1 /*
2 * Copyright (c) 2021, 2023, 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.io.IOException;
40 import java.time.Instant;
41 import java.util.Arrays;
42 import java.util.ArrayList;
43 import java.util.List;
44 import java.util.Set;
45 import java.util.concurrent.Callable;
46 import java.util.concurrent.ConcurrentHashMap;
47 import java.util.concurrent.CountDownLatch;
48 import java.util.concurrent.Executors;
49 import java.util.concurrent.ExecutionException;
50 import java.util.concurrent.Future;
51 import java.util.concurrent.ThreadFactory;
52 import java.util.concurrent.TimeoutException;
53 import java.util.concurrent.TimeUnit;
54 import java.util.concurrent.RejectedExecutionException;
55 import java.util.concurrent.ScheduledExecutorService;
56 import java.util.concurrent.StructuredTaskScope;
57 import java.util.concurrent.StructuredTaskScope.Subtask;
58 import java.util.concurrent.StructuredTaskScope.ShutdownOnSuccess;
59 import java.util.concurrent.StructuredTaskScope.ShutdownOnFailure;
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.Supplier;
65 import java.util.stream.Stream;
66 import static java.lang.Thread.State.*;
67
68 import org.junit.jupiter.api.Test;
69 import org.junit.jupiter.api.BeforeAll;
70 import org.junit.jupiter.api.AfterAll;
71 import org.junit.jupiter.params.ParameterizedTest;
72 import org.junit.jupiter.params.provider.MethodSource;
73 import static org.junit.jupiter.api.Assertions.*;
74
75 class StructuredTaskScopeTest {
76 private static ScheduledExecutorService scheduler;
77 private static List<ThreadFactory> threadFactories;
78
79 @BeforeAll
80 static void setup() throws Exception {
81 scheduler = Executors.newSingleThreadScheduledExecutor();
82
83 // thread factories
84 String value = System.getProperty("threadFactory");
85 List<ThreadFactory> list = new ArrayList<>();
86 if (value == null || value.equals("platform"))
87 list.add(Thread.ofPlatform().factory());
88 if (value == null || value.equals("virtual"))
89 list.add(Thread.ofVirtual().factory());
90 assertTrue(list.size() > 0, "No thread factories for tests");
91 threadFactories = list;
92 }
93
94 @AfterAll
95 static void shutdown() {
96 scheduler.shutdown();
97 }
98
99 private static Stream<ThreadFactory> factories() {
100 return threadFactories.stream();
101 }
102
103 /**
104 * Test that fork creates a new thread for each task.
105 */
106 @ParameterizedTest
107 @MethodSource("factories")
108 void testForkCreatesThread(ThreadFactory factory) throws Exception {
109 Set<Long> tids = ConcurrentHashMap.newKeySet();
110 try (var scope = new StructuredTaskScope<Object>(null, factory)) {
111 for (int i = 0; i < 100; i++) {
112 scope.fork(() -> {
113 tids.add(Thread.currentThread().threadId());
114 return null;
115 });
116 }
117 scope.join();
118 }
119 assertEquals(100, tids.size());
120 }
121
122 /**
123 * Test that fork creates a new virtual thread for each task.
124 */
125 @Test
126 void testForkCreateVirtualThread() throws Exception {
127 Set<Thread> threads = ConcurrentHashMap.newKeySet();
128 try (var scope = new StructuredTaskScope<Object>()) {
129 for (int i = 0; i < 100; i++) {
130 scope.fork(() -> {
131 threads.add(Thread.currentThread());
132 return null;
133 });
134 }
135 scope.join();
136 }
137 assertEquals(100, threads.size());
138 threads.forEach(t -> assertTrue(t.isVirtual()));
139 }
140
141 /**
142 * Test that fork creates a new thread with the given thread factory.
143 */
144 @ParameterizedTest
145 @MethodSource("factories")
146 void testForkUsesFactory(ThreadFactory factory) throws Exception {
147 var count = new AtomicInteger();
148 ThreadFactory countingFactory = task -> {
149 count.incrementAndGet();
150 return factory.newThread(task);
151 };
152 try (var scope = new StructuredTaskScope<Object>(null, countingFactory)) {
153 for (int i = 0; i < 100; i++) {
154 scope.fork(() -> null);
155 }
156 scope.join();
157 }
158 assertEquals(100, count.get());
159 }
160
161 /**
162 * Test fork is confined to threads in the scope "tree".
163 */
164 @ParameterizedTest
165 @MethodSource("factories")
166 void testForkConfined(ThreadFactory factory) throws Exception {
167 try (var scope1 = new StructuredTaskScope<Boolean>();
168 var scope2 = new StructuredTaskScope<Boolean>()) {
169
170 // thread in scope1 cannot fork thread in scope2
171 Subtask<Boolean> subtask1 = scope1.fork(() -> {
172 assertThrows(WrongThreadException.class, () -> {
173 scope2.fork(() -> null);
174 });
175 return true;
176 });
177
178 // thread in scope2 can fork thread in scope1
179 Subtask<Boolean> subtask2 = scope2.fork(() -> {
180 scope1.fork(() -> null);
181 return true;
182 });
183
184 scope2.join();
185 scope1.join();
186
187 assertTrue(subtask1.get());
188 assertTrue(subtask2.get());
189
190 // random thread cannot fork
191 try (var pool = Executors.newSingleThreadExecutor()) {
192 Future<Void> future = pool.submit(() -> {
193 assertThrows(WrongThreadException.class, () -> {
194 scope1.fork(() -> null);
195 });
196 assertThrows(WrongThreadException.class, () -> {
197 scope2.fork(() -> null);
198 });
199 return null;
200 });
201 future.get();
202 }
203 }
204 }
205
206 /**
207 * Test fork after join completes.
208 */
209 @ParameterizedTest
210 @MethodSource("factories")
211 void testForkAfterJoin(ThreadFactory factory) throws Exception {
212 try (var scope = new StructuredTaskScope<String>(null, factory)) {
213 // round 1
214 var subtask1 = scope.fork(() -> "foo");
215 assertThrows(IllegalStateException.class, subtask1::get);
216 scope.join();
217 assertEquals("foo", subtask1.get());
218
219 // round 2
220 var subtask2 = scope.fork(() -> "bar");
221 assertEquals("foo", subtask1.get());
222 assertThrows(IllegalStateException.class, subtask2::get);
223 scope.join();
224 assertEquals("foo", subtask1.get());
225 assertEquals("bar", subtask2.get());
226
227 // round 3
228 var subtask3 = scope.fork(() -> "baz");
229 assertEquals("foo", subtask1.get());
230 assertEquals("bar", subtask2.get());
231 assertThrows(IllegalStateException.class, subtask3::get);
232 scope.join();
233 assertEquals("foo", subtask1.get());
234 assertEquals("bar", subtask2.get());
235 assertEquals("baz", subtask3.get());
236 }
237 }
238
239 /**
240 * Test fork after join throws.
241 */
242 @ParameterizedTest
243 @MethodSource("factories")
244 void testForkAfterJoinThrows(ThreadFactory factory) throws Exception {
245 try (var scope = new StructuredTaskScope<String>(null, factory)) {
246 var latch = new CountDownLatch(1);
247 var subtask1 = scope.fork(() -> {
248 latch.await();
249 return "foo";
250 });
251
252 // join throws
253 Thread.currentThread().interrupt();
254 assertThrows(InterruptedException.class, scope::join);
255
256 // allow subtask1 to finish
257 latch.countDown();
258
259 // continue to fork
260 var subtask2 = scope.fork(() -> "bar");
261 assertThrows(IllegalStateException.class, subtask1::get);
262 assertThrows(IllegalStateException.class, subtask2::get);
263 scope.join();
264 assertEquals("foo", subtask1.get());
265 assertEquals("bar", subtask2.get());
266 }
267 }
268
269 /**
270 * Test fork after scope is shutdown.
271 */
272 @ParameterizedTest
273 @MethodSource("factories")
274 void testForkAfterShutdown(ThreadFactory factory) throws Exception {
275 var executed = new AtomicBoolean();
276 try (var scope = new StructuredTaskScope<Object>(null, factory)) {
277 scope.shutdown();
278 Subtask<String> subtask = scope.fork(() -> {
279 executed.set(true);
280 return null;
281 });
282 scope.join();
283 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
284 assertThrows(IllegalStateException.class, subtask::get);
285 assertThrows(IllegalStateException.class, subtask::exception);
286 }
287 assertFalse(executed.get());
288 }
289
290 /**
291 * Test fork after scope is closed.
292 */
293 @ParameterizedTest
294 @MethodSource("factories")
295 void testForkAfterClose(ThreadFactory factory) throws Exception {
296 try (var scope = new StructuredTaskScope<Object>(null, factory)) {
297 scope.close();
298 assertThrows(IllegalStateException.class, () -> scope.fork(() -> null));
299 }
300 }
301
302 /**
303 * Test fork when the thread factory rejects creating a thread.
304 */
305 @Test
306 void testForkRejectedExecutionException() throws Exception {
307 ThreadFactory factory = task -> null;
308 try (var scope = new StructuredTaskScope(null, factory)) {
309 assertThrows(RejectedExecutionException.class, () -> scope.fork(() -> null));
310 scope.join();
311 }
312 }
313
314 /**
315 * Test join with no subtasks.
316 */
317 @Test
318 void testJoinWithNoSubtasks() throws Exception {
319 try (var scope = new StructuredTaskScope()) {
320 scope.join();
321 }
322 }
323
324 /**
325 * Test join with unfinished subtasks.
326 */
327 @ParameterizedTest
328 @MethodSource("factories")
329 void testJoinWithSubtasks(ThreadFactory factory) throws Exception {
330 try (var scope = new StructuredTaskScope(null, factory)) {
331 Subtask<String> subtask = scope.fork(() -> {
332 Thread.sleep(Duration.ofMillis(50));
333 return "foo";
334 });
335 scope.join();
336 assertEquals("foo", subtask.get());
337 }
338 }
339
340 /**
341 * Test join is owner confined.
342 */
343 @ParameterizedTest
344 @MethodSource("factories")
345 void testJoinConfined(ThreadFactory factory) throws Exception {
346 try (var scope = new StructuredTaskScope<Boolean>()) {
347
348 // thread in scope cannot join
349 Subtask<Boolean> subtask = scope.fork(() -> {
350 assertThrows(WrongThreadException.class, () -> { scope.join(); });
351 return true;
352 });
353
354 scope.join();
355
356 assertTrue(subtask.get());
357
358 // random thread cannot join
359 try (var pool = Executors.newSingleThreadExecutor()) {
360 Future<Void> future = pool.submit(() -> {
361 assertThrows(WrongThreadException.class, scope::join);
362 return null;
363 });
364 future.get();
365 }
366 }
367 }
368
369 /**
370 * Test join with interrupt status set.
371 */
372 @ParameterizedTest
373 @MethodSource("factories")
374 void testInterruptJoin1(ThreadFactory factory) throws Exception {
375 try (var scope = new StructuredTaskScope(null, factory)) {
376 var latch = new CountDownLatch(1);
377
378 Subtask<String> subtask = scope.fork(() -> {
379 latch.await();
380 return "foo";
381 });
382
383 // join should throw
384 Thread.currentThread().interrupt();
385 try {
386 scope.join();
387 fail("join did not throw");
388 } catch (InterruptedException expected) {
389 assertFalse(Thread.interrupted()); // interrupt status should be clear
390 } finally {
391 // let task continue
392 latch.countDown();
393 }
394
395 // join should complete
396 scope.join();
397 assertEquals("foo", subtask.get());
398 }
399 }
400
401 /**
402 * Test interrupt of thread blocked in join.
403 */
404 @ParameterizedTest
405 @MethodSource("factories")
406 void testInterruptJoin2(ThreadFactory factory) throws Exception {
407 try (var scope = new StructuredTaskScope(null, factory)) {
408 var latch = new CountDownLatch(1);
409 Subtask<String> subtask = scope.fork(() -> {
410 latch.await();
411 return "foo";
412 });
413
414 // join should throw
415 scheduleInterruptAt("java.util.concurrent.StructuredTaskScope.join");
416 try {
417 scope.join();
418 fail("join did not throw");
419 } catch (InterruptedException expected) {
420 assertFalse(Thread.interrupted()); // interrupt status should be clear
421 } finally {
422 // let task continue
423 latch.countDown();
424 }
425
426 // join should complete
427 scope.join();
428 assertEquals("foo", subtask.get());
429 }
430 }
431
432 /**
433 * Test join when scope is shutdown.
434 */
435 @ParameterizedTest
436 @MethodSource("factories")
437 void testJoinWithShutdown1(ThreadFactory factory) throws Exception {
438 try (var scope = new StructuredTaskScope<String>(null, factory)) {
439 var interrupted = new CountDownLatch(1);
440 var finish = new CountDownLatch(1);
441
442 Subtask<String> subtask = scope.fork(() -> {
443 try {
444 Thread.sleep(Duration.ofDays(1));
445 } catch (InterruptedException e) {
446 interrupted.countDown();
447 }
448 finish.await();
449 return "foo";
450 });
451
452 scope.shutdown(); // should interrupt task
453
454 interrupted.await();
455
456 scope.join();
457
458 // signal task to finish
459 finish.countDown();
460 }
461 }
462
463 /**
464 * Test shutdown when owner is blocked in join.
465 */
466 @ParameterizedTest
467 @MethodSource("factories")
468 void testJoinWithShutdown2(ThreadFactory factory) throws Exception {
469 class MyScope<T> extends StructuredTaskScope<T> {
470 MyScope(ThreadFactory factory) {
471 super(null, factory);
472 }
473 @Override
474 protected void handleComplete(Subtask<? extends T> subtask) {
475 shutdown();
476 }
477 }
478
479 try (var scope = new MyScope<String>(factory)) {
480 Subtask<String> subtask1 = scope.fork(() -> {
481 Thread.sleep(Duration.ofMillis(50));
482 return "foo";
483 });
484 Subtask<String> subtask2 = scope.fork(() -> {
485 Thread.sleep(Duration.ofDays(1));
486 return "bar";
487 });
488
489 // join should wakeup when shutdown is called
490 scope.join();
491
492 // task1 should have completed successfully
493 assertEquals(Subtask.State.SUCCESS, subtask1.state());
494 assertEquals("foo", subtask1.get());
495 assertThrows(IllegalStateException.class, subtask1::exception);
496
497 // task2 result/exception not available
498 assertEquals(Subtask.State.UNAVAILABLE, subtask2.state());
499 assertThrows(IllegalStateException.class, subtask2::get);
500 assertThrows(IllegalStateException.class, subtask2::exception);
501 }
502 }
503
504 /**
505 * Test join after scope is closed.
506 */
507 @Test
508 void testJoinAfterClose() throws Exception {
509 try (var scope = new StructuredTaskScope()) {
510 scope.join();
511 scope.close();
512 assertThrows(IllegalStateException.class, () -> scope.join());
513 assertThrows(IllegalStateException.class, () -> scope.joinUntil(Instant.now()));
514 }
515 }
516
517 /**
518 * Test joinUntil, subtasks finish before deadline expires.
519 */
520 @ParameterizedTest
521 @MethodSource("factories")
522 void testJoinUntil1(ThreadFactory factory) throws Exception {
523 try (var scope = new StructuredTaskScope<String>(null, factory)) {
524 Subtask<String> subtask = scope.fork(() -> {
525 try {
526 Thread.sleep(Duration.ofSeconds(2));
527 } catch (InterruptedException e) { }
528 return "foo";
529 });
530
531 long startMillis = millisTime();
532 scope.joinUntil(Instant.now().plusSeconds(30));
533 expectDuration(startMillis, /*min*/1900, /*max*/20_000);
534 assertEquals("foo", subtask.get());
535 }
536 }
537
538 /**
539 * Test joinUntil, deadline expires before subtasks finish.
540 */
541 @ParameterizedTest
542 @MethodSource("factories")
543 void testJoinUntil2(ThreadFactory factory) throws Exception {
544 try (var scope = new StructuredTaskScope<Object>(null, factory)) {
545 Subtask<Void> subtask = scope.fork(() -> {
546 Thread.sleep(Duration.ofDays(1));
547 return null;
548 });
549
550 long startMillis = millisTime();
551 try {
552 scope.joinUntil(Instant.now().plusSeconds(2));
553 } catch (TimeoutException e) {
554 expectDuration(startMillis, /*min*/1900, /*max*/20_000);
555 }
556 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
557 }
558 }
559
560 /**
561 * Test joinUntil many times.
562 */
563 @ParameterizedTest
564 @MethodSource("factories")
565 void testJoinUntil3(ThreadFactory factory) throws Exception {
566 try (var scope = new StructuredTaskScope<String>(null, factory)) {
567 Subtask<String> subtask = scope.fork(() -> {
568 Thread.sleep(Duration.ofDays(1));
569 return null;
570 });
571
572 for (int i = 0; i < 3; i++) {
573 try {
574 scope.joinUntil(Instant.now().plusMillis(50));
575 fail("joinUntil did not throw");
576 } catch (TimeoutException expected) {
577 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
578 }
579 }
580 }
581 }
582
583 /**
584 * Test joinUntil with a deadline that has already expired.
585 */
586 @ParameterizedTest
587 @MethodSource("factories")
588 void testJoinUntil4(ThreadFactory factory) throws Exception {
589 try (var scope = new StructuredTaskScope<Object>(null, factory)) {
590 Subtask<Void> subtask = scope.fork(() -> {
591 Thread.sleep(Duration.ofDays(1));
592 return null;
593 });
594
595 // now
596 try {
597 scope.joinUntil(Instant.now());
598 fail("joinUntil did not throw");
599 } catch (TimeoutException expected) {
600 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
601 }
602
603 // in the past
604 try {
605 scope.joinUntil(Instant.now().minusSeconds(1));
606 fail("joinUntil did not throw");
607 } catch (TimeoutException expected) {
608 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
609 }
610 }
611 }
612
613 /**
614 * Test joinUntil with interrupt status set.
615 */
616 @ParameterizedTest
617 @MethodSource("factories")
618 void testInterruptJoinUntil1(ThreadFactory factory) throws Exception {
619 try (var scope = new StructuredTaskScope<String>(null, factory)) {
620 var latch = new CountDownLatch(1);
621
622 Subtask<String> subtask = scope.fork(() -> {
623 latch.await();
624 return "foo";
625 });
626
627 // joinUntil should throw
628 Thread.currentThread().interrupt();
629 try {
630 scope.joinUntil(Instant.now().plusSeconds(30));
631 fail("joinUntil did not throw");
632 } catch (InterruptedException expected) {
633 assertFalse(Thread.interrupted()); // interrupt status should be clear
634 } finally {
635 // let task continue
636 latch.countDown();
637 }
638
639 // join should complete
640 scope.join();
641 assertEquals("foo", subtask.get());
642 }
643 }
644
645 /**
646 * Test interrupt of thread blocked in joinUntil.
647 */
648 @ParameterizedTest
649 @MethodSource("factories")
650 void testInterruptJoinUntil2(ThreadFactory factory) throws Exception {
651 try (var scope = new StructuredTaskScope(null, factory)) {
652 var latch = new CountDownLatch(1);
653
654 Subtask<String> subtask = scope.fork(() -> {
655 latch.await();
656 return "foo";
657 });
658
659 // joinUntil should throw
660 scheduleInterruptAt("java.util.concurrent.StructuredTaskScope.joinUntil");
661 try {
662 scope.joinUntil(Instant.now().plusSeconds(30));
663 fail("joinUntil did not throw");
664 } catch (InterruptedException expected) {
665 assertFalse(Thread.interrupted()); // interrupt status should be clear
666 } finally {
667 // let task continue
668 latch.countDown();
669 }
670
671 // join should complete
672 scope.join();
673 assertEquals("foo", subtask.get());
674 }
675 }
676
677 /**
678 * Test that shutdown interrupts unfinished subtasks.
679 */
680 @ParameterizedTest
681 @MethodSource("factories")
682 void testShutdownInterruptsThreads1(ThreadFactory factory) throws Exception {
683 try (var scope = new StructuredTaskScope<Object>(null, factory)) {
684 var interrupted = new AtomicBoolean();
685 var latch = new CountDownLatch(1);
686 var subtask = scope.fork(() -> {
687 try {
688 Thread.sleep(Duration.ofDays(1));
689 } catch (InterruptedException e) {
690 interrupted.set(true);
691 } finally {
692 latch.countDown();
693 }
694 return null;
695 });
696
697 scope.shutdown();
698
699 // wait for task to complete
700 latch.await();
701 assertTrue(interrupted.get());
702
703 scope.join();
704
705 // subtask result/exception not available
706 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
707 assertThrows(IllegalStateException.class, subtask::get);
708 assertThrows(IllegalStateException.class, subtask::exception);
709 }
710 }
711
712 /**
713 * Test that shutdown does not interrupt current thread.
714 */
715 @ParameterizedTest
716 @MethodSource("factories")
717 void testShutdownInterruptsThreads2(ThreadFactory factory) throws Exception {
718 try (var scope = new StructuredTaskScope<Object>(null, factory)) {
719 var interrupted = new AtomicBoolean();
720 var latch = new CountDownLatch(1);
721 var subtask = scope.fork(() -> {
722 try {
723 scope.shutdown();
724 interrupted.set(Thread.currentThread().isInterrupted());
725 } finally {
726 latch.countDown();
727 }
728 return null;
729 });
730
731 // wait for task to complete
732 latch.await();
733 assertFalse(interrupted.get());
734
735 scope.join();
736 }
737 }
738
739 /**
740 * Test shutdown wakes join.
741 */
742 @ParameterizedTest
743 @MethodSource("factories")
744 void testShutdownWakesJoin(ThreadFactory factory) throws Exception {
745 try (var scope = new StructuredTaskScope<Object>(null, factory)) {
746 var latch = new CountDownLatch(1);
747 scope.fork(() -> {
748 Thread.sleep(Duration.ofMillis(100)); // give time for join to block
749 scope.shutdown();
750 latch.await();
751 return null;
752 });
753
754 scope.join();
755
756 // join woke up, allow task to complete
757 latch.countDown();
758 }
759 }
760
761 /**
762 * Test shutdown after scope is closed.
763 */
764 @Test
765 void testShutdownAfterClose() throws Exception {
766 try (var scope = new StructuredTaskScope<Object>()) {
767 scope.join();
768 scope.close();
769 assertThrows(IllegalStateException.class, scope::shutdown);
770 }
771 }
772
773 /**
774 * Test shutdown is confined to threads in the scope "tree".
775 */
776 @ParameterizedTest
777 @MethodSource("factories")
778 void testShutdownConfined(ThreadFactory factory) throws Exception {
779 try (var scope1 = new StructuredTaskScope<Boolean>();
780 var scope2 = new StructuredTaskScope<Boolean>()) {
781
782 // thread in scope1 cannot shutdown scope2
783 Subtask<Boolean> subtask1 = scope1.fork(() -> {
784 assertThrows(WrongThreadException.class, scope2::shutdown);
785 return true;
786 });
787
788 // wait for task in scope1 to complete to avoid racing with task in scope2
789 while (subtask1.state() == Subtask.State.UNAVAILABLE) {
790 Thread.sleep(10);
791 }
792
793 // thread in scope2 shutdown scope1
794 Subtask<Boolean> subtask2 = scope2.fork(() -> {
795 scope1.shutdown();
796 return true;
797 });
798
799 scope2.join();
800 scope1.join();
801
802 assertTrue(subtask1.get());
803 assertTrue(subtask1.get());
804
805 // random thread cannot shutdown
806 try (var pool = Executors.newSingleThreadExecutor()) {
807 Future<Void> future = pool.submit(() -> {
808 assertThrows(WrongThreadException.class, scope1::shutdown);
809 assertThrows(WrongThreadException.class, scope2::shutdown);
810 return null;
811 });
812 future.get();
813 }
814 }
815 }
816
817 /**
818 * Test isShutdown.
819 */
820 @Test
821 void testIsShutdown() {
822 try (var scope = new StructuredTaskScope<Object>()) {
823 assertFalse(scope.isShutdown()); // before shutdown
824 scope.shutdown();
825 assertTrue(scope.isShutdown()); // after shutdown
826 scope.close();
827 assertTrue(scope.isShutdown()); // after cose
828 }
829 }
830
831 /**
832 * Test close without join, no subtasks forked.
833 */
834 @Test
835 void testCloseWithoutJoin1() {
836 try (var scope = new StructuredTaskScope<Object>()) {
837 // do nothing
838 }
839 }
840
841 /**
842 * Test close without join, unfinished subtasks.
843 */
844 @ParameterizedTest
845 @MethodSource("factories")
846 void testCloseWithoutJoin2(ThreadFactory factory) {
847 try (var scope = new StructuredTaskScope<String>(null, factory)) {
848 Subtask<String> subtask = scope.fork(() -> {
849 Thread.sleep(Duration.ofDays(1));
850 return null;
851 });
852 assertThrows(IllegalStateException.class, scope::close);
853
854 // subtask result/exception not available
855 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
856 assertThrows(IllegalStateException.class, subtask::get);
857 assertThrows(IllegalStateException.class, subtask::exception);
858 }
859 }
860
861 /**
862 * Test close without join, unfinished subtasks forked after join.
863 */
864 @ParameterizedTest
865 @MethodSource("factories")
866 void testCloseWithoutJoin3(ThreadFactory factory) throws Exception {
867 try (var scope = new StructuredTaskScope(null, factory)) {
868 scope.fork(() -> "foo");
869 scope.join();
870
871 Subtask<String> subtask = scope.fork(() -> {
872 Thread.sleep(Duration.ofDays(1));
873 return null;
874 });
875 assertThrows(IllegalStateException.class, scope::close);
876
877 // subtask result/exception not available
878 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
879 assertThrows(IllegalStateException.class, subtask::get);
880 assertThrows(IllegalStateException.class, subtask::exception);
881 }
882 }
883
884 /**
885 * Test close after join throws. Close should not throw as join attempted.
886 */
887 @ParameterizedTest
888 @MethodSource("factories")
889 void testCloseAfterJoinThrows(ThreadFactory factory) throws Exception {
890 try (var scope = new StructuredTaskScope<Object>()) {
891 var subtask = scope.fork(() -> {
892 Thread.sleep(Duration.ofDays(1));
893 return null;
894 });
895
896 // join throws
897 Thread.currentThread().interrupt();
898 assertThrows(InterruptedException.class, scope::join);
899 assertThrows(IllegalStateException.class, subtask::get);
900 }
901 }
902
903 /**
904 * Test close after joinUntil throws. Close should not throw as join attempted.
905 */
906 @ParameterizedTest
907 @MethodSource("factories")
908 void testCloseAfterJoinUntilThrows(ThreadFactory factory) throws Exception {
909 try (var scope = new StructuredTaskScope<Object>()) {
910 var subtask = scope.fork(() -> {
911 Thread.sleep(Duration.ofDays(1));
912 return null;
913 });
914
915 // joinUntil throws
916 assertThrows(TimeoutException.class, () -> scope.joinUntil(Instant.now()));
917 assertThrows(IllegalStateException.class, subtask::get);
918 }
919 }
920
921 /**
922 * Test close is owner confined.
923 */
924 @ParameterizedTest
925 @MethodSource("factories")
926 void testCloseConfined(ThreadFactory factory) throws Exception {
927 try (var scope = new StructuredTaskScope<Boolean>()) {
928
929 // attempt to close from thread in scope
930 Subtask<Boolean> subtask = scope.fork(() -> {
931 assertThrows(WrongThreadException.class, scope::close);
932 return true;
933 });
934
935 scope.join();
936 assertTrue(subtask.get());
937
938 // random thread cannot close scope
939 try (var pool = Executors.newCachedThreadPool(factory)) {
940 Future<Boolean> future = pool.submit(() -> {
941 assertThrows(WrongThreadException.class, scope::close);
942 return null;
943 });
944 future.get();
945 }
946 }
947 }
948
949 /**
950 * Test close with interrupt status set.
951 */
952 @ParameterizedTest
953 @MethodSource("factories")
954 void testInterruptClose1(ThreadFactory factory) throws Exception {
955 try (var scope = new StructuredTaskScope<Object>(null, factory)) {
956 var done = new AtomicBoolean();
957 scope.fork(() -> {
958 try {
959 Thread.sleep(Duration.ofDays(1));
960 } catch (InterruptedException e) {
961 // interrupted by shutdown, expected
962 }
963 Thread.sleep(Duration.ofMillis(100)); // force close to wait
964 done.set(true);
965 return null;
966 });
967
968 scope.shutdown();
969 scope.join();
970
971 // invoke close with interrupt status set
972 Thread.currentThread().interrupt();
973 try {
974 scope.close();
975 } finally {
976 assertTrue(Thread.interrupted()); // clear interrupt status
977 assertTrue(done.get());
978 }
979 }
980 }
981
982 /**
983 * Test interrupting thread waiting in close.
984 */
985 @ParameterizedTest
986 @MethodSource("factories")
987 void testInterruptClose2(ThreadFactory factory) throws Exception {
988 try (var scope = new StructuredTaskScope<Object>(null, factory)) {
989 var done = new AtomicBoolean();
990 Thread mainThread = Thread.currentThread();
991 scope.fork(() -> {
992 try {
993 Thread.sleep(Duration.ofDays(1));
994 } catch (InterruptedException e) {
995 // interrupted by shutdown, expected
996 }
997
998 // interrupt main thread when it blocks in close
999 interruptThreadAt(mainThread, "java.util.concurrent.StructuredTaskScope.close");
1000
1001 Thread.sleep(Duration.ofMillis(100)); // force close to wait
1002 done.set(true);
1003 return null;
1004 });
1005
1006 scope.shutdown(); // interrupts task
1007 scope.join();
1008 try {
1009 scope.close();
1010 } finally {
1011 assertTrue(Thread.interrupted()); // clear interrupt status
1012 assertTrue(done.get());
1013 }
1014 }
1015 }
1016
1017 /**
1018 * Test that closing an enclosing scope closes the thread flock of a nested scope.
1019 */
1020 @Test
1021 void testCloseThrowsStructureViolation() throws Exception {
1022 try (var scope1 = new StructuredTaskScope<Object>()) {
1023 try (var scope2 = new StructuredTaskScope<Object>()) {
1024
1025 // join + close enclosing scope
1026 scope1.join();
1027 try {
1028 scope1.close();
1029 fail("close did not throw");
1030 } catch (StructureViolationException expected) { }
1031
1032 // underlying flock should be closed, fork should return a cancelled task
1033 var executed = new AtomicBoolean();
1034 Subtask<Void> subtask = scope2.fork(() -> {
1035 executed.set(true);
1036 return null;
1037 });
1038 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
1039 scope2.join();
1040 assertFalse(executed.get());
1041 }
1042 }
1043 }
1044
1045 /**
1046 * A StructuredTaskScope that collects the subtasks notified to the handleComplete method.
1047 */
1048 private static class CollectAll<T> extends StructuredTaskScope<T> {
1049 private final Set<Subtask<? extends T>> subtasks = ConcurrentHashMap.newKeySet();
1050
1051 CollectAll(ThreadFactory factory) {
1052 super(null, factory);
1053 }
1054
1055 @Override
1056 protected void handleComplete(Subtask<? extends T> subtask) {
1057 subtasks.add(subtask);
1058 }
1059
1060 Set<Subtask<? extends T>> subtasks() {
1061 return subtasks;
1062 }
1063
1064 Subtask<? extends T> find(Callable<T> task) {
1065 return subtasks.stream()
1066 .filter(h -> task.equals(h.task()))
1067 .findAny()
1068 .orElseThrow();
1069 }
1070 }
1071
1072 /**
1073 * Test that handleComplete method is invoked for tasks that complete before shutdown.
1074 */
1075 @ParameterizedTest
1076 @MethodSource("factories")
1077 void testHandleCompleteBeforeShutdown(ThreadFactory factory) throws Exception {
1078 try (var scope = new CollectAll<String>(factory)) {
1079 Callable<String> task1 = () -> "foo";
1080 Callable<String> task2 = () -> { throw new FooException(); };
1081 scope.fork(task1);
1082 scope.fork(task2);
1083 scope.join();
1084
1085 var subtask1 = scope.find(task1);
1086 assertEquals("foo", subtask1.get());
1087
1088 var subtask2 = scope.find(task2);
1089 assertTrue(subtask2.exception() instanceof FooException);
1090 }
1091 }
1092
1093 /**
1094 * Test that handleComplete method is not invoked for tasks that finish after shutdown
1095 * or are forked after shutdown.
1096 */
1097 @ParameterizedTest
1098 @MethodSource("factories")
1099 void testHandleCompleteAfterShutdown(ThreadFactory factory) throws Exception {
1100 try (var scope = new CollectAll<String>(factory)) {
1101 Callable<String> task1 = () -> {
1102 try {
1103 Thread.sleep(Duration.ofDays(1));
1104 } catch (InterruptedException ignore) { }
1105 return "foo";
1106 };
1107 Callable<String> task2 = () -> {
1108 Thread.sleep(Duration.ofDays(1));
1109 return "bar";
1110 };
1111 Callable<String> task3 = () -> "baz";
1112
1113 // forked before shutdown, will complete after shutdown
1114 var subtask1 = scope.fork(task1);
1115 var subtask2 = scope.fork(task2);
1116
1117 scope.shutdown();
1118
1119 // forked after shutdown
1120 var subtask3 = scope.fork(task3);
1121
1122 scope.join();
1123
1124 // handleComplete should not be called
1125 for (int i = 0; i < 3; i++) {
1126 assertEquals(0, scope.subtasks().size());
1127 Thread.sleep(20);
1128 }
1129
1130 assertEquals(Subtask.State.UNAVAILABLE, subtask1.state());
1131 assertEquals(Subtask.State.UNAVAILABLE, subtask2.state());
1132 assertEquals(Subtask.State.UNAVAILABLE, subtask3.state());
1133 }
1134 }
1135
1136 /**
1137 * Test that the default handleComplete throws IllegalArgumentException if called
1138 * with a running task.
1139 */
1140 @Test
1141 void testHandleCompleteThrows() throws Exception {
1142 class TestScope<T> extends StructuredTaskScope<T> {
1143 protected void handleComplete(Subtask<? extends T> subtask) {
1144 super.handleComplete(subtask);
1145 }
1146 }
1147
1148 try (var scope = new TestScope<String>()) {
1149 var subtask = scope.fork(() -> {
1150 Thread.sleep(Duration.ofDays(1));
1151 return "foo";
1152 });
1153
1154 // running task
1155 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
1156 assertThrows(IllegalArgumentException.class, () -> scope.handleComplete(subtask));
1157 scope.shutdown();
1158
1159 // null task
1160 assertThrows(NullPointerException.class, () -> scope.handleComplete(null));
1161
1162 scope.join();
1163 }
1164 }
1165
1166 /**
1167 * Test ensureOwnerAndJoined.
1168 */
1169 @ParameterizedTest
1170 @MethodSource("factories")
1171 void testEnsureOwnerAndJoined(ThreadFactory factory) throws Exception {
1172 class MyScope<T> extends StructuredTaskScope<T> {
1173 MyScope(ThreadFactory factory) {
1174 super(null, factory);
1175 }
1176 void invokeEnsureOwnerAndJoined() {
1177 super.ensureOwnerAndJoined();
1178 }
1179 }
1180
1181 try (var scope = new MyScope<Boolean>(factory)) {
1182 // owner thread, before join
1183 scope.fork(() -> true);
1184 assertThrows(IllegalStateException.class, () -> {
1185 scope.invokeEnsureOwnerAndJoined();
1186 });
1187
1188 // owner thread, after join
1189 scope.join();
1190 scope.invokeEnsureOwnerAndJoined();
1191
1192 // thread in scope cannot invoke ensureOwnerAndJoined
1193 Subtask<Boolean> subtask = scope.fork(() -> {
1194 assertThrows(WrongThreadException.class, () -> {
1195 scope.invokeEnsureOwnerAndJoined();
1196 });
1197 return true;
1198 });
1199 scope.join();
1200 assertTrue(subtask.get());
1201
1202 // random thread cannot invoke ensureOwnerAndJoined
1203 try (var pool = Executors.newSingleThreadExecutor()) {
1204 Future<Void> future = pool.submit(() -> {
1205 assertThrows(WrongThreadException.class, () -> {
1206 scope.invokeEnsureOwnerAndJoined();
1207 });
1208 return null;
1209 });
1210 future.get();
1211 }
1212 }
1213 }
1214
1215 /**
1216 * Test ensureOwnerAndJoined after the task scope has been closed.
1217 */
1218 @ParameterizedTest
1219 @MethodSource("factories")
1220 void testEnsureOwnerAndJoinedAfterClose(ThreadFactory factory) throws Exception {
1221 class MyScope<T> extends StructuredTaskScope<T> {
1222 MyScope(ThreadFactory factory) {
1223 super(null, factory);
1224 }
1225 public void invokeEnsureOwnerAndJoined() {
1226 super.ensureOwnerAndJoined();
1227 }
1228 }
1229
1230 // ensureOwnerAndJoined after close, join invoked
1231 try (var scope = new MyScope<String>(factory)) {
1232 scope.fork(() -> "foo");
1233 scope.join();
1234 scope.close();
1235 scope.invokeEnsureOwnerAndJoined(); // should not throw
1236 }
1237
1238 // ensureOwnerAndJoined after close, join not invoked
1239 try (var scope = new MyScope<String>(factory)) {
1240 scope.fork(() -> "foo");
1241 assertThrows(IllegalStateException.class, scope::close);
1242 scope.invokeEnsureOwnerAndJoined(); // should not throw
1243 }
1244 }
1245
1246
1247 /**
1248 * Test toString.
1249 */
1250 @Test
1251 void testToString() throws Exception {
1252 ThreadFactory factory = Thread.ofVirtual().factory();
1253 try (var scope = new StructuredTaskScope<Object>("duke", factory)) {
1254 // open
1255 assertTrue(scope.toString().contains("duke"));
1256
1257 // shutdown
1258 scope.shutdown();
1259 assertTrue(scope.toString().contains("duke"));
1260
1261 // closed
1262 scope.join();
1263 scope.close();
1264 assertTrue(scope.toString().contains("duke"));
1265 }
1266 }
1267
1268 /**
1269 * Test Subtask with task that completes successfully.
1270 */
1271 @ParameterizedTest
1272 @MethodSource("factories")
1273 void testSubtaskWhenSuccess(ThreadFactory factory) throws Exception {
1274 try (var scope = new StructuredTaskScope<String>(null, factory)) {
1275 Callable<String> task = () -> "foo";
1276 Subtask<String> subtask = scope.fork(task);
1277
1278 // before join, owner thread
1279 assertEquals(task, subtask.task());
1280 assertThrows(IllegalStateException.class, subtask::get);
1281 assertThrows(IllegalStateException.class, subtask::exception);
1282
1283 scope.join();
1284
1285 // after join
1286 assertEquals(task, subtask.task());
1287 assertEquals(Subtask.State.SUCCESS, subtask.state());
1288 assertEquals("foo", subtask.get());
1289 assertThrows(IllegalStateException.class, subtask::exception);
1290 }
1291 }
1292
1293 /**
1294 * Test Subtask with task that fails.
1295 */
1296 @ParameterizedTest
1297 @MethodSource("factories")
1298 void testSubtaskWhenFailed(ThreadFactory factory) throws Exception {
1299 try (var scope = new StructuredTaskScope<String>(null, factory)) {
1300 Callable<String> task = () -> { throw new FooException(); };
1301 Subtask<String> subtask = scope.fork(task);
1302
1303 // before join, owner thread
1304 assertEquals(task, subtask.task());
1305 assertThrows(IllegalStateException.class, subtask::get);
1306 assertThrows(IllegalStateException.class, subtask::exception);
1307
1308 scope.join();
1309
1310 // after join
1311 assertEquals(task, subtask.task());
1312 assertEquals(Subtask.State.FAILED, subtask.state());
1313 assertThrows(IllegalStateException.class, subtask::get);
1314 assertTrue(subtask.exception() instanceof FooException);
1315 }
1316 }
1317
1318 /**
1319 * Test Subtask with a task that has not completed.
1320 */
1321 @ParameterizedTest
1322 @MethodSource("factories")
1323 void testSubtaskWhenNotCompleted(ThreadFactory factory) throws Exception {
1324 try (var scope = new StructuredTaskScope<Object>(null, factory)) {
1325 Callable<Void> task = () -> {
1326 Thread.sleep(Duration.ofDays(1));
1327 return null;
1328 };
1329 Subtask<Void> subtask = scope.fork(task);
1330
1331 // before join
1332 assertEquals(task, subtask.task());
1333 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
1334 assertThrows(IllegalStateException.class, subtask::get);
1335 assertThrows(IllegalStateException.class, subtask::exception);
1336
1337 // attempt join, join throws
1338 Thread.currentThread().interrupt();
1339 assertThrows(InterruptedException.class, scope::join);
1340
1341 // after join
1342 assertEquals(task, subtask.task());
1343 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
1344 assertThrows(IllegalStateException.class, subtask::get);
1345 assertThrows(IllegalStateException.class, subtask::exception);
1346 }
1347 }
1348
1349 /**
1350 * Test Subtask when forked after shutdown.
1351 */
1352 @ParameterizedTest
1353 @MethodSource("factories")
1354 void testSubtaskWhenShutdown(ThreadFactory factory) throws Exception {
1355 try (var scope = new StructuredTaskScope<Object>(null, factory)) {
1356 Callable<Void> task = () -> {
1357 Thread.sleep(Duration.ofDays(1));
1358 return null;
1359 };
1360
1361 scope.shutdown();
1362
1363 // fork after shutdown
1364 Subtask<Void> subtask = scope.fork(task);
1365 scope.join();
1366 assertEquals(task, subtask.task());
1367 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
1368 assertThrows(IllegalStateException.class, subtask::get);
1369 assertThrows(IllegalStateException.class, subtask::exception);
1370 }
1371 }
1372
1373 /**
1374 * Test Subtask::toString.
1375 */
1376 @Test
1377 void testSubtaskToString() throws Exception {
1378 try (var scope = new StructuredTaskScope<Object>()) {
1379 // success
1380 var subtask1 = scope.fork(() -> "foo");
1381 scope.join();
1382 assertTrue(subtask1.toString().contains("Completed successfully"));
1383
1384 // failed
1385 var subtask2 = scope.fork(() -> { throw new FooException(); });
1386 scope.join();
1387 assertTrue(subtask2.toString().contains("Failed"));
1388
1389 // not completed
1390 Callable<Void> sleepForDay = () -> {
1391 Thread.sleep(Duration.ofDays(1));
1392 return null;
1393 };
1394 var subtask3 = scope.fork(sleepForDay);
1395 assertTrue(subtask3.toString().contains("Unavailable"));
1396
1397 scope.shutdown();
1398
1399 // forked after shutdown
1400 var subtask4 = scope.fork(sleepForDay);
1401 assertTrue(subtask4.toString().contains("Unavailable"));
1402
1403 scope.join();
1404 }
1405 }
1406
1407 /**
1408 * Test ShutdownOnSuccess with no completed tasks.
1409 */
1410 @Test
1411 void testShutdownOnSuccess1() throws Exception {
1412 try (var scope = new ShutdownOnSuccess<Object>()) {
1413 assertThrows(IllegalStateException.class, () -> scope.result());
1414 assertThrows(IllegalStateException.class, () -> scope.result(e -> null));
1415 }
1416 }
1417
1418 /**
1419 * Test ShutdownOnSuccess with tasks that complete successfully.
1420 */
1421 @ParameterizedTest
1422 @MethodSource("factories")
1423 void testShutdownOnSuccess2(ThreadFactory factory) throws Exception {
1424 try (var scope = new ShutdownOnSuccess<String>(null, factory)) {
1425 scope.fork(() -> "foo");
1426 scope.join(); // ensures foo completes first
1427 scope.fork(() -> "bar");
1428 scope.join();
1429 assertEquals("foo", scope.result());
1430 assertEquals("foo", scope.result(e -> null));
1431 }
1432 }
1433
1434 /**
1435 * Test ShutdownOnSuccess with a task that completes successfully with a null result.
1436 */
1437 @ParameterizedTest
1438 @MethodSource("factories")
1439 void testShutdownOnSuccess3(ThreadFactory factory) throws Exception {
1440 try (var scope = new ShutdownOnSuccess<Object>(null, factory)) {
1441 scope.fork(() -> null);
1442 scope.join();
1443 assertNull(scope.result());
1444 assertNull(scope.result(e -> null));
1445 }
1446 }
1447
1448 /**
1449 * Test ShutdownOnSuccess with tasks that complete succcessfully and tasks that fail.
1450 */
1451 @ParameterizedTest
1452 @MethodSource("factories")
1453 void testShutdownOnSuccess4(ThreadFactory factory) throws Exception {
1454 try (var scope = new ShutdownOnSuccess<String>(null, factory)) {
1455 scope.fork(() -> "foo");
1456 scope.fork(() -> { throw new ArithmeticException(); });
1457 scope.join();
1458 assertEquals("foo", scope.result());
1459 assertEquals("foo", scope.result(e -> null));
1460 }
1461 }
1462
1463 /**
1464 * Test ShutdownOnSuccess with a task that fails.
1465 */
1466 @ParameterizedTest
1467 @MethodSource("factories")
1468 void testShutdownOnSuccess5(ThreadFactory factory) throws Exception {
1469 try (var scope = new ShutdownOnSuccess<Object>(null, factory)) {
1470 scope.fork(() -> { throw new ArithmeticException(); });
1471 scope.join();
1472 Throwable ex = assertThrows(ExecutionException.class, () -> scope.result());
1473 assertTrue(ex.getCause() instanceof ArithmeticException);
1474 ex = assertThrows(FooException.class, () -> scope.result(e -> new FooException(e)));
1475 assertTrue(ex.getCause() instanceof ArithmeticException);
1476 }
1477 }
1478
1479 /**
1480 * Test ShutdownOnSuccess methods are confined to the owner.
1481 */
1482 @ParameterizedTest
1483 @MethodSource("factories")
1484 void testShutdownOnSuccessConfined(ThreadFactory factory) throws Exception {
1485 // owner before join
1486 try (var scope = new ShutdownOnSuccess<Boolean>(null, factory)) {
1487 scope.fork(() -> { throw new FooException(); });
1488 assertThrows(IllegalStateException.class, scope::result);
1489 assertThrows(IllegalStateException.class, () -> {
1490 scope.result(e -> new RuntimeException(e));
1491 });
1492 scope.join();
1493 }
1494
1495 // non-owner
1496 try (var scope = new ShutdownOnSuccess<Boolean>(null, factory)) {
1497 Subtask<Boolean> subtask = scope.fork(() -> {
1498 assertThrows(WrongThreadException.class, scope::result);
1499 assertThrows(WrongThreadException.class, () -> {
1500 scope.result(e -> new RuntimeException(e));
1501 });
1502 return true;
1503 });
1504 scope.join();
1505 assertTrue(subtask.get());
1506 }
1507 }
1508
1509 /**
1510 * Test ShutdownOnFailure with no completed tasks.
1511 */
1512 @Test
1513 void testShutdownOnFailure1() throws Throwable {
1514 try (var scope = new ShutdownOnFailure()) {
1515 assertTrue(scope.exception().isEmpty());
1516 scope.throwIfFailed();
1517 scope.throwIfFailed(e -> new FooException(e));
1518 }
1519 }
1520
1521 /**
1522 * Test ShutdownOnFailure with tasks that complete successfully.
1523 */
1524 @ParameterizedTest
1525 @MethodSource("factories")
1526 void testShutdownOnFailure2(ThreadFactory factory) throws Throwable {
1527 try (var scope = new ShutdownOnFailure(null, factory)) {
1528 scope.fork(() -> "foo");
1529 scope.fork(() -> "bar");
1530 scope.join();
1531
1532 // no exception
1533 assertTrue(scope.exception().isEmpty());
1534 scope.throwIfFailed();
1535 scope.throwIfFailed(e -> new FooException(e));
1536 }
1537 }
1538
1539 /**
1540 * Test ShutdownOnFailure with tasks that complete succcessfully and tasks that fail.
1541 */
1542 @ParameterizedTest
1543 @MethodSource("factories")
1544 void testShutdownOnFailure3(ThreadFactory factory) throws Throwable {
1545 try (var scope = new ShutdownOnFailure(null, factory)) {
1546
1547 // one task completes successfully, the other fails
1548 scope.fork(() -> "foo");
1549 scope.fork(() -> { throw new ArithmeticException(); });
1550 scope.join();
1551
1552 Throwable ex = scope.exception().orElse(null);
1553 assertTrue(ex instanceof ArithmeticException);
1554
1555 ex = assertThrows(ExecutionException.class, () -> scope.throwIfFailed());
1556 assertTrue(ex.getCause() instanceof ArithmeticException);
1557
1558 ex = assertThrows(FooException.class,
1559 () -> scope.throwIfFailed(e -> new FooException(e)));
1560 assertTrue(ex.getCause() instanceof ArithmeticException);
1561 }
1562 }
1563
1564 /**
1565 * Test ShutdownOnFailure methods are confined to the owner.
1566 */
1567 @ParameterizedTest
1568 @MethodSource("factories")
1569 void testShutdownOnFailureConfined(ThreadFactory factory) throws Exception {
1570 // owner before join
1571 try (var scope = new ShutdownOnFailure(null, factory)) {
1572 scope.fork(() -> "foo");
1573 assertThrows(IllegalStateException.class, scope::exception);
1574 assertThrows(IllegalStateException.class, scope::throwIfFailed);
1575 assertThrows(IllegalStateException.class, () -> {
1576 scope.throwIfFailed(e -> new RuntimeException(e));
1577 });
1578 scope.join();
1579 }
1580
1581 // non-owner
1582 try (var scope = new ShutdownOnFailure(null, factory)) {
1583 Subtask<Boolean> subtask = scope.fork(() -> {
1584 assertThrows(WrongThreadException.class, scope::exception);
1585 assertThrows(WrongThreadException.class, scope::throwIfFailed);
1586 assertThrows(WrongThreadException.class, () -> {
1587 scope.throwIfFailed(e -> new RuntimeException(e));
1588 });
1589 return true;
1590 });
1591 scope.join();
1592 assertTrue(subtask.get());
1593 }
1594 }
1595
1596 /**
1597 * Test for NullPointerException.
1598 */
1599 @Test
1600 void testNulls() throws Exception {
1601 assertThrows(NullPointerException.class, () -> new StructuredTaskScope("", null));
1602 try (var scope = new StructuredTaskScope<Object>()) {
1603 assertThrows(NullPointerException.class, () -> scope.fork(null));
1604 assertThrows(NullPointerException.class, () -> scope.joinUntil(null));
1605 }
1606
1607 assertThrows(NullPointerException.class, () -> new ShutdownOnSuccess<Object>("", null));
1608 try (var scope = new ShutdownOnSuccess<Object>()) {
1609 assertThrows(NullPointerException.class, () -> scope.fork(null));
1610 assertThrows(NullPointerException.class, () -> scope.joinUntil(null));
1611 assertThrows(NullPointerException.class, () -> scope.result(null));
1612 }
1613
1614 assertThrows(NullPointerException.class, () -> new ShutdownOnFailure("", null));
1615 try (var scope = new ShutdownOnFailure()) {
1616 assertThrows(NullPointerException.class, () -> scope.fork(null));
1617 assertThrows(NullPointerException.class, () -> scope.joinUntil(null));
1618 assertThrows(NullPointerException.class, () -> scope.throwIfFailed(null));
1619 }
1620 }
1621
1622 /**
1623 * A runtime exception for tests.
1624 */
1625 private static class FooException extends RuntimeException {
1626 FooException() { }
1627 FooException(Throwable cause) { super(cause); }
1628 }
1629
1630 /**
1631 * Returns the current time in milliseconds.
1632 */
1633 private long millisTime() {
1634 long now = System.nanoTime();
1635 return TimeUnit.MILLISECONDS.convert(now, TimeUnit.NANOSECONDS);
1636 }
1637
1638 /**
|
1 /*
2 * Copyright (c) 2021, 2024, 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.ExecutionException;
49 import java.util.concurrent.Future;
50 import java.util.concurrent.LinkedTransferQueue;
51 import java.util.concurrent.ThreadFactory;
52 import java.util.concurrent.TimeoutException;
53 import java.util.concurrent.TimeUnit;
54 import java.util.concurrent.RejectedExecutionException;
55 import java.util.concurrent.ScheduledExecutorService;
56 import java.util.concurrent.StructuredTaskScope;
57 import java.util.concurrent.StructuredTaskScope.Config;
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.function.Function;
64 import java.util.function.Predicate;
65 import java.util.stream.Stream;
66 import static java.lang.Thread.State.*;
67
68 import org.junit.jupiter.api.Test;
69 import org.junit.jupiter.api.BeforeAll;
70 import org.junit.jupiter.api.AfterAll;
71 import org.junit.jupiter.params.ParameterizedTest;
72 import org.junit.jupiter.params.provider.MethodSource;
73 import static org.junit.jupiter.api.Assertions.*;
74
75 class StructuredTaskScopeTest {
76 private static ScheduledExecutorService scheduler;
77 private static List<ThreadFactory> threadFactories;
78
79 @BeforeAll
80 static void setup() throws Exception {
81 scheduler = Executors.newSingleThreadScheduledExecutor();
82
83 // thread factories
84 String value = System.getProperty("threadFactory");
85 List<ThreadFactory> list = new ArrayList<>();
86 if (value == null || value.equals("platform"))
87 list.add(Thread.ofPlatform().factory());
88 if (value == null || value.equals("virtual"))
89 list.add(Thread.ofVirtual().factory());
90 assertTrue(list.size() > 0, "No thread factories for tests");
91 threadFactories = list;
92 }
93
94 @AfterAll
95 static void shutdown() {
96 scheduler.shutdown();
97 }
98
99 private static Stream<ThreadFactory> factories() {
100 return threadFactories.stream();
101 }
102
103 /**
104 * Test that fork creates virtual threads when no ThreadFactory is configured.
105 */
106 @Test
107 void testForkCreateVirtualThread() throws Exception {
108 Set<Thread> threads = ConcurrentHashMap.newKeySet();
109 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
110 for (int i = 0; i < 50; i++) {
111 // runnable
112 scope.fork(() -> {
113 threads.add(Thread.currentThread());
114 });
115
116 // callable
117 scope.fork(() -> {
118 threads.add(Thread.currentThread());
119 return null;
120 });
121 }
122 scope.join();
123 }
124 assertEquals(100, threads.size());
125 threads.forEach(t -> assertTrue(t.isVirtual()));
126 }
127
128 /**
129 * Test that fork create threads with the configured ThreadFactory.
130 */
131 @ParameterizedTest
132 @MethodSource("factories")
133 void testForkUsesThreadFactory(ThreadFactory factory) throws Exception {
134 // TheadFactory that keeps reference to all threads it creates
135 class RecordingThreadFactory implements ThreadFactory {
136 final ThreadFactory delegate;
137 final Set<Thread> threads = ConcurrentHashMap.newKeySet();
138 RecordingThreadFactory(ThreadFactory delegate) {
139 this.delegate = delegate;
140 }
141 @Override
142 public Thread newThread(Runnable task) {
143 Thread thread = delegate.newThread(task);
144 threads.add(thread);
145 return thread;
146 }
147 Set<Thread> threads() {
148 return threads;
149 }
150 }
151 var recordingThreadFactory = new RecordingThreadFactory(factory);
152 Set<Thread> threads = ConcurrentHashMap.newKeySet();
153 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
154 cf -> cf.withThreadFactory(recordingThreadFactory))) {
155
156 for (int i = 0; i < 50; i++) {
157 // runnable
158 scope.fork(() -> {
159 threads.add(Thread.currentThread());
160 });
161
162 // callable
163 scope.fork(() -> {
164 threads.add(Thread.currentThread());
165 return null;
166 });
167 }
168 scope.join();
169 }
170 assertEquals(100, threads.size());
171 assertEquals(recordingThreadFactory.threads(), threads);
172 }
173
174 /**
175 * Test fork method is owner confined.
176 */
177 @ParameterizedTest
178 @MethodSource("factories")
179 void testForkConfined(ThreadFactory factory) throws Exception {
180 try (var scope = StructuredTaskScope.open(Joiner.<Boolean>awaitAll(),
181 cf -> cf.withThreadFactory(factory))) {
182
183 // random thread cannot fork
184 try (var pool = Executors.newSingleThreadExecutor()) {
185 Future<Void> future = pool.submit(() -> {
186 assertThrows(WrongThreadException.class, () -> {
187 scope.fork(() -> null);
188 });
189 return null;
190 });
191 future.get();
192 }
193
194 // subtask cannot fork
195 Subtask<Boolean> subtask = scope.fork(() -> {
196 assertThrows(WrongThreadException.class, () -> {
197 scope.fork(() -> null);
198 });
199 return true;
200 });
201 scope.join();
202 assertTrue(subtask.get());
203 }
204 }
205
206 /**
207 * Test fork after join, no subtasks forked before join.
208 */
209 @ParameterizedTest
210 @MethodSource("factories")
211 void testForkAfterJoin1(ThreadFactory factory) throws Exception {
212 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
213 cf -> cf.withThreadFactory(factory))) {
214 scope.join();
215 assertThrows(IllegalStateException.class, () -> scope.fork(() -> "bar"));
216 }
217 }
218
219 /**
220 * Test fork after join, subtasks forked before join.
221 */
222 @ParameterizedTest
223 @MethodSource("factories")
224 void testForkAfterJoin2(ThreadFactory factory) throws Exception {
225 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
226 cf -> cf.withThreadFactory(factory))) {
227 scope.fork(() -> "foo");
228 scope.join();
229 assertThrows(IllegalStateException.class, () -> scope.fork(() -> "bar"));
230 }
231 }
232
233 /**
234 * Test fork after join throws.
235 */
236 @ParameterizedTest
237 @MethodSource("factories")
238 void testForkAfterJoinThrows(ThreadFactory factory) throws Exception {
239 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
240 cf -> cf.withThreadFactory(factory))) {
241 var latch = new CountDownLatch(1);
242 var subtask1 = scope.fork(() -> {
243 latch.await();
244 return "foo";
245 });
246
247 // join throws
248 Thread.currentThread().interrupt();
249 assertThrows(InterruptedException.class, scope::join);
250
251 // allow subtask1 to finish
252 latch.countDown();
253
254 // continue to fork
255 var subtask2 = scope.fork(() -> "bar");
256 scope.join();
257 assertEquals("foo", subtask1.get());
258 assertEquals("bar", subtask2.get());
259 }
260 }
261
262 /**
263 * Test fork after task scope is cancelled. This test uses the cancel method to
264 * cancel execution explicitly.
265 */
266 @ParameterizedTest
267 @MethodSource("factories")
268 void testForkAfterCancel1(ThreadFactory factory) throws Exception {
269 var countingThreadFactory = new CountingThreadFactory(factory);
270 var testJoiner = new CountingJoiner<String>();
271
272 try (var scope = StructuredTaskScope.open(testJoiner,
273 cf -> cf.withThreadFactory(countingThreadFactory))) {
274
275 scope.cancel();
276
277 // fork subtask
278 var subtask = scope.fork(() -> "foo");
279
280 assertEquals(0, countingThreadFactory.threadCount());
281 assertEquals(1, testJoiner.onForkCount());
282 assertEquals(0, testJoiner.onCompleteCount());
283
284 scope.join();
285
286 assertEquals(0, countingThreadFactory.threadCount());
287 assertEquals(1, testJoiner.onForkCount());
288 assertEquals(0, testJoiner.onCompleteCount());
289
290 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
291 }
292 }
293
294
295 /**
296 * Test fork after task scope is cancelled. This test uses a custom Joiner to
297 * cancel execution.
298 */
299 @ParameterizedTest
300 @MethodSource("factories")
301 void testForkAfterCancel2(ThreadFactory factory) throws Exception {
302 var countingThreadFactory = new CountingThreadFactory(factory);
303 var testJoiner = new CancelAfterOneJoiner<String>();
304
305 try (var scope = StructuredTaskScope.open(testJoiner,
306 cf -> cf.withThreadFactory(countingThreadFactory))) {
307
308 // fork subtask, the scope should be cancelled when the subtask completes
309 var subtask1 = scope.fork(() -> "foo");
310 while (!scope.isCancelled()) {
311 Thread.sleep(20);
312 }
313
314 assertEquals(1, countingThreadFactory.threadCount());
315 assertEquals(1, testJoiner.onForkCount());
316 assertEquals(1, testJoiner.onCompleteCount());
317
318 // fork second subtask, it should not run
319 var subtask2 = scope.fork(() -> "bar");
320
321 // onFork should be invoked, newThread and onComplete should not be invoked
322 assertEquals(1, countingThreadFactory.threadCount());
323 assertEquals(2, testJoiner.onForkCount());
324 assertEquals(1, testJoiner.onCompleteCount());
325
326 scope.join();
327
328 assertEquals(1, countingThreadFactory.threadCount());
329 assertEquals(2, testJoiner.onForkCount());
330 assertEquals(1, testJoiner.onCompleteCount());
331 assertEquals("foo", subtask1.get());
332 assertEquals(Subtask.State.UNAVAILABLE, subtask2.state());
333 }
334 }
335
336 /**
337 * Test fork after task scope is closed.
338 */
339 @Test
340 void testForkAfterClose() {
341 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
342 scope.close();
343 assertThrows(IllegalStateException.class, () -> scope.fork(() -> null));
344 }
345 }
346
347 /**
348 * Test fork when the ThreadFactory rejects creating a thread.
349 */
350 @Test
351 void testForkRejectedExecutionException() {
352 ThreadFactory factory = task -> null;
353 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
354 cf -> cf.withThreadFactory(factory))) {
355 assertThrows(RejectedExecutionException.class, () -> scope.fork(() -> null));
356 }
357 }
358
359 /**
360 * Test join with no subtasks.
361 */
362 @Test
363 void testJoinWithNoSubtasks() throws Exception {
364 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
365 scope.join();
366 }
367 }
368
369 /**
370 * Test join with a remaining subtask.
371 */
372 @ParameterizedTest
373 @MethodSource("factories")
374 void testJoinWithRemainingSubtasks(ThreadFactory factory) throws Exception {
375 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
376 cf -> cf.withThreadFactory(factory))) {
377 Subtask<String> subtask = scope.fork(() -> {
378 Thread.sleep(Duration.ofMillis(100));
379 return "foo";
380 });
381 scope.join();
382 assertEquals("foo", subtask.get());
383 }
384 }
385
386 /**
387 * Test repeated calls to join.
388 */
389 @Test
390 void testJoinAfterJoin() throws Exception {
391 var results = new LinkedTransferQueue<>(List.of("foo", "bar", "baz"));
392 Joiner<Object, String> joiner = results::take;
393 try (var scope = StructuredTaskScope.open(joiner)) {
394 scope.fork(() -> "foo");
395
396 // each call to join should invoke Joiner::result
397 assertEquals("foo", scope.join());
398 assertEquals("bar", scope.join());
399 assertEquals("baz", scope.join());
400 }
401 }
402
403 /**
404 * Test join method is owner confined.
405 */
406 @ParameterizedTest
407 @MethodSource("factories")
408 void testJoinConfined(ThreadFactory factory) throws Exception {
409 try (var scope = StructuredTaskScope.open(Joiner.<Boolean>awaitAll(),
410 cf -> cf.withThreadFactory(factory))) {
411
412 // random thread cannot join
413 try (var pool = Executors.newSingleThreadExecutor()) {
414 Future<Void> future = pool.submit(() -> {
415 assertThrows(WrongThreadException.class, scope::join);
416 return null;
417 });
418 future.get();
419 }
420
421 // subtask cannot join
422 Subtask<Boolean> subtask = scope.fork(() -> {
423 assertThrows(WrongThreadException.class, () -> { scope.join(); });
424 return true;
425 });
426 scope.join();
427 assertTrue(subtask.get());
428 }
429 }
430
431 /**
432 * Test join with interrupt status set.
433 */
434 @ParameterizedTest
435 @MethodSource("factories")
436 void testInterruptJoin1(ThreadFactory factory) throws Exception {
437 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
438 cf -> cf.withThreadFactory(factory))) {
439
440 var latch = new CountDownLatch(1);
441
442 Subtask<String> subtask = scope.fork(() -> {
443 latch.await();
444 return "foo";
445 });
446
447 // join should throw
448 Thread.currentThread().interrupt();
449 try {
450 scope.join();
451 fail("join did not throw");
452 } catch (InterruptedException expected) {
453 assertFalse(Thread.interrupted()); // interrupt status should be cleared
454 } finally {
455 // let task continue
456 latch.countDown();
457 }
458
459 // join should complete
460 scope.join();
461 assertEquals("foo", subtask.get());
462 }
463 }
464
465 /**
466 * Test interrupt of thread blocked in join.
467 */
468 @ParameterizedTest
469 @MethodSource("factories")
470 void testInterruptJoin2(ThreadFactory factory) throws Exception {
471 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
472 cf -> cf.withThreadFactory(factory))) {
473
474 var latch = new CountDownLatch(1);
475 Subtask<String> subtask = scope.fork(() -> {
476 latch.await();
477 return "foo";
478 });
479
480 // join should throw
481 scheduleInterruptAt("java.util.concurrent.StructuredTaskScope.join");
482 try {
483 scope.join();
484 fail("join did not throw");
485 } catch (InterruptedException expected) {
486 assertFalse(Thread.interrupted()); // interrupt status should be clear
487 } finally {
488 // let task continue
489 latch.countDown();
490 }
491
492 // join should complete
493 scope.join();
494 assertEquals("foo", subtask.get());
495 }
496 }
497
498 /**
499 * Test join when scope is cancelled.
500 */
501 @ParameterizedTest
502 @MethodSource("factories")
503 void testJoinWhenCancelled(ThreadFactory factory) throws Exception {
504 var countingThreadFactory = new CountingThreadFactory(factory);
505 var testJoiner = new CancelAfterOneJoiner<String>();
506
507 try (var scope = StructuredTaskScope.open(testJoiner,
508 cf -> cf.withThreadFactory(countingThreadFactory))) {
509
510 // fork subtask, the scope should be cancelled when the subtask completes
511 var subtask1 = scope.fork(() -> "foo");
512 while (!scope.isCancelled()) {
513 Thread.sleep(20);
514 }
515
516 // fork second subtask, it should not run
517 var subtask2 = scope.fork(() -> {
518 Thread.sleep(Duration.ofDays(1));
519 return "bar";
520 });
521
522 scope.join();
523
524 assertEquals("foo", subtask1.get());
525 assertEquals(Subtask.State.UNAVAILABLE, subtask2.state());
526 }
527 }
528
529 /**
530 * Test join after scope is closed.
531 */
532 @Test
533 void testJoinAfterClose() throws Exception {
534 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
535 scope.close();
536 assertThrows(IllegalStateException.class, () -> scope.join());
537 }
538 }
539
540 /**
541 * Test join with timeout, subtasks finish before timeout expires.
542 */
543 @ParameterizedTest
544 @MethodSource("factories")
545 void testJoinWithTimeout1(ThreadFactory factory) throws Exception {
546 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
547 cf -> cf.withThreadFactory(factory)
548 .withTimeout(Duration.ofDays(1)))) {
549
550 Subtask<String> subtask = scope.fork(() -> {
551 Thread.sleep(Duration.ofSeconds(1));
552 return "foo";
553 });
554
555 scope.join();
556
557 assertFalse(scope.isCancelled());
558 assertEquals("foo", subtask.get());
559 }
560 }
561
562 /**
563 * Test join with timeout, timeout expires before subtasks finish.
564 */
565 @ParameterizedTest
566 @MethodSource("factories")
567 void testJoinWithTimeout2(ThreadFactory factory) throws Exception {
568 long startMillis = millisTime();
569 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
570 cf -> cf.withThreadFactory(factory)
571 .withTimeout(Duration.ofSeconds(2)))) {
572
573 Subtask<Void> subtask = scope.fork(() -> {
574 Thread.sleep(Duration.ofDays(1));
575 return null;
576 });
577
578 try {
579 scope.join();
580 fail();
581 } catch (ExecutionException e) {
582 assertTrue(e.getCause() instanceof TimeoutException);
583 }
584 expectDuration(startMillis, /*min*/1900, /*max*/20_000);
585
586 assertTrue(scope.isCancelled());
587 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
588 }
589 }
590
591 /**
592 * Test join with timeout that has already expired.
593 */
594 @ParameterizedTest
595 @MethodSource("factories")
596 void testJoinWithTimeout3(ThreadFactory factory) throws Exception {
597 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
598 cf -> cf.withThreadFactory(factory)
599 .withTimeout(Duration.ofSeconds(-1)))) {
600
601 Subtask<Void> subtask = scope.fork(() -> {
602 Thread.sleep(Duration.ofDays(1));
603 return null;
604 });
605
606 try {
607 scope.join();
608 fail();
609 } catch (ExecutionException e) {
610 assertTrue(e.getCause() instanceof TimeoutException);
611 }
612 assertTrue(scope.isCancelled());
613 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
614 }
615 }
616
617 /**
618 * Test that cancelling execution interrupts unfinished threads. This test uses the
619 * cancel method to cancel execution explicitly.
620 */
621 @ParameterizedTest
622 @MethodSource("factories")
623 void testCancelInterruptsThreads1(ThreadFactory factory) throws Exception {
624 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
625 cf -> cf.withThreadFactory(factory))) {
626
627 // fork subtask that runs for a long time
628 var started = new CountDownLatch(1);
629 var interrupted = new CountDownLatch(1);
630 var subtask = scope.fork(() -> {
631 started.countDown();
632 try {
633 Thread.sleep(Duration.ofDays(1));
634 } catch (InterruptedException e) {
635 interrupted.countDown();
636 }
637 });
638 started.await();
639
640 scope.cancel();
641
642 // subtask should be interrupted
643 interrupted.await();
644
645 scope.join();
646 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
647 }
648 }
649
650 /**
651 * Test that cancelling execution interrupts unfinished threads. This test uses
652 * a custom Joiner to cancel execution.
653 */
654 @ParameterizedTest
655 @MethodSource("factories")
656 void testCancelInterruptsThreads2(ThreadFactory factory) throws Exception {
657 var testJoiner = new CancelAfterOneJoiner<String>();
658
659 try (var scope = StructuredTaskScope.open(testJoiner,
660 cf -> cf.withThreadFactory(factory))) {
661
662 // fork subtask1 that runs for a long time
663 var started = new CountDownLatch(1);
664 var interrupted = new CountDownLatch(1);
665 var subtask1 = scope.fork(() -> {
666 started.countDown();
667 try {
668 Thread.sleep(Duration.ofDays(1));
669 } catch (InterruptedException e) {
670 interrupted.countDown();
671 }
672 });
673 started.await();
674
675 // fork subtask2, the scope should be cancelled when the subtask completes
676 var subtask2 = scope.fork(() -> "bar");
677 while (!scope.isCancelled()) {
678 Thread.sleep(20);
679 }
680
681 // subtask1 should be interrupted
682 interrupted.await();
683
684 scope.join();
685 assertEquals(Subtask.State.UNAVAILABLE, subtask1.state());
686 assertEquals("bar", subtask2.get());
687 }
688 }
689
690 /**
691 * Test that timeout interrupts unfinished threads.
692 */
693 @ParameterizedTest
694 @MethodSource("factories")
695 void testTimeoutInterruptsThreads(ThreadFactory factory) throws Exception {
696 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
697 cf -> cf.withThreadFactory(factory)
698 .withTimeout(Duration.ofSeconds(2)))) {
699
700 var started = new AtomicBoolean();
701 var interrupted = new CountDownLatch(1);
702 Subtask<Void> subtask = scope.fork(() -> {
703 started.set(true);
704 try {
705 Thread.sleep(Duration.ofDays(1));
706 } catch (InterruptedException e) {
707 interrupted.countDown();
708 }
709 return null;
710 });
711
712 while (!scope.isCancelled()) {
713 Thread.sleep(50);
714 }
715
716 // if subtask started then it should be interrupted
717 if (started.get()) {
718 interrupted.await();
719 }
720
721 try {
722 scope.join();
723 fail();
724 } catch (ExecutionException e) {
725 assertTrue(e.getCause() instanceof TimeoutException);
726 }
727 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
728 }
729 }
730
731 /**
732 * Test close without join, no subtasks forked.
733 */
734 @Test
735 void testCloseWithoutJoin1() {
736 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
737 // do nothing
738 }
739 }
740
741 /**
742 * Test close without join, subtasks forked.
743 */
744 @ParameterizedTest
745 @MethodSource("factories")
746 void testCloseWithoutJoin2(ThreadFactory factory) {
747 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
748 cf -> cf.withThreadFactory(factory))) {
749 Subtask<String> subtask = scope.fork(() -> {
750 Thread.sleep(Duration.ofDays(1));
751 return null;
752 });
753 assertThrows(IllegalStateException.class, scope::close);
754
755 // subtask result/exception not available
756 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
757 assertThrows(IllegalStateException.class, subtask::get);
758 assertThrows(IllegalStateException.class, subtask::exception);
759 }
760 }
761
762 /**
763 * Test close after join throws. Close should not throw as join attempted.
764 */
765 @ParameterizedTest
766 @MethodSource("factories")
767 void testCloseAfterJoinThrows(ThreadFactory factory) throws Exception {
768 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
769 cf -> cf.withThreadFactory(factory))) {
770 var subtask = scope.fork(() -> {
771 Thread.sleep(Duration.ofDays(1));
772 return null;
773 });
774
775 // join throws
776 Thread.currentThread().interrupt();
777 assertThrows(InterruptedException.class, scope::join);
778 assertThrows(IllegalStateException.class, subtask::get);
779
780 } // close should not throw
781 }
782
783 /**
784 * Test close method is owner confined.
785 */
786 @ParameterizedTest
787 @MethodSource("factories")
788 void testCloseConfined(ThreadFactory factory) throws Exception {
789 try (var scope = StructuredTaskScope.open(Joiner.<Boolean>awaitAll(),
790 cf -> cf.withThreadFactory(factory))) {
791
792 // random thread cannot close scope
793 try (var pool = Executors.newCachedThreadPool(factory)) {
794 Future<Boolean> future = pool.submit(() -> {
795 assertThrows(WrongThreadException.class, scope::close);
796 return null;
797 });
798 future.get();
799 }
800
801 // subtask cannot close
802 Subtask<Boolean> subtask = scope.fork(() -> {
803 assertThrows(WrongThreadException.class, scope::close);
804 return true;
805 });
806 scope.join();
807 assertTrue(subtask.get());
808 }
809 }
810
811 /**
812 * Test close with interrupt status set.
813 */
814 @ParameterizedTest
815 @MethodSource("factories")
816 void testInterruptClose1(ThreadFactory factory) throws Exception {
817 var testJoiner = new CancelAfterOneJoiner<String>();
818 try (var scope = StructuredTaskScope.open(testJoiner,
819 cf -> cf.withThreadFactory(factory))) {
820
821 // fork first subtask, a straggler as it continues after being interrupted
822 var started = new CountDownLatch(1);
823 var done = new AtomicBoolean();
824 scope.fork(() -> {
825 started.countDown();
826 try {
827 Thread.sleep(Duration.ofDays(1));
828 } catch (InterruptedException e) {
829 // interrupted by cancel, expected
830 }
831 Thread.sleep(Duration.ofMillis(100)); // force close to wait
832 done.set(true);
833 return null;
834 });
835 started.await();
836
837 // fork second subtask, the scope should be cancelled when this subtask completes
838 scope.fork(() -> "bar");
839 while (!scope.isCancelled()) {
840 Thread.sleep(20);
841 }
842
843 scope.join();
844
845 // invoke close with interrupt status set
846 Thread.currentThread().interrupt();
847 try {
848 scope.close();
849 } finally {
850 assertTrue(Thread.interrupted()); // clear interrupt status
851 assertTrue(done.get());
852 }
853 }
854 }
855
856 /**
857 * Test interrupting thread waiting in close.
858 */
859 @ParameterizedTest
860 @MethodSource("factories")
861 void testInterruptClose2(ThreadFactory factory) throws Exception {
862 var testJoiner = new CancelAfterOneJoiner<String>();
863 try (var scope = StructuredTaskScope.open(testJoiner,
864 cf -> cf.withThreadFactory(factory))) {
865
866 Thread mainThread = Thread.currentThread();
867
868 // fork first subtask, a straggler as it continues after being interrupted
869 var started = new CountDownLatch(1);
870 var done = new AtomicBoolean();
871 scope.fork(() -> {
872 started.countDown();
873 try {
874 Thread.sleep(Duration.ofDays(1));
875 } catch (InterruptedException e) {
876 // interrupted by cancel, expected
877 }
878
879 // interrupt main thread when it blocks in close
880 interruptThreadAt(mainThread, "java.util.concurrent.StructuredTaskScope.close");
881
882 Thread.sleep(Duration.ofMillis(100)); // force close to wait
883 done.set(true);
884 return null;
885 });
886 started.await();
887
888 // fork second subtask, the scope should be cancelled when this subtask completes
889 scope.fork(() -> "bar");
890 while (!scope.isCancelled()) {
891 Thread.sleep(20);
892 }
893
894 scope.join();
895
896 // main thread will be interrupted while blocked in close
897 try {
898 scope.close();
899 } finally {
900 assertTrue(Thread.interrupted()); // clear interrupt status
901 assertTrue(done.get());
902 }
903 }
904 }
905
906 /**
907 * Test that closing an enclosing scope closes the thread flock of a nested scope.
908 */
909 @Test
910 void testCloseThrowsStructureViolation() throws Exception {
911 try (var scope1 = StructuredTaskScope.open(Joiner.awaitAll())) {
912 try (var scope2 = StructuredTaskScope.open(Joiner.awaitAll())) {
913
914 // close enclosing scope
915 try {
916 scope1.close();
917 fail("close did not throw");
918 } catch (StructureViolationException expected) { }
919
920 // underlying flock should be closed
921 var executed = new AtomicBoolean();
922 Subtask<?> subtask = scope2.fork(() -> executed.set(true));
923 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
924 scope2.join();
925 assertFalse(executed.get());
926 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
927 }
928 }
929 }
930
931
932 /**
933 * Test cancel after task scope is cancelled.
934 */
935 @Test
936 void testCancelAfterCancel() {
937 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
938 scope.cancel();
939 }
940 }
941
942 /**
943 * Test cancel after task scope is closed.
944 */
945 @Test
946 void testCancelAfterClose() {
947 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
948 assertFalse(scope.isCancelled());
949 scope.cancel();
950 assertTrue(scope.isCancelled());
951 scope.cancel();
952 assertTrue(scope.isCancelled());
953 }
954 }
955
956 /**
957 * Test cancel method is owner confined.
958 */
959 @ParameterizedTest
960 @MethodSource("factories")
961 void testCancelConfined(ThreadFactory factory) throws Exception {
962 try (var scope = StructuredTaskScope.open(Joiner.<Boolean>awaitAll(),
963 cf -> cf.withThreadFactory(factory))) {
964
965 // random thread cannot cancel scope
966 try (var pool = Executors.newCachedThreadPool(factory)) {
967 Future<Boolean> future = pool.submit(() -> {
968 assertThrows(WrongThreadException.class, scope::cancel);
969 return null;
970 });
971 future.get();
972 }
973
974 // subtask cannot cancel
975 Subtask<Boolean> subtask = scope.fork(() -> {
976 assertThrows(WrongThreadException.class, scope::cancel);
977 return true;
978 });
979 scope.join();
980 assertTrue(subtask.get());
981 }
982 }
983
984 /**
985 * Test that isCancelled returns true after close.
986 */
987 @Test
988 void testIsCancelledAfterClose() throws Exception {
989 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
990 assertFalse(scope.isCancelled());
991 scope.close();
992 assertTrue(scope.isCancelled());
993 }
994 }
995
996 /**
997 * Test Joiner.onFork throwing exception.
998 */
999 @Test
1000 void testOnForkThrows() throws Exception {
1001 var joiner = new Joiner<String, Void>() {
1002 @Override
1003 public boolean onFork(Subtask<? extends String> subtask) {
1004 throw new FooException();
1005 }
1006 @Override
1007 public Void result() {
1008 return null;
1009 }
1010 };
1011 try (var scope = StructuredTaskScope.open(joiner)) {
1012 assertThrows(FooException.class, () -> scope.fork(() -> "foo"));
1013 }
1014 }
1015
1016 /**
1017 * Test Joiner.onFork returning true to cancel execution.
1018 */
1019 @Test
1020 void testOnForkCancelsExecution() throws Exception {
1021 var joiner = new Joiner<String, Void>() {
1022 @Override
1023 public boolean onFork(Subtask<? extends String> subtask) {
1024 return true;
1025 }
1026 @Override
1027 public Void result() {
1028 return null;
1029 }
1030 };
1031 try (var scope = StructuredTaskScope.open(joiner)) {
1032 assertFalse(scope.isCancelled());
1033 scope.fork(() -> "foo");
1034 assertTrue(scope.isCancelled());
1035 scope.join();
1036 }
1037 }
1038
1039 /**
1040 * Test Joiner.onComplete returning true to cancel execution.
1041 */
1042 @Test
1043 void testOnCompleteCancelsExecution() throws Exception {
1044 var joiner = new Joiner<String, Void>() {
1045 @Override
1046 public boolean onComplete(Subtask<? extends String> subtask) {
1047 return true;
1048 }
1049 @Override
1050 public Void result() {
1051 return null;
1052 }
1053 };
1054 try (var scope = StructuredTaskScope.open(joiner)) {
1055 assertFalse(scope.isCancelled());
1056 scope.fork(() -> "foo");
1057 while (!scope.isCancelled()) {
1058 Thread.sleep(10);
1059 }
1060 scope.join();
1061 }
1062 }
1063
1064 /**
1065 * Test toString.
1066 */
1067 @Test
1068 void testToString() throws Exception {
1069 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
1070 cf -> cf.withName("duke"))) {
1071
1072 // open
1073 assertTrue(scope.toString().contains("duke"));
1074
1075 // closed
1076 scope.close();
1077 assertTrue(scope.toString().contains("duke"));
1078 }
1079 }
1080
1081 /**
1082 * Test Subtask with task that completes successfully.
1083 */
1084 @ParameterizedTest
1085 @MethodSource("factories")
1086 void testSubtaskWhenSuccess(ThreadFactory factory) throws Exception {
1087 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAll(),
1088 cf -> cf.withThreadFactory(factory))) {
1089
1090 Subtask<String> subtask = scope.fork(() -> "foo");
1091
1092 // before join
1093 assertThrows(IllegalStateException.class, subtask::get);
1094 assertThrows(IllegalStateException.class, subtask::exception);
1095
1096 scope.join();
1097
1098 // after join
1099 assertEquals(Subtask.State.SUCCESS, subtask.state());
1100 assertEquals("foo", subtask.get());
1101 assertThrows(IllegalStateException.class, subtask::exception);
1102 }
1103 }
1104
1105 /**
1106 * Test Subtask with task that fails.
1107 */
1108 @ParameterizedTest
1109 @MethodSource("factories")
1110 void testSubtaskWhenFailed(ThreadFactory factory) throws Exception {
1111 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAll(),
1112 cf -> cf.withThreadFactory(factory))) {
1113
1114 Subtask<String> subtask = scope.fork(() -> { throw new FooException(); });
1115
1116 // before join
1117 assertThrows(IllegalStateException.class, subtask::get);
1118 assertThrows(IllegalStateException.class, subtask::exception);
1119
1120 scope.join();
1121
1122 // after join
1123 assertEquals(Subtask.State.FAILED, subtask.state());
1124 assertThrows(IllegalStateException.class, subtask::get);
1125 assertTrue(subtask.exception() instanceof FooException);
1126 }
1127 }
1128
1129 /**
1130 * Test Subtask with a task that has not completed.
1131 */
1132 @ParameterizedTest
1133 @MethodSource("factories")
1134 void testSubtaskWhenNotCompleted(ThreadFactory factory) throws Exception {
1135 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
1136 cf -> cf.withThreadFactory(factory))) {
1137 Subtask<Void> subtask = scope.fork(() -> {
1138 Thread.sleep(Duration.ofDays(1));
1139 return null;
1140 });
1141
1142 // before join
1143 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
1144 assertThrows(IllegalStateException.class, subtask::get);
1145 assertThrows(IllegalStateException.class, subtask::exception);
1146
1147 // attempt join, join throws
1148 Thread.currentThread().interrupt();
1149 assertThrows(InterruptedException.class, scope::join);
1150
1151 // after join
1152 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
1153 assertThrows(IllegalStateException.class, subtask::get);
1154 assertThrows(IllegalStateException.class, subtask::exception);
1155 }
1156 }
1157
1158 /**
1159 * Test Subtask forked after execution cancelled.
1160 */
1161 @ParameterizedTest
1162 @MethodSource("factories")
1163 void testSubtaskWhenCancelled(ThreadFactory factory) throws Exception {
1164 try (var scope = StructuredTaskScope.open(new CancelAfterOneJoiner<String>())) {
1165 scope.fork(() -> "foo");
1166 while (!scope.isCancelled()) {
1167 Thread.sleep(20);
1168 }
1169
1170 var subtask = scope.fork(() -> "foo");
1171
1172 // before join
1173 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
1174 assertThrows(IllegalStateException.class, subtask::get);
1175 assertThrows(IllegalStateException.class, subtask::exception);
1176
1177 scope.join();
1178
1179 // after join
1180 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
1181 assertThrows(IllegalStateException.class, subtask::get);
1182 assertThrows(IllegalStateException.class, subtask::exception);
1183 }
1184 }
1185
1186 /**
1187 * Test Subtask::toString.
1188 */
1189 @Test
1190 void testSubtaskToString() throws Exception {
1191 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
1192 var latch = new CountDownLatch(1);
1193 var subtask1 = scope.fork(() -> {
1194 latch.await();
1195 return "foo";
1196 });
1197 var subtask2 = scope.fork(() -> { throw new FooException(); });
1198
1199 // subtask1 result is unavailable
1200 assertTrue(subtask1.toString().contains("Unavailable"));
1201 latch.countDown();
1202
1203 scope.join();
1204
1205 assertTrue(subtask1.toString().contains("Completed successfully"));
1206 assertTrue(subtask2.toString().contains("Failed"));
1207 }
1208 }
1209
1210 /**
1211 * Test Joiner.allSuccessfulOrThrow() with no subtasks.
1212 */
1213 @Test
1214 void testAllSuccessfulOrThrow1() throws Throwable {
1215 try (var scope = StructuredTaskScope.open(Joiner.allSuccessfulOrThrow())) {
1216 var subtasks = scope.join().toList();
1217 assertTrue(subtasks.isEmpty());
1218 }
1219 }
1220
1221 /**
1222 * Test Joiner.allSuccessfulOrThrow() with subtasks that complete successfully.
1223 */
1224 @ParameterizedTest
1225 @MethodSource("factories")
1226 void testAllSuccessfulOrThrow2(ThreadFactory factory) throws Throwable {
1227 try (var scope = StructuredTaskScope.open(Joiner.<String>allSuccessfulOrThrow(),
1228 cf -> cf.withThreadFactory(factory))) {
1229 var subtask1 = scope.fork(() -> "foo");
1230 var subtask2 = scope.fork(() -> "bar");
1231 var subtasks = scope.join().toList();
1232 assertEquals(List.of(subtask1, subtask2), subtasks);
1233 assertEquals("foo", subtask1.get());
1234 assertEquals("bar", subtask2.get());
1235 }
1236 }
1237
1238 /**
1239 * Test Joiner.allSuccessfulOrThrow() with a subtask that complete successfully and
1240 * a subtask that fails.
1241 */
1242 @ParameterizedTest
1243 @MethodSource("factories")
1244 void testAllSuccessfulOrThrow3(ThreadFactory factory) throws Throwable {
1245 try (var scope = StructuredTaskScope.open(Joiner.<String>allSuccessfulOrThrow(),
1246 cf -> cf.withThreadFactory(factory))) {
1247 scope.fork(() -> "foo");
1248 scope.fork(() -> { throw new FooException(); });
1249 try {
1250 scope.join();
1251 } catch (ExecutionException e) {
1252 assertTrue(e.getCause() instanceof FooException);
1253 }
1254 }
1255 }
1256
1257 /**
1258 * Test Joiner.anySuccessfulResultOrThrow() with no subtasks.
1259 */
1260 @Test
1261 void testAnySuccessfulResultOrThrow1() throws Exception {
1262 try (var scope = StructuredTaskScope.open(Joiner.anySuccessfulResultOrThrow())) {
1263 try {
1264 scope.join();
1265 } catch (ExecutionException e) {
1266 assertTrue(e.getCause() instanceof NoSuchElementException);
1267 }
1268 }
1269 }
1270
1271 /**
1272 * Test Joiner.anySuccessfulResultOrThrow() with a subtask that completes successfully.
1273 */
1274 @ParameterizedTest
1275 @MethodSource("factories")
1276 void testAnySuccessfulResultOrThrow2(ThreadFactory factory) throws Exception {
1277 try (var scope = StructuredTaskScope.open(Joiner.<String>anySuccessfulResultOrThrow(),
1278 cf -> cf.withThreadFactory(factory))) {
1279 scope.fork(() -> "foo");
1280 String result = scope.join();
1281 assertEquals("foo", result);
1282 }
1283 }
1284
1285 /**
1286 * Test Joiner.anySuccessfulResultOrThrow() with a subtask that completes successfully
1287 * with a null result.
1288 */
1289 @ParameterizedTest
1290 @MethodSource("factories")
1291 void testAnySuccessfulResultOrThrow3(ThreadFactory factory) throws Exception {
1292 try (var scope = StructuredTaskScope.open(Joiner.<String>anySuccessfulResultOrThrow(),
1293 cf -> cf.withThreadFactory(factory))) {
1294 scope.fork(() -> null);
1295 String result = scope.join();
1296 assertNull(result);
1297 }
1298 }
1299
1300 /**
1301 * Test Joiner.anySuccessfulResultOrThrow() with a subtask that complete succcessfully
1302 * and a subtask that fails.
1303 */
1304 @ParameterizedTest
1305 @MethodSource("factories")
1306 void testAnySuccessfulResultOrThrow4(ThreadFactory factory) throws Exception {
1307 try (var scope = StructuredTaskScope.open(Joiner.<String>anySuccessfulResultOrThrow(),
1308 cf -> cf.withThreadFactory(factory))) {
1309 scope.fork(() -> "foo");
1310 scope.fork(() -> { throw new FooException(); });
1311 String first = scope.join();
1312 assertEquals("foo", first);
1313 }
1314 }
1315
1316 /**
1317 * Test Joiner.anySuccessfulResultOrThrow() with a subtask that fails.
1318 */
1319 @ParameterizedTest
1320 @MethodSource("factories")
1321 void testAnySuccessfulResultOrThrow5(ThreadFactory factory) throws Exception {
1322 try (var scope = StructuredTaskScope.open(Joiner.anySuccessfulResultOrThrow(),
1323 cf -> cf.withThreadFactory(factory))) {
1324 scope.fork(() -> { throw new FooException(); });
1325 Throwable ex = assertThrows(ExecutionException.class, scope::join);
1326 assertTrue(ex.getCause() instanceof FooException);
1327 }
1328 }
1329
1330 /**
1331 * Test Joiner.awaitAllSuccessfulOrThrow() with no subtasks.
1332 */
1333 @Test
1334 void testIgnoreSuccessfulOrThrow1() throws Throwable {
1335 try (var scope = StructuredTaskScope.open(Joiner.awaitAllSuccessfulOrThrow())) {
1336 var result = scope.join();
1337 assertNull(result);
1338 }
1339 }
1340
1341 /**
1342 * Test Joiner.awaitAllSuccessfulOrThrow() with subtasks that complete successfully.
1343 */
1344 @ParameterizedTest
1345 @MethodSource("factories")
1346 void testIgnoreSuccessfulOrThrow2(ThreadFactory factory) throws Throwable {
1347 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAllSuccessfulOrThrow(),
1348 cf -> cf.withThreadFactory(factory))) {
1349 var subtask1 = scope.fork(() -> "foo");
1350 var subtask2 = scope.fork(() -> "bar");
1351 var result = scope.join();
1352 assertNull(result);
1353 assertEquals("foo", subtask1.get());
1354 assertEquals("bar", subtask2.get());
1355 }
1356 }
1357
1358 /**
1359 * Test Joiner.awaitAllSuccessfulOrThrow() with a subtask that complete successfully and
1360 * a subtask that fails.
1361 */
1362 @ParameterizedTest
1363 @MethodSource("factories")
1364 void testIgnoreSuccessfulOrThrow3(ThreadFactory factory) throws Throwable {
1365 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAllSuccessfulOrThrow(),
1366 cf -> cf.withThreadFactory(factory))) {
1367 scope.fork(() -> "foo");
1368 scope.fork(() -> { throw new FooException(); });
1369 try {
1370 scope.join();
1371 } catch (ExecutionException e) {
1372 assertTrue(e.getCause() instanceof FooException);
1373 }
1374 }
1375 }
1376
1377 /**
1378 * Test Joiner.awaitAll() with no subtasks.
1379 */
1380 @Test
1381 void testIgnoreAll1() throws Throwable {
1382 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
1383 var result = scope.join();
1384 assertNull(result);
1385 }
1386 }
1387
1388 /**
1389 * Test Joiner.awaitAll() with subtasks that complete successfully.
1390 */
1391 @ParameterizedTest
1392 @MethodSource("factories")
1393 void testIgnoreAll2(ThreadFactory factory) throws Throwable {
1394 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAll(),
1395 cf -> cf.withThreadFactory(factory))) {
1396 var subtask1 = scope.fork(() -> "foo");
1397 var subtask2 = scope.fork(() -> "bar");
1398 var result = scope.join();
1399 assertNull(result);
1400 assertEquals("foo", subtask1.get());
1401 assertEquals("bar", subtask2.get());
1402 }
1403 }
1404
1405 /**
1406 * Test Joiner.awaitAll() with a subtask that complete successfully and a subtask
1407 * that fails.
1408 */
1409 @ParameterizedTest
1410 @MethodSource("factories")
1411 void testIgnoreAll3(ThreadFactory factory) throws Throwable {
1412 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAll(),
1413 cf -> cf.withThreadFactory(factory))) {
1414 var subtask1 = scope.fork(() -> "foo");
1415 var subtask2 = scope.fork(() -> { throw new FooException(); });
1416 var result = scope.join();
1417 assertNull(result);
1418 assertEquals("foo", subtask1.get());
1419 assertTrue(subtask2.exception() instanceof FooException);
1420 }
1421 }
1422
1423 /**
1424 * Test Joiner.all(Predicate) with no subtasks.
1425 */
1426 @Test
1427 void testAllWithPredicate1() throws Throwable {
1428 try (var scope = StructuredTaskScope.open(Joiner.all(s -> false))) {
1429 var subtasks = scope.join();
1430 assertEquals(0, subtasks.count());
1431 }
1432 }
1433
1434 /**
1435 * Test Joiner.all(Predicate) with no cancellation.
1436 */
1437 @ParameterizedTest
1438 @MethodSource("factories")
1439 void testAllWithPredicate2(ThreadFactory factory) throws Exception {
1440 try (var scope = StructuredTaskScope.open(Joiner.<String>all(s -> false),
1441 cf -> cf.withThreadFactory(factory))) {
1442
1443 var subtask1 = scope.fork(() -> "foo");
1444 var subtask2 = scope.fork(() -> { throw new FooException(); });
1445
1446 var subtasks = scope.join().toList();
1447 assertEquals(2, subtasks.size());
1448
1449 assertTrue(subtasks.get(0) == subtask1);
1450 assertTrue(subtasks.get(1) == subtask2);
1451 assertEquals("foo", subtask1.get());
1452 assertTrue(subtask2.exception() instanceof FooException);
1453 }
1454 }
1455
1456 /**
1457 * Test Joiner.all(Predicate) with cancellation after one subtask completes.
1458 */
1459 @ParameterizedTest
1460 @MethodSource("factories")
1461 void testAllWithPredicate3(ThreadFactory factory) throws Exception {
1462 try (var scope = StructuredTaskScope.open(Joiner.<String>all(s -> true),
1463 cf -> cf.withThreadFactory(factory))) {
1464
1465 var subtask1 = scope.fork(() -> "foo");
1466 var subtask2 = scope.fork(() -> {
1467 Thread.sleep(Duration.ofDays(1));
1468 return "bar";
1469 });
1470
1471 var subtasks = scope.join().toList();
1472
1473 assertEquals(2, subtasks.size());
1474 assertTrue(subtasks.get(0) == subtask1);
1475 assertTrue(subtasks.get(1) == subtask2);
1476 assertEquals("foo", subtask1.get());
1477 assertEquals(Subtask.State.UNAVAILABLE, subtask2.state());
1478 }
1479 }
1480
1481 /**
1482 * Test Joiner.all(Predicate) with cancellation after serveral subtasks complete.
1483 */
1484 @ParameterizedTest
1485 @MethodSource("factories")
1486 void testAllWithPredicate4(ThreadFactory factory) throws Exception {
1487
1488 // cancel execution after two or more failures
1489 class CancelAfterTwoFailures<T> implements Predicate<Subtask<? extends T>> {
1490 final AtomicInteger failedCount = new AtomicInteger();
1491 @Override
1492 public boolean test(Subtask<? extends T> subtask) {
1493 return subtask.state() == Subtask.State.FAILED
1494 && failedCount.incrementAndGet() >= 2;
1495 }
1496 }
1497 var joiner = Joiner.all(new CancelAfterTwoFailures<String>());
1498
1499 try (var scope = StructuredTaskScope.open(joiner)) {
1500 int forkCount = 0;
1501
1502 // fork subtasks until execution cancelled
1503 while (!scope.isCancelled()) {
1504 scope.fork(() -> "foo");
1505 scope.fork(() -> { throw new FooException(); });
1506 forkCount += 2;
1507 Thread.sleep(Duration.ofMillis(10));
1508 }
1509
1510 var subtasks = scope.join().toList();
1511 assertEquals(forkCount, subtasks.size());
1512
1513 long failedCount = subtasks.stream()
1514 .filter(s -> s.state() == Subtask.State.FAILED)
1515 .count();
1516 assertTrue(failedCount >= 2);
1517 }
1518 }
1519
1520 /**
1521 * Test Config equals/hashCode/toString
1522 */
1523 @Test
1524 void testConfigMethods() throws Exception {
1525 Function<Config, Config> testConfig = cf -> {
1526 var name = "duke";
1527 var threadFactory = Thread.ofPlatform().factory();
1528 var timeout = Duration.ofSeconds(10);
1529
1530 assertEquals(cf, cf);
1531 assertEquals(cf.withName(name), cf.withName(name));
1532 assertEquals(cf.withThreadFactory(threadFactory), cf.withThreadFactory(threadFactory));
1533 assertEquals(cf.withTimeout(timeout), cf.withTimeout(timeout));
1534
1535 assertNotEquals(cf, cf.withName(name));
1536 assertNotEquals(cf, cf.withThreadFactory(threadFactory));
1537 assertNotEquals(cf, cf.withTimeout(timeout));
1538
1539 assertEquals(cf.withName(name).hashCode(), cf.withName(name).hashCode());
1540 assertEquals(cf.withThreadFactory(threadFactory).hashCode(),
1541 cf.withThreadFactory(threadFactory).hashCode());
1542 assertEquals(cf.withTimeout(timeout).hashCode(), cf.withTimeout(timeout).hashCode());
1543
1544 assertTrue(cf.withName(name).toString().contains(name));
1545 assertTrue(cf.withThreadFactory(threadFactory).toString().contains(threadFactory.toString()));
1546 assertTrue(cf.withTimeout(timeout).toString().contains(timeout.toString()));
1547
1548 return cf;
1549 };
1550 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(), testConfig)) {
1551 // do nothing
1552 }
1553 }
1554
1555 /**
1556 * Test Joiner default methods.
1557 */
1558 @Test
1559 void testJoinerDefaultMethods() throws Exception {
1560 try (var scope = StructuredTaskScope.open(new CancelAfterOneJoiner<String>())) {
1561
1562 // need subtasks to test default methods
1563 var subtask1 = scope.fork(() -> "foo");
1564 while (!scope.isCancelled()) {
1565 Thread.sleep(20);
1566 }
1567 var subtask2 = scope.fork(() -> "bar");
1568 scope.join();
1569
1570 assertEquals(Subtask.State.SUCCESS, subtask1.state());
1571 assertEquals(Subtask.State.UNAVAILABLE, subtask2.state());
1572
1573 // Joiner that does not override default methods
1574 Joiner<Object, Void> joiner = () -> null;
1575 assertThrows(NullPointerException.class, () -> joiner.onFork(null));
1576 assertThrows(NullPointerException.class, () -> joiner.onComplete(null));
1577 assertThrows(IllegalArgumentException.class, () -> joiner.onFork(subtask1));
1578 assertFalse(joiner.onFork(subtask2));
1579 assertFalse(joiner.onComplete(subtask1));
1580 assertThrows(IllegalArgumentException.class, () -> joiner.onComplete(subtask2));
1581 }
1582 }
1583
1584 /**
1585 * Test for NullPointerException.
1586 */
1587 @Test
1588 void testNulls() throws Exception {
1589 assertThrows(NullPointerException.class,
1590 () -> StructuredTaskScope.open(null));
1591 assertThrows(NullPointerException.class,
1592 () -> StructuredTaskScope.open(null, cf -> cf));
1593 assertThrows(NullPointerException.class,
1594 () -> StructuredTaskScope.open(Joiner.awaitAll(), null));
1595 assertThrows(NullPointerException.class,
1596 () -> StructuredTaskScope.open(Joiner.awaitAll(), cf -> null));
1597
1598 assertThrows(NullPointerException.class, () -> Joiner.all(null));
1599
1600 // fork
1601 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
1602 assertThrows(NullPointerException.class, () -> scope.fork((Callable<Object>) null));
1603 assertThrows(NullPointerException.class, () -> scope.fork((Runnable) null));
1604 }
1605
1606 // withXXX
1607 assertThrows(NullPointerException.class,
1608 () -> StructuredTaskScope.open(Joiner.awaitAll(), cf -> cf.withName(null)));
1609 assertThrows(NullPointerException.class,
1610 () -> StructuredTaskScope.open(Joiner.awaitAll(), cf -> cf.withThreadFactory(null)));
1611 assertThrows(NullPointerException.class,
1612 () -> StructuredTaskScope.open(Joiner.awaitAll(), cf -> cf.withTimeout(null)));
1613 }
1614
1615 /**
1616 * ThreadFactory that counts usage.
1617 */
1618 private static class CountingThreadFactory implements ThreadFactory {
1619 final ThreadFactory delegate;
1620 final AtomicInteger threadCount = new AtomicInteger();
1621 CountingThreadFactory(ThreadFactory delegate) {
1622 this.delegate = delegate;
1623 }
1624 @Override
1625 public Thread newThread(Runnable task) {
1626 threadCount.incrementAndGet();
1627 return delegate.newThread(task);
1628 }
1629 int threadCount() {
1630 return threadCount.get();
1631 }
1632 }
1633
1634 /**
1635 * A joiner that counts that counts the number of subtasks that are forked and the
1636 * number of subtasks that complete.
1637 */
1638 private static class CountingJoiner<T> implements Joiner<T, Void> {
1639 final AtomicInteger onForkCount = new AtomicInteger();
1640 final AtomicInteger onCompleteCount = new AtomicInteger();
1641 @Override
1642 public boolean onFork(Subtask<? extends T> subtask) {
1643 onForkCount.incrementAndGet();
1644 return false;
1645 }
1646 @Override
1647 public boolean onComplete(Subtask<? extends T> subtask) {
1648 onCompleteCount.incrementAndGet();
1649 return false;
1650 }
1651 @Override
1652 public Void result() {
1653 return null;
1654 }
1655 int onForkCount() {
1656 return onForkCount.get();
1657 }
1658 int onCompleteCount() {
1659 return onCompleteCount.get();
1660 }
1661 }
1662
1663 /**
1664 * A joiner that cancels execution when a subtask completes. It also keeps a count
1665 * of the number of subtasks that are forked and the number of subtasks that complete.
1666 */
1667 private static class CancelAfterOneJoiner<T> implements Joiner<T, Void> {
1668 final AtomicInteger onForkCount = new AtomicInteger();
1669 final AtomicInteger onCompleteCount = new AtomicInteger();
1670 @Override
1671 public boolean onFork(Subtask<? extends T> subtask) {
1672 onForkCount.incrementAndGet();
1673 return false;
1674 }
1675 @Override
1676 public boolean onComplete(Subtask<? extends T> subtask) {
1677 onCompleteCount.incrementAndGet();
1678 return true;
1679 }
1680 @Override
1681 public Void result() {
1682 return null;
1683 }
1684 int onForkCount() {
1685 return onForkCount.get();
1686 }
1687 int onCompleteCount() {
1688 return onCompleteCount.get();
1689 }
1690 }
1691
1692 /**
1693 * A runtime exception for tests.
1694 */
1695 private static class FooException extends RuntimeException {
1696 FooException() { }
1697 FooException(Throwable cause) { super(cause); }
1698 }
1699
1700 /**
1701 * Returns the current time in milliseconds.
1702 */
1703 private long millisTime() {
1704 long now = System.nanoTime();
1705 return TimeUnit.MILLISECONDS.convert(now, TimeUnit.NANOSECONDS);
1706 }
1707
1708 /**
|