1 /*
2 * Copyright (c) 2021, 2025, 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.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24 /*
25 * @test id=platform
26 * @bug 8284199 8296779 8306647
27 * @summary Basic tests for StructuredTaskScope
28 * @enablePreview
29 * @run junit/othervm -DthreadFactory=platform StructuredTaskScopeTest
30 */
31
32 /*
33 * @test id=virtual
34 * @enablePreview
35 * @run junit/othervm -DthreadFactory=virtual StructuredTaskScopeTest
36 */
37
38 import java.time.Duration;
39 import java.util.Arrays;
40 import java.util.ArrayList;
41 import java.util.List;
42 import java.util.Set;
43 import java.util.NoSuchElementException;
44 import java.util.concurrent.Callable;
45 import java.util.concurrent.ConcurrentHashMap;
46 import java.util.concurrent.CountDownLatch;
47 import java.util.concurrent.Executors;
48 import java.util.concurrent.Future;
49 import java.util.concurrent.LinkedTransferQueue;
50 import java.util.concurrent.ThreadFactory;
51 import java.util.concurrent.TimeUnit;
52 import java.util.concurrent.RejectedExecutionException;
53 import java.util.concurrent.ScheduledExecutorService;
54 import java.util.concurrent.StructuredTaskScope;
55 import java.util.concurrent.StructuredTaskScope.TimeoutException;
56 import java.util.concurrent.StructuredTaskScope.Configuration;
57 import java.util.concurrent.StructuredTaskScope.FailedException;
58 import java.util.concurrent.StructuredTaskScope.Joiner;
59 import java.util.concurrent.StructuredTaskScope.Subtask;
60 import java.util.concurrent.StructureViolationException;
61 import java.util.concurrent.atomic.AtomicBoolean;
62 import java.util.concurrent.atomic.AtomicInteger;
63 import java.util.concurrent.atomic.AtomicReference;
64 import java.util.function.Function;
65 import java.util.function.Predicate;
66 import java.util.stream.Stream;
67 import static java.lang.Thread.State.*;
68
69 import org.junit.jupiter.api.Test;
70 import org.junit.jupiter.api.BeforeAll;
71 import org.junit.jupiter.api.AfterAll;
72 import org.junit.jupiter.params.ParameterizedTest;
73 import org.junit.jupiter.params.provider.MethodSource;
74 import static org.junit.jupiter.api.Assertions.*;
75
76 class StructuredTaskScopeTest {
77 private static ScheduledExecutorService scheduler;
78 private static List<ThreadFactory> threadFactories;
79
80 @BeforeAll
81 static void setup() throws Exception {
82 scheduler = Executors.newSingleThreadScheduledExecutor();
83
84 // thread factories
85 String value = System.getProperty("threadFactory");
86 List<ThreadFactory> list = new ArrayList<>();
87 if (value == null || value.equals("platform"))
88 list.add(Thread.ofPlatform().factory());
89 if (value == null || value.equals("virtual"))
90 list.add(Thread.ofVirtual().factory());
91 assertTrue(list.size() > 0, "No thread factories for tests");
92 threadFactories = list;
93 }
94
95 @AfterAll
96 static void shutdown() {
97 scheduler.shutdown();
98 }
99
100 private static Stream<ThreadFactory> factories() {
101 return threadFactories.stream();
102 }
103
104 /**
105 * Test that fork creates virtual threads when no ThreadFactory is configured.
106 */
107 @Test
108 void testForkCreatesVirtualThread() throws Exception {
109 Set<Thread> threads = ConcurrentHashMap.newKeySet();
110 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
111 for (int i = 0; i < 50; i++) {
112 // runnable
113 scope.fork(() -> {
114 threads.add(Thread.currentThread());
115 });
116
117 // callable
118 scope.fork(() -> {
119 threads.add(Thread.currentThread());
120 return null;
121 });
122 }
123 scope.join();
124 }
125 assertEquals(100, threads.size());
126 threads.forEach(t -> assertTrue(t.isVirtual()));
127 }
128
129 /**
130 * Test that fork create threads with the configured ThreadFactory.
131 */
132 @ParameterizedTest
133 @MethodSource("factories")
134 void testForkUsesThreadFactory(ThreadFactory factory) throws Exception {
135 // TheadFactory that keeps reference to all threads it creates
136 class RecordingThreadFactory implements ThreadFactory {
137 final ThreadFactory delegate;
138 final Set<Thread> threads = ConcurrentHashMap.newKeySet();
139 RecordingThreadFactory(ThreadFactory delegate) {
140 this.delegate = delegate;
141 }
142 @Override
143 public Thread newThread(Runnable task) {
144 Thread thread = delegate.newThread(task);
145 threads.add(thread);
146 return thread;
147 }
148 Set<Thread> threads() {
149 return threads;
150 }
151 }
152 var recordingThreadFactory = new RecordingThreadFactory(factory);
153 Set<Thread> threads = ConcurrentHashMap.newKeySet();
154 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
155 cf -> cf.withThreadFactory(recordingThreadFactory))) {
156
157 for (int i = 0; i < 50; i++) {
158 // runnable
159 scope.fork(() -> {
160 threads.add(Thread.currentThread());
161 });
162
163 // callable
164 scope.fork(() -> {
165 threads.add(Thread.currentThread());
166 return null;
167 });
168 }
169 scope.join();
170 }
171 assertEquals(100, threads.size());
172 assertEquals(recordingThreadFactory.threads(), threads);
173 }
174
175 /**
176 * Test fork method is owner confined.
177 */
178 @ParameterizedTest
179 @MethodSource("factories")
180 void testForkConfined(ThreadFactory factory) throws Exception {
181 try (var scope = StructuredTaskScope.open(Joiner.<Boolean>awaitAll(),
182 cf -> cf.withThreadFactory(factory))) {
183
184 // random thread cannot fork
185 try (var pool = Executors.newSingleThreadExecutor()) {
186 Future<Void> future = pool.submit(() -> {
187 assertThrows(WrongThreadException.class, () -> {
188 scope.fork(() -> null);
189 });
190 return null;
191 });
192 future.get();
193 }
194
195 // subtask cannot fork
196 Subtask<Boolean> subtask = scope.fork(() -> {
197 assertThrows(WrongThreadException.class, () -> {
198 scope.fork(() -> null);
199 });
200 return true;
201 });
202 scope.join();
203 assertTrue(subtask.get());
204 }
205 }
206
207 /**
208 * Test fork after join, no subtasks forked before join.
209 */
210 @ParameterizedTest
211 @MethodSource("factories")
212 void testForkAfterJoin1(ThreadFactory factory) throws Exception {
213 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
214 cf -> cf.withThreadFactory(factory))) {
215 scope.join();
216 assertThrows(IllegalStateException.class, () -> scope.fork(() -> "bar"));
217 }
218 }
219
220 /**
221 * Test fork after join, subtasks forked before join.
222 */
223 @ParameterizedTest
224 @MethodSource("factories")
225 void testForkAfterJoin2(ThreadFactory factory) throws Exception {
226 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
227 cf -> cf.withThreadFactory(factory))) {
228 scope.fork(() -> "foo");
229 scope.join();
230 assertThrows(IllegalStateException.class, () -> scope.fork(() -> "bar"));
231 }
232 }
233
234 /**
235 * Test fork after join throws.
236 */
237 @ParameterizedTest
238 @MethodSource("factories")
239 void testForkAfterJoinThrows(ThreadFactory factory) throws Exception {
240 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
241 cf -> cf.withThreadFactory(factory))) {
242 var latch = new CountDownLatch(1);
243 var subtask1 = scope.fork(() -> {
244 latch.await();
245 return "foo";
246 });
247
248 // join throws
249 Thread.currentThread().interrupt();
250 assertThrows(InterruptedException.class, scope::join);
251
252 // fork should throw
253 assertThrows(IllegalStateException.class, () -> scope.fork(() -> "bar"));
254 }
255 }
256
257 /**
258 * Test fork after task scope is cancelled. This test uses a custom Joiner to
259 * cancel execution.
260 */
261 @ParameterizedTest
262 @MethodSource("factories")
263 void testForkAfterCancel2(ThreadFactory factory) throws Exception {
264 var countingThreadFactory = new CountingThreadFactory(factory);
265 var testJoiner = new CancelAfterOneJoiner<String>();
266
267 try (var scope = StructuredTaskScope.open(testJoiner,
268 cf -> cf.withThreadFactory(countingThreadFactory))) {
269
270 // fork subtask, the scope should be cancelled when the subtask completes
271 var subtask1 = scope.fork(() -> "foo");
272 awaitCancelled(scope);
273
274 assertEquals(1, countingThreadFactory.threadCount());
275 assertEquals(1, testJoiner.onForkCount());
276 assertEquals(1, testJoiner.onCompleteCount());
277
278 // fork second subtask, it should not run
279 var subtask2 = scope.fork(() -> "bar");
280
281 // onFork should be invoked, newThread and onComplete should not be invoked
282 assertEquals(1, countingThreadFactory.threadCount());
283 assertEquals(2, testJoiner.onForkCount());
284 assertEquals(1, testJoiner.onCompleteCount());
285
286 scope.join();
287
288 assertEquals(1, countingThreadFactory.threadCount());
289 assertEquals(2, testJoiner.onForkCount());
290 assertEquals(1, testJoiner.onCompleteCount());
291 assertEquals("foo", subtask1.get());
292 assertEquals(Subtask.State.UNAVAILABLE, subtask2.state());
293 }
294 }
295
296 /**
297 * Test fork after task scope is closed.
298 */
299 @Test
300 void testForkAfterClose() {
301 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
302 scope.close();
303 assertThrows(IllegalStateException.class, () -> scope.fork(() -> null));
304 }
305 }
306
307 /**
308 * Test fork with a ThreadFactory that rejects creating a thread.
309 */
310 @Test
311 void testForkRejectedExecutionException() {
312 ThreadFactory factory = task -> null;
313 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
314 cf -> cf.withThreadFactory(factory))) {
315 assertThrows(RejectedExecutionException.class, () -> scope.fork(() -> null));
316 }
317 }
318
319 /**
320 * Test join with no subtasks.
321 */
322 @Test
323 void testJoinWithNoSubtasks() throws Exception {
324 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
325 scope.join();
326 }
327 }
328
329 /**
330 * Test join with a remaining subtask.
331 */
332 @ParameterizedTest
333 @MethodSource("factories")
334 void testJoinWithRemainingSubtasks(ThreadFactory factory) throws Exception {
335 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
336 cf -> cf.withThreadFactory(factory))) {
337 Subtask<String> subtask = scope.fork(() -> {
338 Thread.sleep(Duration.ofMillis(100));
339 return "foo";
340 });
341 scope.join();
342 assertEquals("foo", subtask.get());
343 }
344 }
345
346 /**
347 * Test join after join completed with a result.
348 */
349 @Test
350 void testJoinAfterJoin1() throws Exception {
351 var results = new LinkedTransferQueue<>(List.of("foo", "bar", "baz"));
352 Joiner<Object, String> joiner = results::take;
353 try (var scope = StructuredTaskScope.open(joiner)) {
354 scope.fork(() -> "foo");
355 assertEquals("foo", scope.join());
356
357 // join already called
358 for (int i = 0 ; i < 3; i++) {
359 assertThrows(IllegalStateException.class, scope::join);
360 }
361 }
362 }
363
364 /**
365 * Test join after join completed with an exception.
366 */
367 @Test
368 void testJoinAfterJoin2() throws Exception {
369 try (var scope = StructuredTaskScope.open(Joiner.anySuccessfulResultOrThrow())) {
370 scope.fork(() -> { throw new FooException(); });
371 Throwable ex = assertThrows(FailedException.class, scope::join);
372 assertTrue(ex.getCause() instanceof FooException);
373
374 // join already called
375 for (int i = 0 ; i < 3; i++) {
376 assertThrows(IllegalStateException.class, scope::join);
377 }
378 }
379 }
380
381 /**
382 * Test join after join completed with a timeout.
383 */
384 @Test
385 void testJoinAfterJoin3() throws Exception {
386 try (var scope = StructuredTaskScope.open(Joiner.anySuccessfulResultOrThrow(),
387 cf -> cf.withTimeout(Duration.ofMillis(100)))) {
388 // wait for scope to be cancelled by timeout
389 awaitCancelled(scope);
390 assertThrows(TimeoutException.class, scope::join);
391
392 // join already called
393 for (int i = 0 ; i < 3; i++) {
394 assertThrows(IllegalStateException.class, scope::join);
395 }
396 }
397 }
398
399 /**
400 * Test join method is owner confined.
401 */
402 @ParameterizedTest
403 @MethodSource("factories")
404 void testJoinConfined(ThreadFactory factory) throws Exception {
405 try (var scope = StructuredTaskScope.open(Joiner.<Boolean>awaitAll(),
406 cf -> cf.withThreadFactory(factory))) {
407
408 // random thread cannot join
409 try (var pool = Executors.newSingleThreadExecutor()) {
410 Future<Void> future = pool.submit(() -> {
411 assertThrows(WrongThreadException.class, scope::join);
412 return null;
413 });
414 future.get();
415 }
416
417 // subtask cannot join
418 Subtask<Boolean> subtask = scope.fork(() -> {
419 assertThrows(WrongThreadException.class, () -> { scope.join(); });
420 return true;
421 });
422 scope.join();
423 assertTrue(subtask.get());
424 }
425 }
426
427 /**
428 * Test join with interrupt status set.
429 */
430 @ParameterizedTest
431 @MethodSource("factories")
432 void testInterruptJoin1(ThreadFactory factory) throws Exception {
433 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
434 cf -> cf.withThreadFactory(factory))) {
435
436 Subtask<String> subtask = scope.fork(() -> {
437 Thread.sleep(60_000);
438 return "foo";
439 });
440
441 // join should throw
442 Thread.currentThread().interrupt();
443 try {
444 scope.join();
445 fail("join did not throw");
446 } catch (InterruptedException expected) {
447 assertFalse(Thread.interrupted()); // interrupt status should be cleared
448 }
449 }
450 }
451
452 /**
453 * Test interrupt of thread blocked in join.
454 */
455 @ParameterizedTest
456 @MethodSource("factories")
457 void testInterruptJoin2(ThreadFactory factory) throws Exception {
458 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
459 cf -> cf.withThreadFactory(factory))) {
460
461 var latch = new CountDownLatch(1);
462 Subtask<String> subtask = scope.fork(() -> {
463 Thread.sleep(60_000);
464 return "foo";
465 });
466
467 // interrupt main thread when it blocks in join
468 scheduleInterruptAt("java.util.concurrent.StructuredTaskScopeImpl.join");
469 try {
470 scope.join();
471 fail("join did not throw");
472 } catch (InterruptedException expected) {
473 assertFalse(Thread.interrupted()); // interrupt status should be clear
474 }
475 }
476 }
477
478 /**
479 * Test join when scope is cancelled.
480 */
481 @ParameterizedTest
482 @MethodSource("factories")
483 void testJoinWhenCancelled(ThreadFactory factory) throws Exception {
484 var countingThreadFactory = new CountingThreadFactory(factory);
485 var testJoiner = new CancelAfterOneJoiner<String>();
486
487 try (var scope = StructuredTaskScope.open(testJoiner,
488 cf -> cf.withThreadFactory(countingThreadFactory))) {
489
490 // fork subtask, the scope should be cancelled when the subtask completes
491 var subtask1 = scope.fork(() -> "foo");
492 awaitCancelled(scope);
493
494 // fork second subtask, it should not run
495 var subtask2 = scope.fork(() -> {
496 Thread.sleep(Duration.ofDays(1));
497 return "bar";
498 });
499
500 scope.join();
501
502 assertEquals("foo", subtask1.get());
503 assertEquals(Subtask.State.UNAVAILABLE, subtask2.state());
504 }
505 }
506
507 /**
508 * Test join after scope is closed.
509 */
510 @Test
511 void testJoinAfterClose() throws Exception {
512 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
513 scope.close();
514 assertThrows(IllegalStateException.class, () -> scope.join());
515 }
516 }
517
518 /**
519 * Test join with timeout, subtasks finish before timeout expires.
520 */
521 @ParameterizedTest
522 @MethodSource("factories")
523 void testJoinWithTimeout1(ThreadFactory factory) throws Exception {
524 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
525 cf -> cf.withThreadFactory(factory)
526 .withTimeout(Duration.ofDays(1)))) {
527
528 Subtask<String> subtask = scope.fork(() -> {
529 Thread.sleep(Duration.ofSeconds(1));
530 return "foo";
531 });
532
533 scope.join();
534
535 assertFalse(scope.isCancelled());
536 assertEquals("foo", subtask.get());
537 }
538 }
539
540 /**
541 * Test join with timeout, timeout expires before subtasks finish.
542 */
543 @ParameterizedTest
544 @MethodSource("factories")
545 void testJoinWithTimeout2(ThreadFactory factory) throws Exception {
546 long startMillis = millisTime();
547 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
548 cf -> cf.withThreadFactory(factory)
549 .withTimeout(Duration.ofSeconds(2)))) {
550
551 Subtask<Void> subtask = scope.fork(() -> {
552 Thread.sleep(Duration.ofDays(1));
553 return null;
554 });
555
556 assertThrows(TimeoutException.class, scope::join);
557 expectDuration(startMillis, /*min*/1900, /*max*/20_000);
558
559 assertTrue(scope.isCancelled());
560 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
561 }
562 }
563
564 /**
565 * Test join with timeout that has already expired.
566 */
567 @ParameterizedTest
568 @MethodSource("factories")
569 void testJoinWithTimeout3(ThreadFactory factory) throws Exception {
570 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
571 cf -> cf.withThreadFactory(factory)
572 .withTimeout(Duration.ofSeconds(-1)))) {
573
574 Subtask<Void> subtask = scope.fork(() -> {
575 Thread.sleep(Duration.ofDays(1));
576 return null;
577 });
578
579 assertThrows(TimeoutException.class, scope::join);
580
581 assertTrue(scope.isCancelled());
582 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
583 }
584 }
585
586 /**
587 * Test that cancelling execution interrupts unfinished threads. This test uses
588 * a custom Joiner to cancel execution.
589 */
590 @ParameterizedTest
591 @MethodSource("factories")
592 void testCancelInterruptsThreads2(ThreadFactory factory) throws Exception {
593 var testJoiner = new CancelAfterOneJoiner<String>();
594
595 try (var scope = StructuredTaskScope.open(testJoiner,
596 cf -> cf.withThreadFactory(factory))) {
597
598 // fork subtask1 that runs for a long time
599 var started = new CountDownLatch(1);
600 var interrupted = new CountDownLatch(1);
601 var subtask1 = scope.fork(() -> {
602 started.countDown();
603 try {
604 Thread.sleep(Duration.ofDays(1));
605 } catch (InterruptedException e) {
606 interrupted.countDown();
607 }
608 });
609 started.await();
610
611 // fork subtask2, the scope should be cancelled when the subtask completes
612 var subtask2 = scope.fork(() -> "bar");
613 awaitCancelled(scope);
614
615 // subtask1 should be interrupted
616 interrupted.await();
617
618 scope.join();
619 assertEquals(Subtask.State.UNAVAILABLE, subtask1.state());
620 assertEquals("bar", subtask2.get());
621 }
622 }
623
624 /**
625 * Test that timeout interrupts unfinished threads.
626 */
627 @ParameterizedTest
628 @MethodSource("factories")
629 void testTimeoutInterruptsThreads(ThreadFactory factory) throws Exception {
630 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
631 cf -> cf.withThreadFactory(factory)
632 .withTimeout(Duration.ofSeconds(2)))) {
633
634 var started = new AtomicBoolean();
635 var interrupted = new CountDownLatch(1);
636 Subtask<Void> subtask = scope.fork(() -> {
637 started.set(true);
638 try {
639 Thread.sleep(Duration.ofDays(1));
640 } catch (InterruptedException e) {
641 interrupted.countDown();
642 }
643 return null;
644 });
645
646 // wait for scope to be cancelled by timeout
647 awaitCancelled(scope);
648
649 // if subtask started then it should be interrupted
650 if (started.get()) {
651 interrupted.await();
652 }
653
654 assertThrows(TimeoutException.class, scope::join);
655
656 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
657 }
658 }
659
660 /**
661 * Test close without join, no subtasks forked.
662 */
663 @Test
664 void testCloseWithoutJoin1() {
665 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
666 // do nothing
667 }
668 }
669
670 /**
671 * Test close without join, subtasks forked.
672 */
673 @ParameterizedTest
674 @MethodSource("factories")
675 void testCloseWithoutJoin2(ThreadFactory factory) {
676 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
677 cf -> cf.withThreadFactory(factory))) {
678 Subtask<String> subtask = scope.fork(() -> {
679 Thread.sleep(Duration.ofDays(1));
680 return null;
681 });
682
683 // first call to close should throw
684 assertThrows(IllegalStateException.class, scope::close);
685
686 // subsequent calls to close should not throw
687 for (int i = 0; i < 3; i++) {
688 scope.close();
689 }
690
691 // subtask result/exception not available
692 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
693 assertThrows(IllegalStateException.class, subtask::get);
694 assertThrows(IllegalStateException.class, subtask::exception);
695 }
696 }
697
698 /**
699 * Test close after join throws. Close should not throw as join attempted.
700 */
701 @ParameterizedTest
702 @MethodSource("factories")
703 void testCloseAfterJoinThrows(ThreadFactory factory) throws Exception {
704 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
705 cf -> cf.withThreadFactory(factory))) {
706 var subtask = scope.fork(() -> {
707 Thread.sleep(Duration.ofDays(1));
708 return null;
709 });
710
711 // join throws
712 Thread.currentThread().interrupt();
713 assertThrows(InterruptedException.class, scope::join);
714 assertThrows(IllegalStateException.class, subtask::get);
715
716 } // close should not throw
717 }
718
719 /**
720 * Test close method is owner confined.
721 */
722 @ParameterizedTest
723 @MethodSource("factories")
724 void testCloseConfined(ThreadFactory factory) throws Exception {
725 try (var scope = StructuredTaskScope.open(Joiner.<Boolean>awaitAll(),
726 cf -> cf.withThreadFactory(factory))) {
727
728 // random thread cannot close scope
729 try (var pool = Executors.newCachedThreadPool(factory)) {
730 Future<Boolean> future = pool.submit(() -> {
731 assertThrows(WrongThreadException.class, scope::close);
732 return null;
733 });
734 future.get();
735 }
736
737 // subtask cannot close
738 Subtask<Boolean> subtask = scope.fork(() -> {
739 assertThrows(WrongThreadException.class, scope::close);
740 return true;
741 });
742 scope.join();
743 assertTrue(subtask.get());
744 }
745 }
746
747 /**
748 * Test close with interrupt status set.
749 */
750 @ParameterizedTest
751 @MethodSource("factories")
752 void testInterruptClose1(ThreadFactory factory) throws Exception {
753 var testJoiner = new CancelAfterOneJoiner<String>();
754 try (var scope = StructuredTaskScope.open(testJoiner,
755 cf -> cf.withThreadFactory(factory))) {
756
757 // fork first subtask, a straggler as it continues after being interrupted
758 var started = new CountDownLatch(1);
759 var done = new AtomicBoolean();
760 scope.fork(() -> {
761 started.countDown();
762 try {
763 Thread.sleep(Duration.ofDays(1));
764 } catch (InterruptedException e) {
765 // interrupted by cancel, expected
766 }
767 Thread.sleep(Duration.ofMillis(100)); // force close to wait
768 done.set(true);
769 return null;
770 });
771 started.await();
772
773 // fork second subtask, the scope should be cancelled when this subtask completes
774 scope.fork(() -> "bar");
775 awaitCancelled(scope);
776
777 scope.join();
778
779 // invoke close with interrupt status set
780 Thread.currentThread().interrupt();
781 try {
782 scope.close();
783 } finally {
784 assertTrue(Thread.interrupted()); // clear interrupt status
785 assertTrue(done.get());
786 }
787 }
788 }
789
790 /**
791 * Test interrupting thread waiting in close.
792 */
793 @ParameterizedTest
794 @MethodSource("factories")
795 void testInterruptClose2(ThreadFactory factory) throws Exception {
796 var testJoiner = new CancelAfterOneJoiner<String>();
797 try (var scope = StructuredTaskScope.open(testJoiner,
798 cf -> cf.withThreadFactory(factory))) {
799
800 Thread mainThread = Thread.currentThread();
801
802 // fork first subtask, a straggler as it continues after being interrupted
803 var started = new CountDownLatch(1);
804 var done = new AtomicBoolean();
805 scope.fork(() -> {
806 started.countDown();
807 try {
808 Thread.sleep(Duration.ofDays(1));
809 } catch (InterruptedException e) {
810 // interrupted by cancel, expected
811 }
812
813 // interrupt main thread when it blocks in close
814 interruptThreadAt(mainThread, "java.util.concurrent.StructuredTaskScopeImpl.close");
815
816 Thread.sleep(Duration.ofMillis(100)); // force close to wait
817 done.set(true);
818 return null;
819 });
820 started.await();
821
822 // fork second subtask, the scope should be cancelled when this subtask completes
823 scope.fork(() -> "bar");
824 awaitCancelled(scope);
825
826 scope.join();
827
828 // main thread will be interrupted while blocked in close
829 try {
830 scope.close();
831 } finally {
832 assertTrue(Thread.interrupted()); // clear interrupt status
833 assertTrue(done.get());
834 }
835 }
836 }
837
838 /**
839 * Test that closing an enclosing scope closes the thread flock of a nested scope.
840 */
841 @Test
842 void testCloseThrowsStructureViolation() throws Exception {
843 try (var scope1 = StructuredTaskScope.open(Joiner.awaitAll())) {
844 try (var scope2 = StructuredTaskScope.open(Joiner.awaitAll())) {
845
846 // close enclosing scope
847 try {
848 scope1.close();
849 fail("close did not throw");
850 } catch (StructureViolationException expected) { }
851
852 // underlying flock should be closed
853 var executed = new AtomicBoolean();
854 Subtask<?> subtask = scope2.fork(() -> executed.set(true));
855 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
856 scope2.join();
857 assertFalse(executed.get());
858 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
859 }
860 }
861 }
862
863 /**
864 * Test that isCancelled returns true after close.
865 */
866 @Test
867 void testIsCancelledAfterClose() throws Exception {
868 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
869 assertFalse(scope.isCancelled());
870 scope.close();
871 assertTrue(scope.isCancelled());
872 }
873 }
874
875 /**
876 * Test Joiner.onFork throwing exception.
877 */
878 @Test
879 void testOnForkThrows() throws Exception {
880 var joiner = new Joiner<String, Void>() {
881 @Override
882 public boolean onFork(Subtask<? extends String> subtask) {
883 throw new FooException();
884 }
885 @Override
886 public Void result() {
887 return null;
888 }
889 };
890 try (var scope = StructuredTaskScope.open(joiner)) {
891 assertThrows(FooException.class, () -> scope.fork(() -> "foo"));
892 }
893 }
894
895 /**
896 * Test Joiner.onFork returning true to cancel execution.
897 */
898 @Test
899 void testOnForkCancelsExecution() throws Exception {
900 var joiner = new Joiner<String, Void>() {
901 @Override
902 public boolean onFork(Subtask<? extends String> subtask) {
903 return true;
904 }
905 @Override
906 public Void result() {
907 return null;
908 }
909 };
910 try (var scope = StructuredTaskScope.open(joiner)) {
911 assertFalse(scope.isCancelled());
912 scope.fork(() -> "foo");
913 assertTrue(scope.isCancelled());
914 scope.join();
915 }
916 }
917
918 /**
919 * Test Joiner.onComplete throwing exception causes UHE to be invoked.
920 */
921 @Test
922 void testOnCompleteThrows() throws Exception {
923 var joiner = new Joiner<String, Void>() {
924 @Override
925 public boolean onComplete(Subtask<? extends String> subtask) {
926 throw new FooException();
927 }
928 @Override
929 public Void result() {
930 return null;
931 }
932 };
933 var excRef = new AtomicReference<Throwable>();
934 Thread.UncaughtExceptionHandler uhe = (t, e) -> excRef.set(e);
935 ThreadFactory factory = Thread.ofVirtual()
936 .uncaughtExceptionHandler(uhe)
937 .factory();
938 try (var scope = StructuredTaskScope.open(joiner, cf -> cf.withThreadFactory(factory))) {
939 scope.fork(() -> "foo");
940 scope.join();
941 assertInstanceOf(FooException.class, excRef.get());
942 }
943 }
944
945 /**
946 * Test Joiner.onComplete returning true to cancel execution.
947 */
948 @Test
949 void testOnCompleteCancelsExecution() throws Exception {
950 var joiner = new Joiner<String, Void>() {
951 @Override
952 public boolean onComplete(Subtask<? extends String> subtask) {
953 return true;
954 }
955 @Override
956 public Void result() {
957 return null;
958 }
959 };
960 try (var scope = StructuredTaskScope.open(joiner)) {
961 assertFalse(scope.isCancelled());
962 scope.fork(() -> "foo");
963 awaitCancelled(scope);
964 scope.join();
965 }
966 }
967
968 /**
969 * Test toString.
970 */
971 @Test
972 void testToString() throws Exception {
973 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
974 cf -> cf.withName("duke"))) {
975
976 // open
977 assertTrue(scope.toString().contains("duke"));
978
979 // closed
980 scope.close();
981 assertTrue(scope.toString().contains("duke"));
982 }
983 }
984
985 /**
986 * Test Subtask with task that completes successfully.
987 */
988 @ParameterizedTest
989 @MethodSource("factories")
990 void testSubtaskWhenSuccess(ThreadFactory factory) throws Exception {
991 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAll(),
992 cf -> cf.withThreadFactory(factory))) {
993
994 Subtask<String> subtask = scope.fork(() -> "foo");
995
996 // before join
997 assertThrows(IllegalStateException.class, subtask::get);
998 assertThrows(IllegalStateException.class, subtask::exception);
999
1000 scope.join();
1001
1002 // after join
1003 assertEquals(Subtask.State.SUCCESS, subtask.state());
1004 assertEquals("foo", subtask.get());
1005 assertThrows(IllegalStateException.class, subtask::exception);
1006 }
1007 }
1008
1009 /**
1010 * Test Subtask with task that fails.
1011 */
1012 @ParameterizedTest
1013 @MethodSource("factories")
1014 void testSubtaskWhenFailed(ThreadFactory factory) throws Exception {
1015 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAll(),
1016 cf -> cf.withThreadFactory(factory))) {
1017
1018 Subtask<String> subtask = scope.fork(() -> { throw new FooException(); });
1019
1020 // before join
1021 assertThrows(IllegalStateException.class, subtask::get);
1022 assertThrows(IllegalStateException.class, subtask::exception);
1023
1024 scope.join();
1025
1026 // after join
1027 assertEquals(Subtask.State.FAILED, subtask.state());
1028 assertThrows(IllegalStateException.class, subtask::get);
1029 assertTrue(subtask.exception() instanceof FooException);
1030 }
1031 }
1032
1033 /**
1034 * Test Subtask with a task that has not completed.
1035 */
1036 @ParameterizedTest
1037 @MethodSource("factories")
1038 void testSubtaskWhenNotCompleted(ThreadFactory factory) throws Exception {
1039 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
1040 cf -> cf.withThreadFactory(factory))) {
1041 Subtask<Void> subtask = scope.fork(() -> {
1042 Thread.sleep(Duration.ofDays(1));
1043 return null;
1044 });
1045
1046 // before join
1047 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
1048 assertThrows(IllegalStateException.class, subtask::get);
1049 assertThrows(IllegalStateException.class, subtask::exception);
1050
1051 // attempt join, join throws
1052 Thread.currentThread().interrupt();
1053 assertThrows(InterruptedException.class, scope::join);
1054
1055 // after join
1056 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
1057 assertThrows(IllegalStateException.class, subtask::get);
1058 assertThrows(IllegalStateException.class, subtask::exception);
1059 }
1060 }
1061
1062 /**
1063 * Test Subtask forked after execution cancelled.
1064 */
1065 @ParameterizedTest
1066 @MethodSource("factories")
1067 void testSubtaskWhenCancelled(ThreadFactory factory) throws Exception {
1068 try (var scope = StructuredTaskScope.open(new CancelAfterOneJoiner<String>())) {
1069 scope.fork(() -> "foo");
1070 awaitCancelled(scope);
1071
1072 var subtask = scope.fork(() -> "foo");
1073
1074 // before join
1075 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
1076 assertThrows(IllegalStateException.class, subtask::get);
1077 assertThrows(IllegalStateException.class, subtask::exception);
1078
1079 scope.join();
1080
1081 // after join
1082 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
1083 assertThrows(IllegalStateException.class, subtask::get);
1084 assertThrows(IllegalStateException.class, subtask::exception);
1085 }
1086 }
1087
1088 /**
1089 * Test Subtask::toString.
1090 */
1091 @Test
1092 void testSubtaskToString() throws Exception {
1093 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
1094 var latch = new CountDownLatch(1);
1095 var subtask1 = scope.fork(() -> {
1096 latch.await();
1097 return "foo";
1098 });
1099 var subtask2 = scope.fork(() -> { throw new FooException(); });
1100
1101 // subtask1 result is unavailable
1102 assertTrue(subtask1.toString().contains("Unavailable"));
1103 latch.countDown();
1104
1105 scope.join();
1106
1107 assertTrue(subtask1.toString().contains("Completed successfully"));
1108 assertTrue(subtask2.toString().contains("Failed"));
1109 }
1110 }
1111
1112 /**
1113 * Test Joiner.allSuccessfulOrThrow() with no subtasks.
1114 */
1115 @Test
1116 void testAllSuccessfulOrThrow1() throws Throwable {
1117 try (var scope = StructuredTaskScope.open(Joiner.allSuccessfulOrThrow())) {
1118 var subtasks = scope.join().toList();
1119 assertTrue(subtasks.isEmpty());
1120 }
1121 }
1122
1123 /**
1124 * Test Joiner.allSuccessfulOrThrow() with subtasks that complete successfully.
1125 */
1126 @ParameterizedTest
1127 @MethodSource("factories")
1128 void testAllSuccessfulOrThrow2(ThreadFactory factory) throws Throwable {
1129 try (var scope = StructuredTaskScope.open(Joiner.<String>allSuccessfulOrThrow(),
1130 cf -> cf.withThreadFactory(factory))) {
1131 var subtask1 = scope.fork(() -> "foo");
1132 var subtask2 = scope.fork(() -> "bar");
1133 var subtasks = scope.join().toList();
1134 assertEquals(List.of(subtask1, subtask2), subtasks);
1135 assertEquals("foo", subtask1.get());
1136 assertEquals("bar", subtask2.get());
1137 }
1138 }
1139
1140 /**
1141 * Test Joiner.allSuccessfulOrThrow() with a subtask that complete successfully and
1142 * a subtask that fails.
1143 */
1144 @ParameterizedTest
1145 @MethodSource("factories")
1146 void testAllSuccessfulOrThrow3(ThreadFactory factory) throws Throwable {
1147 try (var scope = StructuredTaskScope.open(Joiner.<String>allSuccessfulOrThrow(),
1148 cf -> cf.withThreadFactory(factory))) {
1149 scope.fork(() -> "foo");
1150 scope.fork(() -> { throw new FooException(); });
1151 try {
1152 scope.join();
1153 } catch (FailedException e) {
1154 assertTrue(e.getCause() instanceof FooException);
1155 }
1156 }
1157 }
1158
1159 /**
1160 * Test Joiner.anySuccessfulResultOrThrow() with no subtasks.
1161 */
1162 @Test
1163 void testAnySuccessfulResultOrThrow1() throws Exception {
1164 try (var scope = StructuredTaskScope.open(Joiner.anySuccessfulResultOrThrow())) {
1165 try {
1166 scope.join();
1167 } catch (FailedException e) {
1168 assertTrue(e.getCause() instanceof NoSuchElementException);
1169 }
1170 }
1171 }
1172
1173 /**
1174 * Test Joiner.anySuccessfulResultOrThrow() with a subtask that completes successfully.
1175 */
1176 @ParameterizedTest
1177 @MethodSource("factories")
1178 void testAnySuccessfulResultOrThrow2(ThreadFactory factory) throws Exception {
1179 try (var scope = StructuredTaskScope.open(Joiner.<String>anySuccessfulResultOrThrow(),
1180 cf -> cf.withThreadFactory(factory))) {
1181 scope.fork(() -> "foo");
1182 String result = scope.join();
1183 assertEquals("foo", result);
1184 }
1185 }
1186
1187 /**
1188 * Test Joiner.anySuccessfulResultOrThrow() with a subtask that completes successfully
1189 * with a null result.
1190 */
1191 @ParameterizedTest
1192 @MethodSource("factories")
1193 void testAnySuccessfulResultOrThrow3(ThreadFactory factory) throws Exception {
1194 try (var scope = StructuredTaskScope.open(Joiner.<String>anySuccessfulResultOrThrow(),
1195 cf -> cf.withThreadFactory(factory))) {
1196 scope.fork(() -> null);
1197 String result = scope.join();
1198 assertNull(result);
1199 }
1200 }
1201
1202 /**
1203 * Test Joiner.anySuccessfulResultOrThrow() with a subtask that complete succcessfully
1204 * and a subtask that fails.
1205 */
1206 @ParameterizedTest
1207 @MethodSource("factories")
1208 void testAnySuccessfulResultOrThrow4(ThreadFactory factory) throws Exception {
1209 try (var scope = StructuredTaskScope.open(Joiner.<String>anySuccessfulResultOrThrow(),
1210 cf -> cf.withThreadFactory(factory))) {
1211 scope.fork(() -> "foo");
1212 scope.fork(() -> { throw new FooException(); });
1213 String first = scope.join();
1214 assertEquals("foo", first);
1215 }
1216 }
1217
1218 /**
1219 * Test Joiner.anySuccessfulResultOrThrow() with a subtask that fails.
1220 */
1221 @ParameterizedTest
1222 @MethodSource("factories")
1223 void testAnySuccessfulResultOrThrow5(ThreadFactory factory) throws Exception {
1224 try (var scope = StructuredTaskScope.open(Joiner.anySuccessfulResultOrThrow(),
1225 cf -> cf.withThreadFactory(factory))) {
1226 scope.fork(() -> { throw new FooException(); });
1227 Throwable ex = assertThrows(FailedException.class, scope::join);
1228 assertTrue(ex.getCause() instanceof FooException);
1229 }
1230 }
1231
1232 /**
1233 * Test Joiner.awaitAllSuccessfulOrThrow() with no subtasks.
1234 */
1235 @Test
1236 void testAwaitSuccessfulOrThrow1() throws Throwable {
1237 try (var scope = StructuredTaskScope.open(Joiner.awaitAllSuccessfulOrThrow())) {
1238 var result = scope.join();
1239 assertNull(result);
1240 }
1241 }
1242
1243 /**
1244 * Test Joiner.awaitAllSuccessfulOrThrow() with subtasks that complete successfully.
1245 */
1246 @ParameterizedTest
1247 @MethodSource("factories")
1248 void testAwaitSuccessfulOrThrow2(ThreadFactory factory) throws Throwable {
1249 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAllSuccessfulOrThrow(),
1250 cf -> cf.withThreadFactory(factory))) {
1251 var subtask1 = scope.fork(() -> "foo");
1252 var subtask2 = scope.fork(() -> "bar");
1253 var result = scope.join();
1254 assertNull(result);
1255 assertEquals("foo", subtask1.get());
1256 assertEquals("bar", subtask2.get());
1257 }
1258 }
1259
1260 /**
1261 * Test Joiner.awaitAllSuccessfulOrThrow() with a subtask that complete successfully and
1262 * a subtask that fails.
1263 */
1264 @ParameterizedTest
1265 @MethodSource("factories")
1266 void testAwaitSuccessfulOrThrow3(ThreadFactory factory) throws Throwable {
1267 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAllSuccessfulOrThrow(),
1268 cf -> cf.withThreadFactory(factory))) {
1269 scope.fork(() -> "foo");
1270 scope.fork(() -> { throw new FooException(); });
1271 try {
1272 scope.join();
1273 } catch (FailedException e) {
1274 assertTrue(e.getCause() instanceof FooException);
1275 }
1276 }
1277 }
1278
1279 /**
1280 * Test Joiner.awaitAll() with no subtasks.
1281 */
1282 @Test
1283 void testAwaitAll1() throws Throwable {
1284 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
1285 var result = scope.join();
1286 assertNull(result);
1287 }
1288 }
1289
1290 /**
1291 * Test Joiner.awaitAll() with subtasks that complete successfully.
1292 */
1293 @ParameterizedTest
1294 @MethodSource("factories")
1295 void testAwaitAll2(ThreadFactory factory) throws Throwable {
1296 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAll(),
1297 cf -> cf.withThreadFactory(factory))) {
1298 var subtask1 = scope.fork(() -> "foo");
1299 var subtask2 = scope.fork(() -> "bar");
1300 var result = scope.join();
1301 assertNull(result);
1302 assertEquals("foo", subtask1.get());
1303 assertEquals("bar", subtask2.get());
1304 }
1305 }
1306
1307 /**
1308 * Test Joiner.awaitAll() with a subtask that complete successfully and a subtask
1309 * that fails.
1310 */
1311 @ParameterizedTest
1312 @MethodSource("factories")
1313 void testAwaitAll3(ThreadFactory factory) throws Throwable {
1314 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAll(),
1315 cf -> cf.withThreadFactory(factory))) {
1316 var subtask1 = scope.fork(() -> "foo");
1317 var subtask2 = scope.fork(() -> { throw new FooException(); });
1318 var result = scope.join();
1319 assertNull(result);
1320 assertEquals("foo", subtask1.get());
1321 assertTrue(subtask2.exception() instanceof FooException);
1322 }
1323 }
1324
1325 /**
1326 * Test Joiner.allUntil(Predicate) with no subtasks.
1327 */
1328 @Test
1329 void testAllUntil1() throws Throwable {
1330 try (var scope = StructuredTaskScope.open(Joiner.allUntil(s -> false))) {
1331 var subtasks = scope.join();
1332 assertEquals(0, subtasks.count());
1333 }
1334 }
1335
1336 /**
1337 * Test Joiner.allUntil(Predicate) with no cancellation.
1338 */
1339 @ParameterizedTest
1340 @MethodSource("factories")
1341 void testAllUntil2(ThreadFactory factory) throws Exception {
1342 try (var scope = StructuredTaskScope.open(Joiner.<String>allUntil(s -> false),
1343 cf -> cf.withThreadFactory(factory))) {
1344
1345 var subtask1 = scope.fork(() -> "foo");
1346 var subtask2 = scope.fork(() -> { throw new FooException(); });
1347
1348 var subtasks = scope.join().toList();
1349 assertEquals(2, subtasks.size());
1350
1351 assertSame(subtask1, subtasks.get(0));
1352 assertSame(subtask2, subtasks.get(1));
1353 assertEquals("foo", subtask1.get());
1354 assertTrue(subtask2.exception() instanceof FooException);
1355 }
1356 }
1357
1358 /**
1359 * Test Joiner.allUntil(Predicate) with cancellation after one subtask completes.
1360 */
1361 @ParameterizedTest
1362 @MethodSource("factories")
1363 void testAllUntil3(ThreadFactory factory) throws Exception {
1364 try (var scope = StructuredTaskScope.open(Joiner.<String>allUntil(s -> true),
1365 cf -> cf.withThreadFactory(factory))) {
1366
1367 var subtask1 = scope.fork(() -> "foo");
1368 var subtask2 = scope.fork(() -> {
1369 Thread.sleep(Duration.ofDays(1));
1370 return "bar";
1371 });
1372
1373 var subtasks = scope.join().toList();
1374
1375 assertEquals(2, subtasks.size());
1376 assertSame(subtask1, subtasks.get(0));
1377 assertSame(subtask2, subtasks.get(1));
1378 assertEquals("foo", subtask1.get());
1379 assertEquals(Subtask.State.UNAVAILABLE, subtask2.state());
1380 }
1381 }
1382
1383 /**
1384 * Test Joiner.allUntil(Predicate) with cancellation after serveral subtasks complete.
1385 */
1386 @ParameterizedTest
1387 @MethodSource("factories")
1388 void testAllUntil4(ThreadFactory factory) throws Exception {
1389
1390 // cancel execution after two or more failures
1391 class CancelAfterTwoFailures<T> implements Predicate<Subtask<? extends T>> {
1392 final AtomicInteger failedCount = new AtomicInteger();
1393 @Override
1394 public boolean test(Subtask<? extends T> subtask) {
1395 return subtask.state() == Subtask.State.FAILED
1396 && failedCount.incrementAndGet() >= 2;
1397 }
1398 }
1399 var joiner = Joiner.allUntil(new CancelAfterTwoFailures<String>());
1400
1401 try (var scope = StructuredTaskScope.open(joiner)) {
1402 int forkCount = 0;
1403
1404 // fork subtasks until execution cancelled
1405 while (!scope.isCancelled()) {
1406 scope.fork(() -> "foo");
1407 scope.fork(() -> { throw new FooException(); });
1408 forkCount += 2;
1409 Thread.sleep(Duration.ofMillis(20));
1410 }
1411
1412 var subtasks = scope.join().toList();
1413 assertEquals(forkCount, subtasks.size());
1414
1415 long failedCount = subtasks.stream()
1416 .filter(s -> s.state() == Subtask.State.FAILED)
1417 .count();
1418 assertTrue(failedCount >= 2);
1419 }
1420 }
1421
1422 /**
1423 * Test Test Joiner.allUntil(Predicate) where the Predicate's test method throws.
1424 */
1425 @Test
1426 void testAllUntil5() throws Exception {
1427 var joiner = Joiner.allUntil(_ -> { throw new FooException(); });
1428 var excRef = new AtomicReference<Throwable>();
1429 Thread.UncaughtExceptionHandler uhe = (t, e) -> excRef.set(e);
1430 ThreadFactory factory = Thread.ofVirtual()
1431 .uncaughtExceptionHandler(uhe)
1432 .factory();
1433 try (var scope = StructuredTaskScope.open(joiner, cf -> cf.withThreadFactory(factory))) {
1434 scope.fork(() -> "foo");
1435 scope.join();
1436 assertInstanceOf(FooException.class, excRef.get());
1437 }
1438 }
1439
1440 /**
1441 * Test Joiner default methods.
1442 */
1443 @Test
1444 void testJoinerDefaultMethods() throws Exception {
1445 try (var scope = StructuredTaskScope.open(new CancelAfterOneJoiner<String>())) {
1446
1447 // need subtasks to test default methods
1448 var subtask1 = scope.fork(() -> "foo");
1449 awaitCancelled(scope);
1450 var subtask2 = scope.fork(() -> "bar");
1451 scope.join();
1452
1453 assertEquals(Subtask.State.SUCCESS, subtask1.state());
1454 assertEquals(Subtask.State.UNAVAILABLE, subtask2.state());
1455
1456 // Joiner that does not override default methods
1457 Joiner<Object, Void> joiner = () -> null;
1458 assertThrows(NullPointerException.class, () -> joiner.onFork(null));
1459 assertThrows(NullPointerException.class, () -> joiner.onComplete(null));
1460 assertThrows(IllegalArgumentException.class, () -> joiner.onFork(subtask1));
1461 assertFalse(joiner.onFork(subtask2));
1462 assertFalse(joiner.onComplete(subtask1));
1463 assertThrows(IllegalArgumentException.class, () -> joiner.onComplete(subtask2));
1464 }
1465 }
1466
1467 /**
1468 * Test Joiners onFork/onComplete methods with a subtask in an unexpected state.
1469 */
1470 @Test
1471 void testJoinersWithUnavailableResult() throws Exception {
1472 try (var scope = StructuredTaskScope.open()) {
1473 var done = new CountDownLatch(1);
1474 var subtask = scope.fork(() -> {
1475 done.await();
1476 return null;
1477 });
1478
1479 // onComplete with uncompleted task should throw IAE
1480 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
1481 assertThrows(IllegalArgumentException.class,
1482 () -> Joiner.allSuccessfulOrThrow().onComplete(subtask));
1483 assertThrows(IllegalArgumentException.class,
1484 () -> Joiner.anySuccessfulResultOrThrow().onComplete(subtask));
1485 assertThrows(IllegalArgumentException.class,
1486 () -> Joiner.awaitAllSuccessfulOrThrow().onComplete(subtask));
1487 assertThrows(IllegalArgumentException.class,
1488 () -> Joiner.awaitAll().onComplete(subtask));
1489 assertThrows(IllegalArgumentException.class,
1490 () -> Joiner.allUntil(_ -> false).onComplete(subtask));
1491
1492 done.countDown();
1493 scope.join();
1494
1495 // onFork with completed task should throw IAE
1496 assertEquals(Subtask.State.SUCCESS, subtask.state());
1497 assertThrows(IllegalArgumentException.class,
1498 () -> Joiner.allSuccessfulOrThrow().onFork(subtask));
1499 assertThrows(IllegalArgumentException.class,
1500 () -> Joiner.anySuccessfulResultOrThrow().onFork(subtask));
1501 assertThrows(IllegalArgumentException.class,
1502 () -> Joiner.awaitAllSuccessfulOrThrow().onFork(subtask));
1503 assertThrows(IllegalArgumentException.class,
1504 () -> Joiner.awaitAll().onFork(subtask));
1505 assertThrows(IllegalArgumentException.class,
1506 () -> Joiner.allUntil(_ -> false).onFork(subtask));
1507 }
1508
1509 }
1510
1511 /**
1512 * Test the Configuration function apply method throwing an exception.
1513 */
1514 @Test
1515 void testConfigFunctionThrows() throws Exception {
1516 assertThrows(FooException.class,
1517 () -> StructuredTaskScope.open(Joiner.awaitAll(),
1518 cf -> { throw new FooException(); }));
1519 }
1520
1521 /**
1522 * Test Configuration equals/hashCode/toString
1523 */
1524 @Test
1525 void testConfigMethods() throws Exception {
1526 Function<Configuration, Configuration> testConfig = cf -> {
1527 var name = "duke";
1528 var threadFactory = Thread.ofPlatform().factory();
1529 var timeout = Duration.ofSeconds(10);
1530
1531 assertEquals(cf, cf);
1532 assertEquals(cf.withName(name), cf.withName(name));
1533 assertEquals(cf.withThreadFactory(threadFactory), cf.withThreadFactory(threadFactory));
1534 assertEquals(cf.withTimeout(timeout), cf.withTimeout(timeout));
1535
1536 assertNotEquals(cf, cf.withName(name));
1537 assertNotEquals(cf, cf.withThreadFactory(threadFactory));
1538 assertNotEquals(cf, cf.withTimeout(timeout));
1539
1540 assertEquals(cf.withName(name).hashCode(), cf.withName(name).hashCode());
1541 assertEquals(cf.withThreadFactory(threadFactory).hashCode(),
1542 cf.withThreadFactory(threadFactory).hashCode());
1543 assertEquals(cf.withTimeout(timeout).hashCode(), cf.withTimeout(timeout).hashCode());
1544
1545 assertTrue(cf.withName(name).toString().contains(name));
1546 assertTrue(cf.withThreadFactory(threadFactory).toString().contains(threadFactory.toString()));
1547 assertTrue(cf.withTimeout(timeout).toString().contains(timeout.toString()));
1548
1549 return cf;
1550 };
1551 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(), testConfig)) {
1552 // do nothing
1553 }
1554 }
1555
1556 /**
1557 * Test for NullPointerException.
1558 */
1559 @Test
1560 void testNulls() throws Exception {
1561 assertThrows(NullPointerException.class,
1562 () -> StructuredTaskScope.open(null));
1563 assertThrows(NullPointerException.class,
1564 () -> StructuredTaskScope.open(null, cf -> cf));
1565 assertThrows(NullPointerException.class,
1566 () -> StructuredTaskScope.open(Joiner.awaitAll(), null));
1567
1568 assertThrows(NullPointerException.class, () -> Joiner.allUntil(null));
1569
1570 // fork
1571 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
1572 assertThrows(NullPointerException.class, () -> scope.fork((Callable<Object>) null));
1573 assertThrows(NullPointerException.class, () -> scope.fork((Runnable) null));
1574 }
1575
1576 // Configuration and withXXX methods
1577 assertThrows(NullPointerException.class,
1578 () -> StructuredTaskScope.open(Joiner.awaitAll(), cf -> null));
1579 assertThrows(NullPointerException.class,
1580 () -> StructuredTaskScope.open(Joiner.awaitAll(), cf -> cf.withName(null)));
1581 assertThrows(NullPointerException.class,
1582 () -> StructuredTaskScope.open(Joiner.awaitAll(), cf -> cf.withThreadFactory(null)));
1583 assertThrows(NullPointerException.class,
1584 () -> StructuredTaskScope.open(Joiner.awaitAll(), cf -> cf.withTimeout(null)));
1585
1586 // Joiner.onFork/onComplete
1587 assertThrows(NullPointerException.class,
1588 () -> Joiner.awaitAllSuccessfulOrThrow().onFork(null));
1589 assertThrows(NullPointerException.class,
1590 () -> Joiner.awaitAllSuccessfulOrThrow().onComplete(null));
1591 assertThrows(NullPointerException.class,
1592 () -> Joiner.awaitAll().onFork(null));
1593 assertThrows(NullPointerException.class,
1594 () -> Joiner.awaitAll().onComplete(null));
1595 assertThrows(NullPointerException.class,
1596 () -> Joiner.allSuccessfulOrThrow().onFork(null));
1597 assertThrows(NullPointerException.class,
1598 () -> Joiner.allSuccessfulOrThrow().onComplete(null));
1599 assertThrows(NullPointerException.class,
1600 () -> Joiner.anySuccessfulResultOrThrow().onFork(null));
1601 assertThrows(NullPointerException.class,
1602 () -> Joiner.anySuccessfulResultOrThrow().onComplete(null));
1603 }
1604
1605 /**
1606 * ThreadFactory that counts usage.
1607 */
1608 private static class CountingThreadFactory implements ThreadFactory {
1609 final ThreadFactory delegate;
1610 final AtomicInteger threadCount = new AtomicInteger();
1611 CountingThreadFactory(ThreadFactory delegate) {
1612 this.delegate = delegate;
1613 }
1614 @Override
1615 public Thread newThread(Runnable task) {
1616 threadCount.incrementAndGet();
1617 return delegate.newThread(task);
1618 }
1619 int threadCount() {
1620 return threadCount.get();
1621 }
1622 }
1623
1624 /**
1625 * A joiner that counts that counts the number of subtasks that are forked and the
1626 * number of subtasks that complete.
1627 */
1628 private static class CountingJoiner<T> implements Joiner<T, Void> {
1629 final AtomicInteger onForkCount = new AtomicInteger();
1630 final AtomicInteger onCompleteCount = new AtomicInteger();
1631 @Override
1632 public boolean onFork(Subtask<? extends T> subtask) {
1633 onForkCount.incrementAndGet();
1634 return false;
1635 }
1636 @Override
1637 public boolean onComplete(Subtask<? extends T> subtask) {
1638 onCompleteCount.incrementAndGet();
1639 return false;
1640 }
1641 @Override
1642 public Void result() {
1643 return null;
1644 }
1645 int onForkCount() {
1646 return onForkCount.get();
1647 }
1648 int onCompleteCount() {
1649 return onCompleteCount.get();
1650 }
1651 }
1652
1653 /**
1654 * A joiner that cancels execution when a subtask completes. It also keeps a count
1655 * of the number of subtasks that are forked and the number of subtasks that complete.
1656 */
1657 private static class CancelAfterOneJoiner<T> implements Joiner<T, Void> {
1658 final AtomicInteger onForkCount = new AtomicInteger();
1659 final AtomicInteger onCompleteCount = new AtomicInteger();
1660 @Override
1661 public boolean onFork(Subtask<? extends T> subtask) {
1662 onForkCount.incrementAndGet();
1663 return false;
1664 }
1665 @Override
1666 public boolean onComplete(Subtask<? extends T> subtask) {
1667 onCompleteCount.incrementAndGet();
1668 return true;
1669 }
1670 @Override
1671 public Void result() {
1672 return null;
1673 }
1674 int onForkCount() {
1675 return onForkCount.get();
1676 }
1677 int onCompleteCount() {
1678 return onCompleteCount.get();
1679 }
1680 }
1681
1682 /**
1683 * A runtime exception for tests.
1684 */
1685 private static class FooException extends RuntimeException {
1686 FooException() { }
1687 FooException(Throwable cause) { super(cause); }
1688 }
1689
1690 /**
1691 * Returns the current time in milliseconds.
1692 */
1693 private long millisTime() {
1694 long now = System.nanoTime();
1695 return TimeUnit.MILLISECONDS.convert(now, TimeUnit.NANOSECONDS);
1696 }
1697
1698 /**
1699 * Check the duration of a task
1700 * @param start start time, in milliseconds
1701 * @param min minimum expected duration, in milliseconds
1702 * @param max maximum expected duration, in milliseconds
1703 * @return the duration (now - start), in milliseconds
1704 */
1705 private long expectDuration(long start, long min, long max) {
1706 long duration = millisTime() - start;
1707 assertTrue(duration >= min,
1708 "Duration " + duration + "ms, expected >= " + min + "ms");
1709 assertTrue(duration <= max,
1710 "Duration " + duration + "ms, expected <= " + max + "ms");
1711 return duration;
1712 }
1713
1714 /**
1715 * Wait for the given scope to be cancelled.
1716 */
1717 private static void awaitCancelled(StructuredTaskScope<?, ?> scope) throws InterruptedException {
1718 while (!scope.isCancelled()) {
1719 Thread.sleep(Duration.ofMillis(20));
1720 }
1721 }
1722
1723 /**
1724 * Interrupts a thread when it waits (timed or untimed) at location "{@code c.m}".
1725 * {@code c} is the fully qualified class name and {@code m} is the method name.
1726 */
1727 private void interruptThreadAt(Thread target, String location) throws InterruptedException {
1728 int index = location.lastIndexOf('.');
1729 String className = location.substring(0, index);
1730 String methodName = location.substring(index + 1);
1731
1732 boolean found = false;
1733 while (!found) {
1734 Thread.State state = target.getState();
1735 assertTrue(state != TERMINATED);
1736 if ((state == WAITING || state == TIMED_WAITING)
1737 && contains(target.getStackTrace(), className, methodName)) {
1738 found = true;
1739 } else {
1740 Thread.sleep(20);
1741 }
1742 }
1743 target.interrupt();
1744 }
1745
1746 /**
1747 * Schedules the current thread to be interrupted when it waits (timed or untimed)
1748 * at the given location.
1749 */
1750 private void scheduleInterruptAt(String location) {
1751 Thread target = Thread.currentThread();
1752 scheduler.submit(() -> {
1753 interruptThreadAt(target, location);
1754 return null;
1755 });
1756 }
1757
1758 /**
1759 * Returns true if the given stack trace contains an element for the given class
1760 * and method name.
1761 */
1762 private boolean contains(StackTraceElement[] stack, String className, String methodName) {
1763 return Arrays.stream(stack)
1764 .anyMatch(e -> className.equals(e.getClassName())
1765 && methodName.equals(e.getMethodName()));
1766 }
1767 }