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Comparing jsr166/src/test/tck/CompletableFutureTest.java (file contents):
Revision 1.92 by jsr166, Tue Jun 17 20:50:01 2014 UTC vs.
Revision 1.134 by jsr166, Sun Nov 15 19:55:38 2015 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	>	assertEquals(defaultExecutorIsCommonPool,
644	>	(ForkJoinPool.commonPool() == ForkJoinTask.getPool()));
645		}
646		public CompletableFuture<Void> runAsync(Runnable a) {
647		return CompletableFuture.runAsync(a);
#	Line 850 | Line 840 | public class CompletableFutureTest exten
840		if (!createIncomplete) assertTrue(f.complete(v1));
841		final CompletableFuture<Integer> g = f.exceptionally
842		((Throwable t) -> {
853	–	// Should not be called
843		a.getAndIncrement();
844	<	throw new AssertionError();
844	>	threadFail("should not be called");
845	>	return null;            // unreached
846		});
847		if (createIncomplete) assertTrue(f.complete(v1));
848
#	Line 875 | Line 865 | public class CompletableFutureTest exten
865		if (!createIncomplete) f.completeExceptionally(ex);
866		final CompletableFuture<Integer> g = f.exceptionally
867		((Throwable t) -> {
868	<	ExecutionMode.DEFAULT.checkExecutionMode();
868	>	ExecutionMode.SYNC.checkExecutionMode();
869		threadAssertSame(t, ex);
870		a.getAndIncrement();
871		return v1;
#	Line 888 | Line 878 | public class CompletableFutureTest exten
878
879		public void testExceptionally_exceptionalCompletionActionFailed() {
880		for (boolean createIncomplete : new boolean[] { true, false })
891	–	for (Integer v1 : new Integer[] { 1, null })
881		{
882		final AtomicInteger a = new AtomicInteger(0);
883		final CFException ex1 = new CFException();
#	Line 897 | Line 886 | public class CompletableFutureTest exten
886		if (!createIncomplete) f.completeExceptionally(ex1);
887		final CompletableFuture<Integer> g = f.exceptionally
888		((Throwable t) -> {
889	<	ExecutionMode.DEFAULT.checkExecutionMode();
889	>	ExecutionMode.SYNC.checkExecutionMode();
890		threadAssertSame(t, ex1);
891		a.getAndIncrement();
892		throw ex2;
#	Line 912 | Line 901 | public class CompletableFutureTest exten
901		* whenComplete action executes on normal completion, propagating
902		* source result.
903		*/
904	<	public void testWhenComplete_normalCompletion1() {
904	>	public void testWhenComplete_normalCompletion() {
905		for (ExecutionMode m : ExecutionMode.values())
906		for (boolean createIncomplete : new boolean[] { true, false })
907		for (Integer v1 : new Integer[] { 1, null })
#	Line 942 | Line 931 | public class CompletableFutureTest exten
931		public void testWhenComplete_exceptionalCompletion() {
932		for (ExecutionMode m : ExecutionMode.values())
933		for (boolean createIncomplete : new boolean[] { true, false })
945	–	for (Integer v1 : new Integer[] { 1, null })
934		{
935		final AtomicInteger a = new AtomicInteger(0);
936		final CFException ex = new CFException();
#	Line 994 | Line 982 | public class CompletableFutureTest exten
982		* If a whenComplete action throws an exception when triggered by
983		* a normal completion, it completes exceptionally
984		*/
985	<	public void testWhenComplete_actionFailed() {
985	>	public void testWhenComplete_sourceCompletedNormallyActionFailed() {
986		for (boolean createIncomplete : new boolean[] { true, false })
987		for (ExecutionMode m : ExecutionMode.values())
988		for (Integer v1 : new Integer[] { 1, null })
#	Line 1022 | Line 1010 | public class CompletableFutureTest exten
1010		/**
1011		* If a whenComplete action throws an exception when triggered by
1012		* a source completion that also throws an exception, the source
1013	<	* exception takes precedence.
1013	>	* exception takes precedence (unlike handle)
1014		*/
1015	<	public void testWhenComplete_actionFailedSourceFailed() {
1015	>	public void testWhenComplete_sourceFailedActionFailed() {
1016		for (boolean createIncomplete : new boolean[] { true, false })
1017		for (ExecutionMode m : ExecutionMode.values())
1030	–	for (Integer v1 : new Integer[] { 1, null })
1018		{
1019		final AtomicInteger a = new AtomicInteger(0);
1020		final CFException ex1 = new CFException();
#	Line 1138 | Line 1125 | public class CompletableFutureTest exten
1125		}}
1126
1127		/**
1128	<	* handle result completes exceptionally if action does
1128	>	* If a "handle action" throws an exception when triggered by
1129	>	* a normal completion, it completes exceptionally
1130		*/
1131	<	public void testHandle_sourceFailedActionFailed() {
1131	>	public void testHandle_sourceCompletedNormallyActionFailed() {
1132		for (ExecutionMode m : ExecutionMode.values())
1133		for (boolean createIncomplete : new boolean[] { true, false })
1134	+	for (Integer v1 : new Integer[] { 1, null })
1135		{
1136		final CompletableFuture<Integer> f = new CompletableFuture<>();
1137		final AtomicInteger a = new AtomicInteger(0);
1138	<	final CFException ex1 = new CFException();
1139	<	final CFException ex2 = new CFException();
1151	<	if (!createIncomplete) f.completeExceptionally(ex1);
1138	>	final CFException ex = new CFException();
1139	>	if (!createIncomplete) assertTrue(f.complete(v1));
1140		final CompletableFuture<Integer> g = m.handle
1141		(f,
1142		(Integer x, Throwable t) -> {
1143		m.checkExecutionMode();
1144	<	threadAssertNull(x);
1145	<	threadAssertSame(ex1, t);
1144	>	threadAssertSame(x, v1);
1145	>	threadAssertNull(t);
1146		a.getAndIncrement();
1147	<	throw ex2;
1147	>	throw ex;
1148		});
1149	<	if (createIncomplete) f.completeExceptionally(ex1);
1149	>	if (createIncomplete) assertTrue(f.complete(v1));
1150
1151	<	checkCompletedWithWrappedException(g, ex2);
1152	<	checkCompletedExceptionally(f, ex1);
1151	>	checkCompletedWithWrappedException(g, ex);
1152	>	checkCompletedNormally(f, v1);
1153		assertEquals(1, a.get());
1154		}}
1155
1156	<	public void testHandle_sourceCompletedNormallyActionFailed() {
1157	<	for (ExecutionMode m : ExecutionMode.values())
1156	>	/**
1157	>	* If a "handle action" throws an exception when triggered by
1158	>	* a source completion that also throws an exception, the action
1159	>	* exception takes precedence (unlike whenComplete)
1160	>	*/
1161	>	public void testHandle_sourceFailedActionFailed() {
1162		for (boolean createIncomplete : new boolean[] { true, false })
1163	<	for (Integer v1 : new Integer[] { 1, null })
1163	>	for (ExecutionMode m : ExecutionMode.values())
1164		{
1173	–	final CompletableFuture<Integer> f = new CompletableFuture<>();
1165		final AtomicInteger a = new AtomicInteger(0);
1166	<	final CFException ex = new CFException();
1167	<	if (!createIncomplete) assertTrue(f.complete(v1));
1166	>	final CFException ex1 = new CFException();
1167	>	final CFException ex2 = new CFException();
1168	>	final CompletableFuture<Integer> f = new CompletableFuture<>();
1169	>
1170	>	if (!createIncomplete) f.completeExceptionally(ex1);
1171		final CompletableFuture<Integer> g = m.handle
1172		(f,
1173		(Integer x, Throwable t) -> {
1174		m.checkExecutionMode();
1175	<	threadAssertSame(x, v1);
1176	<	threadAssertNull(t);
1175	>	threadAssertNull(x);
1176	>	threadAssertSame(ex1, t);
1177		a.getAndIncrement();
1178	<	throw ex;
1178	>	throw ex2;
1179		});
1180	<	if (createIncomplete) assertTrue(f.complete(v1));
1180	>	if (createIncomplete) f.completeExceptionally(ex1);
1181
1182	<	checkCompletedWithWrappedException(g, ex);
1183	<	checkCompletedNormally(f, v1);
1182	>	checkCompletedWithWrappedException(g, ex2);
1183	>	checkCompletedExceptionally(f, ex1);
1184		assertEquals(1, a.get());
1185		}}
1186
#	Line 1600 | Line 1594 | public class CompletableFutureTest exten
1594		{
1595		final CompletableFuture<Integer> f = new CompletableFuture<>();
1596		final CompletableFuture<Integer> g = new CompletableFuture<>();
1597	<	final SubtractFunction r1 = new SubtractFunction(m);
1598	<	final SubtractFunction r2 = new SubtractFunction(m);
1605	<	final SubtractFunction r3 = new SubtractFunction(m);
1597	>	final SubtractFunction[] rs = new SubtractFunction[6];
1598	>	for (int i = 0; i < rs.length; i++) rs[i] = new SubtractFunction(m);
1599
1600		final CompletableFuture<Integer> fst =  fFirst ? f : g;
1601		final CompletableFuture<Integer> snd = !fFirst ? f : g;
1602		final Integer w1 =  fFirst ? v1 : v2;
1603		final Integer w2 = !fFirst ? v1 : v2;
1604
1605	<	final CompletableFuture<Integer> h1 = m.thenCombine(f, g, r1);
1605	>	final CompletableFuture<Integer> h0 = m.thenCombine(f, g, rs[0]);
1606	>	final CompletableFuture<Integer> h1 = m.thenCombine(fst, fst, rs[1]);
1607		assertTrue(fst.complete(w1));
1608	<	final CompletableFuture<Integer> h2 = m.thenCombine(f, g, r2);
1609	<	checkIncomplete(h1);
1610	<	checkIncomplete(h2);
1611	<	r1.assertNotInvoked();
1612	<	r2.assertNotInvoked();
1608	>	final CompletableFuture<Integer> h2 = m.thenCombine(f, g, rs[2]);
1609	>	final CompletableFuture<Integer> h3 = m.thenCombine(fst, fst, rs[3]);
1610	>	checkIncomplete(h0); rs[0].assertNotInvoked();
1611	>	checkIncomplete(h2); rs[2].assertNotInvoked();
1612	>	checkCompletedNormally(h1, subtract(w1, w1));
1613	>	checkCompletedNormally(h3, subtract(w1, w1));
1614	>	rs[1].assertValue(subtract(w1, w1));
1615	>	rs[3].assertValue(subtract(w1, w1));
1616		assertTrue(snd.complete(w2));
1617	<	final CompletableFuture<Integer> h3 = m.thenCombine(f, g, r3);
1617	>	final CompletableFuture<Integer> h4 = m.thenCombine(f, g, rs[4]);
1618
1619	<	checkCompletedNormally(h1, subtract(v1, v2));
1619	>	checkCompletedNormally(h0, subtract(v1, v2));
1620		checkCompletedNormally(h2, subtract(v1, v2));
1621	<	checkCompletedNormally(h3, subtract(v1, v2));
1622	<	r1.assertValue(subtract(v1, v2));
1623	<	r2.assertValue(subtract(v1, v2));
1624	<	r3.assertValue(subtract(v1, v2));
1621	>	checkCompletedNormally(h4, subtract(v1, v2));
1622	>	rs[0].assertValue(subtract(v1, v2));
1623	>	rs[2].assertValue(subtract(v1, v2));
1624	>	rs[4].assertValue(subtract(v1, v2));
1625	>
1626		checkCompletedNormally(f, v1);
1627		checkCompletedNormally(g, v2);
1628		}}
#	Line 2971 | Line 2969 | public class CompletableFutureTest exten
2969		checkCancelled(f);
2970		}}
2971
2972	+	/**
2973	+	* thenCompose result completes exceptionally if the result of the action does
2974	+	*/
2975	+	public void testThenCompose_actionReturnsFailingFuture() {
2976	+	for (ExecutionMode m : ExecutionMode.values())
2977	+	for (int order = 0; order < 6; order++)
2978	+	for (Integer v1 : new Integer[] { 1, null })
2979	+	{
2980	+	final CFException ex = new CFException();
2981	+	final CompletableFuture<Integer> f = new CompletableFuture<>();
2982	+	final CompletableFuture<Integer> g = new CompletableFuture<>();
2983	+	final CompletableFuture<Integer> h;
2984	+	// Test all permutations of orders
2985	+	switch (order) {
2986	+	case 0:
2987	+	assertTrue(f.complete(v1));
2988	+	assertTrue(g.completeExceptionally(ex));
2989	+	h = m.thenCompose(f, (x -> g));
2990	+	break;
2991	+	case 1:
2992	+	assertTrue(f.complete(v1));
2993	+	h = m.thenCompose(f, (x -> g));
2994	+	assertTrue(g.completeExceptionally(ex));
2995	+	break;
2996	+	case 2:
2997	+	assertTrue(g.completeExceptionally(ex));
2998	+	assertTrue(f.complete(v1));
2999	+	h = m.thenCompose(f, (x -> g));
3000	+	break;
3001	+	case 3:
3002	+	assertTrue(g.completeExceptionally(ex));
3003	+	h = m.thenCompose(f, (x -> g));
3004	+	assertTrue(f.complete(v1));
3005	+	break;
3006	+	case 4:
3007	+	h = m.thenCompose(f, (x -> g));
3008	+	assertTrue(f.complete(v1));
3009	+	assertTrue(g.completeExceptionally(ex));
3010	+	break;
3011	+	case 5:
3012	+	h = m.thenCompose(f, (x -> g));
3013	+	assertTrue(f.complete(v1));
3014	+	assertTrue(g.completeExceptionally(ex));
3015	+	break;
3016	+	default: throw new AssertionError();
3017	+	}
3018	+
3019	+	checkCompletedExceptionally(g, ex);
3020	+	checkCompletedWithWrappedException(h, ex);
3021	+	checkCompletedNormally(f, v1);
3022	+	}}
3023	+
3024		// other static methods
3025
3026		/**
#	Line 3031 | Line 3081 | public class CompletableFutureTest exten
3081		for (int i = 0; i < k; i++) {
3082		checkIncomplete(f);
3083		checkIncomplete(CompletableFuture.allOf(fs));
3084	<	if (i != k/2) {
3084	>	if (i != k / 2) {
3085		fs[i].complete(i);
3086		checkCompletedNormally(fs[i], i);
3087		} else {
#	Line 3138 | Line 3188 | public class CompletableFutureTest exten
3188		CompletableFuture<Integer> f = new CompletableFuture<>();
3189		CompletableFuture<Integer> g = new CompletableFuture<>();
3190		CompletableFuture<Integer> nullFuture = (CompletableFuture<Integer>)null;
3141	–	CompletableFuture<?> h;
3191		ThreadExecutor exec = new ThreadExecutor();
3192
3193		Runnable[] throwingActions = {
3194		() -> CompletableFuture.supplyAsync(null),
3195		() -> CompletableFuture.supplyAsync(null, exec),
3196	<	() -> CompletableFuture.supplyAsync(new IntegerSupplier(ExecutionMode.DEFAULT, 42), null),
3196	>	() -> CompletableFuture.supplyAsync(new IntegerSupplier(ExecutionMode.SYNC, 42), null),
3197
3198		() -> CompletableFuture.runAsync(null),
3199		() -> CompletableFuture.runAsync(null, exec),
#	Line 3235 | Line 3284 | public class CompletableFutureTest exten
3284		() -> CompletableFuture.anyOf(null, f),
3285
3286		() -> f.obtrudeException(null),
3287	+
3288	+	() -> CompletableFuture.delayedExecutor(1L, SECONDS, null),
3289	+	() -> CompletableFuture.delayedExecutor(1L, null, new ThreadExecutor()),
3290	+	() -> CompletableFuture.delayedExecutor(1L, null),
3291	+
3292	+	() -> f.orTimeout(1L, null),
3293	+	() -> f.completeOnTimeout(42, 1L, null),
3294	+
3295	+	() -> CompletableFuture.failedFuture(null),
3296	+	() -> CompletableFuture.failedStage(null),
3297		};
3298
3299		assertThrows(NullPointerException.class, throwingActions);
#	Line 3249 | Line 3308 | public class CompletableFutureTest exten
3308		assertSame(f, f.toCompletableFuture());
3309		}
3310
3311	+	// jdk9
3312	+
3313	+	/**
3314	+	* newIncompleteFuture returns an incomplete CompletableFuture
3315	+	*/
3316	+	public void testNewIncompleteFuture() {
3317	+	for (Integer v1 : new Integer[] { 1, null })
3318	+	{
3319	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3320	+	CompletableFuture<Integer> g = f.newIncompleteFuture();
3321	+	checkIncomplete(f);
3322	+	checkIncomplete(g);
3323	+	f.complete(v1);
3324	+	checkCompletedNormally(f, v1);
3325	+	checkIncomplete(g);
3326	+	g.complete(v1);
3327	+	checkCompletedNormally(g, v1);
3328	+	assertSame(g.getClass(), CompletableFuture.class);
3329	+	}}
3330	+
3331	+	/**
3332	+	* completedStage returns a completed CompletionStage
3333	+	*/
3334	+	public void testCompletedStage() {
3335	+	AtomicInteger x = new AtomicInteger(0);
3336	+	AtomicReference<Throwable> r = new AtomicReference<Throwable>();
3337	+	CompletionStage<Integer> f = CompletableFuture.completedStage(1);
3338	+	f.whenComplete((v, e) -> {if (e != null) r.set(e); else x.set(v);});
3339	+	assertEquals(x.get(), 1);
3340	+	assertNull(r.get());
3341	+	}
3342	+
3343	+	/**
3344	+	* defaultExecutor by default returns the commonPool if
3345	+	* it supports more than one thread.
3346	+	*/
3347	+	public void testDefaultExecutor() {
3348	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3349	+	Executor e = f.defaultExecutor();
3350	+	Executor c = ForkJoinPool.commonPool();
3351	+	if (ForkJoinPool.getCommonPoolParallelism() > 1)
3352	+	assertSame(e, c);
3353	+	else
3354	+	assertNotSame(e, c);
3355	+	}
3356	+
3357	+	/**
3358	+	* failedFuture returns a CompletableFuture completed
3359	+	* exceptionally with the given Exception
3360	+	*/
3361	+	public void testFailedFuture() {
3362	+	CFException ex = new CFException();
3363	+	CompletableFuture<Integer> f = CompletableFuture.failedFuture(ex);
3364	+	checkCompletedExceptionally(f, ex);
3365	+	}
3366	+
3367	+	/**
3368	+	* failedFuture(null) throws NPE
3369	+	*/
3370	+	public void testFailedFuture_null() {
3371	+	try {
3372	+	CompletableFuture<Integer> f = CompletableFuture.failedFuture(null);
3373	+	shouldThrow();
3374	+	} catch (NullPointerException success) {}
3375	+	}
3376	+
3377	+	/**
3378	+	* copy returns a CompletableFuture that is completed normally,
3379	+	* with the same value, when source is.
3380	+	*/
3381	+	public void testCopy() {
3382	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3383	+	CompletableFuture<Integer> g = f.copy();
3384	+	checkIncomplete(f);
3385	+	checkIncomplete(g);
3386	+	f.complete(1);
3387	+	checkCompletedNormally(f, 1);
3388	+	checkCompletedNormally(g, 1);
3389	+	}
3390	+
3391	+	/**
3392	+	* copy returns a CompletableFuture that is completed exceptionally
3393	+	* when source is.
3394	+	*/
3395	+	public void testCopy2() {
3396	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3397	+	CompletableFuture<Integer> g = f.copy();
3398	+	checkIncomplete(f);
3399	+	checkIncomplete(g);
3400	+	CFException ex = new CFException();
3401	+	f.completeExceptionally(ex);
3402	+	checkCompletedExceptionally(f, ex);
3403	+	checkCompletedWithWrappedException(g, ex);
3404	+	}
3405	+
3406	+	/**
3407	+	* minimalCompletionStage returns a CompletableFuture that is
3408	+	* completed normally, with the same value, when source is.
3409	+	*/
3410	+	public void testMinimalCompletionStage() {
3411	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3412	+	CompletionStage<Integer> g = f.minimalCompletionStage();
3413	+	AtomicInteger x = new AtomicInteger(0);
3414	+	AtomicReference<Throwable> r = new AtomicReference<Throwable>();
3415	+	checkIncomplete(f);
3416	+	g.whenComplete((v, e) -> {if (e != null) r.set(e); else x.set(v);});
3417	+	f.complete(1);
3418	+	checkCompletedNormally(f, 1);
3419	+	assertEquals(x.get(), 1);
3420	+	assertNull(r.get());
3421	+	}
3422	+
3423	+	/**
3424	+	* minimalCompletionStage returns a CompletableFuture that is
3425	+	* completed exceptionally when source is.
3426	+	*/
3427	+	public void testMinimalCompletionStage2() {
3428	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3429	+	CompletionStage<Integer> g = f.minimalCompletionStage();
3430	+	AtomicInteger x = new AtomicInteger(0);
3431	+	AtomicReference<Throwable> r = new AtomicReference<Throwable>();
3432	+	g.whenComplete((v, e) -> {if (e != null) r.set(e); else x.set(v);});
3433	+	checkIncomplete(f);
3434	+	CFException ex = new CFException();
3435	+	f.completeExceptionally(ex);
3436	+	checkCompletedExceptionally(f, ex);
3437	+	assertEquals(x.get(), 0);
3438	+	assertEquals(r.get().getCause(), ex);
3439	+	}
3440	+
3441	+	/**
3442	+	* failedStage returns a CompletionStage completed
3443	+	* exceptionally with the given Exception
3444	+	*/
3445	+	public void testFailedStage() {
3446	+	CFException ex = new CFException();
3447	+	CompletionStage<Integer> f = CompletableFuture.failedStage(ex);
3448	+	AtomicInteger x = new AtomicInteger(0);
3449	+	AtomicReference<Throwable> r = new AtomicReference<Throwable>();
3450	+	f.whenComplete((v, e) -> {if (e != null) r.set(e); else x.set(v);});
3451	+	assertEquals(x.get(), 0);
3452	+	assertEquals(r.get(), ex);
3453	+	}
3454	+
3455	+	/**
3456	+	* completeAsync completes with value of given supplier
3457	+	*/
3458	+	public void testCompleteAsync() {
3459	+	for (Integer v1 : new Integer[] { 1, null })
3460	+	{
3461	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3462	+	f.completeAsync(() -> v1);
3463	+	f.join();
3464	+	checkCompletedNormally(f, v1);
3465	+	}}
3466	+
3467	+	/**
3468	+	* completeAsync completes exceptionally if given supplier throws
3469	+	*/
3470	+	public void testCompleteAsync2() {
3471	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3472	+	CFException ex = new CFException();
3473	+	f.completeAsync(() -> {if (true) throw ex; return 1;});
3474	+	try {
3475	+	f.join();
3476	+	shouldThrow();
3477	+	} catch (CompletionException success) {}
3478	+	checkCompletedWithWrappedException(f, ex);
3479	+	}
3480	+
3481	+	/**
3482	+	* completeAsync with given executor completes with value of given supplier
3483	+	*/
3484	+	public void testCompleteAsync3() {
3485	+	for (Integer v1 : new Integer[] { 1, null })
3486	+	{
3487	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3488	+	ThreadExecutor executor = new ThreadExecutor();
3489	+	f.completeAsync(() -> v1, executor);
3490	+	assertSame(v1, f.join());
3491	+	checkCompletedNormally(f, v1);
3492	+	assertEquals(1, executor.count.get());
3493	+	}}
3494	+
3495	+	/**
3496	+	* completeAsync with given executor completes exceptionally if
3497	+	* given supplier throws
3498	+	*/
3499	+	public void testCompleteAsync4() {
3500	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3501	+	CFException ex = new CFException();
3502	+	ThreadExecutor executor = new ThreadExecutor();
3503	+	f.completeAsync(() -> {if (true) throw ex; return 1;}, executor);
3504	+	try {
3505	+	f.join();
3506	+	shouldThrow();
3507	+	} catch (CompletionException success) {}
3508	+	checkCompletedWithWrappedException(f, ex);
3509	+	assertEquals(1, executor.count.get());
3510	+	}
3511	+
3512	+	/**
3513	+	* orTimeout completes with TimeoutException if not complete
3514	+	*/
3515	+	public void testOrTimeout_timesOut() {
3516	+	long timeoutMillis = timeoutMillis();
3517	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3518	+	long startTime = System.nanoTime();
3519	+	f.orTimeout(timeoutMillis, MILLISECONDS);
3520	+	checkCompletedWithTimeoutException(f);
3521	+	assertTrue(millisElapsedSince(startTime) >= timeoutMillis);
3522	+	}
3523	+
3524	+	/**
3525	+	* orTimeout completes normally if completed before timeout
3526	+	*/
3527	+	public void testOrTimeout_completed() {
3528	+	for (Integer v1 : new Integer[] { 1, null })
3529	+	{
3530	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3531	+	CompletableFuture<Integer> g = new CompletableFuture<>();
3532	+	long startTime = System.nanoTime();
3533	+	f.complete(v1);
3534	+	f.orTimeout(LONG_DELAY_MS, MILLISECONDS);
3535	+	g.orTimeout(LONG_DELAY_MS, MILLISECONDS);
3536	+	g.complete(v1);
3537	+	checkCompletedNormally(f, v1);
3538	+	checkCompletedNormally(g, v1);
3539	+	assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS / 2);
3540	+	}}
3541	+
3542	+	/**
3543	+	* completeOnTimeout completes with given value if not complete
3544	+	*/
3545	+	public void testCompleteOnTimeout_timesOut() {
3546	+	testInParallel(() -> testCompleteOnTimeout_timesOut(42),
3547	+	() -> testCompleteOnTimeout_timesOut(null));
3548	+	}
3549	+
3550	+	public void testCompleteOnTimeout_timesOut(Integer v) {
3551	+	long timeoutMillis = timeoutMillis();
3552	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3553	+	long startTime = System.nanoTime();
3554	+	f.completeOnTimeout(v, timeoutMillis, MILLISECONDS);
3555	+	assertSame(v, f.join());
3556	+	assertTrue(millisElapsedSince(startTime) >= timeoutMillis);
3557	+	f.complete(99);         // should have no effect
3558	+	checkCompletedNormally(f, v);
3559	+	}
3560	+
3561	+	/**
3562	+	* completeOnTimeout has no effect if completed within timeout
3563	+	*/
3564	+	public void testCompleteOnTimeout_completed() {
3565	+	for (Integer v1 : new Integer[] { 1, null })
3566	+	{
3567	+	CompletableFuture<Integer> f = new CompletableFuture<>();
3568	+	CompletableFuture<Integer> g = new CompletableFuture<>();
3569	+	long startTime = System.nanoTime();
3570	+	f.complete(v1);
3571	+	f.completeOnTimeout(-1, LONG_DELAY_MS, MILLISECONDS);
3572	+	g.completeOnTimeout(-1, LONG_DELAY_MS, MILLISECONDS);
3573	+	g.complete(v1);
3574	+	checkCompletedNormally(f, v1);
3575	+	checkCompletedNormally(g, v1);
3576	+	assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS / 2);
3577	+	}}
3578	+
3579	+	/**
3580	+	* delayedExecutor returns an executor that delays submission
3581	+	*/
3582	+	public void testDelayedExecutor() {
3583	+	testInParallel(() -> testDelayedExecutor(null, null),
3584	+	() -> testDelayedExecutor(null, 1),
3585	+	() -> testDelayedExecutor(new ThreadExecutor(), 1),
3586	+	() -> testDelayedExecutor(new ThreadExecutor(), 1));
3587	+	}
3588	+
3589	+	public void testDelayedExecutor(Executor executor, Integer v) throws Exception {
3590	+	long timeoutMillis = timeoutMillis();
3591	+	// Use an "unreasonably long" long timeout to catch lingering threads
3592	+	long longTimeoutMillis = 1000 * 60 * 60 * 24;
3593	+	final Executor delayer, longDelayer;
3594	+	if (executor == null) {
3595	+	delayer = CompletableFuture.delayedExecutor(timeoutMillis, MILLISECONDS);
3596	+	longDelayer = CompletableFuture.delayedExecutor(longTimeoutMillis, MILLISECONDS);
3597	+	} else {
3598	+	delayer = CompletableFuture.delayedExecutor(timeoutMillis, MILLISECONDS, executor);
3599	+	longDelayer = CompletableFuture.delayedExecutor(longTimeoutMillis, MILLISECONDS, executor);
3600	+	}
3601	+	long startTime = System.nanoTime();
3602	+	CompletableFuture<Integer> f =
3603	+	CompletableFuture.supplyAsync(() -> v, delayer);
3604	+	CompletableFuture<Integer> g =
3605	+	CompletableFuture.supplyAsync(() -> v, longDelayer);
3606	+
3607	+	assertNull(g.getNow(null));
3608	+
3609	+	assertSame(v, f.get(LONG_DELAY_MS, MILLISECONDS));
3610	+	long millisElapsed = millisElapsedSince(startTime);
3611	+	assertTrue(millisElapsed >= timeoutMillis);
3612	+	assertTrue(millisElapsed < LONG_DELAY_MS / 2);
3613	+
3614	+	checkCompletedNormally(f, v);
3615	+
3616	+	checkIncomplete(g);
3617	+	assertTrue(g.cancel(true));
3618	+	}
3619	+
3620		//--- tests of implementation details; not part of official tck ---
3621
3622		Object resultOf(CompletableFuture<?> f) {
#	Line 3339 | Line 3707 | public class CompletableFutureTest exten
3707		}
3708		}}
3709
3710	+	/**
3711	+	* Minimal completion stages throw UOE for all non-CompletionStage methods
3712	+	*/
3713	+	public void testMinimalCompletionStage_minimality() {
3714	+	if (!testImplementationDetails) return;
3715	+	Function<Method, String> toSignature =
3716	+	(method) -> method.getName() + Arrays.toString(method.getParameterTypes());
3717	+	Predicate<Method> isNotStatic =
3718	+	(method) -> (method.getModifiers() & Modifier.STATIC) == 0;
3719	+	List<Method> minimalMethods =
3720	+	Stream.of(Object.class, CompletionStage.class)
3721	+	.flatMap((klazz) -> Stream.of(klazz.getMethods()))
3722	+	.filter(isNotStatic)
3723	+	.collect(Collectors.toList());
3724	+	// Methods from CompletableFuture permitted NOT to throw UOE
3725	+	String[] signatureWhitelist = {
3726	+	"newIncompleteFuture[]",
3727	+	"defaultExecutor[]",
3728	+	"minimalCompletionStage[]",
3729	+	"copy[]",
3730	+	};
3731	+	Set<String> permittedMethodSignatures =
3732	+	Stream.concat(minimalMethods.stream().map(toSignature),
3733	+	Stream.of(signatureWhitelist))
3734	+	.collect(Collectors.toSet());
3735	+	List<Method> allMethods = Stream.of(CompletableFuture.class.getMethods())
3736	+	.filter(isNotStatic)
3737	+	.filter((method) -> !permittedMethodSignatures.contains(toSignature.apply(method)))
3738	+	.collect(Collectors.toList());
3739	+
3740	+	CompletionStage<Integer> minimalStage =
3741	+	new CompletableFuture<Integer>().minimalCompletionStage();
3742	+
3743	+	List<Method> bugs = new ArrayList<>();
3744	+	for (Method method : allMethods) {
3745	+	Class<?>[] parameterTypes = method.getParameterTypes();
3746	+	Object[] args = new Object[parameterTypes.length];
3747	+	// Manufacture boxed primitives for primitive params
3748	+	for (int i = 0; i < args.length; i++) {
3749	+	Class<?> type = parameterTypes[i];
3750	+	if (parameterTypes[i] == boolean.class)
3751	+	args[i] = false;
3752	+	else if (parameterTypes[i] == int.class)
3753	+	args[i] = 0;
3754	+	else if (parameterTypes[i] == long.class)
3755	+	args[i] = 0L;
3756	+	}
3757	+	try {
3758	+	method.invoke(minimalStage, args);
3759	+	bugs.add(method);
3760	+	}
3761	+	catch (java.lang.reflect.InvocationTargetException expected) {
3762	+	if (! (expected.getCause() instanceof UnsupportedOperationException)) {
3763	+	bugs.add(method);
3764	+	// expected.getCause().printStackTrace();
3765	+	}
3766	+	}
3767	+	catch (ReflectiveOperationException bad) { throw new Error(bad); }
3768	+	}
3769	+	if (!bugs.isEmpty())
3770	+	throw new Error("Methods did not throw UOE: " + bugs.toString());
3771	+	}
3772	+
3773	+	static class Monad {
3774	+	static class ZeroException extends RuntimeException {
3775	+	public ZeroException() { super("monadic zero"); }
3776	+	}
3777	+	// "return", "unit"
3778	+	static <T> CompletableFuture<T> unit(T value) {
3779	+	return completedFuture(value);
3780	+	}
3781	+	// monadic zero ?
3782	+	static <T> CompletableFuture<T> zero() {
3783	+	return failedFuture(new ZeroException());
3784	+	}
3785	+	// >=>
3786	+	static <T,U,V> Function<T, CompletableFuture<V>> compose
3787	+	(Function<T, CompletableFuture<U>> f,
3788	+	Function<U, CompletableFuture<V>> g) {
3789	+	return (x) -> f.apply(x).thenCompose(g);
3790	+	}
3791	+
3792	+	static void assertZero(CompletableFuture<?> f) {
3793	+	try {
3794	+	f.getNow(null);
3795	+	throw new AssertionFailedError("should throw");
3796	+	} catch (CompletionException success) {
3797	+	assertTrue(success.getCause() instanceof ZeroException);
3798	+	}
3799	+	}
3800	+
3801	+	static <T> void assertFutureEquals(CompletableFuture<T> f,
3802	+	CompletableFuture<T> g) {
3803	+	T fval = null, gval = null;
3804	+	Throwable fex = null, gex = null;
3805	+
3806	+	try { fval = f.get(); }
3807	+	catch (ExecutionException ex) { fex = ex.getCause(); }
3808	+	catch (Throwable ex) { fex = ex; }
3809	+
3810	+	try { gval = g.get(); }
3811	+	catch (ExecutionException ex) { gex = ex.getCause(); }
3812	+	catch (Throwable ex) { gex = ex; }
3813	+
3814	+	if (fex != null || gex != null)
3815	+	assertSame(fex.getClass(), gex.getClass());
3816	+	else
3817	+	assertEquals(fval, gval);
3818	+	}
3819	+
3820	+	static class PlusFuture<T> extends CompletableFuture<T> {
3821	+	AtomicReference<Throwable> firstFailure = new AtomicReference<>(null);
3822	+	}
3823	+
3824	+	// Monadic "plus"
3825	+	static <T> CompletableFuture<T> plus(CompletableFuture<? extends T> f,
3826	+	CompletableFuture<? extends T> g) {
3827	+	PlusFuture<T> plus = new PlusFuture<T>();
3828	+	BiConsumer<T, Throwable> action = (T result, Throwable ex) -> {
3829	+	if (ex == null) {
3830	+	if (plus.complete(result))
3831	+	if (plus.firstFailure.get() != null)
3832	+	plus.firstFailure.set(null);
3833	+	}
3834	+	else if (plus.firstFailure.compareAndSet(null, ex)) {
3835	+	if (plus.isDone())
3836	+	plus.firstFailure.set(null);
3837	+	}
3838	+	else {
3839	+	// first failure has precedence
3840	+	Throwable first = plus.firstFailure.getAndSet(null);
3841	+
3842	+	// may fail with "Self-suppression not permitted"
3843	+	try { first.addSuppressed(ex); }
3844	+	catch (Exception ignored) {}
3845	+
3846	+	plus.completeExceptionally(first);
3847	+	}
3848	+	};
3849	+	f.whenComplete(action);
3850	+	g.whenComplete(action);
3851	+	return plus;
3852	+	}
3853	+	}
3854	+
3855	+	/**
3856	+	* CompletableFuture is an additive monad - sort of.
3857	+	* https://en.wikipedia.org/wiki/Monad_(functional_programming)#Additive_monads
3858	+	*/
3859	+	public void testAdditiveMonad() throws Throwable {
3860	+	Function<Long, CompletableFuture<Long>> unit = Monad::unit;
3861	+	CompletableFuture<Long> zero = Monad.zero();
3862	+
3863	+	// Some mutually non-commutative functions
3864	+	Function<Long, CompletableFuture<Long>> triple
3865	+	= (x) -> Monad.unit(3 * x);
3866	+	Function<Long, CompletableFuture<Long>> inc
3867	+	= (x) -> Monad.unit(x + 1);
3868	+
3869	+	// unit is a right identity: m >>= unit === m
3870	+	Monad.assertFutureEquals(inc.apply(5L).thenCompose(unit),
3871	+	inc.apply(5L));
3872	+	// unit is a left identity: (unit x) >>= f === f x
3873	+	Monad.assertFutureEquals(unit.apply(5L).thenCompose(inc),
3874	+	inc.apply(5L));
3875	+
3876	+	// associativity: (m >>= f) >>= g === m >>= ( \x -> (f x >>= g) )
3877	+	Monad.assertFutureEquals(
3878	+	unit.apply(5L).thenCompose(inc).thenCompose(triple),
3879	+	unit.apply(5L).thenCompose((x) -> inc.apply(x).thenCompose(triple)));
3880	+
3881	+	// The case for CompletableFuture as an additive monad is weaker...
3882	+
3883	+	// zero is a monadic zero
3884	+	Monad.assertZero(zero);
3885	+
3886	+	// left zero: zero >>= f === zero
3887	+	Monad.assertZero(zero.thenCompose(inc));
3888	+	// right zero: f >>= (\x -> zero) === zero
3889	+	Monad.assertZero(inc.apply(5L).thenCompose((x) -> zero));
3890	+
3891	+	// f plus zero === f
3892	+	Monad.assertFutureEquals(Monad.unit(5L),
3893	+	Monad.plus(Monad.unit(5L), zero));
3894	+	// zero plus f === f
3895	+	Monad.assertFutureEquals(Monad.unit(5L),
3896	+	Monad.plus(zero, Monad.unit(5L)));
3897	+	// zero plus zero === zero
3898	+	Monad.assertZero(Monad.plus(zero, zero));
3899	+	{
3900	+	CompletableFuture<Long> f = Monad.plus(Monad.unit(5L),
3901	+	Monad.unit(8L));
3902	+	// non-determinism
3903	+	assertTrue(f.get() == 5L || f.get() == 8L);
3904	+	}
3905	+
3906	+	CompletableFuture<Long> godot = new CompletableFuture<>();
3907	+	// f plus godot === f (doesn't wait for godot)
3908	+	Monad.assertFutureEquals(Monad.unit(5L),
3909	+	Monad.plus(Monad.unit(5L), godot));
3910	+	// godot plus f === f (doesn't wait for godot)
3911	+	Monad.assertFutureEquals(Monad.unit(5L),
3912	+	Monad.plus(godot, Monad.unit(5L)));
3913	+	}
3914	+
3915	+	//     static <U> U join(CompletionStage<U> stage) {
3916	+	//         CompletableFuture<U> f = new CompletableFuture<>();
3917	+	//         stage.whenComplete((v, ex) -> {
3918	+	//             if (ex != null) f.completeExceptionally(ex); else f.complete(v);
3919	+	//         });
3920	+	//         return f.join();
3921	+	//     }
3922	+
3923	+	//     static <U> boolean isDone(CompletionStage<U> stage) {
3924	+	//         CompletableFuture<U> f = new CompletableFuture<>();
3925	+	//         stage.whenComplete((v, ex) -> {
3926	+	//             if (ex != null) f.completeExceptionally(ex); else f.complete(v);
3927	+	//         });
3928	+	//         return f.isDone();
3929	+	//     }
3930	+
3931	+	//     static <U> U join2(CompletionStage<U> stage) {
3932	+	//         return stage.toCompletableFuture().copy().join();
3933	+	//     }
3934	+
3935	+	//     static <U> boolean isDone2(CompletionStage<U> stage) {
3936	+	//         return stage.toCompletableFuture().copy().isDone();
3937	+	//     }
3938	+
3939		}

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