| 5 |
|
*/ |
| 6 |
|
|
| 7 |
|
package java.util.concurrent; |
| 8 |
– |
import java.util.function.Block; |
| 8 |
|
import java.util.function.Supplier; |
| 9 |
|
import java.util.function.Function; |
| 10 |
|
import java.util.function.BiFunction; |
| 658 |
|
} |
| 659 |
|
|
| 660 |
|
/** |
| 661 |
< |
* Creates and returns a CompletableFuture that is completed after |
| 662 |
< |
* performing the given action with the exception triggering this |
| 663 |
< |
* CompletableFuture's completion if/when it completes |
| 664 |
< |
* exceptionally. |
| 665 |
< |
* |
| 666 |
< |
* @param action the action to perform before completing the |
| 667 |
< |
* returned CompletableFuture |
| 661 |
> |
* Creates and returns a CompletableFuture that is completed with |
| 662 |
> |
* the result of the given function of the exception triggering |
| 663 |
> |
* this CompletableFuture's completion if/when it completes |
| 664 |
> |
* exceptionally; Otherwise, if this CompletableFuture completes |
| 665 |
> |
* normally, then the returned CompletableFuture also completes |
| 666 |
> |
* normally with the same value. |
| 667 |
> |
* |
| 668 |
> |
* @param fn the function to use to compute the value of the |
| 669 |
> |
* returned CompletableFuture if this CompletableFuture completed |
| 670 |
> |
* exceptionally |
| 671 |
|
* @return the new CompletableFuture |
| 672 |
|
*/ |
| 673 |
< |
public CompletableFuture<Void> exceptionally(Block<Throwable> action) { |
| 674 |
< |
if (action == null) throw new NullPointerException(); |
| 675 |
< |
CompletableFuture<Void> dst = new CompletableFuture<Void>(); |
| 673 |
> |
public CompletableFuture<T> exceptionally(Function<Throwable, ? extends T> fn) { |
| 674 |
> |
if (fn == null) throw new NullPointerException(); |
| 675 |
> |
CompletableFuture<T> dst = new CompletableFuture<T>(); |
| 676 |
|
ExceptionAction<T> d = null; |
| 677 |
< |
Object r; Throwable ex; |
| 677 |
> |
Object r; |
| 678 |
|
if ((r = result) == null) { |
| 679 |
|
CompletionNode p = |
| 680 |
< |
new CompletionNode(d = new ExceptionAction<T>(this, action, dst)); |
| 680 |
> |
new CompletionNode(d = new ExceptionAction<T>(this, fn, dst)); |
| 681 |
|
while ((r = result) == null) { |
| 682 |
|
if (UNSAFE.compareAndSwapObject(this, COMPLETIONS, |
| 683 |
|
p.next = completions, p)) |
| 684 |
|
break; |
| 685 |
|
} |
| 686 |
|
} |
| 687 |
< |
if (r != null && (d == null || d.compareAndSet(0, 1)) && |
| 688 |
< |
(r instanceof AltResult) && (ex = ((AltResult)r).ex) != null) { |
| 689 |
< |
try { |
| 690 |
< |
action.accept(ex); |
| 691 |
< |
dst.complete(null); |
| 692 |
< |
} catch (Throwable rex) { |
| 693 |
< |
dst.completeExceptionally(rex); |
| 687 |
> |
if (r != null && (d == null || d.compareAndSet(0, 1))) { |
| 688 |
> |
T t; Throwable ex = null; |
| 689 |
> |
if (r instanceof AltResult) { |
| 690 |
> |
if ((ex = ((AltResult)r).ex) != null) { |
| 691 |
> |
try { |
| 692 |
> |
dst.complete(fn.apply(ex)); |
| 693 |
> |
} catch (Throwable rex) { |
| 694 |
> |
dst.completeExceptionally(rex); |
| 695 |
> |
} |
| 696 |
> |
} |
| 697 |
> |
t = null; |
| 698 |
|
} |
| 699 |
+ |
else |
| 700 |
+ |
t = (T) r; |
| 701 |
+ |
if (ex == null) |
| 702 |
+ |
dst.complete(t); |
| 703 |
|
} |
| 704 |
|
if (r != null) |
| 705 |
|
postComplete(); |
| 744 |
|
} |
| 745 |
|
|
| 746 |
|
/** |
| 747 |
< |
* Whether or not already completed, sets the value subsequently |
| 748 |
< |
* returned by method get() and related methods to the given |
| 749 |
< |
* value. This method is designed for use in error recovery |
| 750 |
< |
* actions, and is very unlikely to be useful otherwise. |
| 747 |
> |
* Forcibly sets or resets the value subsequently returned by |
| 748 |
> |
* method get() and related methods, whether or not already |
| 749 |
> |
* completed. This method is designed for use only in error |
| 750 |
> |
* recovery actions, and even in such situations may result in |
| 751 |
> |
* ongoing dependent completions using established versus |
| 752 |
> |
* overwritten values. |
| 753 |
|
* |
| 754 |
|
* @param value the completion value |
| 755 |
|
*/ |
| 756 |
< |
public void force(T value) { |
| 756 |
> |
public void obtrudeValue(T value) { |
| 757 |
|
result = (value == null) ? NIL : value; |
| 758 |
|
postComplete(); |
| 759 |
|
} |
| 1302 |
|
|
| 1303 |
|
static final class ExceptionAction<T> extends Completion { |
| 1304 |
|
final CompletableFuture<? extends T> src; |
| 1305 |
< |
final Block<? super Throwable> fn; |
| 1306 |
< |
final CompletableFuture<Void> dst; |
| 1305 |
> |
final Function<? super Throwable, ? extends T> fn; |
| 1306 |
> |
final CompletableFuture<T> dst; |
| 1307 |
|
ExceptionAction(CompletableFuture<? extends T> src, |
| 1308 |
< |
Block<? super Throwable> fn, |
| 1309 |
< |
CompletableFuture<Void> dst) { |
| 1308 |
> |
Function<? super Throwable, ? extends T> fn, |
| 1309 |
> |
CompletableFuture<T> dst) { |
| 1310 |
|
this.src = src; this.fn = fn; this.dst = dst; |
| 1311 |
|
} |
| 1312 |
|
public void run() { |
| 1313 |
|
CompletableFuture<? extends T> a; |
| 1314 |
< |
Block<? super Throwable> fn; |
| 1315 |
< |
CompletableFuture<Void> dst; |
| 1316 |
< |
Object r; Throwable ex; |
| 1314 |
> |
Function<? super Throwable, ? extends T> fn; |
| 1315 |
> |
CompletableFuture<T> dst; |
| 1316 |
> |
Object r; T t; Throwable ex; |
| 1317 |
|
if ((dst = this.dst) != null && |
| 1318 |
|
(fn = this.fn) != null && |
| 1319 |
|
(a = this.src) != null && |
| 1320 |
|
(r = a.result) != null && |
| 1321 |
|
compareAndSet(0, 1)) { |
| 1322 |
< |
if ((r instanceof AltResult) && |
| 1323 |
< |
(ex = ((AltResult)r).ex) != null) { |
| 1324 |
< |
try { |
| 1325 |
< |
fn.accept(ex); |
| 1326 |
< |
dst.complete(null); |
| 1327 |
< |
} catch (Throwable rex) { |
| 1328 |
< |
dst.completeExceptionally(rex); |
| 1322 |
> |
if (r instanceof AltResult) { |
| 1323 |
> |
if ((ex = ((AltResult)r).ex) != null) { |
| 1324 |
> |
try { |
| 1325 |
> |
dst.complete(fn.apply(ex)); |
| 1326 |
> |
} catch (Throwable rex) { |
| 1327 |
> |
dst.completeExceptionally(rex); |
| 1328 |
> |
} |
| 1329 |
> |
return; |
| 1330 |
|
} |
| 1331 |
+ |
t = null; |
| 1332 |
|
} |
| 1333 |
+ |
else |
| 1334 |
+ |
t = (T) r; |
| 1335 |
+ |
dst.complete(t); |
| 1336 |
|
} |
| 1337 |
|
} |
| 1338 |
|
} |
