81 else
82 return new LockedUpdater<U>(tclass, fieldName);
83 }
84
85 /**
86 * Protected do-nothing constructor for use by subclasses.
87 */
88 protected AtomicLongFieldUpdater() {
89 }
90
91 /**
92 * Atomically sets the field of the given object managed by this updater
93 * to the given updated value if the current value {@code ==} the
94 * expected value. This method is guaranteed to be atomic with respect to
95 * other calls to {@code compareAndSet} and {@code set}, but not
96 * necessarily with respect to other changes in the field.
97 *
98 * @param obj An object whose field to conditionally set
99 * @param expect the expected value
100 * @param update the new value
101 * @return true if successful.
102 * @throws ClassCastException if {@code obj} is not an instance
103 * of the class possessing the field established in the constructor.
104 */
105 public abstract boolean compareAndSet(T obj, long expect, long update);
106
107 /**
108 * Atomically sets the field of the given object managed by this updater
109 * to the given updated value if the current value {@code ==} the
110 * expected value. This method is guaranteed to be atomic with respect to
111 * other calls to {@code compareAndSet} and {@code set}, but not
112 * necessarily with respect to other changes in the field.
113 *
114 * <p>May <a href="package-summary.html#Spurious">fail spuriously</a>
115 * and does not provide ordering guarantees, so is only rarely an
116 * appropriate alternative to {@code compareAndSet}.
117 *
118 * @param obj An object whose field to conditionally set
119 * @param expect the expected value
120 * @param update the new value
121 * @return true if successful.
122 * @throws ClassCastException if {@code obj} is not an instance
123 * of the class possessing the field established in the constructor.
124 */
125 public abstract boolean weakCompareAndSet(T obj, long expect, long update);
126
127 /**
128 * Sets the field of the given object managed by this updater to the
129 * given updated value. This operation is guaranteed to act as a volatile
130 * store with respect to subsequent invocations of {@code compareAndSet}.
131 *
132 * @param obj An object whose field to set
133 * @param newValue the new value
134 */
135 public abstract void set(T obj, long newValue);
136
137 /**
138 * Eventually sets the field of the given object managed by this
139 * updater to the given updated value.
140 *
141 * @param obj An object whose field to set
145 public abstract void lazySet(T obj, long newValue);
146
147 /**
148 * Gets the current value held in the field of the given object managed
149 * by this updater.
150 *
151 * @param obj An object whose field to get
152 * @return the current value
153 */
154 public abstract long get(T obj);
155
156 /**
157 * Atomically sets the field of the given object managed by this updater
158 * to the given value and returns the old value.
159 *
160 * @param obj An object whose field to get and set
161 * @param newValue the new value
162 * @return the previous value
163 */
164 public long getAndSet(T obj, long newValue) {
165 for (;;) {
166 long current = get(obj);
167 if (compareAndSet(obj, current, newValue))
168 return current;
169 }
170 }
171
172 /**
173 * Atomically increments by one the current value of the field of the
174 * given object managed by this updater.
175 *
176 * @param obj An object whose field to get and set
177 * @return the previous value
178 */
179 public long getAndIncrement(T obj) {
180 for (;;) {
181 long current = get(obj);
182 long next = current + 1;
183 if (compareAndSet(obj, current, next))
184 return current;
185 }
186 }
187
188 /**
189 * Atomically decrements by one the current value of the field of the
190 * given object managed by this updater.
191 *
192 * @param obj An object whose field to get and set
193 * @return the previous value
194 */
195 public long getAndDecrement(T obj) {
196 for (;;) {
197 long current = get(obj);
198 long next = current - 1;
199 if (compareAndSet(obj, current, next))
200 return current;
201 }
202 }
203
204 /**
205 * Atomically adds the given value to the current value of the field of
206 * the given object managed by this updater.
207 *
208 * @param obj An object whose field to get and set
209 * @param delta the value to add
210 * @return the previous value
211 */
212 public long getAndAdd(T obj, long delta) {
213 for (;;) {
214 long current = get(obj);
215 long next = current + delta;
216 if (compareAndSet(obj, current, next))
217 return current;
218 }
219 }
220
221 /**
222 * Atomically increments by one the current value of the field of the
223 * given object managed by this updater.
224 *
225 * @param obj An object whose field to get and set
226 * @return the updated value
227 */
228 public long incrementAndGet(T obj) {
229 for (;;) {
230 long current = get(obj);
231 long next = current + 1;
232 if (compareAndSet(obj, current, next))
233 return next;
234 }
235 }
236
237 /**
238 * Atomically decrements by one the current value of the field of the
239 * given object managed by this updater.
240 *
241 * @param obj An object whose field to get and set
242 * @return the updated value
243 */
244 public long decrementAndGet(T obj) {
245 for (;;) {
246 long current = get(obj);
247 long next = current - 1;
248 if (compareAndSet(obj, current, next))
249 return next;
250 }
251 }
252
253 /**
254 * Atomically adds the given value to the current value of the field of
255 * the given object managed by this updater.
256 *
257 * @param obj An object whose field to get and set
258 * @param delta the value to add
259 * @return the updated value
260 */
261 public long addAndGet(T obj, long delta) {
262 for (;;) {
263 long current = get(obj);
264 long next = current + delta;
265 if (compareAndSet(obj, current, next))
266 return next;
267 }
268 }
269
270 private static class CASUpdater<T> extends AtomicLongFieldUpdater<T> {
271 private static final Unsafe unsafe = Unsafe.getUnsafe();
272 private final long offset;
273 private final Class<T> tclass;
274 private final Class<?> cclass;
275
276 CASUpdater(final Class<T> tclass, final String fieldName) {
277 final Field field;
278 final Class<?> caller;
279 final int modifiers;
280 try {
281 field = AccessController.doPrivileged(
282 new PrivilegedExceptionAction<Field>() {
283 public Field run() throws NoSuchFieldException {
284 return tclass.getDeclaredField(fieldName);
285 }
286 });
287 caller = sun.reflect.Reflection.getCallerClass(3);
288 modifiers = field.getModifiers();
328 public boolean weakCompareAndSet(T obj, long expect, long update) {
329 if (obj == null || obj.getClass() != tclass || cclass != null) fullCheck(obj);
330 return unsafe.compareAndSwapLong(obj, offset, expect, update);
331 }
332
333 public void set(T obj, long newValue) {
334 if (obj == null || obj.getClass() != tclass || cclass != null) fullCheck(obj);
335 unsafe.putLongVolatile(obj, offset, newValue);
336 }
337
338 public void lazySet(T obj, long newValue) {
339 if (obj == null || obj.getClass() != tclass || cclass != null) fullCheck(obj);
340 unsafe.putOrderedLong(obj, offset, newValue);
341 }
342
343 public long get(T obj) {
344 if (obj == null || obj.getClass() != tclass || cclass != null) fullCheck(obj);
345 return unsafe.getLongVolatile(obj, offset);
346 }
347
348 private void ensureProtectedAccess(T obj) {
349 if (cclass.isInstance(obj)) {
350 return;
351 }
352 throw new RuntimeException(
353 new IllegalAccessException("Class " +
354 cclass.getName() +
355 " can not access a protected member of class " +
356 tclass.getName() +
357 " using an instance of " +
358 obj.getClass().getName()
359 )
360 );
361 }
362 }
363
364
365 private static class LockedUpdater<T> extends AtomicLongFieldUpdater<T> {
366 private static final Unsafe unsafe = Unsafe.getUnsafe();
367 private final long offset;
|
81 else
82 return new LockedUpdater<U>(tclass, fieldName);
83 }
84
85 /**
86 * Protected do-nothing constructor for use by subclasses.
87 */
88 protected AtomicLongFieldUpdater() {
89 }
90
91 /**
92 * Atomically sets the field of the given object managed by this updater
93 * to the given updated value if the current value {@code ==} the
94 * expected value. This method is guaranteed to be atomic with respect to
95 * other calls to {@code compareAndSet} and {@code set}, but not
96 * necessarily with respect to other changes in the field.
97 *
98 * @param obj An object whose field to conditionally set
99 * @param expect the expected value
100 * @param update the new value
101 * @return true if successful
102 * @throws ClassCastException if {@code obj} is not an instance
103 * of the class possessing the field established in the constructor.
104 */
105 public abstract boolean compareAndSet(T obj, long expect, long update);
106
107 /**
108 * Atomically sets the field of the given object managed by this updater
109 * to the given updated value if the current value {@code ==} the
110 * expected value. This method is guaranteed to be atomic with respect to
111 * other calls to {@code compareAndSet} and {@code set}, but not
112 * necessarily with respect to other changes in the field.
113 *
114 * <p>May <a href="package-summary.html#Spurious">fail spuriously</a>
115 * and does not provide ordering guarantees, so is only rarely an
116 * appropriate alternative to {@code compareAndSet}.
117 *
118 * @param obj An object whose field to conditionally set
119 * @param expect the expected value
120 * @param update the new value
121 * @return true if successful
122 * @throws ClassCastException if {@code obj} is not an instance
123 * of the class possessing the field established in the constructor.
124 */
125 public abstract boolean weakCompareAndSet(T obj, long expect, long update);
126
127 /**
128 * Sets the field of the given object managed by this updater to the
129 * given updated value. This operation is guaranteed to act as a volatile
130 * store with respect to subsequent invocations of {@code compareAndSet}.
131 *
132 * @param obj An object whose field to set
133 * @param newValue the new value
134 */
135 public abstract void set(T obj, long newValue);
136
137 /**
138 * Eventually sets the field of the given object managed by this
139 * updater to the given updated value.
140 *
141 * @param obj An object whose field to set
145 public abstract void lazySet(T obj, long newValue);
146
147 /**
148 * Gets the current value held in the field of the given object managed
149 * by this updater.
150 *
151 * @param obj An object whose field to get
152 * @return the current value
153 */
154 public abstract long get(T obj);
155
156 /**
157 * Atomically sets the field of the given object managed by this updater
158 * to the given value and returns the old value.
159 *
160 * @param obj An object whose field to get and set
161 * @param newValue the new value
162 * @return the previous value
163 */
164 public long getAndSet(T obj, long newValue) {
165 long prev;
166 do {
167 prev = get(obj);
168 } while (!compareAndSet(obj, prev, newValue));
169 return prev;
170 }
171
172 /**
173 * Atomically increments by one the current value of the field of the
174 * given object managed by this updater.
175 *
176 * @param obj An object whose field to get and set
177 * @return the previous value
178 */
179 public long getAndIncrement(T obj) {
180 long prev, next;
181 do {
182 prev = get(obj);
183 next = prev + 1;
184 } while (!compareAndSet(obj, prev, next));
185 return prev;
186 }
187
188 /**
189 * Atomically decrements by one the current value of the field of the
190 * given object managed by this updater.
191 *
192 * @param obj An object whose field to get and set
193 * @return the previous value
194 */
195 public long getAndDecrement(T obj) {
196 long prev, next;
197 do {
198 prev = get(obj);
199 next = prev - 1;
200 } while (!compareAndSet(obj, prev, next));
201 return prev;
202 }
203
204 /**
205 * Atomically adds the given value to the current value of the field of
206 * the given object managed by this updater.
207 *
208 * @param obj An object whose field to get and set
209 * @param delta the value to add
210 * @return the previous value
211 */
212 public long getAndAdd(T obj, long delta) {
213 long prev, next;
214 do {
215 prev = get(obj);
216 next = prev + delta;
217 } while (!compareAndSet(obj, prev, next));
218 return prev;
219 }
220
221 /**
222 * Atomically increments by one the current value of the field of the
223 * given object managed by this updater.
224 *
225 * @param obj An object whose field to get and set
226 * @return the updated value
227 */
228 public long incrementAndGet(T obj) {
229 long prev, next;
230 do {
231 prev = get(obj);
232 next = prev + 1;
233 } while (!compareAndSet(obj, prev, next));
234 return next;
235 }
236
237 /**
238 * Atomically decrements by one the current value of the field of the
239 * given object managed by this updater.
240 *
241 * @param obj An object whose field to get and set
242 * @return the updated value
243 */
244 public long decrementAndGet(T obj) {
245 long prev, next;
246 do {
247 prev = get(obj);
248 next = prev - 1;
249 } while (!compareAndSet(obj, prev, next));
250 return next;
251 }
252
253 /**
254 * Atomically adds the given value to the current value of the field of
255 * the given object managed by this updater.
256 *
257 * @param obj An object whose field to get and set
258 * @param delta the value to add
259 * @return the updated value
260 */
261 public long addAndGet(T obj, long delta) {
262 long prev, next;
263 do {
264 prev = get(obj);
265 next = prev + delta;
266 } while (!compareAndSet(obj, prev, next));
267 return next;
268 }
269
270 private static class CASUpdater<T> extends AtomicLongFieldUpdater<T> {
271 private static final Unsafe unsafe = Unsafe.getUnsafe();
272 private final long offset;
273 private final Class<T> tclass;
274 private final Class<?> cclass;
275
276 CASUpdater(final Class<T> tclass, final String fieldName) {
277 final Field field;
278 final Class<?> caller;
279 final int modifiers;
280 try {
281 field = AccessController.doPrivileged(
282 new PrivilegedExceptionAction<Field>() {
283 public Field run() throws NoSuchFieldException {
284 return tclass.getDeclaredField(fieldName);
285 }
286 });
287 caller = sun.reflect.Reflection.getCallerClass(3);
288 modifiers = field.getModifiers();
328 public boolean weakCompareAndSet(T obj, long expect, long update) {
329 if (obj == null || obj.getClass() != tclass || cclass != null) fullCheck(obj);
330 return unsafe.compareAndSwapLong(obj, offset, expect, update);
331 }
332
333 public void set(T obj, long newValue) {
334 if (obj == null || obj.getClass() != tclass || cclass != null) fullCheck(obj);
335 unsafe.putLongVolatile(obj, offset, newValue);
336 }
337
338 public void lazySet(T obj, long newValue) {
339 if (obj == null || obj.getClass() != tclass || cclass != null) fullCheck(obj);
340 unsafe.putOrderedLong(obj, offset, newValue);
341 }
342
343 public long get(T obj) {
344 if (obj == null || obj.getClass() != tclass || cclass != null) fullCheck(obj);
345 return unsafe.getLongVolatile(obj, offset);
346 }
347
348 public long getAndSet(T obj, long newValue) {
349 if (obj == null || obj.getClass() != tclass || cclass != null) fullCheck(obj);
350 return unsafe.getAndSetLong(obj, offset, newValue);
351 }
352
353 public long getAndIncrement(T obj) {
354 return getAndAdd(obj, 1);
355 }
356
357 public long getAndDecrement(T obj) {
358 return getAndAdd(obj, -1);
359 }
360
361 public long getAndAdd(T obj, long delta) {
362 if (obj == null || obj.getClass() != tclass || cclass != null) fullCheck(obj);
363 return unsafe.getAndAddLong(obj, offset, delta);
364 }
365
366 public long incrementAndGet(T obj) {
367 return getAndAdd(obj, 1) + 1;
368 }
369
370 public long decrementAndGet(T obj) {
371 return getAndAdd(obj, -1) - 1;
372 }
373
374 public long addAndGet(T obj, long delta) {
375 return getAndAdd(obj, delta) + delta;
376 }
377
378 private void ensureProtectedAccess(T obj) {
379 if (cclass.isInstance(obj)) {
380 return;
381 }
382 throw new RuntimeException(
383 new IllegalAccessException("Class " +
384 cclass.getName() +
385 " can not access a protected member of class " +
386 tclass.getName() +
387 " using an instance of " +
388 obj.getClass().getName()
389 )
390 );
391 }
392 }
393
394
395 private static class LockedUpdater<T> extends AtomicLongFieldUpdater<T> {
396 private static final Unsafe unsafe = Unsafe.getUnsafe();
397 private final long offset;
|