44 import java.util.concurrent.Callable;
45 import java.util.concurrent.ConcurrentHashMap;
46 import java.util.concurrent.CountDownLatch;
47 import java.util.concurrent.Executors;
48 import java.util.concurrent.Future;
49 import java.util.concurrent.LinkedTransferQueue;
50 import java.util.concurrent.ThreadFactory;
51 import java.util.concurrent.TimeUnit;
52 import java.util.concurrent.RejectedExecutionException;
53 import java.util.concurrent.ScheduledExecutorService;
54 import java.util.concurrent.StructuredTaskScope;
55 import java.util.concurrent.StructuredTaskScope.TimeoutException;
56 import java.util.concurrent.StructuredTaskScope.Configuration;
57 import java.util.concurrent.StructuredTaskScope.FailedException;
58 import java.util.concurrent.StructuredTaskScope.Joiner;
59 import java.util.concurrent.StructuredTaskScope.Subtask;
60 import java.util.concurrent.StructureViolationException;
61 import java.util.concurrent.atomic.AtomicBoolean;
62 import java.util.concurrent.atomic.AtomicInteger;
63 import java.util.concurrent.atomic.AtomicReference;
64 import java.util.function.Function;
65 import java.util.function.Predicate;
66 import java.util.stream.Stream;
67 import static java.lang.Thread.State.*;
68
69 import org.junit.jupiter.api.Test;
70 import org.junit.jupiter.api.BeforeAll;
71 import org.junit.jupiter.api.AfterAll;
72 import org.junit.jupiter.params.ParameterizedTest;
73 import org.junit.jupiter.params.provider.MethodSource;
74 import static org.junit.jupiter.api.Assertions.*;
75
76 class StructuredTaskScopeTest {
77 private static ScheduledExecutorService scheduler;
78 private static List<ThreadFactory> threadFactories;
79
80 @BeforeAll
81 static void setup() throws Exception {
82 scheduler = Executors.newSingleThreadScheduledExecutor();
83
84 // thread factories
85 String value = System.getProperty("threadFactory");
192 future.get();
193 }
194
195 // subtask cannot fork
196 Subtask<Boolean> subtask = scope.fork(() -> {
197 assertThrows(WrongThreadException.class, () -> {
198 scope.fork(() -> null);
199 });
200 return true;
201 });
202 scope.join();
203 assertTrue(subtask.get());
204 }
205 }
206
207 /**
208 * Test fork after join, no subtasks forked before join.
209 */
210 @ParameterizedTest
211 @MethodSource("factories")
212 void testForkAfterJoin1(ThreadFactory factory) throws Exception {
213 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
214 cf -> cf.withThreadFactory(factory))) {
215 scope.join();
216 assertThrows(IllegalStateException.class, () -> scope.fork(() -> "bar"));
217 }
218 }
219
220 /**
221 * Test fork after join, subtasks forked before join.
222 */
223 @ParameterizedTest
224 @MethodSource("factories")
225 void testForkAfterJoin2(ThreadFactory factory) throws Exception {
226 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
227 cf -> cf.withThreadFactory(factory))) {
228 scope.fork(() -> "foo");
229 scope.join();
230 assertThrows(IllegalStateException.class, () -> scope.fork(() -> "bar"));
231 }
232 }
233
234 /**
235 * Test fork after join throws.
236 */
237 @ParameterizedTest
238 @MethodSource("factories")
239 void testForkAfterJoinThrows(ThreadFactory factory) throws Exception {
240 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
241 cf -> cf.withThreadFactory(factory))) {
242 var latch = new CountDownLatch(1);
243 var subtask1 = scope.fork(() -> {
244 latch.await();
245 return "foo";
246 });
247
248 // join throws
249 Thread.currentThread().interrupt();
250 assertThrows(InterruptedException.class, scope::join);
251
252 // fork should throw
253 assertThrows(IllegalStateException.class, () -> scope.fork(() -> "bar"));
254 }
255 }
256
257 /**
258 * Test fork after task scope is cancelled. This test uses a custom Joiner to
259 * cancel execution.
260 */
261 @ParameterizedTest
262 @MethodSource("factories")
263 void testForkAfterCancel2(ThreadFactory factory) throws Exception {
264 var countingThreadFactory = new CountingThreadFactory(factory);
265 var testJoiner = new CancelAfterOneJoiner<String>();
266
267 try (var scope = StructuredTaskScope.open(testJoiner,
268 cf -> cf.withThreadFactory(countingThreadFactory))) {
269
270 // fork subtask, the scope should be cancelled when the subtask completes
271 var subtask1 = scope.fork(() -> "foo");
272 awaitCancelled(scope);
273
274 assertEquals(1, countingThreadFactory.threadCount());
275 assertEquals(1, testJoiner.onForkCount());
276 assertEquals(1, testJoiner.onCompleteCount());
279 var subtask2 = scope.fork(() -> "bar");
280
281 // onFork should be invoked, newThread and onComplete should not be invoked
282 assertEquals(1, countingThreadFactory.threadCount());
283 assertEquals(2, testJoiner.onForkCount());
284 assertEquals(1, testJoiner.onCompleteCount());
285
286 scope.join();
287
288 assertEquals(1, countingThreadFactory.threadCount());
289 assertEquals(2, testJoiner.onForkCount());
290 assertEquals(1, testJoiner.onCompleteCount());
291 assertEquals("foo", subtask1.get());
292 assertEquals(Subtask.State.UNAVAILABLE, subtask2.state());
293 }
294 }
295
296 /**
297 * Test fork after task scope is closed.
298 */
299 @Test
300 void testForkAfterClose() {
301 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
302 scope.close();
303 assertThrows(IllegalStateException.class, () -> scope.fork(() -> null));
304 }
305 }
306
307 /**
308 * Test fork with a ThreadFactory that rejects creating a thread.
309 */
310 @Test
311 void testForkRejectedExecutionException() {
312 ThreadFactory factory = task -> null;
313 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
314 cf -> cf.withThreadFactory(factory))) {
315 assertThrows(RejectedExecutionException.class, () -> scope.fork(() -> null));
316 }
317 }
318
319 /**
320 * Test join with no subtasks.
321 */
365 * Test join after join completed with an exception.
366 */
367 @Test
368 void testJoinAfterJoin2() throws Exception {
369 try (var scope = StructuredTaskScope.open(Joiner.anySuccessfulResultOrThrow())) {
370 scope.fork(() -> { throw new FooException(); });
371 Throwable ex = assertThrows(FailedException.class, scope::join);
372 assertTrue(ex.getCause() instanceof FooException);
373
374 // join already called
375 for (int i = 0 ; i < 3; i++) {
376 assertThrows(IllegalStateException.class, scope::join);
377 }
378 }
379 }
380
381 /**
382 * Test join after join completed with a timeout.
383 */
384 @Test
385 void testJoinAfterJoin3() throws Exception {
386 try (var scope = StructuredTaskScope.open(Joiner.anySuccessfulResultOrThrow(),
387 cf -> cf.withTimeout(Duration.ofMillis(100)))) {
388 // wait for scope to be cancelled by timeout
389 awaitCancelled(scope);
390 assertThrows(TimeoutException.class, scope::join);
391
392 // join already called
393 for (int i = 0 ; i < 3; i++) {
394 assertThrows(IllegalStateException.class, scope::join);
395 }
396 }
397 }
398
399 /**
400 * Test join method is owner confined.
401 */
402 @ParameterizedTest
403 @MethodSource("factories")
404 void testJoinConfined(ThreadFactory factory) throws Exception {
405 try (var scope = StructuredTaskScope.open(Joiner.<Boolean>awaitAll(),
406 cf -> cf.withThreadFactory(factory))) {
407
408 // random thread cannot join
409 try (var pool = Executors.newSingleThreadExecutor()) {
410 Future<Void> future = pool.submit(() -> {
411 assertThrows(WrongThreadException.class, scope::join);
412 return null;
413 });
414 future.get();
415 }
416
417 // subtask cannot join
418 Subtask<Boolean> subtask = scope.fork(() -> {
419 assertThrows(WrongThreadException.class, () -> { scope.join(); });
420 return true;
421 });
422 scope.join();
423 assertTrue(subtask.get());
424 }
425 }
426
427 /**
428 * Test join with interrupt status set.
429 */
430 @ParameterizedTest
431 @MethodSource("factories")
432 void testInterruptJoin1(ThreadFactory factory) throws Exception {
433 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
434 cf -> cf.withThreadFactory(factory))) {
435
436 Subtask<String> subtask = scope.fork(() -> {
437 Thread.sleep(60_000);
438 return "foo";
439 });
440
441 // join should throw
442 Thread.currentThread().interrupt();
443 try {
444 scope.join();
445 fail("join did not throw");
446 } catch (InterruptedException expected) {
447 assertFalse(Thread.interrupted()); // interrupt status should be cleared
448 }
449 }
450 }
451
452 /**
453 * Test interrupt of thread blocked in join.
454 */
455 @ParameterizedTest
456 @MethodSource("factories")
457 void testInterruptJoin2(ThreadFactory factory) throws Exception {
458 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
459 cf -> cf.withThreadFactory(factory))) {
460
461 var latch = new CountDownLatch(1);
462 Subtask<String> subtask = scope.fork(() -> {
463 Thread.sleep(60_000);
464 return "foo";
465 });
466
467 // interrupt main thread when it blocks in join
468 scheduleInterruptAt("java.util.concurrent.StructuredTaskScopeImpl.join");
469 try {
470 scope.join();
471 fail("join did not throw");
472 } catch (InterruptedException expected) {
473 assertFalse(Thread.interrupted()); // interrupt status should be clear
474 }
475 }
476 }
477
478 /**
479 * Test join when scope is cancelled.
480 */
481 @ParameterizedTest
482 @MethodSource("factories")
483 void testJoinWhenCancelled(ThreadFactory factory) throws Exception {
948 @Test
949 void testOnCompleteCancelsExecution() throws Exception {
950 var joiner = new Joiner<String, Void>() {
951 @Override
952 public boolean onComplete(Subtask<? extends String> subtask) {
953 return true;
954 }
955 @Override
956 public Void result() {
957 return null;
958 }
959 };
960 try (var scope = StructuredTaskScope.open(joiner)) {
961 assertFalse(scope.isCancelled());
962 scope.fork(() -> "foo");
963 awaitCancelled(scope);
964 scope.join();
965 }
966 }
967
968 /**
969 * Test toString.
970 */
971 @Test
972 void testToString() throws Exception {
973 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
974 cf -> cf.withName("duke"))) {
975
976 // open
977 assertTrue(scope.toString().contains("duke"));
978
979 // closed
980 scope.close();
981 assertTrue(scope.toString().contains("duke"));
982 }
983 }
984
985 /**
986 * Test Subtask with task that completes successfully.
987 */
988 @ParameterizedTest
989 @MethodSource("factories")
990 void testSubtaskWhenSuccess(ThreadFactory factory) throws Exception {
991 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAll(),
992 cf -> cf.withThreadFactory(factory))) {
993
994 Subtask<String> subtask = scope.fork(() -> "foo");
995
996 // before join
997 assertThrows(IllegalStateException.class, subtask::get);
998 assertThrows(IllegalStateException.class, subtask::exception);
999
1000 scope.join();
1001
1002 // after join
1003 assertEquals(Subtask.State.SUCCESS, subtask.state());
1004 assertEquals("foo", subtask.get());
1005 assertThrows(IllegalStateException.class, subtask::exception);
1006 }
1007 }
1008
1009 /**
1010 * Test Subtask with task that fails.
1011 */
1012 @ParameterizedTest
1013 @MethodSource("factories")
1014 void testSubtaskWhenFailed(ThreadFactory factory) throws Exception {
1015 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAll(),
1016 cf -> cf.withThreadFactory(factory))) {
1017
1018 Subtask<String> subtask = scope.fork(() -> { throw new FooException(); });
1019
1020 // before join
1021 assertThrows(IllegalStateException.class, subtask::get);
1022 assertThrows(IllegalStateException.class, subtask::exception);
1023
1024 scope.join();
1025
1026 // after join
1027 assertEquals(Subtask.State.FAILED, subtask.state());
1028 assertThrows(IllegalStateException.class, subtask::get);
1029 assertTrue(subtask.exception() instanceof FooException);
1030 }
1031 }
1032
1033 /**
1034 * Test Subtask with a task that has not completed.
1035 */
1036 @ParameterizedTest
1037 @MethodSource("factories")
1038 void testSubtaskWhenNotCompleted(ThreadFactory factory) throws Exception {
1039 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
1040 cf -> cf.withThreadFactory(factory))) {
1041 Subtask<Void> subtask = scope.fork(() -> {
1042 Thread.sleep(Duration.ofDays(1));
1043 return null;
1044 });
1045
1046 // before join
1047 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
1048 assertThrows(IllegalStateException.class, subtask::get);
1049 assertThrows(IllegalStateException.class, subtask::exception);
1050
1051 // attempt join, join throws
1052 Thread.currentThread().interrupt();
1053 assertThrows(InterruptedException.class, scope::join);
1054
1055 // after join
1056 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
1057 assertThrows(IllegalStateException.class, subtask::get);
1058 assertThrows(IllegalStateException.class, subtask::exception);
1059 }
1060 }
1061
1062 /**
1063 * Test Subtask forked after execution cancelled.
1064 */
1065 @ParameterizedTest
1066 @MethodSource("factories")
1067 void testSubtaskWhenCancelled(ThreadFactory factory) throws Exception {
1068 try (var scope = StructuredTaskScope.open(new CancelAfterOneJoiner<String>())) {
1069 scope.fork(() -> "foo");
1070 awaitCancelled(scope);
1071
1072 var subtask = scope.fork(() -> "foo");
1073
1074 // before join
1075 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
1076 assertThrows(IllegalStateException.class, subtask::get);
1077 assertThrows(IllegalStateException.class, subtask::exception);
1078
1079 scope.join();
1080
1081 // after join
1082 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
1083 assertThrows(IllegalStateException.class, subtask::get);
1084 assertThrows(IllegalStateException.class, subtask::exception);
1085 }
1086 }
1087
1088 /**
1089 * Test Subtask::toString.
1090 */
1091 @Test
1092 void testSubtaskToString() throws Exception {
1093 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
1094 var latch = new CountDownLatch(1);
1095 var subtask1 = scope.fork(() -> {
1096 latch.await();
1097 return "foo";
1098 });
1099 var subtask2 = scope.fork(() -> { throw new FooException(); });
1100
1101 // subtask1 result is unavailable
1102 assertTrue(subtask1.toString().contains("Unavailable"));
1103 latch.countDown();
1104
1139
1140 /**
1141 * Test Joiner.allSuccessfulOrThrow() with a subtask that complete successfully and
1142 * a subtask that fails.
1143 */
1144 @ParameterizedTest
1145 @MethodSource("factories")
1146 void testAllSuccessfulOrThrow3(ThreadFactory factory) throws Throwable {
1147 try (var scope = StructuredTaskScope.open(Joiner.<String>allSuccessfulOrThrow(),
1148 cf -> cf.withThreadFactory(factory))) {
1149 scope.fork(() -> "foo");
1150 scope.fork(() -> { throw new FooException(); });
1151 try {
1152 scope.join();
1153 } catch (FailedException e) {
1154 assertTrue(e.getCause() instanceof FooException);
1155 }
1156 }
1157 }
1158
1159 /**
1160 * Test Joiner.anySuccessfulResultOrThrow() with no subtasks.
1161 */
1162 @Test
1163 void testAnySuccessfulResultOrThrow1() throws Exception {
1164 try (var scope = StructuredTaskScope.open(Joiner.anySuccessfulResultOrThrow())) {
1165 try {
1166 scope.join();
1167 } catch (FailedException e) {
1168 assertTrue(e.getCause() instanceof NoSuchElementException);
1169 }
1170 }
1171 }
1172
1173 /**
1174 * Test Joiner.anySuccessfulResultOrThrow() with a subtask that completes successfully.
1175 */
1176 @ParameterizedTest
1177 @MethodSource("factories")
1178 void testAnySuccessfulResultOrThrow2(ThreadFactory factory) throws Exception {
1212 scope.fork(() -> { throw new FooException(); });
1213 String first = scope.join();
1214 assertEquals("foo", first);
1215 }
1216 }
1217
1218 /**
1219 * Test Joiner.anySuccessfulResultOrThrow() with a subtask that fails.
1220 */
1221 @ParameterizedTest
1222 @MethodSource("factories")
1223 void testAnySuccessfulResultOrThrow5(ThreadFactory factory) throws Exception {
1224 try (var scope = StructuredTaskScope.open(Joiner.anySuccessfulResultOrThrow(),
1225 cf -> cf.withThreadFactory(factory))) {
1226 scope.fork(() -> { throw new FooException(); });
1227 Throwable ex = assertThrows(FailedException.class, scope::join);
1228 assertTrue(ex.getCause() instanceof FooException);
1229 }
1230 }
1231
1232 /**
1233 * Test Joiner.awaitAllSuccessfulOrThrow() with no subtasks.
1234 */
1235 @Test
1236 void testAwaitSuccessfulOrThrow1() throws Throwable {
1237 try (var scope = StructuredTaskScope.open(Joiner.awaitAllSuccessfulOrThrow())) {
1238 var result = scope.join();
1239 assertNull(result);
1240 }
1241 }
1242
1243 /**
1244 * Test Joiner.awaitAllSuccessfulOrThrow() with subtasks that complete successfully.
1245 */
1246 @ParameterizedTest
1247 @MethodSource("factories")
1248 void testAwaitSuccessfulOrThrow2(ThreadFactory factory) throws Throwable {
1249 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAllSuccessfulOrThrow(),
1250 cf -> cf.withThreadFactory(factory))) {
1251 var subtask1 = scope.fork(() -> "foo");
1259
1260 /**
1261 * Test Joiner.awaitAllSuccessfulOrThrow() with a subtask that complete successfully and
1262 * a subtask that fails.
1263 */
1264 @ParameterizedTest
1265 @MethodSource("factories")
1266 void testAwaitSuccessfulOrThrow3(ThreadFactory factory) throws Throwable {
1267 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAllSuccessfulOrThrow(),
1268 cf -> cf.withThreadFactory(factory))) {
1269 scope.fork(() -> "foo");
1270 scope.fork(() -> { throw new FooException(); });
1271 try {
1272 scope.join();
1273 } catch (FailedException e) {
1274 assertTrue(e.getCause() instanceof FooException);
1275 }
1276 }
1277 }
1278
1279 /**
1280 * Test Joiner.awaitAll() with no subtasks.
1281 */
1282 @Test
1283 void testAwaitAll1() throws Throwable {
1284 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
1285 var result = scope.join();
1286 assertNull(result);
1287 }
1288 }
1289
1290 /**
1291 * Test Joiner.awaitAll() with subtasks that complete successfully.
1292 */
1293 @ParameterizedTest
1294 @MethodSource("factories")
1295 void testAwaitAll2(ThreadFactory factory) throws Throwable {
1296 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAll(),
1297 cf -> cf.withThreadFactory(factory))) {
1298 var subtask1 = scope.fork(() -> "foo");
1305 }
1306
1307 /**
1308 * Test Joiner.awaitAll() with a subtask that complete successfully and a subtask
1309 * that fails.
1310 */
1311 @ParameterizedTest
1312 @MethodSource("factories")
1313 void testAwaitAll3(ThreadFactory factory) throws Throwable {
1314 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAll(),
1315 cf -> cf.withThreadFactory(factory))) {
1316 var subtask1 = scope.fork(() -> "foo");
1317 var subtask2 = scope.fork(() -> { throw new FooException(); });
1318 var result = scope.join();
1319 assertNull(result);
1320 assertEquals("foo", subtask1.get());
1321 assertTrue(subtask2.exception() instanceof FooException);
1322 }
1323 }
1324
1325 /**
1326 * Test Joiner.allUntil(Predicate) with no subtasks.
1327 */
1328 @Test
1329 void testAllUntil1() throws Throwable {
1330 try (var scope = StructuredTaskScope.open(Joiner.allUntil(s -> false))) {
1331 var subtasks = scope.join();
1332 assertEquals(0, subtasks.count());
1333 }
1334 }
1335
1336 /**
1337 * Test Joiner.allUntil(Predicate) with no cancellation.
1338 */
1339 @ParameterizedTest
1340 @MethodSource("factories")
1341 void testAllUntil2(ThreadFactory factory) throws Exception {
1342 try (var scope = StructuredTaskScope.open(Joiner.<String>allUntil(s -> false),
1343 cf -> cf.withThreadFactory(factory))) {
1344
1345 var subtask1 = scope.fork(() -> "foo");
1346 var subtask2 = scope.fork(() -> { throw new FooException(); });
1347
1348 var subtasks = scope.join().toList();
1349 assertEquals(2, subtasks.size());
1350
1351 assertSame(subtask1, subtasks.get(0));
1352 assertSame(subtask2, subtasks.get(1));
1353 assertEquals("foo", subtask1.get());
1354 assertTrue(subtask2.exception() instanceof FooException);
1355 }
1356 }
1357
1358 /**
1359 * Test Joiner.allUntil(Predicate) with cancellation after one subtask completes.
1360 */
1361 @ParameterizedTest
1362 @MethodSource("factories")
1363 void testAllUntil3(ThreadFactory factory) throws Exception {
1364 try (var scope = StructuredTaskScope.open(Joiner.<String>allUntil(s -> true),
1365 cf -> cf.withThreadFactory(factory))) {
1366
1367 var subtask1 = scope.fork(() -> "foo");
1368 var subtask2 = scope.fork(() -> {
1369 Thread.sleep(Duration.ofDays(1));
1370 return "bar";
1371 });
1372
1373 var subtasks = scope.join().toList();
1374
1375 assertEquals(2, subtasks.size());
1376 assertSame(subtask1, subtasks.get(0));
1377 assertSame(subtask2, subtasks.get(1));
1378 assertEquals("foo", subtask1.get());
1379 assertEquals(Subtask.State.UNAVAILABLE, subtask2.state());
1380 }
1381 }
1382
1383 /**
1384 * Test Joiner.allUntil(Predicate) with cancellation after serveral subtasks complete.
1385 */
1386 @ParameterizedTest
1387 @MethodSource("factories")
1388 void testAllUntil4(ThreadFactory factory) throws Exception {
1389
1390 // cancel execution after two or more failures
1391 class CancelAfterTwoFailures<T> implements Predicate<Subtask<? extends T>> {
1392 final AtomicInteger failedCount = new AtomicInteger();
1393 @Override
1394 public boolean test(Subtask<? extends T> subtask) {
1395 return subtask.state() == Subtask.State.FAILED
1396 && failedCount.incrementAndGet() >= 2;
1397 }
1420 }
1421
1422 /**
1423 * Test Test Joiner.allUntil(Predicate) where the Predicate's test method throws.
1424 */
1425 @Test
1426 void testAllUntil5() throws Exception {
1427 var joiner = Joiner.allUntil(_ -> { throw new FooException(); });
1428 var excRef = new AtomicReference<Throwable>();
1429 Thread.UncaughtExceptionHandler uhe = (t, e) -> excRef.set(e);
1430 ThreadFactory factory = Thread.ofVirtual()
1431 .uncaughtExceptionHandler(uhe)
1432 .factory();
1433 try (var scope = StructuredTaskScope.open(joiner, cf -> cf.withThreadFactory(factory))) {
1434 scope.fork(() -> "foo");
1435 scope.join();
1436 assertInstanceOf(FooException.class, excRef.get());
1437 }
1438 }
1439
1440 /**
1441 * Test Joiner default methods.
1442 */
1443 @Test
1444 void testJoinerDefaultMethods() throws Exception {
1445 try (var scope = StructuredTaskScope.open(new CancelAfterOneJoiner<String>())) {
1446
1447 // need subtasks to test default methods
1448 var subtask1 = scope.fork(() -> "foo");
1449 awaitCancelled(scope);
1450 var subtask2 = scope.fork(() -> "bar");
1451 scope.join();
1452
1453 assertEquals(Subtask.State.SUCCESS, subtask1.state());
1454 assertEquals(Subtask.State.UNAVAILABLE, subtask2.state());
1455
1456 // Joiner that does not override default methods
1457 Joiner<Object, Void> joiner = () -> null;
1458 assertThrows(NullPointerException.class, () -> joiner.onFork(null));
1459 assertThrows(NullPointerException.class, () -> joiner.onComplete(null));
1460 assertThrows(IllegalArgumentException.class, () -> joiner.onFork(subtask1));
1461 assertFalse(joiner.onFork(subtask2));
1462 assertFalse(joiner.onComplete(subtask1));
1463 assertThrows(IllegalArgumentException.class, () -> joiner.onComplete(subtask2));
1464 }
1465 }
1466
1467 /**
1468 * Test Joiners onFork/onComplete methods with a subtask in an unexpected state.
1469 */
1470 @Test
1471 void testJoinersWithUnavailableResult() throws Exception {
1472 try (var scope = StructuredTaskScope.open()) {
1473 var done = new CountDownLatch(1);
1474 var subtask = scope.fork(() -> {
1475 done.await();
1476 return null;
1477 });
1478
1479 // onComplete with uncompleted task should throw IAE
1480 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
1481 assertThrows(IllegalArgumentException.class,
1482 () -> Joiner.allSuccessfulOrThrow().onComplete(subtask));
1483 assertThrows(IllegalArgumentException.class,
1506 () -> Joiner.allUntil(_ -> false).onFork(subtask));
1507 }
1508
1509 }
1510
1511 /**
1512 * Test the Configuration function apply method throwing an exception.
1513 */
1514 @Test
1515 void testConfigFunctionThrows() throws Exception {
1516 assertThrows(FooException.class,
1517 () -> StructuredTaskScope.open(Joiner.awaitAll(),
1518 cf -> { throw new FooException(); }));
1519 }
1520
1521 /**
1522 * Test Configuration equals/hashCode/toString
1523 */
1524 @Test
1525 void testConfigMethods() throws Exception {
1526 Function<Configuration, Configuration> testConfig = cf -> {
1527 var name = "duke";
1528 var threadFactory = Thread.ofPlatform().factory();
1529 var timeout = Duration.ofSeconds(10);
1530
1531 assertEquals(cf, cf);
1532 assertEquals(cf.withName(name), cf.withName(name));
1533 assertEquals(cf.withThreadFactory(threadFactory), cf.withThreadFactory(threadFactory));
1534 assertEquals(cf.withTimeout(timeout), cf.withTimeout(timeout));
1535
1536 assertNotEquals(cf, cf.withName(name));
1537 assertNotEquals(cf, cf.withThreadFactory(threadFactory));
1538 assertNotEquals(cf, cf.withTimeout(timeout));
1539
1540 assertEquals(cf.withName(name).hashCode(), cf.withName(name).hashCode());
1541 assertEquals(cf.withThreadFactory(threadFactory).hashCode(),
1542 cf.withThreadFactory(threadFactory).hashCode());
1543 assertEquals(cf.withTimeout(timeout).hashCode(), cf.withTimeout(timeout).hashCode());
1544
1545 assertTrue(cf.withName(name).toString().contains(name));
1546 assertTrue(cf.withThreadFactory(threadFactory).toString().contains(threadFactory.toString()));
1547 assertTrue(cf.withTimeout(timeout).toString().contains(timeout.toString()));
1548
1549 return cf;
1550 };
1551 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(), testConfig)) {
1552 // do nothing
1553 }
1554 }
1555
1556 /**
1557 * Test for NullPointerException.
1558 */
1559 @Test
1560 void testNulls() throws Exception {
1561 assertThrows(NullPointerException.class,
1562 () -> StructuredTaskScope.open(null));
1563 assertThrows(NullPointerException.class,
1564 () -> StructuredTaskScope.open(null, cf -> cf));
1565 assertThrows(NullPointerException.class,
1566 () -> StructuredTaskScope.open(Joiner.awaitAll(), null));
1567
1568 assertThrows(NullPointerException.class, () -> Joiner.allUntil(null));
1569
1570 // fork
1571 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
1738 found = true;
1739 } else {
1740 Thread.sleep(20);
1741 }
1742 }
1743 target.interrupt();
1744 }
1745
1746 /**
1747 * Schedules the current thread to be interrupted when it waits (timed or untimed)
1748 * at the given location.
1749 */
1750 private void scheduleInterruptAt(String location) {
1751 Thread target = Thread.currentThread();
1752 scheduler.submit(() -> {
1753 interruptThreadAt(target, location);
1754 return null;
1755 });
1756 }
1757
1758 /**
1759 * Returns true if the given stack trace contains an element for the given class
1760 * and method name.
1761 */
1762 private boolean contains(StackTraceElement[] stack, String className, String methodName) {
1763 return Arrays.stream(stack)
1764 .anyMatch(e -> className.equals(e.getClassName())
1765 && methodName.equals(e.getMethodName()));
1766 }
1767 }
|
44 import java.util.concurrent.Callable;
45 import java.util.concurrent.ConcurrentHashMap;
46 import java.util.concurrent.CountDownLatch;
47 import java.util.concurrent.Executors;
48 import java.util.concurrent.Future;
49 import java.util.concurrent.LinkedTransferQueue;
50 import java.util.concurrent.ThreadFactory;
51 import java.util.concurrent.TimeUnit;
52 import java.util.concurrent.RejectedExecutionException;
53 import java.util.concurrent.ScheduledExecutorService;
54 import java.util.concurrent.StructuredTaskScope;
55 import java.util.concurrent.StructuredTaskScope.TimeoutException;
56 import java.util.concurrent.StructuredTaskScope.Configuration;
57 import java.util.concurrent.StructuredTaskScope.FailedException;
58 import java.util.concurrent.StructuredTaskScope.Joiner;
59 import java.util.concurrent.StructuredTaskScope.Subtask;
60 import java.util.concurrent.StructureViolationException;
61 import java.util.concurrent.atomic.AtomicBoolean;
62 import java.util.concurrent.atomic.AtomicInteger;
63 import java.util.concurrent.atomic.AtomicReference;
64 import java.util.function.Predicate;
65 import java.util.function.UnaryOperator;
66 import java.util.stream.Stream;
67 import static java.lang.Thread.State.*;
68
69 import org.junit.jupiter.api.Test;
70 import org.junit.jupiter.api.BeforeAll;
71 import org.junit.jupiter.api.AfterAll;
72 import org.junit.jupiter.params.ParameterizedTest;
73 import org.junit.jupiter.params.provider.MethodSource;
74 import static org.junit.jupiter.api.Assertions.*;
75
76 class StructuredTaskScopeTest {
77 private static ScheduledExecutorService scheduler;
78 private static List<ThreadFactory> threadFactories;
79
80 @BeforeAll
81 static void setup() throws Exception {
82 scheduler = Executors.newSingleThreadScheduledExecutor();
83
84 // thread factories
85 String value = System.getProperty("threadFactory");
192 future.get();
193 }
194
195 // subtask cannot fork
196 Subtask<Boolean> subtask = scope.fork(() -> {
197 assertThrows(WrongThreadException.class, () -> {
198 scope.fork(() -> null);
199 });
200 return true;
201 });
202 scope.join();
203 assertTrue(subtask.get());
204 }
205 }
206
207 /**
208 * Test fork after join, no subtasks forked before join.
209 */
210 @ParameterizedTest
211 @MethodSource("factories")
212 void testForkAfterJoinCompleted1(ThreadFactory factory) throws Exception {
213 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
214 cf -> cf.withThreadFactory(factory))) {
215 scope.join();
216 assertThrows(IllegalStateException.class, () -> scope.fork(() -> "bar"));
217 }
218 }
219
220 /**
221 * Test fork after join, subtasks forked before join.
222 */
223 @ParameterizedTest
224 @MethodSource("factories")
225 void testForkAfterJoinCompleted2(ThreadFactory factory) throws Exception {
226 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
227 cf -> cf.withThreadFactory(factory))) {
228 scope.fork(() -> "foo");
229 scope.join();
230 assertThrows(IllegalStateException.class, () -> scope.fork(() -> "bar"));
231 }
232 }
233
234 /**
235 * Test fork after join interrupted.
236 */
237 @ParameterizedTest
238 @MethodSource("factories")
239 void testForkAfterJoinInterrupted(ThreadFactory factory) throws Exception {
240 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
241 cf -> cf.withThreadFactory(factory))) {
242 var subtask1 = scope.fork(() -> {
243 Thread.sleep(Duration.ofDays(1));
244 return "foo";
245 });
246
247 // join throws
248 Thread.currentThread().interrupt();
249 assertThrows(InterruptedException.class, scope::join);
250
251 // fork should throw
252 assertThrows(IllegalStateException.class, () -> scope.fork(() -> "bar"));
253 }
254 }
255
256 /**
257 * Test fork after join timeout.
258 */
259 @ParameterizedTest
260 @MethodSource("factories")
261 void testForkAfterJoinTimeout(ThreadFactory factory) throws Exception {
262 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
263 cf -> cf.withThreadFactory(factory)
264 .withTimeout(Duration.ofMillis(100)))) {
265 awaitCancelled(scope);
266
267 // join throws
268 assertThrows(TimeoutException.class, scope::join);
269
270 // fork should throw
271 assertThrows(IllegalStateException.class, () -> scope.fork(() -> "bar"));
272 }
273 }
274
275 /**
276 * Test fork after task scope is cancelled. This test uses a custom Joiner to
277 * cancel execution.
278 */
279 @ParameterizedTest
280 @MethodSource("factories")
281 void testForkAfterCancel2(ThreadFactory factory) throws Exception {
282 var countingThreadFactory = new CountingThreadFactory(factory);
283 var testJoiner = new CancelAfterOneJoiner<String>();
284
285 try (var scope = StructuredTaskScope.open(testJoiner,
286 cf -> cf.withThreadFactory(countingThreadFactory))) {
287
288 // fork subtask, the scope should be cancelled when the subtask completes
289 var subtask1 = scope.fork(() -> "foo");
290 awaitCancelled(scope);
291
292 assertEquals(1, countingThreadFactory.threadCount());
293 assertEquals(1, testJoiner.onForkCount());
294 assertEquals(1, testJoiner.onCompleteCount());
297 var subtask2 = scope.fork(() -> "bar");
298
299 // onFork should be invoked, newThread and onComplete should not be invoked
300 assertEquals(1, countingThreadFactory.threadCount());
301 assertEquals(2, testJoiner.onForkCount());
302 assertEquals(1, testJoiner.onCompleteCount());
303
304 scope.join();
305
306 assertEquals(1, countingThreadFactory.threadCount());
307 assertEquals(2, testJoiner.onForkCount());
308 assertEquals(1, testJoiner.onCompleteCount());
309 assertEquals("foo", subtask1.get());
310 assertEquals(Subtask.State.UNAVAILABLE, subtask2.state());
311 }
312 }
313
314 /**
315 * Test fork after task scope is closed.
316 */
317 @ParameterizedTest
318 @MethodSource("factories")
319 void testForkAfterClose(ThreadFactory factory) {
320 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
321 cf -> cf.withThreadFactory(factory))) {
322 scope.close();
323 assertThrows(IllegalStateException.class, () -> scope.fork(() -> null));
324 }
325 }
326
327 /**
328 * Test fork with a ThreadFactory that rejects creating a thread.
329 */
330 @Test
331 void testForkRejectedExecutionException() {
332 ThreadFactory factory = task -> null;
333 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
334 cf -> cf.withThreadFactory(factory))) {
335 assertThrows(RejectedExecutionException.class, () -> scope.fork(() -> null));
336 }
337 }
338
339 /**
340 * Test join with no subtasks.
341 */
385 * Test join after join completed with an exception.
386 */
387 @Test
388 void testJoinAfterJoin2() throws Exception {
389 try (var scope = StructuredTaskScope.open(Joiner.anySuccessfulResultOrThrow())) {
390 scope.fork(() -> { throw new FooException(); });
391 Throwable ex = assertThrows(FailedException.class, scope::join);
392 assertTrue(ex.getCause() instanceof FooException);
393
394 // join already called
395 for (int i = 0 ; i < 3; i++) {
396 assertThrows(IllegalStateException.class, scope::join);
397 }
398 }
399 }
400
401 /**
402 * Test join after join completed with a timeout.
403 */
404 @Test
405 void testJoinAfterJoinInterrupted() throws Exception {
406 try (var scope = StructuredTaskScope.open()) {
407 var latch = new CountDownLatch(1);
408 var subtask = scope.fork(() -> {
409 latch.await();
410 return "foo";
411 });
412
413 // join throws InterruptedException
414 Thread.currentThread().interrupt();
415 assertThrows(InterruptedException.class, scope::join);
416
417 latch.countDown();
418
419 // retry join to get result
420 scope.join();
421 assertEquals("foo", subtask.get());
422
423 // retry after otbaining result
424 assertThrows(IllegalStateException.class, scope::join);
425 }
426 }
427
428 /**
429 * Test join after join completed with a timeout.
430 */
431 @Test
432 void testJoinAfterJoinTimeout() throws Exception {
433 try (var scope = StructuredTaskScope.open(Joiner.anySuccessfulResultOrThrow(),
434 cf -> cf.withTimeout(Duration.ofMillis(100)))) {
435 // wait for scope to be cancelled by timeout
436 awaitCancelled(scope);
437 assertThrows(TimeoutException.class, scope::join);
438
439 // join already called
440 for (int i = 0 ; i < 3; i++) {
441 assertThrows(IllegalStateException.class, scope::join);
442 }
443 }
444 }
445
446 /**
447 * Test join invoked from Joiner.onTimeout.
448 */
449 @Test
450 void testJoinInOnTimeout() throws Exception {
451 Thread owner = Thread.currentThread();
452 var scopeRef = new AtomicReference<StructuredTaskScope<?, ?>>();
453
454 var joiner = new Joiner<String, Void>() {
455 @Override
456 public void onTimeout() {
457 assertTrue(Thread.currentThread() == owner);
458 var scope = scopeRef.get();
459 assertThrows(IllegalStateException.class, scope::join);
460 }
461 @Override
462 public Void result() {
463 return null;
464 }
465 };
466
467 try (var scope = StructuredTaskScope.open(joiner,
468 cf -> cf.withTimeout(Duration.ofMillis(100)))) {
469 awaitCancelled(scope);
470 scopeRef.set(scope);
471 scope.join(); // invokes onTimeout
472 }
473 }
474
475 /**
476 * Test join method is owner confined.
477 */
478 @ParameterizedTest
479 @MethodSource("factories")
480 void testJoinConfined(ThreadFactory factory) throws Exception {
481 try (var scope = StructuredTaskScope.open(Joiner.<Boolean>awaitAll(),
482 cf -> cf.withThreadFactory(factory))) {
483
484 // random thread cannot join
485 try (var pool = Executors.newSingleThreadExecutor()) {
486 Future<Void> future = pool.submit(() -> {
487 assertThrows(WrongThreadException.class, scope::join);
488 return null;
489 });
490 future.get();
491 }
492
493 // subtask cannot join
494 Subtask<Boolean> subtask = scope.fork(() -> {
495 assertThrows(WrongThreadException.class, () -> { scope.join(); });
496 return true;
497 });
498 scope.join();
499 assertTrue(subtask.get());
500 }
501 }
502
503 /**
504 * Test join with interrupt status set.
505 */
506 @ParameterizedTest
507 @MethodSource("factories")
508 void testInterruptJoin1(ThreadFactory factory) throws Exception {
509 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
510 cf -> cf.withThreadFactory(factory))) {
511
512 Subtask<String> subtask = scope.fork(() -> {
513 Thread.sleep(Duration.ofDays(1));
514 return "foo";
515 });
516
517 // join should throw
518 Thread.currentThread().interrupt();
519 try {
520 scope.join();
521 fail("join did not throw");
522 } catch (InterruptedException expected) {
523 assertFalse(Thread.interrupted()); // interrupt status should be cleared
524 }
525 }
526 }
527
528 /**
529 * Test interrupt of thread blocked in join.
530 */
531 @ParameterizedTest
532 @MethodSource("factories")
533 void testInterruptJoin2(ThreadFactory factory) throws Exception {
534 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
535 cf -> cf.withThreadFactory(factory))) {
536 Subtask<String> subtask = scope.fork(() -> {
537 Thread.sleep(Duration.ofDays(1));
538 return "foo";
539 });
540
541 // interrupt main thread when it blocks in join
542 scheduleInterruptAt("java.util.concurrent.StructuredTaskScopeImpl.join");
543 try {
544 scope.join();
545 fail("join did not throw");
546 } catch (InterruptedException expected) {
547 assertFalse(Thread.interrupted()); // interrupt status should be clear
548 }
549 }
550 }
551
552 /**
553 * Test join when scope is cancelled.
554 */
555 @ParameterizedTest
556 @MethodSource("factories")
557 void testJoinWhenCancelled(ThreadFactory factory) throws Exception {
1022 @Test
1023 void testOnCompleteCancelsExecution() throws Exception {
1024 var joiner = new Joiner<String, Void>() {
1025 @Override
1026 public boolean onComplete(Subtask<? extends String> subtask) {
1027 return true;
1028 }
1029 @Override
1030 public Void result() {
1031 return null;
1032 }
1033 };
1034 try (var scope = StructuredTaskScope.open(joiner)) {
1035 assertFalse(scope.isCancelled());
1036 scope.fork(() -> "foo");
1037 awaitCancelled(scope);
1038 scope.join();
1039 }
1040 }
1041
1042 /**
1043 * Test Joiner.onTimeout invoked by owner thread when timeout expires.
1044 */
1045 @Test
1046 void testOnTimeoutInvoked() throws Exception {
1047 var scopeRef = new AtomicReference<StructuredTaskScope<?, ?>>();
1048 Thread owner = Thread.currentThread();
1049 var invokeCount = new AtomicInteger();
1050 var joiner = new Joiner<String, Void>() {
1051 @Override
1052 public void onTimeout() {
1053 assertTrue(Thread.currentThread() == owner);
1054 assertTrue(scopeRef.get().isCancelled());
1055 invokeCount.incrementAndGet();
1056 }
1057 @Override
1058 public Void result() {
1059 return null;
1060 }
1061 };
1062 try (var scope = StructuredTaskScope.open(joiner,
1063 cf -> cf.withTimeout(Duration.ofMillis(100)))) {
1064 scopeRef.set(scope);
1065 scope.fork(() -> {
1066 Thread.sleep(Duration.ofDays(1));
1067 return null;
1068 });
1069 scope.join();
1070 assertEquals(1, invokeCount.get());
1071 }
1072 }
1073
1074 /**
1075 * Test Joiner.onTimeout throwing an excepiton.
1076 */
1077 @Test
1078 void testOnTimeoutThrows() throws Exception {
1079 var joiner = new Joiner<String, Void>() {
1080 @Override
1081 public void onTimeout() {
1082 throw new FooException();
1083 }
1084 @Override
1085 public Void result() {
1086 return null;
1087 }
1088 };
1089 try (var scope = StructuredTaskScope.open(joiner,
1090 cf -> cf.withTimeout(Duration.ofMillis(100)))) {
1091 // wait for scope to be cancelled by timeout
1092 awaitCancelled(scope);
1093
1094 // join should throw FooException on first usage
1095 assertThrows(FooException.class, scope::join);
1096
1097 // retry after onTimeout fails
1098 assertThrows(IllegalStateException.class, scope::join);
1099 }
1100 }
1101
1102 /**
1103 * Test toString.
1104 */
1105 @Test
1106 void testToString() throws Exception {
1107 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
1108 cf -> cf.withName("duke"))) {
1109
1110 // open
1111 assertTrue(scope.toString().contains("duke"));
1112
1113 // closed
1114 scope.close();
1115 assertTrue(scope.toString().contains("duke"));
1116 }
1117 }
1118
1119 /**
1120 * Test Subtask with task that completes successfully.
1121 */
1122 @ParameterizedTest
1123 @MethodSource("factories")
1124 void testSubtaskWhenSuccess(ThreadFactory factory) throws Exception {
1125 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAll(),
1126 cf -> cf.withThreadFactory(factory))) {
1127 Subtask<String> subtask = scope.fork(() -> "foo");
1128
1129 // before join, owner thread
1130 assertThrows(IllegalStateException.class, subtask::get);
1131 assertThrows(IllegalStateException.class, subtask::exception);
1132
1133 // before join, another thread
1134 assertThrows(IllegalStateException.class, () -> callInOtherThread(subtask::get));
1135 assertThrows(IllegalStateException.class, () -> callInOtherThread(subtask::exception));
1136
1137 scope.join();
1138
1139 assertEquals(Subtask.State.SUCCESS, subtask.state());
1140
1141 // after join, owner thread
1142 assertEquals("foo", subtask.get());
1143 assertThrows(IllegalStateException.class, subtask::exception);
1144
1145 // after join, another thread
1146 assertEquals("foo", callInOtherThread(subtask::get));
1147 assertThrows(IllegalStateException.class, () -> callInOtherThread(subtask::exception));
1148 }
1149 }
1150
1151 /**
1152 * Test Subtask with task that fails.
1153 */
1154 @ParameterizedTest
1155 @MethodSource("factories")
1156 void testSubtaskWhenFailed(ThreadFactory factory) throws Exception {
1157 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAll(),
1158 cf -> cf.withThreadFactory(factory))) {
1159
1160 Subtask<String> subtask = scope.fork(() -> { throw new FooException(); });
1161
1162 // before join, owner thread
1163 assertThrows(IllegalStateException.class, subtask::get);
1164 assertThrows(IllegalStateException.class, subtask::exception);
1165
1166 // before join, another thread
1167 assertThrows(IllegalStateException.class, () -> callInOtherThread(subtask::get));
1168 assertThrows(IllegalStateException.class, () -> callInOtherThread(subtask::exception));
1169
1170 scope.join();
1171
1172 assertEquals(Subtask.State.FAILED, subtask.state());
1173
1174 // after join, owner thread
1175 assertThrows(IllegalStateException.class, subtask::get);
1176 assertTrue(subtask.exception() instanceof FooException);
1177
1178 // after join, another thread
1179 assertThrows(IllegalStateException.class, () -> callInOtherThread(subtask::get));
1180 assertTrue(callInOtherThread(subtask::exception) instanceof FooException);
1181 }
1182 }
1183
1184 /**
1185 * Test Subtask with a task that has not completed.
1186 */
1187 @ParameterizedTest
1188 @MethodSource("factories")
1189 void testSubtaskWhenNotCompleted(ThreadFactory factory) throws Exception {
1190 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(),
1191 cf -> cf.withThreadFactory(factory))) {
1192 Subtask<Void> subtask = scope.fork(() -> {
1193 Thread.sleep(Duration.ofDays(1));
1194 return null;
1195 });
1196 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
1197
1198 // before join, owner thread
1199 assertThrows(IllegalStateException.class, subtask::get);
1200 assertThrows(IllegalStateException.class, subtask::exception);
1201
1202 // before join, another thread
1203 assertThrows(IllegalStateException.class, () -> callInOtherThread(subtask::get));
1204 assertThrows(IllegalStateException.class, () -> callInOtherThread(subtask::exception));
1205
1206 // attempt join, join throws
1207 Thread.currentThread().interrupt();
1208 assertThrows(InterruptedException.class, scope::join);
1209
1210 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
1211
1212 // after join, owner thread
1213 assertThrows(IllegalStateException.class, subtask::get);
1214 assertThrows(IllegalStateException.class, subtask::exception);
1215
1216 // before join, another thread
1217 assertThrows(IllegalStateException.class, () -> callInOtherThread(subtask::get));
1218 assertThrows(IllegalStateException.class, () -> callInOtherThread(subtask::exception));
1219 }
1220 }
1221
1222 /**
1223 * Test Subtask forked after execution cancelled.
1224 */
1225 @ParameterizedTest
1226 @MethodSource("factories")
1227 void testSubtaskWhenCancelled(ThreadFactory factory) throws Exception {
1228 try (var scope = StructuredTaskScope.open(new CancelAfterOneJoiner<String>())) {
1229 scope.fork(() -> "foo");
1230 awaitCancelled(scope);
1231
1232 var subtask = scope.fork(() -> "foo");
1233
1234 // before join, owner thread
1235 assertThrows(IllegalStateException.class, subtask::get);
1236 assertThrows(IllegalStateException.class, subtask::exception);
1237
1238 // before join, another thread
1239 assertThrows(IllegalStateException.class, () -> callInOtherThread(subtask::get));
1240 assertThrows(IllegalStateException.class, () -> callInOtherThread(subtask::exception));
1241
1242 scope.join();
1243
1244 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
1245
1246 // after join, owner thread
1247 assertThrows(IllegalStateException.class, subtask::get);
1248 assertThrows(IllegalStateException.class, subtask::exception);
1249
1250 // before join, another thread
1251 assertThrows(IllegalStateException.class, () -> callInOtherThread(subtask::get));
1252 assertThrows(IllegalStateException.class, () -> callInOtherThread(subtask::exception));
1253 }
1254 }
1255
1256 /**
1257 * Test Subtask::toString.
1258 */
1259 @Test
1260 void testSubtaskToString() throws Exception {
1261 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
1262 var latch = new CountDownLatch(1);
1263 var subtask1 = scope.fork(() -> {
1264 latch.await();
1265 return "foo";
1266 });
1267 var subtask2 = scope.fork(() -> { throw new FooException(); });
1268
1269 // subtask1 result is unavailable
1270 assertTrue(subtask1.toString().contains("Unavailable"));
1271 latch.countDown();
1272
1307
1308 /**
1309 * Test Joiner.allSuccessfulOrThrow() with a subtask that complete successfully and
1310 * a subtask that fails.
1311 */
1312 @ParameterizedTest
1313 @MethodSource("factories")
1314 void testAllSuccessfulOrThrow3(ThreadFactory factory) throws Throwable {
1315 try (var scope = StructuredTaskScope.open(Joiner.<String>allSuccessfulOrThrow(),
1316 cf -> cf.withThreadFactory(factory))) {
1317 scope.fork(() -> "foo");
1318 scope.fork(() -> { throw new FooException(); });
1319 try {
1320 scope.join();
1321 } catch (FailedException e) {
1322 assertTrue(e.getCause() instanceof FooException);
1323 }
1324 }
1325 }
1326
1327 /**
1328 * Test Joiner.allSuccessfulOrThrow() with a timeout.
1329 */
1330 @Test
1331 void testAllSuccessfulOrThrow4() throws Exception {
1332 try (var scope = StructuredTaskScope.open(Joiner.<String>allSuccessfulOrThrow(),
1333 cf -> cf.withTimeout(Duration.ofMillis(100)))) {
1334 scope.fork(() -> "foo");
1335 scope.fork(() -> {
1336 Thread.sleep(Duration.ofDays(1));
1337 return "bar";
1338 });
1339 assertThrows(TimeoutException.class, scope::join);
1340
1341 // retry after join throws TimeoutException
1342 assertThrows(IllegalStateException.class, scope::join);
1343 }
1344 }
1345
1346 /**
1347 * Test Joiner.anySuccessfulResultOrThrow() with no subtasks.
1348 */
1349 @Test
1350 void testAnySuccessfulResultOrThrow1() throws Exception {
1351 try (var scope = StructuredTaskScope.open(Joiner.anySuccessfulResultOrThrow())) {
1352 try {
1353 scope.join();
1354 } catch (FailedException e) {
1355 assertTrue(e.getCause() instanceof NoSuchElementException);
1356 }
1357 }
1358 }
1359
1360 /**
1361 * Test Joiner.anySuccessfulResultOrThrow() with a subtask that completes successfully.
1362 */
1363 @ParameterizedTest
1364 @MethodSource("factories")
1365 void testAnySuccessfulResultOrThrow2(ThreadFactory factory) throws Exception {
1399 scope.fork(() -> { throw new FooException(); });
1400 String first = scope.join();
1401 assertEquals("foo", first);
1402 }
1403 }
1404
1405 /**
1406 * Test Joiner.anySuccessfulResultOrThrow() with a subtask that fails.
1407 */
1408 @ParameterizedTest
1409 @MethodSource("factories")
1410 void testAnySuccessfulResultOrThrow5(ThreadFactory factory) throws Exception {
1411 try (var scope = StructuredTaskScope.open(Joiner.anySuccessfulResultOrThrow(),
1412 cf -> cf.withThreadFactory(factory))) {
1413 scope.fork(() -> { throw new FooException(); });
1414 Throwable ex = assertThrows(FailedException.class, scope::join);
1415 assertTrue(ex.getCause() instanceof FooException);
1416 }
1417 }
1418
1419 /**
1420 * Test Joiner.allSuccessfulOrThrow() with a timeout.
1421 */
1422 @Test
1423 void anySuccessfulResultOrThrow6() throws Exception {
1424 try (var scope = StructuredTaskScope.open(Joiner.<String>anySuccessfulResultOrThrow(),
1425 cf -> cf.withTimeout(Duration.ofMillis(100)))) {
1426 scope.fork(() -> { throw new FooException(); });
1427 scope.fork(() -> {
1428 Thread.sleep(Duration.ofDays(1));
1429 return "bar";
1430 });
1431 assertThrows(TimeoutException.class, scope::join);
1432
1433 // retry after join throws TimeoutException
1434 assertThrows(IllegalStateException.class, scope::join);
1435 }
1436 }
1437
1438 /**
1439 * Test Joiner.awaitAllSuccessfulOrThrow() with no subtasks.
1440 */
1441 @Test
1442 void testAwaitSuccessfulOrThrow1() throws Throwable {
1443 try (var scope = StructuredTaskScope.open(Joiner.awaitAllSuccessfulOrThrow())) {
1444 var result = scope.join();
1445 assertNull(result);
1446 }
1447 }
1448
1449 /**
1450 * Test Joiner.awaitAllSuccessfulOrThrow() with subtasks that complete successfully.
1451 */
1452 @ParameterizedTest
1453 @MethodSource("factories")
1454 void testAwaitSuccessfulOrThrow2(ThreadFactory factory) throws Throwable {
1455 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAllSuccessfulOrThrow(),
1456 cf -> cf.withThreadFactory(factory))) {
1457 var subtask1 = scope.fork(() -> "foo");
1465
1466 /**
1467 * Test Joiner.awaitAllSuccessfulOrThrow() with a subtask that complete successfully and
1468 * a subtask that fails.
1469 */
1470 @ParameterizedTest
1471 @MethodSource("factories")
1472 void testAwaitSuccessfulOrThrow3(ThreadFactory factory) throws Throwable {
1473 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAllSuccessfulOrThrow(),
1474 cf -> cf.withThreadFactory(factory))) {
1475 scope.fork(() -> "foo");
1476 scope.fork(() -> { throw new FooException(); });
1477 try {
1478 scope.join();
1479 } catch (FailedException e) {
1480 assertTrue(e.getCause() instanceof FooException);
1481 }
1482 }
1483 }
1484
1485 /**
1486 * Test Joiner.awaitAllSuccessfulOrThrow() with a timeout.
1487 */
1488 @Test
1489 void testAwaitSuccessfulOrThrow4() throws Exception {
1490 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAllSuccessfulOrThrow(),
1491 cf -> cf.withTimeout(Duration.ofMillis(100)))) {
1492 scope.fork(() -> "foo");
1493 scope.fork(() -> {
1494 Thread.sleep(Duration.ofDays(1));
1495 return "bar";
1496 });
1497 assertThrows(TimeoutException.class, scope::join);
1498
1499 // retry after join throws TimeoutException
1500 assertThrows(IllegalStateException.class, scope::join);
1501 }
1502 }
1503
1504 /**
1505 * Test Joiner.awaitAll() with no subtasks.
1506 */
1507 @Test
1508 void testAwaitAll1() throws Throwable {
1509 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
1510 var result = scope.join();
1511 assertNull(result);
1512 }
1513 }
1514
1515 /**
1516 * Test Joiner.awaitAll() with subtasks that complete successfully.
1517 */
1518 @ParameterizedTest
1519 @MethodSource("factories")
1520 void testAwaitAll2(ThreadFactory factory) throws Throwable {
1521 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAll(),
1522 cf -> cf.withThreadFactory(factory))) {
1523 var subtask1 = scope.fork(() -> "foo");
1530 }
1531
1532 /**
1533 * Test Joiner.awaitAll() with a subtask that complete successfully and a subtask
1534 * that fails.
1535 */
1536 @ParameterizedTest
1537 @MethodSource("factories")
1538 void testAwaitAll3(ThreadFactory factory) throws Throwable {
1539 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAll(),
1540 cf -> cf.withThreadFactory(factory))) {
1541 var subtask1 = scope.fork(() -> "foo");
1542 var subtask2 = scope.fork(() -> { throw new FooException(); });
1543 var result = scope.join();
1544 assertNull(result);
1545 assertEquals("foo", subtask1.get());
1546 assertTrue(subtask2.exception() instanceof FooException);
1547 }
1548 }
1549
1550 /**
1551 * Test Joiner.awaitAll() with a timeout.
1552 */
1553 @Test
1554 void testAwaitAll4() throws Exception {
1555 try (var scope = StructuredTaskScope.open(Joiner.<String>awaitAll(),
1556 cf -> cf.withTimeout(Duration.ofMillis(100)))) {
1557 scope.fork(() -> "foo");
1558 scope.fork(() -> {
1559 Thread.sleep(Duration.ofDays(1));
1560 return "bar";
1561 });
1562 assertThrows(TimeoutException.class, scope::join);
1563
1564 // retry after join throws TimeoutException
1565 assertThrows(IllegalStateException.class, scope::join);
1566 }
1567 }
1568
1569 /**
1570 * Test Joiner.allUntil(Predicate) with no subtasks.
1571 */
1572 @Test
1573 void testAllUntil1() throws Throwable {
1574 try (var scope = StructuredTaskScope.open(Joiner.allUntil(s -> false))) {
1575 var subtasks = scope.join();
1576 assertEquals(0, subtasks.count());
1577 }
1578 }
1579
1580 /**
1581 * Test Joiner.allUntil(Predicate) with no cancellation.
1582 */
1583 @ParameterizedTest
1584 @MethodSource("factories")
1585 void testAllUntil2(ThreadFactory factory) throws Exception {
1586 try (var scope = StructuredTaskScope.open(Joiner.<String>allUntil(s -> false),
1587 cf -> cf.withThreadFactory(factory))) {
1588
1589 var subtask1 = scope.fork(() -> "foo");
1590 var subtask2 = scope.fork(() -> { throw new FooException(); });
1591
1592 var subtasks = scope.join().toList();
1593 assertEquals(List.of(subtask1, subtask2), subtasks);
1594
1595 assertEquals("foo", subtask1.get());
1596 assertTrue(subtask2.exception() instanceof FooException);
1597 }
1598 }
1599
1600 /**
1601 * Test Joiner.allUntil(Predicate) with cancellation after one subtask completes.
1602 */
1603 @ParameterizedTest
1604 @MethodSource("factories")
1605 void testAllUntil3(ThreadFactory factory) throws Exception {
1606 try (var scope = StructuredTaskScope.open(Joiner.<String>allUntil(s -> true),
1607 cf -> cf.withThreadFactory(factory))) {
1608
1609 var subtask1 = scope.fork(() -> "foo");
1610 var subtask2 = scope.fork(() -> {
1611 Thread.sleep(Duration.ofDays(1));
1612 return "bar";
1613 });
1614
1615 var subtasks = scope.join().toList();
1616 assertEquals(List.of(subtask1, subtask2), subtasks);
1617
1618 assertEquals("foo", subtask1.get());
1619 assertEquals(Subtask.State.UNAVAILABLE, subtask2.state());
1620 }
1621 }
1622
1623 /**
1624 * Test Joiner.allUntil(Predicate) with cancellation after serveral subtasks complete.
1625 */
1626 @ParameterizedTest
1627 @MethodSource("factories")
1628 void testAllUntil4(ThreadFactory factory) throws Exception {
1629
1630 // cancel execution after two or more failures
1631 class CancelAfterTwoFailures<T> implements Predicate<Subtask<? extends T>> {
1632 final AtomicInteger failedCount = new AtomicInteger();
1633 @Override
1634 public boolean test(Subtask<? extends T> subtask) {
1635 return subtask.state() == Subtask.State.FAILED
1636 && failedCount.incrementAndGet() >= 2;
1637 }
1660 }
1661
1662 /**
1663 * Test Test Joiner.allUntil(Predicate) where the Predicate's test method throws.
1664 */
1665 @Test
1666 void testAllUntil5() throws Exception {
1667 var joiner = Joiner.allUntil(_ -> { throw new FooException(); });
1668 var excRef = new AtomicReference<Throwable>();
1669 Thread.UncaughtExceptionHandler uhe = (t, e) -> excRef.set(e);
1670 ThreadFactory factory = Thread.ofVirtual()
1671 .uncaughtExceptionHandler(uhe)
1672 .factory();
1673 try (var scope = StructuredTaskScope.open(joiner, cf -> cf.withThreadFactory(factory))) {
1674 scope.fork(() -> "foo");
1675 scope.join();
1676 assertInstanceOf(FooException.class, excRef.get());
1677 }
1678 }
1679
1680 /**
1681 * Test Joiner.allUntil(Predicate) with a timeout.
1682 */
1683 @Test
1684 void testAllUntil6() throws Exception {
1685 try (var scope = StructuredTaskScope.open(Joiner.<String>allUntil(s -> false),
1686 cf -> cf.withTimeout(Duration.ofMillis(100)))) {
1687 var subtask1 = scope.fork(() -> "foo");
1688 var subtask2 = scope.fork(() -> {
1689 Thread.sleep(Duration.ofDays(1));
1690 return "bar";
1691 });
1692
1693 // TimeoutException should not be thrown
1694 var subtasks = scope.join().toList();
1695
1696 // stream should have two elements, subtask1 may or may not have completed
1697 assertEquals(List.of(subtask1, subtask2), subtasks);
1698 assertEquals(Subtask.State.UNAVAILABLE, subtask2.state());
1699
1700 // retry after join throws TimeoutException
1701 assertThrows(IllegalStateException.class, scope::join);
1702 }
1703 }
1704
1705 /**
1706 * Test Joiner default methods.
1707 */
1708 @Test
1709 void testJoinerDefaultMethods() throws Exception {
1710 try (var scope = StructuredTaskScope.open(new CancelAfterOneJoiner<String>())) {
1711
1712 // need subtasks to test default methods
1713 var subtask1 = scope.fork(() -> "foo");
1714 awaitCancelled(scope);
1715 var subtask2 = scope.fork(() -> "bar");
1716 scope.join();
1717
1718 assertEquals(Subtask.State.SUCCESS, subtask1.state());
1719 assertEquals(Subtask.State.UNAVAILABLE, subtask2.state());
1720
1721 // Joiner that does not override default methods
1722 Joiner<Object, Void> joiner = () -> null;
1723 assertThrows(NullPointerException.class, () -> joiner.onFork(null));
1724 assertThrows(NullPointerException.class, () -> joiner.onComplete(null));
1725 assertThrows(IllegalArgumentException.class, () -> joiner.onFork(subtask1));
1726 assertFalse(joiner.onFork(subtask2));
1727 assertFalse(joiner.onComplete(subtask1));
1728 assertThrows(IllegalArgumentException.class, () -> joiner.onComplete(subtask2));
1729 assertThrows(TimeoutException.class, joiner::onTimeout);
1730 }
1731 }
1732
1733 /**
1734 * Test Joiners onFork/onComplete methods with a subtask in an unexpected state.
1735 */
1736 @Test
1737 void testJoinersWithUnavailableResult() throws Exception {
1738 try (var scope = StructuredTaskScope.open()) {
1739 var done = new CountDownLatch(1);
1740 var subtask = scope.fork(() -> {
1741 done.await();
1742 return null;
1743 });
1744
1745 // onComplete with uncompleted task should throw IAE
1746 assertEquals(Subtask.State.UNAVAILABLE, subtask.state());
1747 assertThrows(IllegalArgumentException.class,
1748 () -> Joiner.allSuccessfulOrThrow().onComplete(subtask));
1749 assertThrows(IllegalArgumentException.class,
1772 () -> Joiner.allUntil(_ -> false).onFork(subtask));
1773 }
1774
1775 }
1776
1777 /**
1778 * Test the Configuration function apply method throwing an exception.
1779 */
1780 @Test
1781 void testConfigFunctionThrows() throws Exception {
1782 assertThrows(FooException.class,
1783 () -> StructuredTaskScope.open(Joiner.awaitAll(),
1784 cf -> { throw new FooException(); }));
1785 }
1786
1787 /**
1788 * Test Configuration equals/hashCode/toString
1789 */
1790 @Test
1791 void testConfigMethods() throws Exception {
1792 UnaryOperator<Configuration> configOperator = cf -> {
1793 var name = "duke";
1794 var threadFactory = Thread.ofPlatform().factory();
1795 var timeout = Duration.ofSeconds(10);
1796
1797 assertEquals(cf, cf);
1798 assertEquals(cf.withName(name), cf.withName(name));
1799 assertEquals(cf.withThreadFactory(threadFactory), cf.withThreadFactory(threadFactory));
1800 assertEquals(cf.withTimeout(timeout), cf.withTimeout(timeout));
1801
1802 assertNotEquals(cf, cf.withName(name));
1803 assertNotEquals(cf, cf.withThreadFactory(threadFactory));
1804 assertNotEquals(cf, cf.withTimeout(timeout));
1805
1806 assertEquals(cf.withName(name).hashCode(), cf.withName(name).hashCode());
1807 assertEquals(cf.withThreadFactory(threadFactory).hashCode(),
1808 cf.withThreadFactory(threadFactory).hashCode());
1809 assertEquals(cf.withTimeout(timeout).hashCode(), cf.withTimeout(timeout).hashCode());
1810
1811 assertTrue(cf.withName(name).toString().contains(name));
1812 assertTrue(cf.withThreadFactory(threadFactory).toString().contains(threadFactory.toString()));
1813 assertTrue(cf.withTimeout(timeout).toString().contains(timeout.toString()));
1814
1815 return cf;
1816 };
1817 try (var scope = StructuredTaskScope.open(Joiner.awaitAll(), configOperator)) {
1818 // do nothing
1819 }
1820 }
1821
1822 /**
1823 * Test for NullPointerException.
1824 */
1825 @Test
1826 void testNulls() throws Exception {
1827 assertThrows(NullPointerException.class,
1828 () -> StructuredTaskScope.open(null));
1829 assertThrows(NullPointerException.class,
1830 () -> StructuredTaskScope.open(null, cf -> cf));
1831 assertThrows(NullPointerException.class,
1832 () -> StructuredTaskScope.open(Joiner.awaitAll(), null));
1833
1834 assertThrows(NullPointerException.class, () -> Joiner.allUntil(null));
1835
1836 // fork
1837 try (var scope = StructuredTaskScope.open(Joiner.awaitAll())) {
2004 found = true;
2005 } else {
2006 Thread.sleep(20);
2007 }
2008 }
2009 target.interrupt();
2010 }
2011
2012 /**
2013 * Schedules the current thread to be interrupted when it waits (timed or untimed)
2014 * at the given location.
2015 */
2016 private void scheduleInterruptAt(String location) {
2017 Thread target = Thread.currentThread();
2018 scheduler.submit(() -> {
2019 interruptThreadAt(target, location);
2020 return null;
2021 });
2022 }
2023
2024 /**
2025 * Calls a result returning task from another thread.
2026 */
2027 private <V> V callInOtherThread(Callable<V> task) throws Exception {
2028 var result = new AtomicReference<V>();
2029 var exc = new AtomicReference<Exception>();
2030 Thread thread = Thread.ofVirtual().start(() -> {
2031 try {
2032 result.set(task.call());
2033 } catch (Exception e) {
2034 exc.set(e);
2035 }
2036 });
2037 boolean interrupted = false;
2038 boolean terminated = false;
2039 while (!terminated) {
2040 try {
2041 thread.join();
2042 terminated = true;
2043 } catch (InterruptedException e) {
2044 interrupted = true;
2045 }
2046 }
2047 if (interrupted) {
2048 Thread.currentThread().interrupt();
2049 }
2050 Exception e = exc.get();
2051 if (e != null) {
2052 throw e;
2053 } else {
2054 return result.get();
2055 }
2056 }
2057
2058 /**
2059 * Returns true if the given stack trace contains an element for the given class
2060 * and method name.
2061 */
2062 private boolean contains(StackTraceElement[] stack, String className, String methodName) {
2063 return Arrays.stream(stack)
2064 .anyMatch(e -> className.equals(e.getClassName())
2065 && methodName.equals(e.getMethodName()));
2066 }
2067 }
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