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Comparing jsr166/src/test/tck/CompletableFutureTest.java (file contents):
Revision 1.94 by jsr166, Wed Jun 18 02:37:38 2014 UTC vs.
Revision 1.142 by dl, Fri Apr 1 23:18:00 2016 UTC

#	Line 5 | Line 5
5		* http://creativecommons.org/publicdomain/zero/1.0/
6		*/
7
8	<	import junit.framework.*;
8	>	import static java.util.concurrent.TimeUnit.MILLISECONDS;
9	>	import static java.util.concurrent.TimeUnit.SECONDS;
10	>	import static java.util.concurrent.CompletableFuture.completedFuture;
11	>	import static java.util.concurrent.CompletableFuture.failedFuture;
12	>
13	>	import java.lang.reflect.Method;
14	>	import java.lang.reflect.Modifier;
15	>
16	>	import java.util.stream.Collectors;
17	>	import java.util.stream.Stream;
18	>
19	>	import java.util.ArrayList;
20	>	import java.util.Arrays;
21	>	import java.util.List;
22	>	import java.util.Objects;
23	>	import java.util.Set;
24		import java.util.concurrent.Callable;
10	–	import java.util.concurrent.Executor;
11	–	import java.util.concurrent.ExecutorService;
12	–	import java.util.concurrent.Executors;
25		import java.util.concurrent.CancellationException;
14	–	import java.util.concurrent.CountDownLatch;
15	–	import java.util.concurrent.ExecutionException;
16	–	import java.util.concurrent.Future;
26		import java.util.concurrent.CompletableFuture;
27		import java.util.concurrent.CompletionException;
28		import java.util.concurrent.CompletionStage;
29	+	import java.util.concurrent.ExecutionException;
30	+	import java.util.concurrent.Executor;
31		import java.util.concurrent.ForkJoinPool;
32		import java.util.concurrent.ForkJoinTask;
33		import java.util.concurrent.TimeoutException;
34	+	import java.util.concurrent.TimeUnit;
35		import java.util.concurrent.atomic.AtomicInteger;
36	<	import static java.util.concurrent.TimeUnit.MILLISECONDS;
25	<	import static java.util.concurrent.TimeUnit.SECONDS;
26	<	import java.util.*;
27	<	import java.util.function.Supplier;
28	<	import java.util.function.Consumer;
36	>	import java.util.concurrent.atomic.AtomicReference;
37		import java.util.function.BiConsumer;
30	–	import java.util.function.Function;
38		import java.util.function.BiFunction;
39	+	import java.util.function.Consumer;
40	+	import java.util.function.Function;
41	+	import java.util.function.Predicate;
42	+	import java.util.function.Supplier;
43	+
44	+	import junit.framework.AssertionFailedError;
45	+	import junit.framework.Test;
46	+	import junit.framework.TestSuite;
47
48		public class CompletableFutureTest extends JSR166TestCase {
49
50		public static void main(String[] args) {
51	<	junit.textui.TestRunner.run(suite());
51	>	main(suite(), args);
52		}
53		public static Test suite() {
54		return new TestSuite(CompletableFutureTest.class);
#	Line 44 | Line 59 | public class CompletableFutureTest exten
59		void checkIncomplete(CompletableFuture<?> f) {
60		assertFalse(f.isDone());
61		assertFalse(f.isCancelled());
62	<	assertTrue(f.toString().contains("[Not completed]"));
62	>	assertTrue(f.toString().contains("Not completed"));
63		try {
64		assertNull(f.getNow(null));
65		} catch (Throwable fail) { threadUnexpectedException(fail); }
#	Line 57 | Line 72 | public class CompletableFutureTest exten
72		}
73
74		<T> void checkCompletedNormally(CompletableFuture<T> f, T value) {
75	<	try {
76	<	assertEquals(value, f.get(LONG_DELAY_MS, MILLISECONDS));
62	<	} catch (Throwable fail) { threadUnexpectedException(fail); }
75	>	checkTimedGet(f, value);
76	>
77		try {
78		assertEquals(value, f.join());
79		} catch (Throwable fail) { threadUnexpectedException(fail); }
#	Line 75 | Line 89 | public class CompletableFutureTest exten
89		assertTrue(f.toString().contains("[Completed normally]"));
90		}
91
92	<	void checkCompletedWithWrappedCFException(CompletableFuture<?> f) {
93	<	try {
94	<	f.get(LONG_DELAY_MS, MILLISECONDS);
95	<	shouldThrow();
96	<	} catch (ExecutionException success) {
97	<	assertTrue(success.getCause() instanceof CFException);
98	<	} catch (Throwable fail) { threadUnexpectedException(fail); }
99	<	try {
100	<	f.join();
101	<	shouldThrow();
102	<	} catch (CompletionException success) {
103	<	assertTrue(success.getCause() instanceof CFException);
104	<	}
105	<	try {
106	<	f.getNow(null);
107	<	shouldThrow();
108	<	} catch (CompletionException success) {
95	<	assertTrue(success.getCause() instanceof CFException);
92	>	/**
93	>	* Returns the "raw" internal exceptional completion of f,
94	>	* without any additional wrapping with CompletionException.
95	>	*/
96	>	<U> Throwable exceptionalCompletion(CompletableFuture<U> f) {
97	>	// handle (and whenComplete) can distinguish between "direct"
98	>	// and "wrapped" exceptional completion
99	>	return f.handle((U u, Throwable t) -> t).join();
100	>	}
101	>
102	>	void checkCompletedExceptionally(CompletableFuture<?> f,
103	>	boolean wrapped,
104	>	Consumer<Throwable> checker) {
105	>	Throwable cause = exceptionalCompletion(f);
106	>	if (wrapped) {
107	>	assertTrue(cause instanceof CompletionException);
108	>	cause = cause.getCause();
109		}
110	<	try {
98	<	f.get();
99	<	shouldThrow();
100	<	} catch (ExecutionException success) {
101	<	assertTrue(success.getCause() instanceof CFException);
102	<	} catch (Throwable fail) { threadUnexpectedException(fail); }
103	<	assertTrue(f.isDone());
104	<	assertFalse(f.isCancelled());
105	<	assertTrue(f.toString().contains("[Completed exceptionally]"));
106	<	}
110	>	checker.accept(cause);
111
112	<	<U> void checkCompletedExceptionallyWithRootCause(CompletableFuture<U> f,
109	<	Throwable ex) {
112	>	long startTime = System.nanoTime();
113		try {
114		f.get(LONG_DELAY_MS, MILLISECONDS);
115		shouldThrow();
116		} catch (ExecutionException success) {
117	<	assertSame(ex, success.getCause());
117	>	assertSame(cause, success.getCause());
118		} catch (Throwable fail) { threadUnexpectedException(fail); }
119	+	assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS / 2);
120	+
121		try {
122		f.join();
123		shouldThrow();
124		} catch (CompletionException success) {
125	<	assertSame(ex, success.getCause());
126	<	}
125	>	assertSame(cause, success.getCause());
126	>	} catch (Throwable fail) { threadUnexpectedException(fail); }
127	>
128		try {
129		f.getNow(null);
130		shouldThrow();
131		} catch (CompletionException success) {
132	<	assertSame(ex, success.getCause());
133	<	}
132	>	assertSame(cause, success.getCause());
133	>	} catch (Throwable fail) { threadUnexpectedException(fail); }
134	>
135		try {
136		f.get();
137		shouldThrow();
138		} catch (ExecutionException success) {
139	<	assertSame(ex, success.getCause());
139	>	assertSame(cause, success.getCause());
140		} catch (Throwable fail) { threadUnexpectedException(fail); }
141
135	–	assertTrue(f.isDone());
142		assertFalse(f.isCancelled());
143	+	assertTrue(f.isDone());
144	+	assertTrue(f.isCompletedExceptionally());
145		assertTrue(f.toString().contains("[Completed exceptionally]"));
146		}
147
148	<	<U> void checkCompletedWithWrappedException(CompletableFuture<U> f,
149	<	Throwable ex) {
150	<	checkCompletedExceptionallyWithRootCause(f, ex);
143	<	try {
144	<	CompletableFuture<Throwable> spy = f.handle
145	<	((U u, Throwable t) -> t);
146	<	assertTrue(spy.join() instanceof CompletionException);
147	<	assertSame(ex, spy.join().getCause());
148	<	} catch (Throwable fail) { threadUnexpectedException(fail); }
148	>	void checkCompletedWithWrappedCFException(CompletableFuture<?> f) {
149	>	checkCompletedExceptionally(f, true,
150	>	(t) -> assertTrue(t instanceof CFException));
151		}
152
153	<	<U> void checkCompletedExceptionally(CompletableFuture<U> f, Throwable ex) {
154	<	checkCompletedExceptionallyWithRootCause(f, ex);
155	<	try {
156	<	CompletableFuture<Throwable> spy = f.handle
157	<	((U u, Throwable t) -> t);
158	<	assertSame(ex, spy.join());
159	<	} catch (Throwable fail) { threadUnexpectedException(fail); }
153	>	void checkCompletedWithWrappedCancellationException(CompletableFuture<?> f) {
154	>	checkCompletedExceptionally(f, true,
155	>	(t) -> assertTrue(t instanceof CancellationException));
156	>	}
157	>
158	>	void checkCompletedWithTimeoutException(CompletableFuture<?> f) {
159	>	checkCompletedExceptionally(f, false,
160	>	(t) -> assertTrue(t instanceof TimeoutException));
161	>	}
162	>
163	>	void checkCompletedWithWrappedException(CompletableFuture<?> f,
164	>	Throwable ex) {
165	>	checkCompletedExceptionally(f, true, (t) -> assertSame(t, ex));
166	>	}
167	>
168	>	void checkCompletedExceptionally(CompletableFuture<?> f, Throwable ex) {
169	>	checkCompletedExceptionally(f, false, (t) -> assertSame(t, ex));
170		}
171
172		void checkCancelled(CompletableFuture<?> f) {
173	+	long startTime = System.nanoTime();
174		try {
175		f.get(LONG_DELAY_MS, MILLISECONDS);
176		shouldThrow();
177		} catch (CancellationException success) {
178		} catch (Throwable fail) { threadUnexpectedException(fail); }
179	+	assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS / 2);
180	+
181		try {
182		f.join();
183		shouldThrow();
#	Line 176 | Line 191 | public class CompletableFutureTest exten
191		shouldThrow();
192		} catch (CancellationException success) {
193		} catch (Throwable fail) { threadUnexpectedException(fail); }
179	–	assertTrue(f.isDone());
180	–	assertTrue(f.isCompletedExceptionally());
181	–	assertTrue(f.isCancelled());
182	–	assertTrue(f.toString().contains("[Completed exceptionally]"));
183	–	}
194
195	<	void checkCompletedWithWrappedCancellationException(CompletableFuture<?> f) {
196	<	try {
187	<	f.get(LONG_DELAY_MS, MILLISECONDS);
188	<	shouldThrow();
189	<	} catch (ExecutionException success) {
190	<	assertTrue(success.getCause() instanceof CancellationException);
191	<	} catch (Throwable fail) { threadUnexpectedException(fail); }
192	<	try {
193	<	f.join();
194	<	shouldThrow();
195	<	} catch (CompletionException success) {
196	<	assertTrue(success.getCause() instanceof CancellationException);
197	<	}
198	<	try {
199	<	f.getNow(null);
200	<	shouldThrow();
201	<	} catch (CompletionException success) {
202	<	assertTrue(success.getCause() instanceof CancellationException);
203	<	}
204	<	try {
205	<	f.get();
206	<	shouldThrow();
207	<	} catch (ExecutionException success) {
208	<	assertTrue(success.getCause() instanceof CancellationException);
209	<	} catch (Throwable fail) { threadUnexpectedException(fail); }
195	>	assertTrue(exceptionalCompletion(f) instanceof CancellationException);
196	>
197		assertTrue(f.isDone());
211	–	assertFalse(f.isCancelled());
198		assertTrue(f.isCompletedExceptionally());
199	+	assertTrue(f.isCancelled());
200		assertTrue(f.toString().contains("[Completed exceptionally]"));
201		}
202
#	Line 257 | Line 244 | public class CompletableFutureTest exten
244		{
245		CompletableFuture<Integer> f = new CompletableFuture<>();
246		checkIncomplete(f);
247	<	assertTrue(f.cancel(true));
248	<	assertTrue(f.cancel(true));
247	>	assertTrue(f.cancel(mayInterruptIfRunning));
248	>	assertTrue(f.cancel(mayInterruptIfRunning));
249	>	assertTrue(f.cancel(!mayInterruptIfRunning));
250		checkCancelled(f);
251		}}
252
#	Line 530 | Line 518 | public class CompletableFutureTest exten
518		}
519		}
520
533	–
521		class CompletableFutureInc extends CheckedIntegerAction
522		implements Function<Integer, CompletableFuture<Integer>>
523		{
#	Line 569 | Line 556 | public class CompletableFutureTest exten
556		}
557		}
558
559	+	static final boolean defaultExecutorIsCommonPool
560	+	= ForkJoinPool.getCommonPoolParallelism() > 1;
561	+
562		/**
563		* Permits the testing of parallel code for the 3 different
564		* execution modes without copy/pasting all the test methods.
565		*/
566		enum ExecutionMode {
567	<	DEFAULT {
567	>	SYNC {
568		public void checkExecutionMode() {
569		assertFalse(ThreadExecutor.startedCurrentThread());
570		assertNull(ForkJoinTask.getPool());
#	Line 650 | Line 640 | public class CompletableFutureTest exten
640
641		ASYNC {
642		public void checkExecutionMode() {
643	<	assertSame(ForkJoinPool.commonPool(),
644	<	ForkJoinTask.getPool());
643	>	// If tests are added that may run across different
644	>	// pools, this needs to be weakened to no-op.
645	>	ForkJoinPool p = ForkJoinTask.getPool();
646	>	assertTrue(p == null ||
647	>	(defaultExecutorIsCommonPool &&
648	>	p == ForkJoinPool.commonPool()));
649		}
650		public CompletableFuture<Void> runAsync(Runnable a) {
651		return CompletableFuture.runAsync(a);
#	Line 850 | Line 844 | public class CompletableFutureTest exten
844		if (!createIncomplete) assertTrue(f.complete(v1));
845		final CompletableFuture<Integer> g = f.exceptionally
846		((Throwable t) -> {
853	–	// Should not be called
847		a.getAndIncrement();
848	<	throw new AssertionError();
848	>	threadFail("should not be called");
849	>	return null;            // unreached
850		});
851		if (createIncomplete) assertTrue(f.complete(v1));
852
#	Line 875 | Line 869 | public class CompletableFutureTest exten
869		if (!createIncomplete) f.completeExceptionally(ex);
870		final CompletableFuture<Integer> g = f.exceptionally
871		((Throwable t) -> {
872	<	ExecutionMode.DEFAULT.checkExecutionMode();
872	>	ExecutionMode.SYNC.checkExecutionMode();
873		threadAssertSame(t, ex);
874		a.getAndIncrement();
875		return v1;
#	Line 886 | Line 880 | public class CompletableFutureTest exten
880		assertEquals(1, a.get());
881		}}
882
883	+	/**
884	+	* If an "exceptionally action" throws an exception, it completes
885	+	* exceptionally with that exception
886	+	*/
887		public void testExceptionally_exceptionalCompletionActionFailed() {
888		for (boolean createIncomplete : new boolean[] { true, false })
891	–	for (Integer v1 : new Integer[] { 1, null })
889		{
890		final AtomicInteger a = new AtomicInteger(0);
891		final CFException ex1 = new CFException();
#	Line 897 | Line 894 | public class CompletableFutureTest exten
894		if (!createIncomplete) f.completeExceptionally(ex1);
895		final CompletableFuture<Integer> g = f.exceptionally
896		((Throwable t) -> {
897	<	ExecutionMode.DEFAULT.checkExecutionMode();
897	>	ExecutionMode.SYNC.checkExecutionMode();
898		threadAssertSame(t, ex1);
899		a.getAndIncrement();
900		throw ex2;
#	Line 905 | Line 902 | public class CompletableFutureTest exten
902		if (createIncomplete) f.completeExceptionally(ex1);
903
904		checkCompletedWithWrappedException(g, ex2);
905	+	checkCompletedExceptionally(f, ex1);
906		assertEquals(1, a.get());
907		}}
908
#	Line 912 | Line 910 | public class CompletableFutureTest exten
910		* whenComplete action executes on normal completion, propagating
911		* source result.
912		*/
913	<	public void testWhenComplete_normalCompletion1() {
913	>	public void testWhenComplete_normalCompletion() {
914		for (ExecutionMode m : ExecutionMode.values())
915		for (boolean createIncomplete : new boolean[] { true, false })
916		for (Integer v1 : new Integer[] { 1, null })
#	Line 922 | Line 920 | public class CompletableFutureTest exten
920		if (!createIncomplete) assertTrue(f.complete(v1));
921		final CompletableFuture<Integer> g = m.whenComplete
922		(f,
923	<	(Integer x, Throwable t) -> {
923	>	(Integer result, Throwable t) -> {
924		m.checkExecutionMode();
925	<	threadAssertSame(x, v1);
925	>	threadAssertSame(result, v1);
926		threadAssertNull(t);
927		a.getAndIncrement();
928		});
#	Line 942 | Line 940 | public class CompletableFutureTest exten
940		public void testWhenComplete_exceptionalCompletion() {
941		for (ExecutionMode m : ExecutionMode.values())
942		for (boolean createIncomplete : new boolean[] { true, false })
945	–	for (Integer v1 : new Integer[] { 1, null })
943		{
944		final AtomicInteger a = new AtomicInteger(0);
945		final CFException ex = new CFException();
#	Line 950 | Line 947 | public class CompletableFutureTest exten
947		if (!createIncomplete) f.completeExceptionally(ex);
948		final CompletableFuture<Integer> g = m.whenComplete
949		(f,
950	<	(Integer x, Throwable t) -> {
950	>	(Integer result, Throwable t) -> {
951		m.checkExecutionMode();
952	<	threadAssertNull(x);
952	>	threadAssertNull(result);
953		threadAssertSame(t, ex);
954		a.getAndIncrement();
955		});
#	Line 977 | Line 974 | public class CompletableFutureTest exten
974		if (!createIncomplete) assertTrue(f.cancel(mayInterruptIfRunning));
975		final CompletableFuture<Integer> g = m.whenComplete
976		(f,
977	<	(Integer x, Throwable t) -> {
977	>	(Integer result, Throwable t) -> {
978		m.checkExecutionMode();
979	<	threadAssertNull(x);
979	>	threadAssertNull(result);
980		threadAssertTrue(t instanceof CancellationException);
981		a.getAndIncrement();
982		});
#	Line 994 | Line 991 | public class CompletableFutureTest exten
991		* If a whenComplete action throws an exception when triggered by
992		* a normal completion, it completes exceptionally
993		*/
994	<	public void testWhenComplete_actionFailed() {
994	>	public void testWhenComplete_sourceCompletedNormallyActionFailed() {
995		for (boolean createIncomplete : new boolean[] { true, false })
996		for (ExecutionMode m : ExecutionMode.values())
997		for (Integer v1 : new Integer[] { 1, null })
#	Line 1005 | Line 1002 | public class CompletableFutureTest exten
1002		if (!createIncomplete) assertTrue(f.complete(v1));
1003		final CompletableFuture<Integer> g = m.whenComplete
1004		(f,
1005	<	(Integer x, Throwable t) -> {
1005	>	(Integer result, Throwable t) -> {
1006		m.checkExecutionMode();
1007	<	threadAssertSame(x, v1);
1007	>	threadAssertSame(result, v1);
1008		threadAssertNull(t);
1009		a.getAndIncrement();
1010		throw ex;
#	Line 1022 | Line 1019 | public class CompletableFutureTest exten
1019		/**
1020		* If a whenComplete action throws an exception when triggered by
1021		* a source completion that also throws an exception, the source
1022	<	* exception takes precedence.
1022	>	* exception takes precedence (unlike handle)
1023		*/
1024	<	public void testWhenComplete_actionFailedSourceFailed() {
1024	>	public void testWhenComplete_sourceFailedActionFailed() {
1025		for (boolean createIncomplete : new boolean[] { true, false })
1026		for (ExecutionMode m : ExecutionMode.values())
1030	–	for (Integer v1 : new Integer[] { 1, null })
1027		{
1028		final AtomicInteger a = new AtomicInteger(0);
1029		final CFException ex1 = new CFException();
#	Line 1037 | Line 1033 | public class CompletableFutureTest exten
1033		if (!createIncomplete) f.completeExceptionally(ex1);
1034		final CompletableFuture<Integer> g = m.whenComplete
1035		(f,
1036	<	(Integer x, Throwable t) -> {
1036	>	(Integer result, Throwable t) -> {
1037		m.checkExecutionMode();
1038		threadAssertSame(t, ex1);
1039	<	threadAssertNull(x);
1039	>	threadAssertNull(result);
1040		a.getAndIncrement();
1041		throw ex2;
1042		});
#	Line 1048 | Line 1044 | public class CompletableFutureTest exten
1044
1045		checkCompletedWithWrappedException(g, ex1);
1046		checkCompletedExceptionally(f, ex1);
1047	+	if (testImplementationDetails) {
1048	+	assertEquals(1, ex1.getSuppressed().length);
1049	+	assertSame(ex2, ex1.getSuppressed()[0]);
1050	+	}
1051		assertEquals(1, a.get());
1052		}}
1053
#	Line 1065 | Line 1065 | public class CompletableFutureTest exten
1065		if (!createIncomplete) assertTrue(f.complete(v1));
1066		final CompletableFuture<Integer> g = m.handle
1067		(f,
1068	<	(Integer x, Throwable t) -> {
1068	>	(Integer result, Throwable t) -> {
1069		m.checkExecutionMode();
1070	<	threadAssertSame(x, v1);
1070	>	threadAssertSame(result, v1);
1071		threadAssertNull(t);
1072		a.getAndIncrement();
1073		return inc(v1);
#	Line 1094 | Line 1094 | public class CompletableFutureTest exten
1094		if (!createIncomplete) f.completeExceptionally(ex);
1095		final CompletableFuture<Integer> g = m.handle
1096		(f,
1097	<	(Integer x, Throwable t) -> {
1097	>	(Integer result, Throwable t) -> {
1098		m.checkExecutionMode();
1099	<	threadAssertNull(x);
1099	>	threadAssertNull(result);
1100		threadAssertSame(t, ex);
1101		a.getAndIncrement();
1102		return v1;
#	Line 1123 | Line 1123 | public class CompletableFutureTest exten
1123		if (!createIncomplete) assertTrue(f.cancel(mayInterruptIfRunning));
1124		final CompletableFuture<Integer> g = m.handle
1125		(f,
1126	<	(Integer x, Throwable t) -> {
1126	>	(Integer result, Throwable t) -> {
1127		m.checkExecutionMode();
1128	<	threadAssertNull(x);
1128	>	threadAssertNull(result);
1129		threadAssertTrue(t instanceof CancellationException);
1130		a.getAndIncrement();
1131		return v1;
#	Line 1138 | Line 1138 | public class CompletableFutureTest exten
1138		}}
1139
1140		/**
1141	<	* handle result completes exceptionally if action does
1141	>	* If a "handle action" throws an exception when triggered by
1142	>	* a normal completion, it completes exceptionally
1143		*/
1144	<	public void testHandle_sourceFailedActionFailed() {
1144	>	public void testHandle_sourceCompletedNormallyActionFailed() {
1145		for (ExecutionMode m : ExecutionMode.values())
1146		for (boolean createIncomplete : new boolean[] { true, false })
1147	+	for (Integer v1 : new Integer[] { 1, null })
1148		{
1149		final CompletableFuture<Integer> f = new CompletableFuture<>();
1150		final AtomicInteger a = new AtomicInteger(0);
1151	<	final CFException ex1 = new CFException();
1152	<	final CFException ex2 = new CFException();
1151	<	if (!createIncomplete) f.completeExceptionally(ex1);
1151	>	final CFException ex = new CFException();
1152	>	if (!createIncomplete) assertTrue(f.complete(v1));
1153		final CompletableFuture<Integer> g = m.handle
1154		(f,
1155	<	(Integer x, Throwable t) -> {
1155	>	(Integer result, Throwable t) -> {
1156		m.checkExecutionMode();
1157	<	threadAssertNull(x);
1158	<	threadAssertSame(ex1, t);
1157	>	threadAssertSame(result, v1);
1158	>	threadAssertNull(t);
1159		a.getAndIncrement();
1160	<	throw ex2;
1160	>	throw ex;
1161		});
1162	<	if (createIncomplete) f.completeExceptionally(ex1);
1162	>	if (createIncomplete) assertTrue(f.complete(v1));
1163
1164	<	checkCompletedWithWrappedException(g, ex2);
1165	<	checkCompletedExceptionally(f, ex1);
1164	>	checkCompletedWithWrappedException(g, ex);
1165	>	checkCompletedNormally(f, v1);
1166		assertEquals(1, a.get());
1167		}}
1168
1169	<	public void testHandle_sourceCompletedNormallyActionFailed() {
1170	<	for (ExecutionMode m : ExecutionMode.values())
1169	>	/**
1170	>	* If a "handle action" throws an exception when triggered by
1171	>	* a source completion that also throws an exception, the action
1172	>	* exception takes precedence (unlike whenComplete)
1173	>	*/
1174	>	public void testHandle_sourceFailedActionFailed() {
1175		for (boolean createIncomplete : new boolean[] { true, false })
1176	<	for (Integer v1 : new Integer[] { 1, null })
1176	>	for (ExecutionMode m : ExecutionMode.values())
1177		{
1173	–	final CompletableFuture<Integer> f = new CompletableFuture<>();
1178		final AtomicInteger a = new AtomicInteger(0);
1179	<	final CFException ex = new CFException();
1180	<	if (!createIncomplete) assertTrue(f.complete(v1));
1179	>	final CFException ex1 = new CFException();
1180	>	final CFException ex2 = new CFException();
1181	>	final CompletableFuture<Integer> f = new CompletableFuture<>();
1182	>
1183	>	if (!createIncomplete) f.completeExceptionally(ex1);
1184		final CompletableFuture<Integer> g = m.handle
1185		(f,
1186	<	(Integer x, Throwable t) -> {
1186	>	(Integer result, Throwable t) -> {
1187		m.checkExecutionMode();
1188	<	threadAssertSame(x, v1);
1189	<	threadAssertNull(t);
1188	>	threadAssertNull(result);
1189	>	threadAssertSame(ex1, t);
1190		a.getAndIncrement();
1191	<	throw ex;
1191	>	throw ex2;
1192		});
1193	<	if (createIncomplete) assertTrue(f.complete(v1));
1193	>	if (createIncomplete) f.completeExceptionally(ex1);
1194
1195	<	checkCompletedWithWrappedException(g, ex);
1196	<	checkCompletedNormally(f, v1);
1195	>	checkCompletedWithWrappedException(g, ex2);
1196	>	checkCompletedExceptionally(f, ex1);
1197		assertEquals(1, a.get());
1198		}}
1199
#	Line 2975 | Line 2982 | public class CompletableFutureTest exten
2982		checkCancelled(f);
2983		}}
2984
2985	+	/**
2986	+	* thenCompose result completes exceptionally if the result of the action does
2987	+	*/
2988	+	public void testThenCompose_actionReturnsFailingFuture() {
2989	+	for (ExecutionMode m : ExecutionMode.values())
2990	+	for (int order = 0; order < 6; order++)
2991	+	for (Integer v1 : new Integer[] { 1, null })
2992	+	{
2993	+	final CFException ex = new CFException();
2994	+	final CompletableFuture<Integer> f = new CompletableFuture<>();
2995	+	final CompletableFuture<Integer> g = new CompletableFuture<>();
2996	+	final CompletableFuture<Integer> h;
2997	+	// Test all permutations of orders
2998	+	switch (order) {
2999	+	case 0:
3000	+	assertTrue(f.complete(v1));
3001	+	assertTrue(g.completeExceptionally(ex));
3002	+	h = m.thenCompose(f, (x -> g));
3003	+	break;
3004	+	case 1:
3005	+	assertTrue(f.complete(v1));
3006	+	h = m.thenCompose(f, (x -> g));
3007	+	assertTrue(g.completeExceptionally(ex));
3008	+	break;
3009	+	case 2:
3010	+	assertTrue(g.completeExceptionally(ex));
3011	+	assertTrue(f.complete(v1));
3012	+	h = m.thenCompose(f, (x -> g));
3013	+	break;
3014	+	case 3:
3015	+	assertTrue(g.completeExceptionally(ex));
3016	+	h = m.thenCompose(f, (x -> g));
3017	+	assertTrue(f.complete(v1));
3018	+	break;
3019	+	case 4:
3020	+	h = m.thenCompose(f, (x -> g));
3021	+	assertTrue(f.complete(v1));
3022	+	assertTrue(g.completeExceptionally(ex));
3023	+	break;
3024	+	case 5:
3025	+	h = m.thenCompose(f, (x -> g));
3026	+	assertTrue(f.complete(v1));
3027	+	assertTrue(g.completeExceptionally(ex));
3028	+	break;
3029	+	default: throw new AssertionError();
3030	+	}
3031	+
3032	+	checkCompletedExceptionally(g, ex);
3033	+	checkCompletedWithWrappedException(h, ex);
3034	+	checkCompletedNormally(f, v1);
3035	+	}}
3036	+
3037		// other static methods
3038
3039		/**
#	Line 3035 | Line 3094 | public class CompletableFutureTest exten
3094		for (int i = 0; i < k; i++) {
3095		checkIncomplete(f);
3096		checkIncomplete(CompletableFuture.allOf(fs));
3097	<	if (i != k/2) {
3097	>	if (i != k / 2) {
3098		fs[i].complete(i);
3099		checkCompletedNormally(fs[i], i);
3100		} else {
#	Line 3142 | Line 3201 | public class CompletableFutureTest exten
3201		CompletableFuture<Integer> f = new CompletableFuture<>();
3202		CompletableFuture<Integer> g = new CompletableFuture<>();
3203		CompletableFuture<Integer> nullFuture = (CompletableFuture<Integer>)null;
3145	–	CompletableFuture<?> h;
3204		ThreadExecutor exec = new ThreadExecutor();
3205
3206		Runnable[] throwingActions = {
3207		() -> CompletableFuture.supplyAsync(null),
3208		() -> CompletableFuture.supplyAsync(null, exec),
3209	<	() -> CompletableFuture.supplyAsync(new IntegerSupplier(ExecutionMode.DEFAULT, 42), null),
3209	>	() -> CompletableFuture.supplyAsync(new IntegerSupplier(ExecutionMode.SYNC, 42), null),
3210
3211		() -> CompletableFuture.runAsync(null),
3212		() -> CompletableFuture.runAsync(null, exec),
#	Line 3239 | Line 3297 | public class CompletableFutureTest exten
3297		() -> CompletableFuture.anyOf(null, f),
3298
3299		() -> f.obtrudeException(null),
3300	+
3301	+	() -> CompletableFuture.delayedExecutor(1L, SECONDS, null),
3302	+	() -> CompletableFuture.delayedExecutor(1L, null, new ThreadExecutor()),
3303	+	() -> CompletableFuture.delayedExecutor(1L, null),
3304	+
3305	+	() -> f.orTimeout(1L, null),
3306	+	() -> f.completeOnTimeout(42, 1L, null),
3307	+
3308	+	() -> CompletableFuture.failedFuture(null),
3309	+	() -> CompletableFuture.failedStage(null),
3310		};
3311
3312		assertThrows(NullPointerException.class, throwingActions);
#	Line 3253 | Line 3321 | public class CompletableFutureTest exten
3321		assertSame(f, f.toCompletableFuture());
3322		}
3323
3324	+	// jdk9
3325	+
3326	+	/**
3327	+	* newIncompleteFuture returns an incomplete CompletableFuture
3328	+	*/
3329	+	public void testNewIncompleteFuture() {
3330	+	for (Integer v1 : new Integer[] { 1, null })
3331	+	{
3332	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3333	+	CompletableFuture<Integer> g = f.newIncompleteFuture();
3334	+	checkIncomplete(f);
3335	+	checkIncomplete(g);
3336	+	f.complete(v1);
3337	+	checkCompletedNormally(f, v1);
3338	+	checkIncomplete(g);
3339	+	g.complete(v1);
3340	+	checkCompletedNormally(g, v1);
3341	+	assertSame(g.getClass(), CompletableFuture.class);
3342	+	}}
3343	+
3344	+	/**
3345	+	* completedStage returns a completed CompletionStage
3346	+	*/
3347	+	public void testCompletedStage() {
3348	+	AtomicInteger x = new AtomicInteger(0);
3349	+	AtomicReference<Throwable> r = new AtomicReference<Throwable>();
3350	+	CompletionStage<Integer> f = CompletableFuture.completedStage(1);
3351	+	f.whenComplete((v, e) -> {if (e != null) r.set(e); else x.set(v);});
3352	+	assertEquals(x.get(), 1);
3353	+	assertNull(r.get());
3354	+	}
3355	+
3356	+	/**
3357	+	* defaultExecutor by default returns the commonPool if
3358	+	* it supports more than one thread.
3359	+	*/
3360	+	public void testDefaultExecutor() {
3361	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3362	+	Executor e = f.defaultExecutor();
3363	+	Executor c = ForkJoinPool.commonPool();
3364	+	if (ForkJoinPool.getCommonPoolParallelism() > 1)
3365	+	assertSame(e, c);
3366	+	else
3367	+	assertNotSame(e, c);
3368	+	}
3369	+
3370	+	/**
3371	+	* failedFuture returns a CompletableFuture completed
3372	+	* exceptionally with the given Exception
3373	+	*/
3374	+	public void testFailedFuture() {
3375	+	CFException ex = new CFException();
3376	+	CompletableFuture<Integer> f = CompletableFuture.failedFuture(ex);
3377	+	checkCompletedExceptionally(f, ex);
3378	+	}
3379	+
3380	+	/**
3381	+	* failedFuture(null) throws NPE
3382	+	*/
3383	+	public void testFailedFuture_null() {
3384	+	try {
3385	+	CompletableFuture<Integer> f = CompletableFuture.failedFuture(null);
3386	+	shouldThrow();
3387	+	} catch (NullPointerException success) {}
3388	+	}
3389	+
3390	+	/**
3391	+	* copy returns a CompletableFuture that is completed normally,
3392	+	* with the same value, when source is.
3393	+	*/
3394	+	public void testCopy() {
3395	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3396	+	CompletableFuture<Integer> g = f.copy();
3397	+	checkIncomplete(f);
3398	+	checkIncomplete(g);
3399	+	f.complete(1);
3400	+	checkCompletedNormally(f, 1);
3401	+	checkCompletedNormally(g, 1);
3402	+	}
3403	+
3404	+	/**
3405	+	* copy returns a CompletableFuture that is completed exceptionally
3406	+	* when source is.
3407	+	*/
3408	+	public void testCopy2() {
3409	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3410	+	CompletableFuture<Integer> g = f.copy();
3411	+	checkIncomplete(f);
3412	+	checkIncomplete(g);
3413	+	CFException ex = new CFException();
3414	+	f.completeExceptionally(ex);
3415	+	checkCompletedExceptionally(f, ex);
3416	+	checkCompletedWithWrappedException(g, ex);
3417	+	}
3418	+
3419	+	/**
3420	+	* minimalCompletionStage returns a CompletableFuture that is
3421	+	* completed normally, with the same value, when source is.
3422	+	*/
3423	+	public void testMinimalCompletionStage() {
3424	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3425	+	CompletionStage<Integer> g = f.minimalCompletionStage();
3426	+	AtomicInteger x = new AtomicInteger(0);
3427	+	AtomicReference<Throwable> r = new AtomicReference<Throwable>();
3428	+	checkIncomplete(f);
3429	+	g.whenComplete((v, e) -> {if (e != null) r.set(e); else x.set(v);});
3430	+	f.complete(1);
3431	+	checkCompletedNormally(f, 1);
3432	+	assertEquals(x.get(), 1);
3433	+	assertNull(r.get());
3434	+	}
3435	+
3436	+	/**
3437	+	* minimalCompletionStage returns a CompletableFuture that is
3438	+	* completed exceptionally when source is.
3439	+	*/
3440	+	public void testMinimalCompletionStage2() {
3441	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3442	+	CompletionStage<Integer> g = f.minimalCompletionStage();
3443	+	AtomicInteger x = new AtomicInteger(0);
3444	+	AtomicReference<Throwable> r = new AtomicReference<Throwable>();
3445	+	g.whenComplete((v, e) -> {if (e != null) r.set(e); else x.set(v);});
3446	+	checkIncomplete(f);
3447	+	CFException ex = new CFException();
3448	+	f.completeExceptionally(ex);
3449	+	checkCompletedExceptionally(f, ex);
3450	+	assertEquals(x.get(), 0);
3451	+	assertEquals(r.get().getCause(), ex);
3452	+	}
3453	+
3454	+	/**
3455	+	* failedStage returns a CompletionStage completed
3456	+	* exceptionally with the given Exception
3457	+	*/
3458	+	public void testFailedStage() {
3459	+	CFException ex = new CFException();
3460	+	CompletionStage<Integer> f = CompletableFuture.failedStage(ex);
3461	+	AtomicInteger x = new AtomicInteger(0);
3462	+	AtomicReference<Throwable> r = new AtomicReference<Throwable>();
3463	+	f.whenComplete((v, e) -> {if (e != null) r.set(e); else x.set(v);});
3464	+	assertEquals(x.get(), 0);
3465	+	assertEquals(r.get(), ex);
3466	+	}
3467	+
3468	+	/**
3469	+	* completeAsync completes with value of given supplier
3470	+	*/
3471	+	public void testCompleteAsync() {
3472	+	for (Integer v1 : new Integer[] { 1, null })
3473	+	{
3474	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3475	+	f.completeAsync(() -> v1);
3476	+	f.join();
3477	+	checkCompletedNormally(f, v1);
3478	+	}}
3479	+
3480	+	/**
3481	+	* completeAsync completes exceptionally if given supplier throws
3482	+	*/
3483	+	public void testCompleteAsync2() {
3484	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3485	+	CFException ex = new CFException();
3486	+	f.completeAsync(() -> {if (true) throw ex; return 1;});
3487	+	try {
3488	+	f.join();
3489	+	shouldThrow();
3490	+	} catch (CompletionException success) {}
3491	+	checkCompletedWithWrappedException(f, ex);
3492	+	}
3493	+
3494	+	/**
3495	+	* completeAsync with given executor completes with value of given supplier
3496	+	*/
3497	+	public void testCompleteAsync3() {
3498	+	for (Integer v1 : new Integer[] { 1, null })
3499	+	{
3500	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3501	+	ThreadExecutor executor = new ThreadExecutor();
3502	+	f.completeAsync(() -> v1, executor);
3503	+	assertSame(v1, f.join());
3504	+	checkCompletedNormally(f, v1);
3505	+	assertEquals(1, executor.count.get());
3506	+	}}
3507	+
3508	+	/**
3509	+	* completeAsync with given executor completes exceptionally if
3510	+	* given supplier throws
3511	+	*/
3512	+	public void testCompleteAsync4() {
3513	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3514	+	CFException ex = new CFException();
3515	+	ThreadExecutor executor = new ThreadExecutor();
3516	+	f.completeAsync(() -> {if (true) throw ex; return 1;}, executor);
3517	+	try {
3518	+	f.join();
3519	+	shouldThrow();
3520	+	} catch (CompletionException success) {}
3521	+	checkCompletedWithWrappedException(f, ex);
3522	+	assertEquals(1, executor.count.get());
3523	+	}
3524	+
3525	+	/**
3526	+	* orTimeout completes with TimeoutException if not complete
3527	+	*/
3528	+	public void testOrTimeout_timesOut() {
3529	+	long timeoutMillis = timeoutMillis();
3530	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3531	+	long startTime = System.nanoTime();
3532	+	f.orTimeout(timeoutMillis, MILLISECONDS);
3533	+	checkCompletedWithTimeoutException(f);
3534	+	assertTrue(millisElapsedSince(startTime) >= timeoutMillis);
3535	+	}
3536	+
3537	+	/**
3538	+	* orTimeout completes normally if completed before timeout
3539	+	*/
3540	+	public void testOrTimeout_completed() {
3541	+	for (Integer v1 : new Integer[] { 1, null })
3542	+	{
3543	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3544	+	CompletableFuture<Integer> g = new CompletableFuture<>();
3545	+	long startTime = System.nanoTime();
3546	+	f.complete(v1);
3547	+	f.orTimeout(LONG_DELAY_MS, MILLISECONDS);
3548	+	g.orTimeout(LONG_DELAY_MS, MILLISECONDS);
3549	+	g.complete(v1);
3550	+	checkCompletedNormally(f, v1);
3551	+	checkCompletedNormally(g, v1);
3552	+	assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS / 2);
3553	+	}}
3554	+
3555	+	/**
3556	+	* completeOnTimeout completes with given value if not complete
3557	+	*/
3558	+	public void testCompleteOnTimeout_timesOut() {
3559	+	testInParallel(() -> testCompleteOnTimeout_timesOut(42),
3560	+	() -> testCompleteOnTimeout_timesOut(null));
3561	+	}
3562	+
3563	+	public void testCompleteOnTimeout_timesOut(Integer v) {
3564	+	long timeoutMillis = timeoutMillis();
3565	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3566	+	long startTime = System.nanoTime();
3567	+	f.completeOnTimeout(v, timeoutMillis, MILLISECONDS);
3568	+	assertSame(v, f.join());
3569	+	assertTrue(millisElapsedSince(startTime) >= timeoutMillis);
3570	+	f.complete(99);         // should have no effect
3571	+	checkCompletedNormally(f, v);
3572	+	}
3573	+
3574	+	/**
3575	+	* completeOnTimeout has no effect if completed within timeout
3576	+	*/
3577	+	public void testCompleteOnTimeout_completed() {
3578	+	for (Integer v1 : new Integer[] { 1, null })
3579	+	{
3580	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3581	+	CompletableFuture<Integer> g = new CompletableFuture<>();
3582	+	long startTime = System.nanoTime();
3583	+	f.complete(v1);
3584	+	f.completeOnTimeout(-1, LONG_DELAY_MS, MILLISECONDS);
3585	+	g.completeOnTimeout(-1, LONG_DELAY_MS, MILLISECONDS);
3586	+	g.complete(v1);
3587	+	checkCompletedNormally(f, v1);
3588	+	checkCompletedNormally(g, v1);
3589	+	assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS / 2);
3590	+	}}
3591	+
3592	+	/**
3593	+	* delayedExecutor returns an executor that delays submission
3594	+	*/
3595	+	public void testDelayedExecutor() {
3596	+	testInParallel(() -> testDelayedExecutor(null, null),
3597	+	() -> testDelayedExecutor(null, 1),
3598	+	() -> testDelayedExecutor(new ThreadExecutor(), 1),
3599	+	() -> testDelayedExecutor(new ThreadExecutor(), 1));
3600	+	}
3601	+
3602	+	public void testDelayedExecutor(Executor executor, Integer v) throws Exception {
3603	+	long timeoutMillis = timeoutMillis();
3604	+	// Use an "unreasonably long" long timeout to catch lingering threads
3605	+	long longTimeoutMillis = 1000 * 60 * 60 * 24;
3606	+	final Executor delayer, longDelayer;
3607	+	if (executor == null) {
3608	+	delayer = CompletableFuture.delayedExecutor(timeoutMillis, MILLISECONDS);
3609	+	longDelayer = CompletableFuture.delayedExecutor(longTimeoutMillis, MILLISECONDS);
3610	+	} else {
3611	+	delayer = CompletableFuture.delayedExecutor(timeoutMillis, MILLISECONDS, executor);
3612	+	longDelayer = CompletableFuture.delayedExecutor(longTimeoutMillis, MILLISECONDS, executor);
3613	+	}
3614	+	long startTime = System.nanoTime();
3615	+	CompletableFuture<Integer> f =
3616	+	CompletableFuture.supplyAsync(() -> v, delayer);
3617	+	CompletableFuture<Integer> g =
3618	+	CompletableFuture.supplyAsync(() -> v, longDelayer);
3619	+
3620	+	assertNull(g.getNow(null));
3621	+
3622	+	assertSame(v, f.get(LONG_DELAY_MS, MILLISECONDS));
3623	+	long millisElapsed = millisElapsedSince(startTime);
3624	+	assertTrue(millisElapsed >= timeoutMillis);
3625	+	assertTrue(millisElapsed < LONG_DELAY_MS / 2);
3626	+
3627	+	checkCompletedNormally(f, v);
3628	+
3629	+	checkIncomplete(g);
3630	+	assertTrue(g.cancel(true));
3631	+	}
3632	+
3633		//--- tests of implementation details; not part of official tck ---
3634
3635		Object resultOf(CompletableFuture<?> f) {
#	Line 3287 | Line 3664 | public class CompletableFutureTest exten
3664		funs.add((y) -> m.thenAcceptBoth(y, v42, new SubtractAction(m)));
3665		funs.add((y) -> m.thenCombine(y, v42, new SubtractFunction(m)));
3666
3667	<	funs.add((y) -> m.whenComplete(y, (Integer x, Throwable t) -> {}));
3667	>	funs.add((y) -> m.whenComplete(y, (Integer r, Throwable t) -> {}));
3668
3669		funs.add((y) -> m.thenCompose(y, new CompletableFutureInc(m)));
3670
#	Line 3343 | Line 3720 | public class CompletableFutureTest exten
3720		}
3721		}}
3722
3723	+	/**
3724	+	* Minimal completion stages throw UOE for all non-CompletionStage methods
3725	+	*/
3726	+	public void testMinimalCompletionStage_minimality() {
3727	+	if (!testImplementationDetails) return;
3728	+	Function<Method, String> toSignature =
3729	+	(method) -> method.getName() + Arrays.toString(method.getParameterTypes());
3730	+	Predicate<Method> isNotStatic =
3731	+	(method) -> (method.getModifiers() & Modifier.STATIC) == 0;
3732	+	List<Method> minimalMethods =
3733	+	Stream.of(Object.class, CompletionStage.class)
3734	+	.flatMap((klazz) -> Stream.of(klazz.getMethods()))
3735	+	.filter(isNotStatic)
3736	+	.collect(Collectors.toList());
3737	+	// Methods from CompletableFuture permitted NOT to throw UOE
3738	+	String[] signatureWhitelist = {
3739	+	"newIncompleteFuture[]",
3740	+	"defaultExecutor[]",
3741	+	"minimalCompletionStage[]",
3742	+	"copy[]",
3743	+	};
3744	+	Set<String> permittedMethodSignatures =
3745	+	Stream.concat(minimalMethods.stream().map(toSignature),
3746	+	Stream.of(signatureWhitelist))
3747	+	.collect(Collectors.toSet());
3748	+	List<Method> allMethods = Stream.of(CompletableFuture.class.getMethods())
3749	+	.filter(isNotStatic)
3750	+	.filter((method) -> !permittedMethodSignatures.contains(toSignature.apply(method)))
3751	+	.collect(Collectors.toList());
3752	+
3753	+	CompletionStage<Integer> minimalStage =
3754	+	new CompletableFuture<Integer>().minimalCompletionStage();
3755	+
3756	+	List<Method> bugs = new ArrayList<>();
3757	+	for (Method method : allMethods) {
3758	+	Class<?>[] parameterTypes = method.getParameterTypes();
3759	+	Object[] args = new Object[parameterTypes.length];
3760	+	// Manufacture boxed primitives for primitive params
3761	+	for (int i = 0; i < args.length; i++) {
3762	+	Class<?> type = parameterTypes[i];
3763	+	if (parameterTypes[i] == boolean.class)
3764	+	args[i] = false;
3765	+	else if (parameterTypes[i] == int.class)
3766	+	args[i] = 0;
3767	+	else if (parameterTypes[i] == long.class)
3768	+	args[i] = 0L;
3769	+	}
3770	+	try {
3771	+	method.invoke(minimalStage, args);
3772	+	bugs.add(method);
3773	+	}
3774	+	catch (java.lang.reflect.InvocationTargetException expected) {
3775	+	if (! (expected.getCause() instanceof UnsupportedOperationException)) {
3776	+	bugs.add(method);
3777	+	// expected.getCause().printStackTrace();
3778	+	}
3779	+	}
3780	+	catch (ReflectiveOperationException bad) { throw new Error(bad); }
3781	+	}
3782	+	if (!bugs.isEmpty())
3783	+	throw new Error("Methods did not throw UOE: " + bugs.toString());
3784	+	}
3785	+
3786	+	static class Monad {
3787	+	static class ZeroException extends RuntimeException {
3788	+	public ZeroException() { super("monadic zero"); }
3789	+	}
3790	+	// "return", "unit"
3791	+	static <T> CompletableFuture<T> unit(T value) {
3792	+	return completedFuture(value);
3793	+	}
3794	+	// monadic zero ?
3795	+	static <T> CompletableFuture<T> zero() {
3796	+	return failedFuture(new ZeroException());
3797	+	}
3798	+	// >=>
3799	+	static <T,U,V> Function<T, CompletableFuture<V>> compose
3800	+	(Function<T, CompletableFuture<U>> f,
3801	+	Function<U, CompletableFuture<V>> g) {
3802	+	return (x) -> f.apply(x).thenCompose(g);
3803	+	}
3804	+
3805	+	static void assertZero(CompletableFuture<?> f) {
3806	+	try {
3807	+	f.getNow(null);
3808	+	throw new AssertionFailedError("should throw");
3809	+	} catch (CompletionException success) {
3810	+	assertTrue(success.getCause() instanceof ZeroException);
3811	+	}
3812	+	}
3813	+
3814	+	static <T> void assertFutureEquals(CompletableFuture<T> f,
3815	+	CompletableFuture<T> g) {
3816	+	T fval = null, gval = null;
3817	+	Throwable fex = null, gex = null;
3818	+
3819	+	try { fval = f.get(); }
3820	+	catch (ExecutionException ex) { fex = ex.getCause(); }
3821	+	catch (Throwable ex) { fex = ex; }
3822	+
3823	+	try { gval = g.get(); }
3824	+	catch (ExecutionException ex) { gex = ex.getCause(); }
3825	+	catch (Throwable ex) { gex = ex; }
3826	+
3827	+	if (fex != null || gex != null)
3828	+	assertSame(fex.getClass(), gex.getClass());
3829	+	else
3830	+	assertEquals(fval, gval);
3831	+	}
3832	+
3833	+	static class PlusFuture<T> extends CompletableFuture<T> {
3834	+	AtomicReference<Throwable> firstFailure = new AtomicReference<>(null);
3835	+	}
3836	+
3837	+	/** Implements "monadic plus". */
3838	+	static <T> CompletableFuture<T> plus(CompletableFuture<? extends T> f,
3839	+	CompletableFuture<? extends T> g) {
3840	+	PlusFuture<T> plus = new PlusFuture<T>();
3841	+	BiConsumer<T, Throwable> action = (T result, Throwable ex) -> {
3842	+	try {
3843	+	if (ex == null) {
3844	+	if (plus.complete(result))
3845	+	if (plus.firstFailure.get() != null)
3846	+	plus.firstFailure.set(null);
3847	+	}
3848	+	else if (plus.firstFailure.compareAndSet(null, ex)) {
3849	+	if (plus.isDone())
3850	+	plus.firstFailure.set(null);
3851	+	}
3852	+	else {
3853	+	// first failure has precedence
3854	+	Throwable first = plus.firstFailure.getAndSet(null);
3855	+
3856	+	// may fail with "Self-suppression not permitted"
3857	+	try { first.addSuppressed(ex); }
3858	+	catch (Exception ignored) {}
3859	+
3860	+	plus.completeExceptionally(first);
3861	+	}
3862	+	} catch (Throwable unexpected) {
3863	+	plus.completeExceptionally(unexpected);
3864	+	}
3865	+	};
3866	+	f.whenComplete(action);
3867	+	g.whenComplete(action);
3868	+	return plus;
3869	+	}
3870	+	}
3871	+
3872	+	/**
3873	+	* CompletableFuture is an additive monad - sort of.
3874	+	* https://en.wikipedia.org/wiki/Monad_(functional_programming)#Additive_monads
3875	+	*/
3876	+	public void testAdditiveMonad() throws Throwable {
3877	+	Function<Long, CompletableFuture<Long>> unit = Monad::unit;
3878	+	CompletableFuture<Long> zero = Monad.zero();
3879	+
3880	+	// Some mutually non-commutative functions
3881	+	Function<Long, CompletableFuture<Long>> triple
3882	+	= (x) -> Monad.unit(3 * x);
3883	+	Function<Long, CompletableFuture<Long>> inc
3884	+	= (x) -> Monad.unit(x + 1);
3885	+
3886	+	// unit is a right identity: m >>= unit === m
3887	+	Monad.assertFutureEquals(inc.apply(5L).thenCompose(unit),
3888	+	inc.apply(5L));
3889	+	// unit is a left identity: (unit x) >>= f === f x
3890	+	Monad.assertFutureEquals(unit.apply(5L).thenCompose(inc),
3891	+	inc.apply(5L));
3892	+
3893	+	// associativity: (m >>= f) >>= g === m >>= ( \x -> (f x >>= g) )
3894	+	Monad.assertFutureEquals(
3895	+	unit.apply(5L).thenCompose(inc).thenCompose(triple),
3896	+	unit.apply(5L).thenCompose((x) -> inc.apply(x).thenCompose(triple)));
3897	+
3898	+	// The case for CompletableFuture as an additive monad is weaker...
3899	+
3900	+	// zero is a monadic zero
3901	+	Monad.assertZero(zero);
3902	+
3903	+	// left zero: zero >>= f === zero
3904	+	Monad.assertZero(zero.thenCompose(inc));
3905	+	// right zero: f >>= (\x -> zero) === zero
3906	+	Monad.assertZero(inc.apply(5L).thenCompose((x) -> zero));
3907	+
3908	+	// f plus zero === f
3909	+	Monad.assertFutureEquals(Monad.unit(5L),
3910	+	Monad.plus(Monad.unit(5L), zero));
3911	+	// zero plus f === f
3912	+	Monad.assertFutureEquals(Monad.unit(5L),
3913	+	Monad.plus(zero, Monad.unit(5L)));
3914	+	// zero plus zero === zero
3915	+	Monad.assertZero(Monad.plus(zero, zero));
3916	+	{
3917	+	CompletableFuture<Long> f = Monad.plus(Monad.unit(5L),
3918	+	Monad.unit(8L));
3919	+	// non-determinism
3920	+	assertTrue(f.get() == 5L || f.get() == 8L);
3921	+	}
3922	+
3923	+	CompletableFuture<Long> godot = new CompletableFuture<>();
3924	+	// f plus godot === f (doesn't wait for godot)
3925	+	Monad.assertFutureEquals(Monad.unit(5L),
3926	+	Monad.plus(Monad.unit(5L), godot));
3927	+	// godot plus f === f (doesn't wait for godot)
3928	+	Monad.assertFutureEquals(Monad.unit(5L),
3929	+	Monad.plus(godot, Monad.unit(5L)));
3930	+	}
3931	+
3932	+	/**
3933	+	* A single CompletableFuture with many dependents.
3934	+	* A demo of scalability - runtime is O(n).
3935	+	*/
3936	+	public void testManyDependents() throws Throwable {
3937	+	final int n = 1_000;
3938	+	final CompletableFuture<Void> head = new CompletableFuture<>();
3939	+	final CompletableFuture<Void> complete = CompletableFuture.completedFuture((Void)null);
3940	+	final AtomicInteger count = new AtomicInteger(0);
3941	+	for (int i = 0; i < n; i++) {
3942	+	head.thenRun(() -> count.getAndIncrement());
3943	+	head.thenAccept((x) -> count.getAndIncrement());
3944	+	head.thenApply((x) -> count.getAndIncrement());
3945	+
3946	+	head.runAfterBoth(complete, () -> count.getAndIncrement());
3947	+	head.thenAcceptBoth(complete, (x, y) -> count.getAndIncrement());
3948	+	head.thenCombine(complete, (x, y) -> count.getAndIncrement());
3949	+	complete.runAfterBoth(head, () -> count.getAndIncrement());
3950	+	complete.thenAcceptBoth(head, (x, y) -> count.getAndIncrement());
3951	+	complete.thenCombine(head, (x, y) -> count.getAndIncrement());
3952	+
3953	+	head.runAfterEither(new CompletableFuture<Void>(), () -> count.getAndIncrement());
3954	+	head.acceptEither(new CompletableFuture<Void>(), (x) -> count.getAndIncrement());
3955	+	head.applyToEither(new CompletableFuture<Void>(), (x) -> count.getAndIncrement());
3956	+	new CompletableFuture<Void>().runAfterEither(head, () -> count.getAndIncrement());
3957	+	new CompletableFuture<Void>().acceptEither(head, (x) -> count.getAndIncrement());
3958	+	new CompletableFuture<Void>().applyToEither(head, (x) -> count.getAndIncrement());
3959	+	}
3960	+	head.complete(null);
3961	+	assertEquals(5 * 3 * n, count.get());
3962	+	}
3963	+
3964	+	//     static <U> U join(CompletionStage<U> stage) {
3965	+	//         CompletableFuture<U> f = new CompletableFuture<>();
3966	+	//         stage.whenComplete((v, ex) -> {
3967	+	//             if (ex != null) f.completeExceptionally(ex); else f.complete(v);
3968	+	//         });
3969	+	//         return f.join();
3970	+	//     }
3971	+
3972	+	//     static <U> boolean isDone(CompletionStage<U> stage) {
3973	+	//         CompletableFuture<U> f = new CompletableFuture<>();
3974	+	//         stage.whenComplete((v, ex) -> {
3975	+	//             if (ex != null) f.completeExceptionally(ex); else f.complete(v);
3976	+	//         });
3977	+	//         return f.isDone();
3978	+	//     }
3979	+
3980	+	//     static <U> U join2(CompletionStage<U> stage) {
3981	+	//         return stage.toCompletableFuture().copy().join();
3982	+	//     }
3983	+
3984	+	//     static <U> boolean isDone2(CompletionStage<U> stage) {
3985	+	//         return stage.toCompletableFuture().copy().isDone();
3986	+	//     }
3987	+
3988		}

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