| 83 |
|
* subdivided) to each element of an array or collection; especially |
| 84 |
|
* when the operation takes a significantly different amount of time |
| 85 |
|
* to complete for some elements than others, either because of |
| 86 |
< |
* intrinsic variation (for example IO) or auxiliary effects such as |
| 86 |
> |
* intrinsic variation (for example I/O) or auxiliary effects such as |
| 87 |
|
* garbage collection. Because CountedCompleters provide their own |
| 88 |
|
* continuations, other threads need not block waiting to perform |
| 89 |
|
* them. |
| 183 |
|
* |
| 184 |
|
* <p><b>Searching.</b> A tree of CountedCompleters can search for a |
| 185 |
|
* value or property in different parts of a data structure, and |
| 186 |
< |
* report a result in an {@link java.util.concurrent.AtomicReference} |
| 187 |
< |
* as soon as one is found. The others can poll the result to avoid |
| 188 |
< |
* unnecessary work. (You could additionally {@link #cancel} other |
| 189 |
< |
* tasks, but it is usually simpler and more efficient to just let |
| 190 |
< |
* them notice that the result is set and if so skip further |
| 191 |
< |
* processing.) Illustrating again with an array using full |
| 186 |
> |
* report a result in an {@link |
| 187 |
> |
* java.util.concurrent.atomic.AtomicReference AtomicReference} as |
| 188 |
> |
* soon as one is found. The others can poll the result to avoid |
| 189 |
> |
* unnecessary work. (You could additionally {@linkplain #cancel |
| 190 |
> |
* cancel} other tasks, but it is usually simpler and more efficient |
| 191 |
> |
* to just let them notice that the result is set and if so skip |
| 192 |
> |
* further processing.) Illustrating again with an array using full |
| 193 |
|
* partitioning (again, in practice, leaf tasks will almost always |
| 194 |
|
* process more than one element): |
| 195 |
|
* |
| 224 |
|
* public static <E> E search(E[] array) { |
| 225 |
|
* return new Searcher<E>(null, array, new AtomicReference<E>(), 0, array.length).invoke(); |
| 226 |
|
* } |
| 227 |
< |
*}}</pre> |
| 227 |
> |
* }}</pre> |
| 228 |
|
* |
| 229 |
|
* In this example, as well as others in which tasks have no other |
| 230 |
|
* effects except to compareAndSet a common result, the trailing |
