 Object expected,
1455 Object x);
1456
1457 @IntrinsicCandidate
1458 public final native Object compareAndExchangeReference(Object o, long offset,
1459 Object expected,
1460 Object x);
1461
1462 @IntrinsicCandidate
1463 public final Object compareAndExchangeReferenceAcquire(Object o, long offset,
1464 Object expected,
1465 Object x) {
1466 return compareAndExchangeReference(o, offset, expected, x);
1467 }
1468
1469 @IntrinsicCandidate
1470 public final Object compareAndExchangeReferenceRelease(Object o, long offset,
1471 Object expected,
1472 Object x) {
1473 return compareAndExchangeReference(o, offset, expected, x);
1474 }
1475
1476 @IntrinsicCandidate
1477 public final boolean weakCompareAndSetReferencePlain(Object o, long offset,
1478 Object expected,
1479 Object x) {
1480 return compareAndSetReference(o, offset, expected, x);
1481 }
1482
1483 @IntrinsicCandidate
1484 public final boolean weakCompareAndSetReferenceAcquire(Object o, long offset,
1485 Object expected,
1486 Object x) {
1487 return compareAndSetReference(o, offset, expected, x);
1488 }
1489
1490 @IntrinsicCandidate
1491 public final boolean weakCompareAndSetReferenceRelease(Object o, long offset,
1492 Object expected,
1493 Object x) {
1494 return compareAndSetReference(o, offset, expected, x);
1495 }
1496
1497 @IntrinsicCandidate
1498 public final boolean weakCompareAndSetReference(Object o, long offset,
1499 Object expected,
1500 Object x) {
1501 return compareAndSetReference(o, offset, expected, x);
1502 }
1503
1504 /**
1505 * Atomically updates Java variable to {@code x} if it is currently
1506 * holding {@code expected}.
1507 *
1508 * <p>This operation has memory semantics of a {@code volatile} read
1509 * and write. Corresponds to C11 atomic_compare_exchange_strong.
1510 *
1511 * @return {@code true} if successful
1512 */
1513 @IntrinsicCandidate
1514 public final native boolean compareAndSetInt(Object o, long offset,
1515 int expected,
1516 int x);
1517
1518 @IntrinsicCandidate
1519 public final native int compareAndExchangeInt(Object o, long offset,
1520 int expected,
1521 int x);
1522
1523 @IntrinsicCandidate
2099 public final boolean weakCompareAndSetLongRelease(Object o, long offset,
2100 long expected,
2101 long x) {
2102 return compareAndSetLong(o, offset, expected, x);
2103 }
2104
2105 @IntrinsicCandidate
2106 public final boolean weakCompareAndSetLong(Object o, long offset,
2107 long expected,
2108 long x) {
2109 return compareAndSetLong(o, offset, expected, x);
2110 }
2111
2112 /**
2113 * Fetches a reference value from a given Java variable, with volatile
2114 * load semantics. Otherwise identical to {@link #getReference(Object, long)}
2115 */
2116 @IntrinsicCandidate
2117 public native Object getReferenceVolatile(Object o, long offset);
2118
2119 /**
2120 * Stores a reference value into a given Java variable, with
2121 * volatile store semantics. Otherwise identical to {@link #putReference(Object, long, Object)}
2122 */
2123 @IntrinsicCandidate
2124 public native void putReferenceVolatile(Object o, long offset, Object x);
2125
2126 /** Volatile version of {@link #getInt(Object, long)} */
2127 @IntrinsicCandidate
2128 public native int getIntVolatile(Object o, long offset);
2129
2130 /** Volatile version of {@link #putInt(Object, long, int)} */
2131 @IntrinsicCandidate
2132 public native void putIntVolatile(Object o, long offset, int x);
2133
2134 /** Volatile version of {@link #getBoolean(Object, long)} */
2135 @IntrinsicCandidate
2136 public native boolean getBooleanVolatile(Object o, long offset);
2137
2138 /** Volatile version of {@link #putBoolean(Object, long, boolean)} */
2139 @IntrinsicCandidate
2140 public native void putBooleanVolatile(Object o, long offset, boolean x);
2141
2142 /** Volatile version of {@link #getByte(Object, long)} */
2143 @IntrinsicCandidate
2144 public native byte getByteVolatile(Object o, long offset);
2145
2178 /** Volatile version of {@link #putFloat(Object, long, float)} */
2179 @IntrinsicCandidate
2180 public native void putFloatVolatile(Object o, long offset, float x);
2181
2182 /** Volatile version of {@link #getDouble(Object, long)} */
2183 @IntrinsicCandidate
2184 public native double getDoubleVolatile(Object o, long offset);
2185
2186 /** Volatile version of {@link #putDouble(Object, long, double)} */
2187 @IntrinsicCandidate
2188 public native void putDoubleVolatile(Object o, long offset, double x);
2189
2190
2191
2192 /** Acquire version of {@link #getReferenceVolatile(Object, long)} */
2193 @IntrinsicCandidate
2194 public final Object getReferenceAcquire(Object o, long offset) {
2195 return getReferenceVolatile(o, offset);
2196 }
2197
2198 /** Acquire version of {@link #getBooleanVolatile(Object, long)} */
2199 @IntrinsicCandidate
2200 public final boolean getBooleanAcquire(Object o, long offset) {
2201 return getBooleanVolatile(o, offset);
2202 }
2203
2204 /** Acquire version of {@link #getByteVolatile(Object, long)} */
2205 @IntrinsicCandidate
2206 public final byte getByteAcquire(Object o, long offset) {
2207 return getByteVolatile(o, offset);
2208 }
2209
2210 /** Acquire version of {@link #getShortVolatile(Object, long)} */
2211 @IntrinsicCandidate
2212 public final short getShortAcquire(Object o, long offset) {
2213 return getShortVolatile(o, offset);
2214 }
2215
2216 /** Acquire version of {@link #getCharVolatile(Object, long)} */
2217 @IntrinsicCandidate
2242 public final double getDoubleAcquire(Object o, long offset) {
2243 return getDoubleVolatile(o, offset);
2244 }
2245
2246 /*
2247 * Versions of {@link #putReferenceVolatile(Object, long, Object)}
2248 * that do not guarantee immediate visibility of the store to
2249 * other threads. This method is generally only useful if the
2250 * underlying field is a Java volatile (or if an array cell, one
2251 * that is otherwise only accessed using volatile accesses).
2252 *
2253 * Corresponds to C11 atomic_store_explicit(..., memory_order_release).
2254 */
2255
2256 /** Release version of {@link #putReferenceVolatile(Object, long, Object)} */
2257 @IntrinsicCandidate
2258 public final void putReferenceRelease(Object o, long offset, Object x) {
2259 putReferenceVolatile(o, offset, x);
2260 }
2261
2262 /** Release version of {@link #putBooleanVolatile(Object, long, boolean)} */
2263 @IntrinsicCandidate
2264 public final void putBooleanRelease(Object o, long offset, boolean x) {
2265 putBooleanVolatile(o, offset, x);
2266 }
2267
2268 /** Release version of {@link #putByteVolatile(Object, long, byte)} */
2269 @IntrinsicCandidate
2270 public final void putByteRelease(Object o, long offset, byte x) {
2271 putByteVolatile(o, offset, x);
2272 }
2273
2274 /** Release version of {@link #putShortVolatile(Object, long, short)} */
2275 @IntrinsicCandidate
2276 public final void putShortRelease(Object o, long offset, short x) {
2277 putShortVolatile(o, offset, x);
2278 }
2279
2280 /** Release version of {@link #putCharVolatile(Object, long, char)} */
2281 @IntrinsicCandidate
2298 /** Release version of {@link #putLongVolatile(Object, long, long)} */
2299 @IntrinsicCandidate
2300 public final void putLongRelease(Object o, long offset, long x) {
2301 putLongVolatile(o, offset, x);
2302 }
2303
2304 /** Release version of {@link #putDoubleVolatile(Object, long, double)} */
2305 @IntrinsicCandidate
2306 public final void putDoubleRelease(Object o, long offset, double x) {
2307 putDoubleVolatile(o, offset, x);
2308 }
2309
2310 // ------------------------------ Opaque --------------------------------------
2311
2312 /** Opaque version of {@link #getReferenceVolatile(Object, long)} */
2313 @IntrinsicCandidate
2314 public final Object getReferenceOpaque(Object o, long offset) {
2315 return getReferenceVolatile(o, offset);
2316 }
2317
2318 /** Opaque version of {@link #getBooleanVolatile(Object, long)} */
2319 @IntrinsicCandidate
2320 public final boolean getBooleanOpaque(Object o, long offset) {
2321 return getBooleanVolatile(o, offset);
2322 }
2323
2324 /** Opaque version of {@link #getByteVolatile(Object, long)} */
2325 @IntrinsicCandidate
2326 public final byte getByteOpaque(Object o, long offset) {
2327 return getByteVolatile(o, offset);
2328 }
2329
2330 /** Opaque version of {@link #getShortVolatile(Object, long)} */
2331 @IntrinsicCandidate
2332 public final short getShortOpaque(Object o, long offset) {
2333 return getShortVolatile(o, offset);
2334 }
2335
2336 /** Opaque version of {@link #getCharVolatile(Object, long)} */
2337 @IntrinsicCandidate
2352 }
2353
2354 /** Opaque version of {@link #getLongVolatile(Object, long)} */
2355 @IntrinsicCandidate
2356 public final long getLongOpaque(Object o, long offset) {
2357 return getLongVolatile(o, offset);
2358 }
2359
2360 /** Opaque version of {@link #getDoubleVolatile(Object, long)} */
2361 @IntrinsicCandidate
2362 public final double getDoubleOpaque(Object o, long offset) {
2363 return getDoubleVolatile(o, offset);
2364 }
2365
2366 /** Opaque version of {@link #putReferenceVolatile(Object, long, Object)} */
2367 @IntrinsicCandidate
2368 public final void putReferenceOpaque(Object o, long offset, Object x) {
2369 putReferenceVolatile(o, offset, x);
2370 }
2371
2372 /** Opaque version of {@link #putBooleanVolatile(Object, long, boolean)} */
2373 @IntrinsicCandidate
2374 public final void putBooleanOpaque(Object o, long offset, boolean x) {
2375 putBooleanVolatile(o, offset, x);
2376 }
2377
2378 /** Opaque version of {@link #putByteVolatile(Object, long, byte)} */
2379 @IntrinsicCandidate
2380 public final void putByteOpaque(Object o, long offset, byte x) {
2381 putByteVolatile(o, offset, x);
2382 }
2383
2384 /** Opaque version of {@link #putShortVolatile(Object, long, short)} */
2385 @IntrinsicCandidate
2386 public final void putShortOpaque(Object o, long offset, short x) {
2387 putShortVolatile(o, offset, x);
2388 }
2389
2390 /** Opaque version of {@link #putCharVolatile(Object, long, char)} */
2391 @IntrinsicCandidate
2400 }
2401
2402 /** Opaque version of {@link #putFloatVolatile(Object, long, float)} */
2403 @IntrinsicCandidate
2404 public final void putFloatOpaque(Object o, long offset, float x) {
2405 putFloatVolatile(o, offset, x);
2406 }
2407
2408 /** Opaque version of {@link #putLongVolatile(Object, long, long)} */
2409 @IntrinsicCandidate
2410 public final void putLongOpaque(Object o, long offset, long x) {
2411 putLongVolatile(o, offset, x);
2412 }
2413
2414 /** Opaque version of {@link #putDoubleVolatile(Object, long, double)} */
2415 @IntrinsicCandidate
2416 public final void putDoubleOpaque(Object o, long offset, double x) {
2417 putDoubleVolatile(o, offset, x);
2418 }
2419
2420 /**
2421 * Unblocks the given thread blocked on {@code park}, or, if it is
2422 * not blocked, causes the subsequent call to {@code park} not to
2423 * block. Note: this operation is "unsafe" solely because the
2424 * caller must somehow ensure that the thread has not been
2425 * destroyed. Nothing special is usually required to ensure this
2426 * when called from Java (in which there will ordinarily be a live
2427 * reference to the thread) but this is not nearly-automatically
2428 * so when calling from native code.
2429 *
2430 * @param thread the thread to unpark.
2431 */
2432 @IntrinsicCandidate
2433 public native void unpark(Object thread);
2434
2435 /**
2436 * Blocks current thread, returning when a balancing
2437 * {@code unpark} occurs, or a balancing {@code unpark} has
2438 * already occurred, or the thread is interrupted, or, if not
2439 * absolute and time is not zero, the given time nanoseconds have
2786 /**
2787 * Atomically exchanges the given reference value with the current
2788 * reference value of a field or array element within the given
2789 * object {@code o} at the given {@code offset}.
2790 *
2791 * @param o object/array to update the field/element in
2792 * @param offset field/element offset
2793 * @param newValue new value
2794 * @return the previous value
2795 * @since 1.8
2796 */
2797 @IntrinsicCandidate
2798 public final Object getAndSetReference(Object o, long offset, Object newValue) {
2799 Object v;
2800 do {
2801 v = getReferenceVolatile(o, offset);
2802 } while (!weakCompareAndSetReference(o, offset, v, newValue));
2803 return v;
2804 }
2805
2806 @ForceInline
2807 public final Object getAndSetReferenceRelease(Object o, long offset, Object newValue) {
2808 Object v;
2809 do {
2810 v = getReference(o, offset);
2811 } while (!weakCompareAndSetReferenceRelease(o, offset, v, newValue));
2812 return v;
2813 }
2814
2815 @ForceInline
2816 public final Object getAndSetReferenceAcquire(Object o, long offset, Object newValue) {
2817 Object v;
2818 do {
2819 v = getReferenceAcquire(o, offset);
2820 } while (!weakCompareAndSetReferenceAcquire(o, offset, v, newValue));
2821 return v;
2822 }
2823
2824 @IntrinsicCandidate
2825 public final byte getAndSetByte(Object o, long offset, byte newValue) {
2826 byte v;
2827 do {
2828 v = getByteVolatile(o, offset);
2829 } while (!weakCompareAndSetByte(o, offset, v, newValue));
2830 return v;
2831 }
2832
2833 @ForceInline
2834 public final byte getAndSetByteRelease(Object o, long offset, byte newValue) {
2835 byte v;
2836 do {
2837 v = getByte(o, offset);
2838 } while (!weakCompareAndSetByteRelease(o, offset, v, newValue));
2839 return v;
2840 }
2841
2842 @ForceInline
2843 public final byte getAndSetByteAcquire(Object o, long offset, byte newValue) {
3859 private static short convEndian(boolean big, short n) { return big == BIG_ENDIAN ? n : Short.reverseBytes(n) ; }
3860 private static int convEndian(boolean big, int n) { return big == BIG_ENDIAN ? n : Integer.reverseBytes(n) ; }
3861 private static long convEndian(boolean big, long n) { return big == BIG_ENDIAN ? n : Long.reverseBytes(n) ; }
3862
3863
3864
3865 private native long allocateMemory0(long bytes);
3866 private native long reallocateMemory0(long address, long bytes);
3867 private native void freeMemory0(long address);
3868 @IntrinsicCandidate
3869 private native void setMemory0(Object o, long offset, long bytes, byte value);
3870 @IntrinsicCandidate
3871 private native void copyMemory0(Object srcBase, long srcOffset, Object destBase, long destOffset, long bytes);
3872 private native void copySwapMemory0(Object srcBase, long srcOffset, Object destBase, long destOffset, long bytes, long elemSize);
3873 private native long objectFieldOffset0(Field f); // throws IAE
3874 private native long knownObjectFieldOffset0(Class<?> c, String name); // error code: -1 not found, -2 static
3875 private native long staticFieldOffset0(Field f); // throws IAE
3876 private native Object staticFieldBase0(Field f); // throws IAE
3877 private native boolean shouldBeInitialized0(Class<?> c);
3878 private native void ensureClassInitialized0(Class<?> c);
3879 private native int arrayBaseOffset0(Class<?> arrayClass); // public version returns long to promote correct arithmetic
3880 private native int arrayIndexScale0(Class<?> arrayClass);
3881 private native int getLoadAverage0(double[] loadavg, int nelems);
3882
3883
3884 /**
3885 * Invokes the given direct byte buffer's cleaner, if any.
3886 *
3887 * @param directBuffer a direct byte buffer
3888 * @throws NullPointerException if {@code directBuffer} is null
3889 * @throws IllegalArgumentException if {@code directBuffer} is non-direct,
3890 * or is a {@link java.nio.Buffer#slice slice}, or is a
3891 * {@link java.nio.Buffer#duplicate duplicate}
3892 */
3893 public void invokeCleaner(java.nio.ByteBuffer directBuffer) {
3894 if (!directBuffer.isDirect())
3895 throw new IllegalArgumentException("buffer is non-direct");
3896
3897 DirectBuffer db = (DirectBuffer) directBuffer;
3898 if (db.attachment() != null)
3899 throw new IllegalArgumentException("duplicate or slice");
3900
3901 Cleaner cleaner = db.cleaner();
|
169 * The first two parameters are interpreted exactly as with
170 * {@link #getInt(Object, long)} to refer to a specific
171 * Java variable (field or array element). The given value
172 * is stored into that variable.
173 * <p>
174 * The variable must be of the same type as the method
175 * parameter {@code x}.
176 *
177 * @param o Java heap object in which the variable resides, if any, else
178 * null
179 * @param offset indication of where the variable resides in a Java heap
180 * object, if any, else a memory address locating the variable
181 * statically
182 * @param x the value to store into the indicated Java variable
183 * @throws RuntimeException No defined exceptions are thrown, not even
184 * {@link NullPointerException}
185 */
186 @IntrinsicCandidate
187 public native void putInt(Object o, long offset, int x);
188
189
190 /**
191 * Returns true if the given field is flattened.
192 */
193 public boolean isFlatField(Field f) {
194 if (f == null) {
195 throw new NullPointerException();
196 }
197 return isFlatField0(f);
198 }
199
200 private native boolean isFlatField0(Object o);
201
202 /* Returns true if the given field has a null marker
203 * <p>
204 * Nullable flat fields are stored in a flattened representation
205 * and have an associated null marker to indicate if the the field value is
206 * null or the one stored with the flat representation
207 */
208
209 public boolean hasNullMarker(Field f) {
210 if (f == null) {
211 throw new NullPointerException();
212 }
213 return hasNullMarker0(f);
214 }
215
216 private native boolean hasNullMarker0(Object o);
217
218 /* Returns the offset of the null marker of the field,
219 * or -1 if the field doesn't have a null marker
220 */
221
222 public int nullMarkerOffset(Field f) {
223 if (f == null) {
224 throw new NullPointerException();
225 }
226 return nullMarkerOffset0(f);
227 }
228
229 private native int nullMarkerOffset0(Object o);
230
231 public static final int NON_FLAT_LAYOUT = 0;
232
233 /* Reports the kind of layout used for an element in the storage
234 * allocation of the given array. Do not expect to perform any logic
235 * or layout control with this value, it is just an opaque token
236 * used for performance reasons.
237 *
238 * A layout of 0 indicates this array is not flat.
239 */
240 public int arrayLayout(Object[] array) {
241 if (array == null) {
242 throw new NullPointerException();
243 }
244 return arrayLayout0(array);
245 }
246
247 @IntrinsicCandidate
248 private native int arrayLayout0(Object[] array);
249
250
251 /* Reports the kind of layout used for a given field in the storage
252 * allocation of its class. Do not expect to perform any logic
253 * or layout control with this value, it is just an opaque token
254 * used for performance reasons.
255 *
256 * A layout of 0 indicates this field is not flat.
257 */
258 public int fieldLayout(Field f) {
259 if (f == null) {
260 throw new NullPointerException();
261 }
262 return fieldLayout0(f);
263 }
264
265 private native int fieldLayout0(Object o);
266
267 public native Object[] newSpecialArray(Class<?> componentType,
268 int length, int layoutKind);
269
270 /**
271 * Fetches a reference value from a given Java variable.
272 * This method can return a reference to either an object or value
273 * or a null reference.
274 *
275 * @see #getInt(Object, long)
276 */
277 @IntrinsicCandidate
278 public native Object getReference(Object o, long offset);
279
280 /**
281 * Stores a reference value into a given Java variable.
282 * This method can store a reference to either an object or value
283 * or a null reference.
284 * <p>
285 * Unless the reference {@code x} being stored is either null
286 * or matches the field type, the results are undefined.
287 * If the reference {@code o} is non-null, card marks or
288 * other store barriers for that object (if the VM requires them)
289 * are updated.
290 * @see #putInt(Object, long, int)
291 */
292 @IntrinsicCandidate
293 public native void putReference(Object o, long offset, Object x);
294
295 /**
296 * Fetches a value of type {@code <V>} from a given Java variable.
297 * More specifically, fetches a field or array element within the given
298 * {@code o} object at the given offset, or (if {@code o} is null)
299 * from the memory address whose numerical value is the given offset.
300 *
301 * @apiNote
302 * The returned object is newly allocated into the heap, because flat
303 * values lack object headers and thus can't be used as objects directly.
304 *
305 * @param o Java heap object in which the variable resides, if any, else
306 * null
307 * @param offset indication of where the variable resides in a Java heap
308 * object, if any, else a memory address locating the variable
309 * statically
310 * @param layoutKind opaque value used by the VM to know the layout
311 * the field or array element. This value must be retrieved with
312 * {@link #fieldLayout} or {@link #arrayLayout}.
313 * @param valueType value type
314 * @param <V> the type of a value
315 * @return the value fetched from the indicated Java variable
316 * @throws RuntimeException No defined exceptions are thrown, not even
317 * {@link NullPointerException}
318 */
319 @IntrinsicCandidate
320 public native <V> V getFlatValue(Object o, long offset, int layoutKind, Class<?> valueType);
321
322 /**
323 * Stores the given value into a given Java variable.
324 *
325 * Unless the reference {@code o} being stored is either null
326 * or matches the field type, the results are undefined.
327 *
328 * @param o Java heap object in which the variable resides, if any, else
329 * null
330 * @param offset indication of where the variable resides in a Java heap
331 * object, if any, else a memory address locating the variable
332 * statically
333 * @param layoutKind opaque value used by the VM to know the layout
334 * the field or array element. This value must be retrieved with
335 * {@link #fieldLayout} or {@link #arrayLayout}.
336 * @param valueType value type
337 * @param v the value to store into the indicated Java variable
338 * @param <V> the type of a value
339 * @throws RuntimeException No defined exceptions are thrown, not even
340 * {@link NullPointerException}
341 */
342 @IntrinsicCandidate
343 public native <V> void putFlatValue(Object o, long offset, int layoutKind, Class<?> valueType, V v);
344
345 /**
346 * Returns an object instance with a private buffered value whose layout
347 * and contents is exactly the given value instance. The return object
348 * is in the larval state that can be updated using the unsafe put operation.
349 *
350 * @param value a value instance
351 * @param <V> the type of the given value instance
352 */
353 @IntrinsicCandidate
354 public native <V> V makePrivateBuffer(V value);
355
356 /**
357 * Exits the larval state and returns a value instance.
358 *
359 * @param value a value instance
360 * @param <V> the type of the given value instance
361 */
362 @IntrinsicCandidate
363 public native <V> V finishPrivateBuffer(V value);
364
365 /**
366 * Returns the header size of the given value type.
367 *
368 * @param valueType value type
369 * @return the header size of the value type
370 */
371 public native <V> long valueHeaderSize(Class<V> valueType);
372
373 /** @see #getInt(Object, long) */
374 @IntrinsicCandidate
375 public native boolean getBoolean(Object o, long offset);
376
377 /** @see #putInt(Object, long, int) */
378 @IntrinsicCandidate
379 public native void putBoolean(Object o, long offset, boolean x);
380
381 /** @see #getInt(Object, long) */
382 @IntrinsicCandidate
383 public native byte getByte(Object o, long offset);
384
385 /** @see #putInt(Object, long, int) */
386 @IntrinsicCandidate
387 public native void putByte(Object o, long offset, byte x);
388
389 /** @see #getInt(Object, long) */
390 @IntrinsicCandidate
391 public native short getShort(Object o, long offset);
392
1342 }
1343
1344 /**
1345 * Ensures the given class has been initialized (see JVMS-5.5 for details).
1346 * This is often needed in conjunction with obtaining the static field base
1347 * of a class.
1348 *
1349 * The call returns when either class {@code c} is fully initialized or
1350 * class {@code c} is being initialized and the call is performed from
1351 * the initializing thread. In the latter case a subsequent call to
1352 * {@link #shouldBeInitialized} will return {@code true}.
1353 */
1354 public void ensureClassInitialized(Class<?> c) {
1355 if (c == null) {
1356 throw new NullPointerException();
1357 }
1358
1359 ensureClassInitialized0(c);
1360 }
1361
1362 /**
1363 * The reading or writing of strict static fields may require
1364 * special processing. Notify the VM that such an event is about
1365 * to happen. The VM may respond by throwing an exception, in the
1366 * case of a read of an uninitialized field. If the VM allows the
1367 * method to return normally, no further calls are needed, with
1368 * the same arguments.
1369 */
1370 public void notifyStrictStaticAccess(Class<?> c, long staticFieldOffset, boolean writing) {
1371 if (c == null) {
1372 throw new NullPointerException();
1373 }
1374 notifyStrictStaticAccess0(c, staticFieldOffset, writing);
1375 }
1376
1377 /**
1378 * Reports the offset of the first element in the storage allocation of a
1379 * given array class. If {@link #arrayIndexScale} returns a non-zero value
1380 * for the same class, you may use that scale factor, together with this
1381 * base offset, to form new offsets to access elements of arrays of the
1382 * given class.
1383 * <p>
1384 * The return value is in the range of a {@code int}. The return type is
1385 * {@code long} to emphasize that long arithmetic should always be used
1386 * for offset calculations to avoid overflows.
1387 * <p>
1388 * This method doesn't support arrays with an element type that is
1389 * a value class, because this type of array can have multiple layouts.
1390 * For these arrays, {@code arrayInstanceBaseOffset(Object[] array)}
1391 * must be used instead.
1392 *
1393 * @see #getInt(Object, long)
1394 * @see #putInt(Object, long, int)
1395 */
1396 public long arrayBaseOffset(Class<?> arrayClass) {
1397 if (arrayClass == null) {
1398 throw new NullPointerException();
1399 }
1400
1401 return arrayBaseOffset0(arrayClass);
1402 }
1403
1404 public long arrayInstanceBaseOffset(Object[] array) {
1405 if (array == null) {
1406 throw new NullPointerException();
1407 }
1408
1409 return arrayInstanceBaseOffset0(array);
1410 }
1411
1412 /** The value of {@code arrayBaseOffset(boolean[].class)} */
1413 public static final long ARRAY_BOOLEAN_BASE_OFFSET
1414 = theUnsafe.arrayBaseOffset(boolean[].class);
1415
1416 /** The value of {@code arrayBaseOffset(byte[].class)} */
1417 public static final long ARRAY_BYTE_BASE_OFFSET
1418 = theUnsafe.arrayBaseOffset(byte[].class);
1419
1420 /** The value of {@code arrayBaseOffset(short[].class)} */
1421 public static final long ARRAY_SHORT_BASE_OFFSET
1422 = theUnsafe.arrayBaseOffset(short[].class);
1423
1424 /** The value of {@code arrayBaseOffset(char[].class)} */
1425 public static final long ARRAY_CHAR_BASE_OFFSET
1426 = theUnsafe.arrayBaseOffset(char[].class);
1427
1428 /** The value of {@code arrayBaseOffset(int[].class)} */
1429 public static final long ARRAY_INT_BASE_OFFSET
1430 = theUnsafe.arrayBaseOffset(int[].class);
1437 public static final long ARRAY_FLOAT_BASE_OFFSET
1438 = theUnsafe.arrayBaseOffset(float[].class);
1439
1440 /** The value of {@code arrayBaseOffset(double[].class)} */
1441 public static final long ARRAY_DOUBLE_BASE_OFFSET
1442 = theUnsafe.arrayBaseOffset(double[].class);
1443
1444 /** The value of {@code arrayBaseOffset(Object[].class)} */
1445 public static final long ARRAY_OBJECT_BASE_OFFSET
1446 = theUnsafe.arrayBaseOffset(Object[].class);
1447
1448 /**
1449 * Reports the scale factor for addressing elements in the storage
1450 * allocation of a given array class. However, arrays of "narrow" types
1451 * will generally not work properly with accessors like {@link
1452 * #getByte(Object, long)}, so the scale factor for such classes is reported
1453 * as zero.
1454 * <p>
1455 * The computation of the actual memory offset should always use {@code
1456 * long} arithmetic to avoid overflows.
1457 * <p>
1458 * This method doesn't support arrays with an element type that is
1459 * a value class, because this type of array can have multiple layouts.
1460 * For these arrays, {@code arrayInstanceIndexScale(Object[] array)}
1461 * must be used instead.
1462 *
1463 * @see #arrayBaseOffset
1464 * @see #getInt(Object, long)
1465 * @see #putInt(Object, long, int)
1466 */
1467 public int arrayIndexScale(Class<?> arrayClass) {
1468 if (arrayClass == null) {
1469 throw new NullPointerException();
1470 }
1471
1472 return arrayIndexScale0(arrayClass);
1473 }
1474
1475 public int arrayInstanceIndexScale(Object[] array) {
1476 if (array == null) {
1477 throw new NullPointerException();
1478 }
1479
1480 return arrayInstanceIndexScale0(array);
1481 }
1482
1483 public int[] getFieldMap(Class<? extends Object> c) {
1484 if (c == null) {
1485 throw new NullPointerException();
1486 }
1487 return getFieldMap0(c);
1488 }
1489
1490 /**
1491 * Return the size of the object in the heap.
1492 * @param o an object
1493 * @return the objects's size
1494 * @since Valhalla
1495 */
1496 public long getObjectSize(Object o) {
1497 if (o == null)
1498 throw new NullPointerException();
1499 return getObjectSize0(o);
1500 }
1501
1502 /** The value of {@code arrayIndexScale(boolean[].class)} */
1503 public static final int ARRAY_BOOLEAN_INDEX_SCALE
1504 = theUnsafe.arrayIndexScale(boolean[].class);
1505
1506 /** The value of {@code arrayIndexScale(byte[].class)} */
1507 public static final int ARRAY_BYTE_INDEX_SCALE
1508 = theUnsafe.arrayIndexScale(byte[].class);
1509
1510 /** The value of {@code arrayIndexScale(short[].class)} */
1511 public static final int ARRAY_SHORT_INDEX_SCALE
1512 = theUnsafe.arrayIndexScale(short[].class);
1513
1514 /** The value of {@code arrayIndexScale(char[].class)} */
1515 public static final int ARRAY_CHAR_INDEX_SCALE
1516 = theUnsafe.arrayIndexScale(char[].class);
1517
1518 /** The value of {@code arrayIndexScale(int[].class)} */
1519 public static final int ARRAY_INT_INDEX_SCALE
1520 = theUnsafe.arrayIndexScale(int[].class);
1659 return null;
1660 }
1661
1662 /** Throws the exception without telling the verifier. */
1663 public native void throwException(Throwable ee);
1664
1665 /**
1666 * Atomically updates Java variable to {@code x} if it is currently
1667 * holding {@code expected}.
1668 *
1669 * <p>This operation has memory semantics of a {@code volatile} read
1670 * and write. Corresponds to C11 atomic_compare_exchange_strong.
1671 *
1672 * @return {@code true} if successful
1673 */
1674 @IntrinsicCandidate
1675 public final native boolean compareAndSetReference(Object o, long offset,
1676 Object expected,
1677 Object x);
1678
1679 private final boolean isValueObject(Object o) {
1680 return o != null && o.getClass().isValue();
1681 }
1682
1683 /*
1684 * For value type, CAS should do substitutability test as opposed
1685 * to two pointers comparison.
1686 */
1687 @ForceInline
1688 public final <V> boolean compareAndSetReference(Object o, long offset,
1689 Class<?> type,
1690 V expected,
1691 V x) {
1692 if (type.isValue() || isValueObject(expected)) {
1693 while (true) {
1694 Object witness = getReferenceVolatile(o, offset);
1695 if (witness != expected) {
1696 return false;
1697 }
1698 if (compareAndSetReference(o, offset, witness, x)) {
1699 return true;
1700 }
1701 }
1702 } else {
1703 return compareAndSetReference(o, offset, expected, x);
1704 }
1705 }
1706
1707 @ForceInline
1708 public final <V> boolean compareAndSetFlatValue(Object o, long offset,
1709 int layout,
1710 Class<?> valueType,
1711 V expected,
1712 V x) {
1713 Object[] array = newSpecialArray(valueType, 2, layout);
1714 return compareAndSetFlatValueAsBytes(array, o, offset, layout, valueType, expected, x);
1715 }
1716
1717 @IntrinsicCandidate
1718 public final native Object compareAndExchangeReference(Object o, long offset,
1719 Object expected,
1720 Object x);
1721
1722 @ForceInline
1723 public final <V> Object compareAndExchangeReference(Object o, long offset,
1724 Class<?> valueType,
1725 V expected,
1726 V x) {
1727 if (valueType.isValue() || isValueObject(expected)) {
1728 while (true) {
1729 Object witness = getReferenceVolatile(o, offset);
1730 if (witness != expected) {
1731 return witness;
1732 }
1733 if (compareAndSetReference(o, offset, witness, x)) {
1734 return witness;
1735 }
1736 }
1737 } else {
1738 return compareAndExchangeReference(o, offset, expected, x);
1739 }
1740 }
1741
1742 @ForceInline
1743 public final <V> Object compareAndExchangeFlatValue(Object o, long offset,
1744 int layout,
1745 Class<?> valueType,
1746 V expected,
1747 V x) {
1748 Object[] array = newSpecialArray(valueType, 2, layout);
1749 compareAndSetFlatValueAsBytes(array, o, offset, layout, valueType, expected, x);
1750 return array[0];
1751 }
1752
1753 @IntrinsicCandidate
1754 public final Object compareAndExchangeReferenceAcquire(Object o, long offset,
1755 Object expected,
1756 Object x) {
1757 return compareAndExchangeReference(o, offset, expected, x);
1758 }
1759
1760 public final <V> Object compareAndExchangeReferenceAcquire(Object o, long offset,
1761 Class<?> valueType,
1762 V expected,
1763 V x) {
1764 return compareAndExchangeReference(o, offset, valueType, expected, x);
1765 }
1766
1767 @ForceInline
1768 public final <V> Object compareAndExchangeFlatValueAcquire(Object o, long offset,
1769 int layout,
1770 Class<?> valueType,
1771 V expected,
1772 V x) {
1773 return compareAndExchangeFlatValue(o, offset, layout, valueType, expected, x);
1774 }
1775
1776 @IntrinsicCandidate
1777 public final Object compareAndExchangeReferenceRelease(Object o, long offset,
1778 Object expected,
1779 Object x) {
1780 return compareAndExchangeReference(o, offset, expected, x);
1781 }
1782
1783 public final <V> Object compareAndExchangeReferenceRelease(Object o, long offset,
1784 Class<?> valueType,
1785 V expected,
1786 V x) {
1787 return compareAndExchangeReference(o, offset, valueType, expected, x);
1788 }
1789
1790 @ForceInline
1791 public final <V> Object compareAndExchangeFlatValueRelease(Object o, long offset,
1792 int layout,
1793 Class<?> valueType,
1794 V expected,
1795 V x) {
1796 return compareAndExchangeFlatValue(o, offset, layout, valueType, expected, x);
1797 }
1798
1799 @IntrinsicCandidate
1800 public final boolean weakCompareAndSetReferencePlain(Object o, long offset,
1801 Object expected,
1802 Object x) {
1803 return compareAndSetReference(o, offset, expected, x);
1804 }
1805
1806 public final <V> boolean weakCompareAndSetReferencePlain(Object o, long offset,
1807 Class<?> valueType,
1808 V expected,
1809 V x) {
1810 if (valueType.isValue() || isValueObject(expected)) {
1811 return compareAndSetReference(o, offset, valueType, expected, x);
1812 } else {
1813 return weakCompareAndSetReferencePlain(o, offset, expected, x);
1814 }
1815 }
1816
1817 @ForceInline
1818 public final <V> boolean weakCompareAndSetFlatValuePlain(Object o, long offset,
1819 int layout,
1820 Class<?> valueType,
1821 V expected,
1822 V x) {
1823 return compareAndSetFlatValue(o, offset, layout, valueType, expected, x);
1824 }
1825
1826 @IntrinsicCandidate
1827 public final boolean weakCompareAndSetReferenceAcquire(Object o, long offset,
1828 Object expected,
1829 Object x) {
1830 return compareAndSetReference(o, offset, expected, x);
1831 }
1832
1833 public final <V> boolean weakCompareAndSetReferenceAcquire(Object o, long offset,
1834 Class<?> valueType,
1835 V expected,
1836 V x) {
1837 if (valueType.isValue() || isValueObject(expected)) {
1838 return compareAndSetReference(o, offset, valueType, expected, x);
1839 } else {
1840 return weakCompareAndSetReferencePlain(o, offset, expected, x);
1841 }
1842 }
1843
1844 @ForceInline
1845 public final <V> boolean weakCompareAndSetFlatValueAcquire(Object o, long offset,
1846 int layout,
1847 Class<?> valueType,
1848 V expected,
1849 V x) {
1850 return compareAndSetFlatValue(o, offset, layout, valueType, expected, x);
1851 }
1852
1853 @IntrinsicCandidate
1854 public final boolean weakCompareAndSetReferenceRelease(Object o, long offset,
1855 Object expected,
1856 Object x) {
1857 return compareAndSetReference(o, offset, expected, x);
1858 }
1859
1860 public final <V> boolean weakCompareAndSetReferenceRelease(Object o, long offset,
1861 Class<?> valueType,
1862 V expected,
1863 V x) {
1864 if (valueType.isValue() || isValueObject(expected)) {
1865 return compareAndSetReference(o, offset, valueType, expected, x);
1866 } else {
1867 return weakCompareAndSetReferencePlain(o, offset, expected, x);
1868 }
1869 }
1870
1871 @ForceInline
1872 public final <V> boolean weakCompareAndSetFlatValueRelease(Object o, long offset,
1873 int layout,
1874 Class<?> valueType,
1875 V expected,
1876 V x) {
1877 return compareAndSetFlatValue(o, offset, layout, valueType, expected, x);
1878 }
1879
1880 @IntrinsicCandidate
1881 public final boolean weakCompareAndSetReference(Object o, long offset,
1882 Object expected,
1883 Object x) {
1884 return compareAndSetReference(o, offset, expected, x);
1885 }
1886
1887 public final <V> boolean weakCompareAndSetReference(Object o, long offset,
1888 Class<?> valueType,
1889 V expected,
1890 V x) {
1891 if (valueType.isValue() || isValueObject(expected)) {
1892 return compareAndSetReference(o, offset, valueType, expected, x);
1893 } else {
1894 return weakCompareAndSetReferencePlain(o, offset, expected, x);
1895 }
1896 }
1897
1898 @ForceInline
1899 public final <V> boolean weakCompareAndSetFlatValue(Object o, long offset,
1900 int layout,
1901 Class<?> valueType,
1902 V expected,
1903 V x) {
1904 return compareAndSetFlatValue(o, offset, layout, valueType, expected, x);
1905 }
1906
1907 /**
1908 * Atomically updates Java variable to {@code x} if it is currently
1909 * holding {@code expected}.
1910 *
1911 * <p>This operation has memory semantics of a {@code volatile} read
1912 * and write. Corresponds to C11 atomic_compare_exchange_strong.
1913 *
1914 * @return {@code true} if successful
1915 */
1916 @IntrinsicCandidate
1917 public final native boolean compareAndSetInt(Object o, long offset,
1918 int expected,
1919 int x);
1920
1921 @IntrinsicCandidate
1922 public final native int compareAndExchangeInt(Object o, long offset,
1923 int expected,
1924 int x);
1925
1926 @IntrinsicCandidate
2502 public final boolean weakCompareAndSetLongRelease(Object o, long offset,
2503 long expected,
2504 long x) {
2505 return compareAndSetLong(o, offset, expected, x);
2506 }
2507
2508 @IntrinsicCandidate
2509 public final boolean weakCompareAndSetLong(Object o, long offset,
2510 long expected,
2511 long x) {
2512 return compareAndSetLong(o, offset, expected, x);
2513 }
2514
2515 /**
2516 * Fetches a reference value from a given Java variable, with volatile
2517 * load semantics. Otherwise identical to {@link #getReference(Object, long)}
2518 */
2519 @IntrinsicCandidate
2520 public native Object getReferenceVolatile(Object o, long offset);
2521
2522 @ForceInline
2523 public final <V> Object getFlatValueVolatile(Object o, long offset, int layout, Class<?> valueType) {
2524 // we translate using fences (see: https://gee.cs.oswego.edu/dl/html/j9mm.html)
2525 Object res = getFlatValue(o, offset, layout, valueType);
2526 fullFence();
2527 return res;
2528 }
2529
2530 /**
2531 * Stores a reference value into a given Java variable, with
2532 * volatile store semantics. Otherwise identical to {@link #putReference(Object, long, Object)}
2533 */
2534 @IntrinsicCandidate
2535 public native void putReferenceVolatile(Object o, long offset, Object x);
2536
2537 @ForceInline
2538 public final <V> void putFlatValueVolatile(Object o, long offset, int layout, Class<?> valueType, V x) {
2539 // we translate using fences (see: https://gee.cs.oswego.edu/dl/html/j9mm.html)
2540 putFlatValueRelease(o, offset, layout, valueType, x);
2541 fullFence();
2542 }
2543
2544 /** Volatile version of {@link #getInt(Object, long)} */
2545 @IntrinsicCandidate
2546 public native int getIntVolatile(Object o, long offset);
2547
2548 /** Volatile version of {@link #putInt(Object, long, int)} */
2549 @IntrinsicCandidate
2550 public native void putIntVolatile(Object o, long offset, int x);
2551
2552 /** Volatile version of {@link #getBoolean(Object, long)} */
2553 @IntrinsicCandidate
2554 public native boolean getBooleanVolatile(Object o, long offset);
2555
2556 /** Volatile version of {@link #putBoolean(Object, long, boolean)} */
2557 @IntrinsicCandidate
2558 public native void putBooleanVolatile(Object o, long offset, boolean x);
2559
2560 /** Volatile version of {@link #getByte(Object, long)} */
2561 @IntrinsicCandidate
2562 public native byte getByteVolatile(Object o, long offset);
2563
2596 /** Volatile version of {@link #putFloat(Object, long, float)} */
2597 @IntrinsicCandidate
2598 public native void putFloatVolatile(Object o, long offset, float x);
2599
2600 /** Volatile version of {@link #getDouble(Object, long)} */
2601 @IntrinsicCandidate
2602 public native double getDoubleVolatile(Object o, long offset);
2603
2604 /** Volatile version of {@link #putDouble(Object, long, double)} */
2605 @IntrinsicCandidate
2606 public native void putDoubleVolatile(Object o, long offset, double x);
2607
2608
2609
2610 /** Acquire version of {@link #getReferenceVolatile(Object, long)} */
2611 @IntrinsicCandidate
2612 public final Object getReferenceAcquire(Object o, long offset) {
2613 return getReferenceVolatile(o, offset);
2614 }
2615
2616 @ForceInline
2617 public final <V> Object getFlatValueAcquire(Object o, long offset, int layout, Class<?> valueType) {
2618 // we translate using fences (see: https://gee.cs.oswego.edu/dl/html/j9mm.html)
2619 Object res = getFlatValue(o, offset, layout, valueType);
2620 loadFence();
2621 return res;
2622 }
2623
2624 /** Acquire version of {@link #getBooleanVolatile(Object, long)} */
2625 @IntrinsicCandidate
2626 public final boolean getBooleanAcquire(Object o, long offset) {
2627 return getBooleanVolatile(o, offset);
2628 }
2629
2630 /** Acquire version of {@link #getByteVolatile(Object, long)} */
2631 @IntrinsicCandidate
2632 public final byte getByteAcquire(Object o, long offset) {
2633 return getByteVolatile(o, offset);
2634 }
2635
2636 /** Acquire version of {@link #getShortVolatile(Object, long)} */
2637 @IntrinsicCandidate
2638 public final short getShortAcquire(Object o, long offset) {
2639 return getShortVolatile(o, offset);
2640 }
2641
2642 /** Acquire version of {@link #getCharVolatile(Object, long)} */
2643 @IntrinsicCandidate
2668 public final double getDoubleAcquire(Object o, long offset) {
2669 return getDoubleVolatile(o, offset);
2670 }
2671
2672 /*
2673 * Versions of {@link #putReferenceVolatile(Object, long, Object)}
2674 * that do not guarantee immediate visibility of the store to
2675 * other threads. This method is generally only useful if the
2676 * underlying field is a Java volatile (or if an array cell, one
2677 * that is otherwise only accessed using volatile accesses).
2678 *
2679 * Corresponds to C11 atomic_store_explicit(..., memory_order_release).
2680 */
2681
2682 /** Release version of {@link #putReferenceVolatile(Object, long, Object)} */
2683 @IntrinsicCandidate
2684 public final void putReferenceRelease(Object o, long offset, Object x) {
2685 putReferenceVolatile(o, offset, x);
2686 }
2687
2688 @ForceInline
2689 public final <V> void putFlatValueRelease(Object o, long offset, int layout, Class<?> valueType, V x) {
2690 // we translate using fences (see: https://gee.cs.oswego.edu/dl/html/j9mm.html)
2691 storeFence();
2692 putFlatValue(o, offset, layout, valueType, x);
2693 }
2694
2695 /** Release version of {@link #putBooleanVolatile(Object, long, boolean)} */
2696 @IntrinsicCandidate
2697 public final void putBooleanRelease(Object o, long offset, boolean x) {
2698 putBooleanVolatile(o, offset, x);
2699 }
2700
2701 /** Release version of {@link #putByteVolatile(Object, long, byte)} */
2702 @IntrinsicCandidate
2703 public final void putByteRelease(Object o, long offset, byte x) {
2704 putByteVolatile(o, offset, x);
2705 }
2706
2707 /** Release version of {@link #putShortVolatile(Object, long, short)} */
2708 @IntrinsicCandidate
2709 public final void putShortRelease(Object o, long offset, short x) {
2710 putShortVolatile(o, offset, x);
2711 }
2712
2713 /** Release version of {@link #putCharVolatile(Object, long, char)} */
2714 @IntrinsicCandidate
2731 /** Release version of {@link #putLongVolatile(Object, long, long)} */
2732 @IntrinsicCandidate
2733 public final void putLongRelease(Object o, long offset, long x) {
2734 putLongVolatile(o, offset, x);
2735 }
2736
2737 /** Release version of {@link #putDoubleVolatile(Object, long, double)} */
2738 @IntrinsicCandidate
2739 public final void putDoubleRelease(Object o, long offset, double x) {
2740 putDoubleVolatile(o, offset, x);
2741 }
2742
2743 // ------------------------------ Opaque --------------------------------------
2744
2745 /** Opaque version of {@link #getReferenceVolatile(Object, long)} */
2746 @IntrinsicCandidate
2747 public final Object getReferenceOpaque(Object o, long offset) {
2748 return getReferenceVolatile(o, offset);
2749 }
2750
2751 @ForceInline
2752 public final <V> Object getFlatValueOpaque(Object o, long offset, int layout, Class<?> valueType) {
2753 // this is stronger than opaque semantics
2754 return getFlatValueAcquire(o, offset, layout, valueType);
2755 }
2756
2757 /** Opaque version of {@link #getBooleanVolatile(Object, long)} */
2758 @IntrinsicCandidate
2759 public final boolean getBooleanOpaque(Object o, long offset) {
2760 return getBooleanVolatile(o, offset);
2761 }
2762
2763 /** Opaque version of {@link #getByteVolatile(Object, long)} */
2764 @IntrinsicCandidate
2765 public final byte getByteOpaque(Object o, long offset) {
2766 return getByteVolatile(o, offset);
2767 }
2768
2769 /** Opaque version of {@link #getShortVolatile(Object, long)} */
2770 @IntrinsicCandidate
2771 public final short getShortOpaque(Object o, long offset) {
2772 return getShortVolatile(o, offset);
2773 }
2774
2775 /** Opaque version of {@link #getCharVolatile(Object, long)} */
2776 @IntrinsicCandidate
2791 }
2792
2793 /** Opaque version of {@link #getLongVolatile(Object, long)} */
2794 @IntrinsicCandidate
2795 public final long getLongOpaque(Object o, long offset) {
2796 return getLongVolatile(o, offset);
2797 }
2798
2799 /** Opaque version of {@link #getDoubleVolatile(Object, long)} */
2800 @IntrinsicCandidate
2801 public final double getDoubleOpaque(Object o, long offset) {
2802 return getDoubleVolatile(o, offset);
2803 }
2804
2805 /** Opaque version of {@link #putReferenceVolatile(Object, long, Object)} */
2806 @IntrinsicCandidate
2807 public final void putReferenceOpaque(Object o, long offset, Object x) {
2808 putReferenceVolatile(o, offset, x);
2809 }
2810
2811 @ForceInline
2812 public final <V> void putFlatValueOpaque(Object o, long offset, int layout, Class<?> valueType, V x) {
2813 // this is stronger than opaque semantics
2814 putFlatValueRelease(o, offset, layout, valueType, x);
2815 }
2816
2817 /** Opaque version of {@link #putBooleanVolatile(Object, long, boolean)} */
2818 @IntrinsicCandidate
2819 public final void putBooleanOpaque(Object o, long offset, boolean x) {
2820 putBooleanVolatile(o, offset, x);
2821 }
2822
2823 /** Opaque version of {@link #putByteVolatile(Object, long, byte)} */
2824 @IntrinsicCandidate
2825 public final void putByteOpaque(Object o, long offset, byte x) {
2826 putByteVolatile(o, offset, x);
2827 }
2828
2829 /** Opaque version of {@link #putShortVolatile(Object, long, short)} */
2830 @IntrinsicCandidate
2831 public final void putShortOpaque(Object o, long offset, short x) {
2832 putShortVolatile(o, offset, x);
2833 }
2834
2835 /** Opaque version of {@link #putCharVolatile(Object, long, char)} */
2836 @IntrinsicCandidate
2845 }
2846
2847 /** Opaque version of {@link #putFloatVolatile(Object, long, float)} */
2848 @IntrinsicCandidate
2849 public final void putFloatOpaque(Object o, long offset, float x) {
2850 putFloatVolatile(o, offset, x);
2851 }
2852
2853 /** Opaque version of {@link #putLongVolatile(Object, long, long)} */
2854 @IntrinsicCandidate
2855 public final void putLongOpaque(Object o, long offset, long x) {
2856 putLongVolatile(o, offset, x);
2857 }
2858
2859 /** Opaque version of {@link #putDoubleVolatile(Object, long, double)} */
2860 @IntrinsicCandidate
2861 public final void putDoubleOpaque(Object o, long offset, double x) {
2862 putDoubleVolatile(o, offset, x);
2863 }
2864
2865 @ForceInline
2866 private boolean compareAndSetFlatValueAsBytes(Object[] array, Object o, long offset, int layout, Class<?> valueType, Object expected, Object x) {
2867 // We can convert between a value object and a binary value (of suitable size) using array elements.
2868 // This only works if the payload contains no oops (see VarHandles::isAtomicFlat).
2869 // Thus, we can implement the CAS with a plain numeric CAS.
2870
2871 // array[0]: witness (put as binary, get as object), at base
2872 // array[1]: x (put as object, get as binary), at base + scale
2873 // When witness == expected, the witness binary may be different from the expected binary.
2874 // This happens when compiler does not zero unused positions in the witness.
2875 // So we must obtain the witness binary and use it as expected binary for the numeric CAS.
2876 long base = arrayInstanceBaseOffset(array);
2877 int scale = arrayInstanceIndexScale(array);
2878 putFlatValue(array, base + scale, layout, valueType, x); // put x as object
2879 switch (scale) {
2880 case 1: {
2881 do {
2882 byte witnessByte = getByteVolatile(o, offset);
2883 putByte(array, base, witnessByte); // put witness as binary
2884 Object witness = getFlatValue(array, base, layout, valueType); // get witness as object
2885 if (witness != expected) {
2886 return false;
2887 }
2888 byte xByte = getByte(array, base + scale); // get x as binary
2889 if (compareAndSetByte(o, offset, witnessByte, xByte)) {
2890 return true;
2891 }
2892 } while (true);
2893 }
2894 case 2: {
2895 do {
2896 short witnessShort = getShortVolatile(o, offset);
2897 putShort(array, base, witnessShort); // put witness as binary
2898 Object witness = getFlatValue(array, base, layout, valueType); // get witness as object
2899 if (witness != expected) {
2900 return false;
2901 }
2902 short xShort = getShort(array, base + scale); // get x as binary
2903 if (compareAndSetShort(o, offset, witnessShort, xShort)) {
2904 return true;
2905 }
2906 } while (true);
2907 }
2908 case 4: {
2909 do {
2910 int witnessInt = getIntVolatile(o, offset);
2911 putInt(array, base, witnessInt); // put witness as binary
2912 Object witness = getFlatValue(array, base, layout, valueType); // get witness as object
2913 if (witness != expected) {
2914 return false;
2915 }
2916 int xInt = getInt(array, base + scale); // get x as binary
2917 if (compareAndSetInt(o, offset, witnessInt, xInt)) {
2918 return true;
2919 }
2920 } while (true);
2921 }
2922 case 8: {
2923 do {
2924 long witnessLong = getLongVolatile(o, offset);
2925 putLong(array, base, witnessLong); // put witness as binary
2926 Object witness = getFlatValue(array, base, layout, valueType);
2927 if (witness != expected) {
2928 return false;
2929 }
2930 long xLong = getLong(array, base + scale); // get x as binary
2931 if (compareAndSetLong(o, offset, witnessLong, xLong)) {
2932 return true;
2933 }
2934 } while (true);
2935 }
2936 default: {
2937 throw new UnsupportedOperationException();
2938 }
2939 }
2940 }
2941
2942 /**
2943 * Unblocks the given thread blocked on {@code park}, or, if it is
2944 * not blocked, causes the subsequent call to {@code park} not to
2945 * block. Note: this operation is "unsafe" solely because the
2946 * caller must somehow ensure that the thread has not been
2947 * destroyed. Nothing special is usually required to ensure this
2948 * when called from Java (in which there will ordinarily be a live
2949 * reference to the thread) but this is not nearly-automatically
2950 * so when calling from native code.
2951 *
2952 * @param thread the thread to unpark.
2953 */
2954 @IntrinsicCandidate
2955 public native void unpark(Object thread);
2956
2957 /**
2958 * Blocks current thread, returning when a balancing
2959 * {@code unpark} occurs, or a balancing {@code unpark} has
2960 * already occurred, or the thread is interrupted, or, if not
2961 * absolute and time is not zero, the given time nanoseconds have
3308 /**
3309 * Atomically exchanges the given reference value with the current
3310 * reference value of a field or array element within the given
3311 * object {@code o} at the given {@code offset}.
3312 *
3313 * @param o object/array to update the field/element in
3314 * @param offset field/element offset
3315 * @param newValue new value
3316 * @return the previous value
3317 * @since 1.8
3318 */
3319 @IntrinsicCandidate
3320 public final Object getAndSetReference(Object o, long offset, Object newValue) {
3321 Object v;
3322 do {
3323 v = getReferenceVolatile(o, offset);
3324 } while (!weakCompareAndSetReference(o, offset, v, newValue));
3325 return v;
3326 }
3327
3328 @ForceInline
3329 public final Object getAndSetReference(Object o, long offset, Class<?> valueType, Object newValue) {
3330 Object v;
3331 do {
3332 v = getReferenceVolatile(o, offset);
3333 } while (!compareAndSetReference(o, offset, valueType, v, newValue));
3334 return v;
3335 }
3336
3337 @ForceInline
3338 public Object getAndSetFlatValue(Object o, long offset, int layoutKind, Class<?> valueType, Object newValue) {
3339 Object v;
3340 do {
3341 v = getFlatValueVolatile(o, offset, layoutKind, valueType);
3342 } while (!compareAndSetFlatValue(o, offset, layoutKind, valueType, v, newValue));
3343 return v;
3344 }
3345
3346 @ForceInline
3347 public final Object getAndSetReferenceRelease(Object o, long offset, Object newValue) {
3348 Object v;
3349 do {
3350 v = getReference(o, offset);
3351 } while (!weakCompareAndSetReferenceRelease(o, offset, v, newValue));
3352 return v;
3353 }
3354
3355 @ForceInline
3356 public final Object getAndSetReferenceRelease(Object o, long offset, Class<?> valueType, Object newValue) {
3357 return getAndSetReference(o, offset, valueType, newValue);
3358 }
3359
3360 @ForceInline
3361 public Object getAndSetFlatValueRelease(Object o, long offset, int layoutKind, Class<?> valueType, Object x) {
3362 return getAndSetFlatValue(o, offset, layoutKind, valueType, x);
3363 }
3364
3365 @ForceInline
3366 public final Object getAndSetReferenceAcquire(Object o, long offset, Object newValue) {
3367 Object v;
3368 do {
3369 v = getReferenceAcquire(o, offset);
3370 } while (!weakCompareAndSetReferenceAcquire(o, offset, v, newValue));
3371 return v;
3372 }
3373
3374 @ForceInline
3375 public final Object getAndSetReferenceAcquire(Object o, long offset, Class<?> valueType, Object newValue) {
3376 return getAndSetReference(o, offset, valueType, newValue);
3377 }
3378
3379 @ForceInline
3380 public Object getAndSetFlatValueAcquire(Object o, long offset, int layoutKind, Class<?> valueType, Object x) {
3381 return getAndSetFlatValue(o, offset, layoutKind, valueType, x);
3382 }
3383
3384 @IntrinsicCandidate
3385 public final byte getAndSetByte(Object o, long offset, byte newValue) {
3386 byte v;
3387 do {
3388 v = getByteVolatile(o, offset);
3389 } while (!weakCompareAndSetByte(o, offset, v, newValue));
3390 return v;
3391 }
3392
3393 @ForceInline
3394 public final byte getAndSetByteRelease(Object o, long offset, byte newValue) {
3395 byte v;
3396 do {
3397 v = getByte(o, offset);
3398 } while (!weakCompareAndSetByteRelease(o, offset, v, newValue));
3399 return v;
3400 }
3401
3402 @ForceInline
3403 public final byte getAndSetByteAcquire(Object o, long offset, byte newValue) {
4419 private static short convEndian(boolean big, short n) { return big == BIG_ENDIAN ? n : Short.reverseBytes(n) ; }
4420 private static int convEndian(boolean big, int n) { return big == BIG_ENDIAN ? n : Integer.reverseBytes(n) ; }
4421 private static long convEndian(boolean big, long n) { return big == BIG_ENDIAN ? n : Long.reverseBytes(n) ; }
4422
4423
4424
4425 private native long allocateMemory0(long bytes);
4426 private native long reallocateMemory0(long address, long bytes);
4427 private native void freeMemory0(long address);
4428 @IntrinsicCandidate
4429 private native void setMemory0(Object o, long offset, long bytes, byte value);
4430 @IntrinsicCandidate
4431 private native void copyMemory0(Object srcBase, long srcOffset, Object destBase, long destOffset, long bytes);
4432 private native void copySwapMemory0(Object srcBase, long srcOffset, Object destBase, long destOffset, long bytes, long elemSize);
4433 private native long objectFieldOffset0(Field f); // throws IAE
4434 private native long knownObjectFieldOffset0(Class<?> c, String name); // error code: -1 not found, -2 static
4435 private native long staticFieldOffset0(Field f); // throws IAE
4436 private native Object staticFieldBase0(Field f); // throws IAE
4437 private native boolean shouldBeInitialized0(Class<?> c);
4438 private native void ensureClassInitialized0(Class<?> c);
4439 private native void notifyStrictStaticAccess0(Class<?> c, long staticFieldOffset, boolean writing);
4440 private native int arrayBaseOffset0(Class<?> arrayClass); // public version returns long to promote correct arithmetic
4441 @IntrinsicCandidate
4442 private native int arrayInstanceBaseOffset0(Object[] array);
4443 private native int arrayIndexScale0(Class<?> arrayClass);
4444 @IntrinsicCandidate
4445 private native int arrayInstanceIndexScale0(Object[] array);
4446 private native long getObjectSize0(Object o);
4447 private native int getLoadAverage0(double[] loadavg, int nelems);
4448 @IntrinsicCandidate
4449 private native int[] getFieldMap0(Class <?> c);
4450
4451
4452 /**
4453 * Invokes the given direct byte buffer's cleaner, if any.
4454 *
4455 * @param directBuffer a direct byte buffer
4456 * @throws NullPointerException if {@code directBuffer} is null
4457 * @throws IllegalArgumentException if {@code directBuffer} is non-direct,
4458 * or is a {@link java.nio.Buffer#slice slice}, or is a
4459 * {@link java.nio.Buffer#duplicate duplicate}
4460 */
4461 public void invokeCleaner(java.nio.ByteBuffer directBuffer) {
4462 if (!directBuffer.isDirect())
4463 throw new IllegalArgumentException("buffer is non-direct");
4464
4465 DirectBuffer db = (DirectBuffer) directBuffer;
4466 if (db.attachment() != null)
4467 throw new IllegalArgumentException("duplicate or slice");
4468
4469 Cleaner cleaner = db.cleaner();
|