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Comparing jsr166/src/test/tck/CompletableFutureTest.java (file contents):
Revision 1.93 by jsr166, Tue Jun 17 21:09:56 2014 UTC vs.
Revision 1.152 by jsr166, Sun Jun 26 19:03:27 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.RejectedExecutionException;
34   import java.util.concurrent.TimeoutException;
35 + import java.util.concurrent.TimeUnit;
36   import java.util.concurrent.atomic.AtomicInteger;
37 < 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;
37 > import java.util.concurrent.atomic.AtomicReference;
38   import java.util.function.BiConsumer;
30 import java.util.function.Function;
39   import java.util.function.BiFunction;
40 + import java.util.function.Consumer;
41 + import java.util.function.Function;
42 + import java.util.function.Predicate;
43 + import java.util.function.Supplier;
44 +
45 + import junit.framework.AssertionFailedError;
46 + import junit.framework.Test;
47 + import junit.framework.TestSuite;
48  
49   public class CompletableFutureTest extends JSR166TestCase {
50  
51      public static void main(String[] args) {
52 <        junit.textui.TestRunner.run(suite());
52 >        main(suite(), args);
53      }
54      public static Test suite() {
55          return new TestSuite(CompletableFutureTest.class);
# Line 44 | Line 60 | public class CompletableFutureTest exten
60      void checkIncomplete(CompletableFuture<?> f) {
61          assertFalse(f.isDone());
62          assertFalse(f.isCancelled());
63 <        assertTrue(f.toString().contains("[Not completed]"));
63 >        assertTrue(f.toString().contains("Not completed"));
64          try {
65              assertNull(f.getNow(null));
66          } catch (Throwable fail) { threadUnexpectedException(fail); }
# Line 57 | Line 73 | public class CompletableFutureTest exten
73      }
74  
75      <T> void checkCompletedNormally(CompletableFuture<T> f, T value) {
76 <        try {
77 <            assertEquals(value, f.get(LONG_DELAY_MS, MILLISECONDS));
62 <        } catch (Throwable fail) { threadUnexpectedException(fail); }
76 >        checkTimedGet(f, value);
77 >
78          try {
79              assertEquals(value, f.join());
80          } catch (Throwable fail) { threadUnexpectedException(fail); }
# Line 75 | Line 90 | public class CompletableFutureTest exten
90          assertTrue(f.toString().contains("[Completed normally]"));
91      }
92  
93 <    void checkCompletedWithWrappedCFException(CompletableFuture<?> f) {
94 <        try {
95 <            f.get(LONG_DELAY_MS, MILLISECONDS);
96 <            shouldThrow();
97 <        } catch (ExecutionException success) {
98 <            assertTrue(success.getCause() instanceof CFException);
99 <        } catch (Throwable fail) { threadUnexpectedException(fail); }
100 <        try {
101 <            f.join();
102 <            shouldThrow();
103 <        } catch (CompletionException success) {
104 <            assertTrue(success.getCause() instanceof CFException);
105 <        }
106 <        try {
107 <            f.getNow(null);
108 <            shouldThrow();
109 <        } catch (CompletionException success) {
95 <            assertTrue(success.getCause() instanceof CFException);
93 >    /**
94 >     * Returns the "raw" internal exceptional completion of f,
95 >     * without any additional wrapping with CompletionException.
96 >     */
97 >    <U> Throwable exceptionalCompletion(CompletableFuture<U> f) {
98 >        // handle (and whenComplete) can distinguish between "direct"
99 >        // and "wrapped" exceptional completion
100 >        return f.handle((U u, Throwable t) -> t).join();
101 >    }
102 >
103 >    void checkCompletedExceptionally(CompletableFuture<?> f,
104 >                                     boolean wrapped,
105 >                                     Consumer<Throwable> checker) {
106 >        Throwable cause = exceptionalCompletion(f);
107 >        if (wrapped) {
108 >            assertTrue(cause instanceof CompletionException);
109 >            cause = cause.getCause();
110          }
111 <        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 <    }
111 >        checker.accept(cause);
112  
113 <    <U> void checkCompletedExceptionallyWithRootCause(CompletableFuture<U> f,
109 <                                                      Throwable ex) {
113 >        long startTime = System.nanoTime();
114          try {
115              f.get(LONG_DELAY_MS, MILLISECONDS);
116              shouldThrow();
117          } catch (ExecutionException success) {
118 <            assertSame(ex, success.getCause());
118 >            assertSame(cause, success.getCause());
119          } catch (Throwable fail) { threadUnexpectedException(fail); }
120 +        assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS / 2);
121 +
122          try {
123              f.join();
124              shouldThrow();
125          } catch (CompletionException success) {
126 <            assertSame(ex, success.getCause());
127 <        }
126 >            assertSame(cause, success.getCause());
127 >        } catch (Throwable fail) { threadUnexpectedException(fail); }
128 >
129          try {
130              f.getNow(null);
131              shouldThrow();
132          } catch (CompletionException success) {
133 <            assertSame(ex, success.getCause());
134 <        }
133 >            assertSame(cause, success.getCause());
134 >        } catch (Throwable fail) { threadUnexpectedException(fail); }
135 >
136          try {
137              f.get();
138              shouldThrow();
139          } catch (ExecutionException success) {
140 <            assertSame(ex, success.getCause());
140 >            assertSame(cause, success.getCause());
141          } catch (Throwable fail) { threadUnexpectedException(fail); }
142  
135        assertTrue(f.isDone());
143          assertFalse(f.isCancelled());
144 +        assertTrue(f.isDone());
145 +        assertTrue(f.isCompletedExceptionally());
146          assertTrue(f.toString().contains("[Completed exceptionally]"));
147      }
148  
149 <    <U> void checkCompletedWithWrappedException(CompletableFuture<U> f,
150 <                                                Throwable ex) {
151 <        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); }
149 >    void checkCompletedWithWrappedCFException(CompletableFuture<?> f) {
150 >        checkCompletedExceptionally(f, true,
151 >            (t) -> assertTrue(t instanceof CFException));
152      }
153  
154 <    <U> void checkCompletedExceptionally(CompletableFuture<U> f, Throwable ex) {
155 <        checkCompletedExceptionallyWithRootCause(f, ex);
156 <        try {
157 <            CompletableFuture<Throwable> spy = f.handle
158 <                ((U u, Throwable t) -> t);
159 <            assertSame(ex, spy.join());
160 <        } catch (Throwable fail) { threadUnexpectedException(fail); }
154 >    void checkCompletedWithWrappedCancellationException(CompletableFuture<?> f) {
155 >        checkCompletedExceptionally(f, true,
156 >            (t) -> assertTrue(t instanceof CancellationException));
157 >    }
158 >
159 >    void checkCompletedWithTimeoutException(CompletableFuture<?> f) {
160 >        checkCompletedExceptionally(f, false,
161 >            (t) -> assertTrue(t instanceof TimeoutException));
162 >    }
163 >
164 >    void checkCompletedWithWrappedException(CompletableFuture<?> f,
165 >                                            Throwable ex) {
166 >        checkCompletedExceptionally(f, true, (t) -> assertSame(t, ex));
167 >    }
168 >
169 >    void checkCompletedExceptionally(CompletableFuture<?> f, Throwable ex) {
170 >        checkCompletedExceptionally(f, false, (t) -> assertSame(t, ex));
171      }
172  
173      void checkCancelled(CompletableFuture<?> f) {
174 +        long startTime = System.nanoTime();
175          try {
176              f.get(LONG_DELAY_MS, MILLISECONDS);
177              shouldThrow();
178          } catch (CancellationException success) {
179          } catch (Throwable fail) { threadUnexpectedException(fail); }
180 +        assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS / 2);
181 +
182          try {
183              f.join();
184              shouldThrow();
# Line 176 | Line 192 | public class CompletableFutureTest exten
192              shouldThrow();
193          } catch (CancellationException success) {
194          } 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    }
195  
196 <    void checkCompletedWithWrappedCancellationException(CompletableFuture<?> f) {
197 <        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); }
196 >        assertTrue(exceptionalCompletion(f) instanceof CancellationException);
197 >
198          assertTrue(f.isDone());
211        assertFalse(f.isCancelled());
199          assertTrue(f.isCompletedExceptionally());
200 +        assertTrue(f.isCancelled());
201          assertTrue(f.toString().contains("[Completed exceptionally]"));
202      }
203  
# Line 257 | Line 245 | public class CompletableFutureTest exten
245      {
246          CompletableFuture<Integer> f = new CompletableFuture<>();
247          checkIncomplete(f);
248 <        assertTrue(f.cancel(true));
249 <        assertTrue(f.cancel(true));
248 >        assertTrue(f.cancel(mayInterruptIfRunning));
249 >        assertTrue(f.cancel(mayInterruptIfRunning));
250 >        assertTrue(f.cancel(!mayInterruptIfRunning));
251          checkCancelled(f);
252      }}
253  
# Line 471 | Line 460 | public class CompletableFutureTest exten
460      class FailingSupplier extends CheckedAction
461          implements Supplier<Integer>
462      {
463 <        FailingSupplier(ExecutionMode m) { super(m); }
463 >        final CFException ex;
464 >        FailingSupplier(ExecutionMode m) { super(m); ex = new CFException(); }
465          public Integer get() {
466              invoked();
467 <            throw new CFException();
467 >            throw ex;
468          }
469      }
470  
471      class FailingConsumer extends CheckedIntegerAction
472          implements Consumer<Integer>
473      {
474 <        FailingConsumer(ExecutionMode m) { super(m); }
474 >        final CFException ex;
475 >        FailingConsumer(ExecutionMode m) { super(m); ex = new CFException(); }
476          public void accept(Integer x) {
477              invoked();
478              value = x;
479 <            throw new CFException();
479 >            throw ex;
480          }
481      }
482  
483      class FailingBiConsumer extends CheckedIntegerAction
484          implements BiConsumer<Integer, Integer>
485      {
486 <        FailingBiConsumer(ExecutionMode m) { super(m); }
486 >        final CFException ex;
487 >        FailingBiConsumer(ExecutionMode m) { super(m); ex = new CFException(); }
488          public void accept(Integer x, Integer y) {
489              invoked();
490              value = subtract(x, y);
491 <            throw new CFException();
491 >            throw ex;
492          }
493      }
494  
495      class FailingFunction extends CheckedIntegerAction
496          implements Function<Integer, Integer>
497      {
498 <        FailingFunction(ExecutionMode m) { super(m); }
498 >        final CFException ex;
499 >        FailingFunction(ExecutionMode m) { super(m); ex = new CFException(); }
500          public Integer apply(Integer x) {
501              invoked();
502              value = x;
503 <            throw new CFException();
503 >            throw ex;
504          }
505      }
506  
507      class FailingBiFunction extends CheckedIntegerAction
508          implements BiFunction<Integer, Integer, Integer>
509      {
510 <        FailingBiFunction(ExecutionMode m) { super(m); }
510 >        final CFException ex;
511 >        FailingBiFunction(ExecutionMode m) { super(m); ex = new CFException(); }
512          public Integer apply(Integer x, Integer y) {
513              invoked();
514              value = subtract(x, y);
515 <            throw new CFException();
515 >            throw ex;
516          }
517      }
518  
519      class FailingRunnable extends CheckedAction implements Runnable {
520 <        FailingRunnable(ExecutionMode m) { super(m); }
520 >        final CFException ex;
521 >        FailingRunnable(ExecutionMode m) { super(m); ex = new CFException(); }
522          public void run() {
523              invoked();
524 <            throw new CFException();
524 >            throw ex;
525          }
526      }
527  
533
528      class CompletableFutureInc extends CheckedIntegerAction
529          implements Function<Integer, CompletableFuture<Integer>>
530      {
# Line 547 | Line 541 | public class CompletableFutureTest exten
541      class FailingCompletableFutureFunction extends CheckedIntegerAction
542          implements Function<Integer, CompletableFuture<Integer>>
543      {
544 <        FailingCompletableFutureFunction(ExecutionMode m) { super(m); }
544 >        final CFException ex;
545 >        FailingCompletableFutureFunction(ExecutionMode m) { super(m); ex = new CFException(); }
546          public CompletableFuture<Integer> apply(Integer x) {
547              invoked();
548              value = x;
549 <            throw new CFException();
549 >            throw ex;
550          }
551      }
552  
# Line 569 | Line 564 | public class CompletableFutureTest exten
564          }
565      }
566  
567 +    static final boolean defaultExecutorIsCommonPool
568 +        = ForkJoinPool.getCommonPoolParallelism() > 1;
569 +
570      /**
571       * Permits the testing of parallel code for the 3 different
572       * execution modes without copy/pasting all the test methods.
573       */
574      enum ExecutionMode {
575 <        DEFAULT {
575 >        SYNC {
576              public void checkExecutionMode() {
577                  assertFalse(ThreadExecutor.startedCurrentThread());
578                  assertNull(ForkJoinTask.getPool());
# Line 650 | Line 648 | public class CompletableFutureTest exten
648  
649          ASYNC {
650              public void checkExecutionMode() {
651 <                assertSame(ForkJoinPool.commonPool(),
652 <                           ForkJoinTask.getPool());
651 >                assertEquals(defaultExecutorIsCommonPool,
652 >                             (ForkJoinPool.commonPool() == ForkJoinTask.getPool()));
653              }
654              public CompletableFuture<Void> runAsync(Runnable a) {
655                  return CompletableFuture.runAsync(a);
# Line 850 | Line 848 | public class CompletableFutureTest exten
848          if (!createIncomplete) assertTrue(f.complete(v1));
849          final CompletableFuture<Integer> g = f.exceptionally
850              ((Throwable t) -> {
853                // Should not be called
851                  a.getAndIncrement();
852 <                throw new AssertionError();
852 >                threadFail("should not be called");
853 >                return null;            // unreached
854              });
855          if (createIncomplete) assertTrue(f.complete(v1));
856  
# Line 875 | Line 873 | public class CompletableFutureTest exten
873          if (!createIncomplete) f.completeExceptionally(ex);
874          final CompletableFuture<Integer> g = f.exceptionally
875              ((Throwable t) -> {
876 <                ExecutionMode.DEFAULT.checkExecutionMode();
876 >                ExecutionMode.SYNC.checkExecutionMode();
877                  threadAssertSame(t, ex);
878                  a.getAndIncrement();
879                  return v1;
# Line 886 | Line 884 | public class CompletableFutureTest exten
884          assertEquals(1, a.get());
885      }}
886  
887 +    /**
888 +     * If an "exceptionally action" throws an exception, it completes
889 +     * exceptionally with that exception
890 +     */
891      public void testExceptionally_exceptionalCompletionActionFailed() {
892          for (boolean createIncomplete : new boolean[] { true, false })
891        for (Integer v1 : new Integer[] { 1, null })
893      {
894          final AtomicInteger a = new AtomicInteger(0);
895          final CFException ex1 = new CFException();
# Line 897 | Line 898 | public class CompletableFutureTest exten
898          if (!createIncomplete) f.completeExceptionally(ex1);
899          final CompletableFuture<Integer> g = f.exceptionally
900              ((Throwable t) -> {
901 <                ExecutionMode.DEFAULT.checkExecutionMode();
901 >                ExecutionMode.SYNC.checkExecutionMode();
902                  threadAssertSame(t, ex1);
903                  a.getAndIncrement();
904                  throw ex2;
# Line 905 | Line 906 | public class CompletableFutureTest exten
906          if (createIncomplete) f.completeExceptionally(ex1);
907  
908          checkCompletedWithWrappedException(g, ex2);
909 +        checkCompletedExceptionally(f, ex1);
910          assertEquals(1, a.get());
911      }}
912  
# Line 912 | Line 914 | public class CompletableFutureTest exten
914       * whenComplete action executes on normal completion, propagating
915       * source result.
916       */
917 <    public void testWhenComplete_normalCompletion1() {
917 >    public void testWhenComplete_normalCompletion() {
918          for (ExecutionMode m : ExecutionMode.values())
919          for (boolean createIncomplete : new boolean[] { true, false })
920          for (Integer v1 : new Integer[] { 1, null })
# Line 922 | Line 924 | public class CompletableFutureTest exten
924          if (!createIncomplete) assertTrue(f.complete(v1));
925          final CompletableFuture<Integer> g = m.whenComplete
926              (f,
927 <             (Integer x, Throwable t) -> {
927 >             (Integer result, Throwable t) -> {
928                  m.checkExecutionMode();
929 <                threadAssertSame(x, v1);
929 >                threadAssertSame(result, v1);
930                  threadAssertNull(t);
931                  a.getAndIncrement();
932              });
# Line 942 | Line 944 | public class CompletableFutureTest exten
944      public void testWhenComplete_exceptionalCompletion() {
945          for (ExecutionMode m : ExecutionMode.values())
946          for (boolean createIncomplete : new boolean[] { true, false })
945        for (Integer v1 : new Integer[] { 1, null })
947      {
948          final AtomicInteger a = new AtomicInteger(0);
949          final CFException ex = new CFException();
# Line 950 | Line 951 | public class CompletableFutureTest exten
951          if (!createIncomplete) f.completeExceptionally(ex);
952          final CompletableFuture<Integer> g = m.whenComplete
953              (f,
954 <             (Integer x, Throwable t) -> {
954 >             (Integer result, Throwable t) -> {
955                  m.checkExecutionMode();
956 <                threadAssertNull(x);
956 >                threadAssertNull(result);
957                  threadAssertSame(t, ex);
958                  a.getAndIncrement();
959              });
# Line 977 | Line 978 | public class CompletableFutureTest exten
978          if (!createIncomplete) assertTrue(f.cancel(mayInterruptIfRunning));
979          final CompletableFuture<Integer> g = m.whenComplete
980              (f,
981 <             (Integer x, Throwable t) -> {
981 >             (Integer result, Throwable t) -> {
982                  m.checkExecutionMode();
983 <                threadAssertNull(x);
983 >                threadAssertNull(result);
984                  threadAssertTrue(t instanceof CancellationException);
985                  a.getAndIncrement();
986              });
# Line 994 | Line 995 | public class CompletableFutureTest exten
995       * If a whenComplete action throws an exception when triggered by
996       * a normal completion, it completes exceptionally
997       */
998 <    public void testWhenComplete_actionFailed() {
998 >    public void testWhenComplete_sourceCompletedNormallyActionFailed() {
999          for (boolean createIncomplete : new boolean[] { true, false })
1000          for (ExecutionMode m : ExecutionMode.values())
1001          for (Integer v1 : new Integer[] { 1, null })
# Line 1005 | Line 1006 | public class CompletableFutureTest exten
1006          if (!createIncomplete) assertTrue(f.complete(v1));
1007          final CompletableFuture<Integer> g = m.whenComplete
1008              (f,
1009 <             (Integer x, Throwable t) -> {
1009 >             (Integer result, Throwable t) -> {
1010                  m.checkExecutionMode();
1011 <                threadAssertSame(x, v1);
1011 >                threadAssertSame(result, v1);
1012                  threadAssertNull(t);
1013                  a.getAndIncrement();
1014                  throw ex;
# Line 1022 | Line 1023 | public class CompletableFutureTest exten
1023      /**
1024       * If a whenComplete action throws an exception when triggered by
1025       * a source completion that also throws an exception, the source
1026 <     * exception takes precedence.
1026 >     * exception takes precedence (unlike handle)
1027       */
1028 <    public void testWhenComplete_actionFailedSourceFailed() {
1028 >    public void testWhenComplete_sourceFailedActionFailed() {
1029          for (boolean createIncomplete : new boolean[] { true, false })
1030          for (ExecutionMode m : ExecutionMode.values())
1030        for (Integer v1 : new Integer[] { 1, null })
1031      {
1032          final AtomicInteger a = new AtomicInteger(0);
1033          final CFException ex1 = new CFException();
# Line 1037 | Line 1037 | public class CompletableFutureTest exten
1037          if (!createIncomplete) f.completeExceptionally(ex1);
1038          final CompletableFuture<Integer> g = m.whenComplete
1039              (f,
1040 <             (Integer x, Throwable t) -> {
1040 >             (Integer result, Throwable t) -> {
1041                  m.checkExecutionMode();
1042                  threadAssertSame(t, ex1);
1043 <                threadAssertNull(x);
1043 >                threadAssertNull(result);
1044                  a.getAndIncrement();
1045                  throw ex2;
1046              });
# Line 1048 | Line 1048 | public class CompletableFutureTest exten
1048  
1049          checkCompletedWithWrappedException(g, ex1);
1050          checkCompletedExceptionally(f, ex1);
1051 +        if (testImplementationDetails) {
1052 +            assertEquals(1, ex1.getSuppressed().length);
1053 +            assertSame(ex2, ex1.getSuppressed()[0]);
1054 +        }
1055          assertEquals(1, a.get());
1056      }}
1057  
# Line 1065 | Line 1069 | public class CompletableFutureTest exten
1069          if (!createIncomplete) assertTrue(f.complete(v1));
1070          final CompletableFuture<Integer> g = m.handle
1071              (f,
1072 <             (Integer x, Throwable t) -> {
1072 >             (Integer result, Throwable t) -> {
1073                  m.checkExecutionMode();
1074 <                threadAssertSame(x, v1);
1074 >                threadAssertSame(result, v1);
1075                  threadAssertNull(t);
1076                  a.getAndIncrement();
1077                  return inc(v1);
# Line 1094 | Line 1098 | public class CompletableFutureTest exten
1098          if (!createIncomplete) f.completeExceptionally(ex);
1099          final CompletableFuture<Integer> g = m.handle
1100              (f,
1101 <             (Integer x, Throwable t) -> {
1101 >             (Integer result, Throwable t) -> {
1102                  m.checkExecutionMode();
1103 <                threadAssertNull(x);
1103 >                threadAssertNull(result);
1104                  threadAssertSame(t, ex);
1105                  a.getAndIncrement();
1106                  return v1;
# Line 1123 | Line 1127 | public class CompletableFutureTest exten
1127          if (!createIncomplete) assertTrue(f.cancel(mayInterruptIfRunning));
1128          final CompletableFuture<Integer> g = m.handle
1129              (f,
1130 <             (Integer x, Throwable t) -> {
1130 >             (Integer result, Throwable t) -> {
1131                  m.checkExecutionMode();
1132 <                threadAssertNull(x);
1132 >                threadAssertNull(result);
1133                  threadAssertTrue(t instanceof CancellationException);
1134                  a.getAndIncrement();
1135                  return v1;
# Line 1138 | Line 1142 | public class CompletableFutureTest exten
1142      }}
1143  
1144      /**
1145 <     * handle result completes exceptionally if action does
1145 >     * If a "handle action" throws an exception when triggered by
1146 >     * a normal completion, it completes exceptionally
1147       */
1148 <    public void testHandle_sourceFailedActionFailed() {
1148 >    public void testHandle_sourceCompletedNormallyActionFailed() {
1149          for (ExecutionMode m : ExecutionMode.values())
1150          for (boolean createIncomplete : new boolean[] { true, false })
1151 +        for (Integer v1 : new Integer[] { 1, null })
1152      {
1153          final CompletableFuture<Integer> f = new CompletableFuture<>();
1154          final AtomicInteger a = new AtomicInteger(0);
1155 <        final CFException ex1 = new CFException();
1156 <        final CFException ex2 = new CFException();
1151 <        if (!createIncomplete) f.completeExceptionally(ex1);
1155 >        final CFException ex = new CFException();
1156 >        if (!createIncomplete) assertTrue(f.complete(v1));
1157          final CompletableFuture<Integer> g = m.handle
1158              (f,
1159 <             (Integer x, Throwable t) -> {
1159 >             (Integer result, Throwable t) -> {
1160                  m.checkExecutionMode();
1161 <                threadAssertNull(x);
1162 <                threadAssertSame(ex1, t);
1161 >                threadAssertSame(result, v1);
1162 >                threadAssertNull(t);
1163                  a.getAndIncrement();
1164 <                throw ex2;
1164 >                throw ex;
1165              });
1166 <        if (createIncomplete) f.completeExceptionally(ex1);
1166 >        if (createIncomplete) assertTrue(f.complete(v1));
1167  
1168 <        checkCompletedWithWrappedException(g, ex2);
1169 <        checkCompletedExceptionally(f, ex1);
1168 >        checkCompletedWithWrappedException(g, ex);
1169 >        checkCompletedNormally(f, v1);
1170          assertEquals(1, a.get());
1171      }}
1172  
1173 <    public void testHandle_sourceCompletedNormallyActionFailed() {
1174 <        for (ExecutionMode m : ExecutionMode.values())
1173 >    /**
1174 >     * If a "handle action" throws an exception when triggered by
1175 >     * a source completion that also throws an exception, the action
1176 >     * exception takes precedence (unlike whenComplete)
1177 >     */
1178 >    public void testHandle_sourceFailedActionFailed() {
1179          for (boolean createIncomplete : new boolean[] { true, false })
1180 <        for (Integer v1 : new Integer[] { 1, null })
1180 >        for (ExecutionMode m : ExecutionMode.values())
1181      {
1173        final CompletableFuture<Integer> f = new CompletableFuture<>();
1182          final AtomicInteger a = new AtomicInteger(0);
1183 <        final CFException ex = new CFException();
1184 <        if (!createIncomplete) assertTrue(f.complete(v1));
1183 >        final CFException ex1 = new CFException();
1184 >        final CFException ex2 = new CFException();
1185 >        final CompletableFuture<Integer> f = new CompletableFuture<>();
1186 >
1187 >        if (!createIncomplete) f.completeExceptionally(ex1);
1188          final CompletableFuture<Integer> g = m.handle
1189              (f,
1190 <             (Integer x, Throwable t) -> {
1190 >             (Integer result, Throwable t) -> {
1191                  m.checkExecutionMode();
1192 <                threadAssertSame(x, v1);
1193 <                threadAssertNull(t);
1192 >                threadAssertNull(result);
1193 >                threadAssertSame(ex1, t);
1194                  a.getAndIncrement();
1195 <                throw ex;
1195 >                throw ex2;
1196              });
1197 <        if (createIncomplete) assertTrue(f.complete(v1));
1197 >        if (createIncomplete) f.completeExceptionally(ex1);
1198  
1199 <        checkCompletedWithWrappedException(g, ex);
1200 <        checkCompletedNormally(f, v1);
1199 >        checkCompletedWithWrappedException(g, ex2);
1200 >        checkCompletedExceptionally(f, ex1);
1201          assertEquals(1, a.get());
1202      }}
1203  
# Line 1219 | Line 1230 | public class CompletableFutureTest exten
1230      {
1231          final FailingRunnable r = new FailingRunnable(m);
1232          final CompletableFuture<Void> f = m.runAsync(r);
1233 <        checkCompletedWithWrappedCFException(f);
1233 >        checkCompletedWithWrappedException(f, r.ex);
1234          r.assertInvoked();
1235      }}
1236  
# Line 1253 | Line 1264 | public class CompletableFutureTest exten
1264      {
1265          FailingSupplier r = new FailingSupplier(m);
1266          CompletableFuture<Integer> f = m.supplyAsync(r);
1267 <        checkCompletedWithWrappedCFException(f);
1267 >        checkCompletedWithWrappedException(f, r.ex);
1268          r.assertInvoked();
1269      }}
1270  
# Line 1375 | Line 1386 | public class CompletableFutureTest exten
1386          final CompletableFuture<Void> h4 = m.runAfterBoth(f, f, rs[4]);
1387          final CompletableFuture<Void> h5 = m.runAfterEither(f, f, rs[5]);
1388  
1389 <        checkCompletedWithWrappedCFException(h0);
1390 <        checkCompletedWithWrappedCFException(h1);
1391 <        checkCompletedWithWrappedCFException(h2);
1392 <        checkCompletedWithWrappedCFException(h3);
1393 <        checkCompletedWithWrappedCFException(h4);
1394 <        checkCompletedWithWrappedCFException(h5);
1389 >        checkCompletedWithWrappedException(h0, rs[0].ex);
1390 >        checkCompletedWithWrappedException(h1, rs[1].ex);
1391 >        checkCompletedWithWrappedException(h2, rs[2].ex);
1392 >        checkCompletedWithWrappedException(h3, rs[3].ex);
1393 >        checkCompletedWithWrappedException(h4, rs[4].ex);
1394 >        checkCompletedWithWrappedException(h5, rs[5].ex);
1395          checkCompletedNormally(f, v1);
1396      }}
1397  
# Line 1479 | Line 1490 | public class CompletableFutureTest exten
1490          final CompletableFuture<Integer> h2 = m.thenApply(f, rs[2]);
1491          final CompletableFuture<Integer> h3 = m.applyToEither(f, f, rs[3]);
1492  
1493 <        checkCompletedWithWrappedCFException(h0);
1494 <        checkCompletedWithWrappedCFException(h1);
1495 <        checkCompletedWithWrappedCFException(h2);
1496 <        checkCompletedWithWrappedCFException(h3);
1493 >        checkCompletedWithWrappedException(h0, rs[0].ex);
1494 >        checkCompletedWithWrappedException(h1, rs[1].ex);
1495 >        checkCompletedWithWrappedException(h2, rs[2].ex);
1496 >        checkCompletedWithWrappedException(h3, rs[3].ex);
1497          checkCompletedNormally(f, v1);
1498      }}
1499  
# Line 1581 | Line 1592 | public class CompletableFutureTest exten
1592          final CompletableFuture<Void> h2 = m.thenAccept(f, rs[2]);
1593          final CompletableFuture<Void> h3 = m.acceptEither(f, f, rs[3]);
1594  
1595 <        checkCompletedWithWrappedCFException(h0);
1596 <        checkCompletedWithWrappedCFException(h1);
1597 <        checkCompletedWithWrappedCFException(h2);
1598 <        checkCompletedWithWrappedCFException(h3);
1595 >        checkCompletedWithWrappedException(h0, rs[0].ex);
1596 >        checkCompletedWithWrappedException(h1, rs[1].ex);
1597 >        checkCompletedWithWrappedException(h2, rs[2].ex);
1598 >        checkCompletedWithWrappedException(h3, rs[3].ex);
1599          checkCompletedNormally(f, v1);
1600      }}
1601  
# Line 1628 | Line 1639 | public class CompletableFutureTest exten
1639          rs[0].assertValue(subtract(v1, v2));
1640          rs[2].assertValue(subtract(v1, v2));
1641          rs[4].assertValue(subtract(v1, v2));
1642 <      
1642 >
1643          checkCompletedNormally(f, v1);
1644          checkCompletedNormally(g, v2);
1645      }}
# Line 1746 | Line 1757 | public class CompletableFutureTest exten
1757          assertTrue(snd.complete(w2));
1758          final CompletableFuture<Integer> h3 = m.thenCombine(f, g, r3);
1759  
1760 <        checkCompletedWithWrappedCFException(h1);
1761 <        checkCompletedWithWrappedCFException(h2);
1762 <        checkCompletedWithWrappedCFException(h3);
1760 >        checkCompletedWithWrappedException(h1, r1.ex);
1761 >        checkCompletedWithWrappedException(h2, r2.ex);
1762 >        checkCompletedWithWrappedException(h3, r3.ex);
1763          r1.assertInvoked();
1764          r2.assertInvoked();
1765          r3.assertInvoked();
# Line 1910 | Line 1921 | public class CompletableFutureTest exten
1921          assertTrue(snd.complete(w2));
1922          final CompletableFuture<Void> h3 = m.thenAcceptBoth(f, g, r3);
1923  
1924 <        checkCompletedWithWrappedCFException(h1);
1925 <        checkCompletedWithWrappedCFException(h2);
1926 <        checkCompletedWithWrappedCFException(h3);
1924 >        checkCompletedWithWrappedException(h1, r1.ex);
1925 >        checkCompletedWithWrappedException(h2, r2.ex);
1926 >        checkCompletedWithWrappedException(h3, r3.ex);
1927          r1.assertInvoked();
1928          r2.assertInvoked();
1929          r3.assertInvoked();
# Line 2074 | Line 2085 | public class CompletableFutureTest exten
2085          assertTrue(snd.complete(w2));
2086          final CompletableFuture<Void> h3 = m.runAfterBoth(f, g, r3);
2087  
2088 <        checkCompletedWithWrappedCFException(h1);
2089 <        checkCompletedWithWrappedCFException(h2);
2090 <        checkCompletedWithWrappedCFException(h3);
2088 >        checkCompletedWithWrappedException(h1, r1.ex);
2089 >        checkCompletedWithWrappedException(h2, r2.ex);
2090 >        checkCompletedWithWrappedException(h3, r3.ex);
2091          r1.assertInvoked();
2092          r2.assertInvoked();
2093          r3.assertInvoked();
# Line 2366 | Line 2377 | public class CompletableFutureTest exten
2377          f.complete(v1);
2378          final CompletableFuture<Integer> h2 = m.applyToEither(f, g, rs[2]);
2379          final CompletableFuture<Integer> h3 = m.applyToEither(g, f, rs[3]);
2380 <        checkCompletedWithWrappedCFException(h0);
2381 <        checkCompletedWithWrappedCFException(h1);
2382 <        checkCompletedWithWrappedCFException(h2);
2383 <        checkCompletedWithWrappedCFException(h3);
2380 >        checkCompletedWithWrappedException(h0, rs[0].ex);
2381 >        checkCompletedWithWrappedException(h1, rs[1].ex);
2382 >        checkCompletedWithWrappedException(h2, rs[2].ex);
2383 >        checkCompletedWithWrappedException(h3, rs[3].ex);
2384          for (int i = 0; i < 4; i++) rs[i].assertValue(v1);
2385  
2386          g.complete(v2);
# Line 2378 | Line 2389 | public class CompletableFutureTest exten
2389          final CompletableFuture<Integer> h4 = m.applyToEither(f, g, rs[4]);
2390          final CompletableFuture<Integer> h5 = m.applyToEither(g, f, rs[5]);
2391  
2392 <        checkCompletedWithWrappedCFException(h4);
2392 >        checkCompletedWithWrappedException(h4, rs[4].ex);
2393          assertTrue(Objects.equals(v1, rs[4].value) ||
2394                     Objects.equals(v2, rs[4].value));
2395 <        checkCompletedWithWrappedCFException(h5);
2395 >        checkCompletedWithWrappedException(h5, rs[5].ex);
2396          assertTrue(Objects.equals(v1, rs[5].value) ||
2397                     Objects.equals(v2, rs[5].value));
2398  
# Line 2625 | Line 2636 | public class CompletableFutureTest exten
2636          f.complete(v1);
2637          final CompletableFuture<Void> h2 = m.acceptEither(f, g, rs[2]);
2638          final CompletableFuture<Void> h3 = m.acceptEither(g, f, rs[3]);
2639 <        checkCompletedWithWrappedCFException(h0);
2640 <        checkCompletedWithWrappedCFException(h1);
2641 <        checkCompletedWithWrappedCFException(h2);
2642 <        checkCompletedWithWrappedCFException(h3);
2639 >        checkCompletedWithWrappedException(h0, rs[0].ex);
2640 >        checkCompletedWithWrappedException(h1, rs[1].ex);
2641 >        checkCompletedWithWrappedException(h2, rs[2].ex);
2642 >        checkCompletedWithWrappedException(h3, rs[3].ex);
2643          for (int i = 0; i < 4; i++) rs[i].assertValue(v1);
2644  
2645          g.complete(v2);
# Line 2637 | Line 2648 | public class CompletableFutureTest exten
2648          final CompletableFuture<Void> h4 = m.acceptEither(f, g, rs[4]);
2649          final CompletableFuture<Void> h5 = m.acceptEither(g, f, rs[5]);
2650  
2651 <        checkCompletedWithWrappedCFException(h4);
2651 >        checkCompletedWithWrappedException(h4, rs[4].ex);
2652          assertTrue(Objects.equals(v1, rs[4].value) ||
2653                     Objects.equals(v2, rs[4].value));
2654 <        checkCompletedWithWrappedCFException(h5);
2654 >        checkCompletedWithWrappedException(h5, rs[5].ex);
2655          assertTrue(Objects.equals(v1, rs[5].value) ||
2656                     Objects.equals(v2, rs[5].value));
2657  
# Line 2880 | Line 2891 | public class CompletableFutureTest exten
2891          assertTrue(f.complete(v1));
2892          final CompletableFuture<Void> h2 = m.runAfterEither(f, g, rs[2]);
2893          final CompletableFuture<Void> h3 = m.runAfterEither(g, f, rs[3]);
2894 <        checkCompletedWithWrappedCFException(h0);
2895 <        checkCompletedWithWrappedCFException(h1);
2896 <        checkCompletedWithWrappedCFException(h2);
2897 <        checkCompletedWithWrappedCFException(h3);
2894 >        checkCompletedWithWrappedException(h0, rs[0].ex);
2895 >        checkCompletedWithWrappedException(h1, rs[1].ex);
2896 >        checkCompletedWithWrappedException(h2, rs[2].ex);
2897 >        checkCompletedWithWrappedException(h3, rs[3].ex);
2898          for (int i = 0; i < 4; i++) rs[i].assertInvoked();
2899          assertTrue(g.complete(v2));
2900          final CompletableFuture<Void> h4 = m.runAfterEither(f, g, rs[4]);
2901          final CompletableFuture<Void> h5 = m.runAfterEither(g, f, rs[5]);
2902 <        checkCompletedWithWrappedCFException(h4);
2903 <        checkCompletedWithWrappedCFException(h5);
2902 >        checkCompletedWithWrappedException(h4, rs[4].ex);
2903 >        checkCompletedWithWrappedException(h5, rs[5].ex);
2904  
2905          checkCompletedNormally(f, v1);
2906          checkCompletedNormally(g, v2);
# Line 2950 | Line 2961 | public class CompletableFutureTest exten
2961          final CompletableFuture<Integer> g = m.thenCompose(f, r);
2962          if (createIncomplete) assertTrue(f.complete(v1));
2963  
2964 <        checkCompletedWithWrappedCFException(g);
2964 >        checkCompletedWithWrappedException(g, r.ex);
2965          checkCompletedNormally(f, v1);
2966      }}
2967  
# Line 2975 | Line 2986 | public class CompletableFutureTest exten
2986          checkCancelled(f);
2987      }}
2988  
2989 +    /**
2990 +     * thenCompose result completes exceptionally if the result of the action does
2991 +     */
2992 +    public void testThenCompose_actionReturnsFailingFuture() {
2993 +        for (ExecutionMode m : ExecutionMode.values())
2994 +        for (int order = 0; order < 6; order++)
2995 +        for (Integer v1 : new Integer[] { 1, null })
2996 +    {
2997 +        final CFException ex = new CFException();
2998 +        final CompletableFuture<Integer> f = new CompletableFuture<>();
2999 +        final CompletableFuture<Integer> g = new CompletableFuture<>();
3000 +        final CompletableFuture<Integer> h;
3001 +        // Test all permutations of orders
3002 +        switch (order) {
3003 +        case 0:
3004 +            assertTrue(f.complete(v1));
3005 +            assertTrue(g.completeExceptionally(ex));
3006 +            h = m.thenCompose(f, (x -> g));
3007 +            break;
3008 +        case 1:
3009 +            assertTrue(f.complete(v1));
3010 +            h = m.thenCompose(f, (x -> g));
3011 +            assertTrue(g.completeExceptionally(ex));
3012 +            break;
3013 +        case 2:
3014 +            assertTrue(g.completeExceptionally(ex));
3015 +            assertTrue(f.complete(v1));
3016 +            h = m.thenCompose(f, (x -> g));
3017 +            break;
3018 +        case 3:
3019 +            assertTrue(g.completeExceptionally(ex));
3020 +            h = m.thenCompose(f, (x -> g));
3021 +            assertTrue(f.complete(v1));
3022 +            break;
3023 +        case 4:
3024 +            h = m.thenCompose(f, (x -> g));
3025 +            assertTrue(f.complete(v1));
3026 +            assertTrue(g.completeExceptionally(ex));
3027 +            break;
3028 +        case 5:
3029 +            h = m.thenCompose(f, (x -> g));
3030 +            assertTrue(f.complete(v1));
3031 +            assertTrue(g.completeExceptionally(ex));
3032 +            break;
3033 +        default: throw new AssertionError();
3034 +        }
3035 +
3036 +        checkCompletedExceptionally(g, ex);
3037 +        checkCompletedWithWrappedException(h, ex);
3038 +        checkCompletedNormally(f, v1);
3039 +    }}
3040 +
3041      // other static methods
3042  
3043      /**
# Line 3007 | Line 3070 | public class CompletableFutureTest exten
3070          }
3071      }
3072  
3073 <    public void testAllOf_backwards() throws Exception {
3073 >    public void testAllOf_normal_backwards() throws Exception {
3074          for (int k = 1; k < 10; k++) {
3075              CompletableFuture<Integer>[] fs
3076                  = (CompletableFuture<Integer>[]) new CompletableFuture[k];
# Line 3035 | Line 3098 | public class CompletableFutureTest exten
3098              for (int i = 0; i < k; i++) {
3099                  checkIncomplete(f);
3100                  checkIncomplete(CompletableFuture.allOf(fs));
3101 <                if (i != k/2) {
3101 >                if (i != k / 2) {
3102                      fs[i].complete(i);
3103                      checkCompletedNormally(fs[i], i);
3104                  } else {
# Line 3142 | Line 3205 | public class CompletableFutureTest exten
3205          CompletableFuture<Integer> f = new CompletableFuture<>();
3206          CompletableFuture<Integer> g = new CompletableFuture<>();
3207          CompletableFuture<Integer> nullFuture = (CompletableFuture<Integer>)null;
3145        CompletableFuture<?> h;
3208          ThreadExecutor exec = new ThreadExecutor();
3209  
3210          Runnable[] throwingActions = {
3211              () -> CompletableFuture.supplyAsync(null),
3212              () -> CompletableFuture.supplyAsync(null, exec),
3213 <            () -> CompletableFuture.supplyAsync(new IntegerSupplier(ExecutionMode.DEFAULT, 42), null),
3213 >            () -> CompletableFuture.supplyAsync(new IntegerSupplier(ExecutionMode.SYNC, 42), null),
3214  
3215              () -> CompletableFuture.runAsync(null),
3216              () -> CompletableFuture.runAsync(null, exec),
# Line 3239 | Line 3301 | public class CompletableFutureTest exten
3301              () -> CompletableFuture.anyOf(null, f),
3302  
3303              () -> f.obtrudeException(null),
3304 +
3305 +            () -> CompletableFuture.delayedExecutor(1L, SECONDS, null),
3306 +            () -> CompletableFuture.delayedExecutor(1L, null, exec),
3307 +            () -> CompletableFuture.delayedExecutor(1L, null),
3308 +
3309 +            () -> f.orTimeout(1L, null),
3310 +            () -> f.completeOnTimeout(42, 1L, null),
3311 +
3312 +            () -> CompletableFuture.failedFuture(null),
3313 +            () -> CompletableFuture.failedStage(null),
3314          };
3315  
3316          assertThrows(NullPointerException.class, throwingActions);
# Line 3246 | Line 3318 | public class CompletableFutureTest exten
3318      }
3319  
3320      /**
3321 +     * Test submissions to an executor that rejects all tasks.
3322 +     */
3323 +    public void testRejectingExecutor() {
3324 +        final RejectedExecutionException ex = new RejectedExecutionException();
3325 +        final Executor e = (Runnable r) -> { throw ex; };
3326 +
3327 +        for (Integer v : new Integer[] { 1, null }) {
3328 +
3329 +        final CompletableFuture<Integer> complete = CompletableFuture.completedFuture(v);
3330 +        final CompletableFuture<Integer> incomplete = new CompletableFuture<>();
3331 +
3332 +        List<CompletableFuture<?>> futures = new ArrayList<>();
3333 +
3334 +        List<CompletableFuture<Integer>> srcs = new ArrayList<>();
3335 +        srcs.add(complete);
3336 +        srcs.add(incomplete);
3337 +
3338 +        for (CompletableFuture<Integer> src : srcs) {
3339 +            List<CompletableFuture<?>> fs = new ArrayList<>();
3340 +            fs.add(src.thenRunAsync(() -> {}, e));
3341 +            fs.add(src.thenAcceptAsync((z) -> {}, e));
3342 +            fs.add(src.thenApplyAsync((z) -> z, e));
3343 +
3344 +            fs.add(src.thenCombineAsync(src, (x, y) -> x, e));
3345 +            fs.add(src.thenAcceptBothAsync(src, (x, y) -> {}, e));
3346 +            fs.add(src.runAfterBothAsync(src, () -> {}, e));
3347 +
3348 +            fs.add(src.applyToEitherAsync(src, (z) -> z, e));
3349 +            fs.add(src.acceptEitherAsync(src, (z) -> {}, e));
3350 +            fs.add(src.runAfterEitherAsync(src, () -> {}, e));
3351 +
3352 +            fs.add(src.thenComposeAsync((z) -> null, e));
3353 +            fs.add(src.whenCompleteAsync((z, t) -> {}, e));
3354 +            fs.add(src.handleAsync((z, t) -> null, e));
3355 +
3356 +            for (CompletableFuture<?> future : fs) {
3357 +                if (src.isDone())
3358 +                    checkCompletedWithWrappedException(future, ex);
3359 +                else
3360 +                    checkIncomplete(future);
3361 +            }
3362 +            futures.addAll(fs);
3363 +        }
3364 +
3365 +        {
3366 +            List<CompletableFuture<?>> fs = new ArrayList<>();
3367 +
3368 +            fs.add(complete.thenCombineAsync(incomplete, (x, y) -> x, e));
3369 +            fs.add(incomplete.thenCombineAsync(complete, (x, y) -> x, e));
3370 +
3371 +            fs.add(complete.thenAcceptBothAsync(incomplete, (x, y) -> {}, e));
3372 +            fs.add(incomplete.thenAcceptBothAsync(complete, (x, y) -> {}, e));
3373 +
3374 +            fs.add(complete.runAfterBothAsync(incomplete, () -> {}, e));
3375 +            fs.add(incomplete.runAfterBothAsync(complete, () -> {}, e));
3376 +
3377 +            for (CompletableFuture<?> future : fs)
3378 +                checkIncomplete(future);
3379 +            futures.addAll(fs);
3380 +        }
3381 +
3382 +        {
3383 +            List<CompletableFuture<?>> fs = new ArrayList<>();
3384 +
3385 +            fs.add(complete.applyToEitherAsync(incomplete, (z) -> z, e));
3386 +            fs.add(incomplete.applyToEitherAsync(complete, (z) -> z, e));
3387 +
3388 +            fs.add(complete.acceptEitherAsync(incomplete, (z) -> {}, e));
3389 +            fs.add(incomplete.acceptEitherAsync(complete, (z) -> {}, e));
3390 +
3391 +            fs.add(complete.runAfterEitherAsync(incomplete, () -> {}, e));
3392 +            fs.add(incomplete.runAfterEitherAsync(complete, () -> {}, e));
3393 +
3394 +            for (CompletableFuture<?> future : fs)
3395 +                checkCompletedWithWrappedException(future, ex);
3396 +            futures.addAll(fs);
3397 +        }
3398 +
3399 +        incomplete.complete(v);
3400 +
3401 +        for (CompletableFuture<?> future : futures)
3402 +            checkCompletedWithWrappedException(future, ex);
3403 +        }
3404 +    }
3405 +
3406 +    /**
3407       * toCompletableFuture returns this CompletableFuture.
3408       */
3409      public void testToCompletableFuture() {
# Line 3253 | Line 3411 | public class CompletableFutureTest exten
3411          assertSame(f, f.toCompletableFuture());
3412      }
3413  
3414 +    // jdk9
3415 +
3416 +    /**
3417 +     * newIncompleteFuture returns an incomplete CompletableFuture
3418 +     */
3419 +    public void testNewIncompleteFuture() {
3420 +        for (Integer v1 : new Integer[] { 1, null })
3421 +    {
3422 +        CompletableFuture<Integer> f = new CompletableFuture<>();
3423 +        CompletableFuture<Integer> g = f.newIncompleteFuture();
3424 +        checkIncomplete(f);
3425 +        checkIncomplete(g);
3426 +        f.complete(v1);
3427 +        checkCompletedNormally(f, v1);
3428 +        checkIncomplete(g);
3429 +        g.complete(v1);
3430 +        checkCompletedNormally(g, v1);
3431 +        assertSame(g.getClass(), CompletableFuture.class);
3432 +    }}
3433 +
3434 +    /**
3435 +     * completedStage returns a completed CompletionStage
3436 +     */
3437 +    public void testCompletedStage() {
3438 +        AtomicInteger x = new AtomicInteger(0);
3439 +        AtomicReference<Throwable> r = new AtomicReference<Throwable>();
3440 +        CompletionStage<Integer> f = CompletableFuture.completedStage(1);
3441 +        f.whenComplete((v, e) -> {if (e != null) r.set(e); else x.set(v);});
3442 +        assertEquals(x.get(), 1);
3443 +        assertNull(r.get());
3444 +    }
3445 +
3446 +    /**
3447 +     * defaultExecutor by default returns the commonPool if
3448 +     * it supports more than one thread.
3449 +     */
3450 +    public void testDefaultExecutor() {
3451 +        CompletableFuture<Integer> f = new CompletableFuture<>();
3452 +        Executor e = f.defaultExecutor();
3453 +        Executor c = ForkJoinPool.commonPool();
3454 +        if (ForkJoinPool.getCommonPoolParallelism() > 1)
3455 +            assertSame(e, c);
3456 +        else
3457 +            assertNotSame(e, c);
3458 +    }
3459 +
3460 +    /**
3461 +     * failedFuture returns a CompletableFuture completed
3462 +     * exceptionally with the given Exception
3463 +     */
3464 +    public void testFailedFuture() {
3465 +        CFException ex = new CFException();
3466 +        CompletableFuture<Integer> f = CompletableFuture.failedFuture(ex);
3467 +        checkCompletedExceptionally(f, ex);
3468 +    }
3469 +
3470 +    /**
3471 +     * failedFuture(null) throws NPE
3472 +     */
3473 +    public void testFailedFuture_null() {
3474 +        try {
3475 +            CompletableFuture<Integer> f = CompletableFuture.failedFuture(null);
3476 +            shouldThrow();
3477 +        } catch (NullPointerException success) {}
3478 +    }
3479 +
3480 +    /**
3481 +     * copy returns a CompletableFuture that is completed normally,
3482 +     * with the same value, when source is.
3483 +     */
3484 +    public void testCopy() {
3485 +        CompletableFuture<Integer> f = new CompletableFuture<>();
3486 +        CompletableFuture<Integer> g = f.copy();
3487 +        checkIncomplete(f);
3488 +        checkIncomplete(g);
3489 +        f.complete(1);
3490 +        checkCompletedNormally(f, 1);
3491 +        checkCompletedNormally(g, 1);
3492 +    }
3493 +
3494 +    /**
3495 +     * copy returns a CompletableFuture that is completed exceptionally
3496 +     * when source is.
3497 +     */
3498 +    public void testCopy2() {
3499 +        CompletableFuture<Integer> f = new CompletableFuture<>();
3500 +        CompletableFuture<Integer> g = f.copy();
3501 +        checkIncomplete(f);
3502 +        checkIncomplete(g);
3503 +        CFException ex = new CFException();
3504 +        f.completeExceptionally(ex);
3505 +        checkCompletedExceptionally(f, ex);
3506 +        checkCompletedWithWrappedException(g, ex);
3507 +    }
3508 +
3509 +    /**
3510 +     * minimalCompletionStage returns a CompletableFuture that is
3511 +     * completed normally, with the same value, when source is.
3512 +     */
3513 +    public void testMinimalCompletionStage() {
3514 +        CompletableFuture<Integer> f = new CompletableFuture<>();
3515 +        CompletionStage<Integer> g = f.minimalCompletionStage();
3516 +        AtomicInteger x = new AtomicInteger(0);
3517 +        AtomicReference<Throwable> r = new AtomicReference<Throwable>();
3518 +        checkIncomplete(f);
3519 +        g.whenComplete((v, e) -> {if (e != null) r.set(e); else x.set(v);});
3520 +        f.complete(1);
3521 +        checkCompletedNormally(f, 1);
3522 +        assertEquals(x.get(), 1);
3523 +        assertNull(r.get());
3524 +    }
3525 +
3526 +    /**
3527 +     * minimalCompletionStage returns a CompletableFuture that is
3528 +     * completed exceptionally when source is.
3529 +     */
3530 +    public void testMinimalCompletionStage2() {
3531 +        CompletableFuture<Integer> f = new CompletableFuture<>();
3532 +        CompletionStage<Integer> g = f.minimalCompletionStage();
3533 +        AtomicInteger x = new AtomicInteger(0);
3534 +        AtomicReference<Throwable> r = new AtomicReference<Throwable>();
3535 +        g.whenComplete((v, e) -> {if (e != null) r.set(e); else x.set(v);});
3536 +        checkIncomplete(f);
3537 +        CFException ex = new CFException();
3538 +        f.completeExceptionally(ex);
3539 +        checkCompletedExceptionally(f, ex);
3540 +        assertEquals(x.get(), 0);
3541 +        assertEquals(r.get().getCause(), ex);
3542 +    }
3543 +
3544 +    /**
3545 +     * failedStage returns a CompletionStage completed
3546 +     * exceptionally with the given Exception
3547 +     */
3548 +    public void testFailedStage() {
3549 +        CFException ex = new CFException();
3550 +        CompletionStage<Integer> f = CompletableFuture.failedStage(ex);
3551 +        AtomicInteger x = new AtomicInteger(0);
3552 +        AtomicReference<Throwable> r = new AtomicReference<Throwable>();
3553 +        f.whenComplete((v, e) -> {if (e != null) r.set(e); else x.set(v);});
3554 +        assertEquals(x.get(), 0);
3555 +        assertEquals(r.get(), ex);
3556 +    }
3557 +
3558 +    /**
3559 +     * completeAsync completes with value of given supplier
3560 +     */
3561 +    public void testCompleteAsync() {
3562 +        for (Integer v1 : new Integer[] { 1, null })
3563 +    {
3564 +        CompletableFuture<Integer> f = new CompletableFuture<>();
3565 +        f.completeAsync(() -> v1);
3566 +        f.join();
3567 +        checkCompletedNormally(f, v1);
3568 +    }}
3569 +
3570 +    /**
3571 +     * completeAsync completes exceptionally if given supplier throws
3572 +     */
3573 +    public void testCompleteAsync2() {
3574 +        CompletableFuture<Integer> f = new CompletableFuture<>();
3575 +        CFException ex = new CFException();
3576 +        f.completeAsync(() -> {if (true) throw ex; return 1;});
3577 +        try {
3578 +            f.join();
3579 +            shouldThrow();
3580 +        } catch (CompletionException success) {}
3581 +        checkCompletedWithWrappedException(f, ex);
3582 +    }
3583 +
3584 +    /**
3585 +     * completeAsync with given executor completes with value of given supplier
3586 +     */
3587 +    public void testCompleteAsync3() {
3588 +        for (Integer v1 : new Integer[] { 1, null })
3589 +    {
3590 +        CompletableFuture<Integer> f = new CompletableFuture<>();
3591 +        ThreadExecutor executor = new ThreadExecutor();
3592 +        f.completeAsync(() -> v1, executor);
3593 +        assertSame(v1, f.join());
3594 +        checkCompletedNormally(f, v1);
3595 +        assertEquals(1, executor.count.get());
3596 +    }}
3597 +
3598 +    /**
3599 +     * completeAsync with given executor completes exceptionally if
3600 +     * given supplier throws
3601 +     */
3602 +    public void testCompleteAsync4() {
3603 +        CompletableFuture<Integer> f = new CompletableFuture<>();
3604 +        CFException ex = new CFException();
3605 +        ThreadExecutor executor = new ThreadExecutor();
3606 +        f.completeAsync(() -> {if (true) throw ex; return 1;}, executor);
3607 +        try {
3608 +            f.join();
3609 +            shouldThrow();
3610 +        } catch (CompletionException success) {}
3611 +        checkCompletedWithWrappedException(f, ex);
3612 +        assertEquals(1, executor.count.get());
3613 +    }
3614 +
3615 +    /**
3616 +     * orTimeout completes with TimeoutException if not complete
3617 +     */
3618 +    public void testOrTimeout_timesOut() {
3619 +        long timeoutMillis = timeoutMillis();
3620 +        CompletableFuture<Integer> f = new CompletableFuture<>();
3621 +        long startTime = System.nanoTime();
3622 +        assertSame(f, f.orTimeout(timeoutMillis, MILLISECONDS));
3623 +        checkCompletedWithTimeoutException(f);
3624 +        assertTrue(millisElapsedSince(startTime) >= timeoutMillis);
3625 +    }
3626 +
3627 +    /**
3628 +     * orTimeout completes normally if completed before timeout
3629 +     */
3630 +    public void testOrTimeout_completed() {
3631 +        for (Integer v1 : new Integer[] { 1, null })
3632 +    {
3633 +        CompletableFuture<Integer> f = new CompletableFuture<>();
3634 +        CompletableFuture<Integer> g = new CompletableFuture<>();
3635 +        long startTime = System.nanoTime();
3636 +        f.complete(v1);
3637 +        assertSame(f, f.orTimeout(LONG_DELAY_MS, MILLISECONDS));
3638 +        assertSame(g, g.orTimeout(LONG_DELAY_MS, MILLISECONDS));
3639 +        g.complete(v1);
3640 +        checkCompletedNormally(f, v1);
3641 +        checkCompletedNormally(g, v1);
3642 +        assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS / 2);
3643 +    }}
3644 +
3645 +    /**
3646 +     * completeOnTimeout completes with given value if not complete
3647 +     */
3648 +    public void testCompleteOnTimeout_timesOut() {
3649 +        testInParallel(() -> testCompleteOnTimeout_timesOut(42),
3650 +                       () -> testCompleteOnTimeout_timesOut(null));
3651 +    }
3652 +
3653 +    /**
3654 +     * completeOnTimeout completes with given value if not complete
3655 +     */
3656 +    public void testCompleteOnTimeout_timesOut(Integer v) {
3657 +        long timeoutMillis = timeoutMillis();
3658 +        CompletableFuture<Integer> f = new CompletableFuture<>();
3659 +        long startTime = System.nanoTime();
3660 +        assertSame(f, f.completeOnTimeout(v, timeoutMillis, MILLISECONDS));
3661 +        assertSame(v, f.join());
3662 +        assertTrue(millisElapsedSince(startTime) >= timeoutMillis);
3663 +        f.complete(99);         // should have no effect
3664 +        checkCompletedNormally(f, v);
3665 +    }
3666 +
3667 +    /**
3668 +     * completeOnTimeout has no effect if completed within timeout
3669 +     */
3670 +    public void testCompleteOnTimeout_completed() {
3671 +        for (Integer v1 : new Integer[] { 1, null })
3672 +    {
3673 +        CompletableFuture<Integer> f = new CompletableFuture<>();
3674 +        CompletableFuture<Integer> g = new CompletableFuture<>();
3675 +        long startTime = System.nanoTime();
3676 +        f.complete(v1);
3677 +        assertSame(f, f.completeOnTimeout(-1, LONG_DELAY_MS, MILLISECONDS));
3678 +        assertSame(g, g.completeOnTimeout(-1, LONG_DELAY_MS, MILLISECONDS));
3679 +        g.complete(v1);
3680 +        checkCompletedNormally(f, v1);
3681 +        checkCompletedNormally(g, v1);
3682 +        assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS / 2);
3683 +    }}
3684 +
3685 +    /**
3686 +     * delayedExecutor returns an executor that delays submission
3687 +     */
3688 +    public void testDelayedExecutor() {
3689 +        testInParallel(() -> testDelayedExecutor(null, null),
3690 +                       () -> testDelayedExecutor(null, 1),
3691 +                       () -> testDelayedExecutor(new ThreadExecutor(), 1),
3692 +                       () -> testDelayedExecutor(new ThreadExecutor(), 1));
3693 +    }
3694 +
3695 +    public void testDelayedExecutor(Executor executor, Integer v) throws Exception {
3696 +        long timeoutMillis = timeoutMillis();
3697 +        // Use an "unreasonably long" long timeout to catch lingering threads
3698 +        long longTimeoutMillis = 1000 * 60 * 60 * 24;
3699 +        final Executor delayer, longDelayer;
3700 +        if (executor == null) {
3701 +            delayer = CompletableFuture.delayedExecutor(timeoutMillis, MILLISECONDS);
3702 +            longDelayer = CompletableFuture.delayedExecutor(longTimeoutMillis, MILLISECONDS);
3703 +        } else {
3704 +            delayer = CompletableFuture.delayedExecutor(timeoutMillis, MILLISECONDS, executor);
3705 +            longDelayer = CompletableFuture.delayedExecutor(longTimeoutMillis, MILLISECONDS, executor);
3706 +        }
3707 +        long startTime = System.nanoTime();
3708 +        CompletableFuture<Integer> f =
3709 +            CompletableFuture.supplyAsync(() -> v, delayer);
3710 +        CompletableFuture<Integer> g =
3711 +            CompletableFuture.supplyAsync(() -> v, longDelayer);
3712 +
3713 +        assertNull(g.getNow(null));
3714 +
3715 +        assertSame(v, f.get(LONG_DELAY_MS, MILLISECONDS));
3716 +        long millisElapsed = millisElapsedSince(startTime);
3717 +        assertTrue(millisElapsed >= timeoutMillis);
3718 +        assertTrue(millisElapsed < LONG_DELAY_MS / 2);
3719 +
3720 +        checkCompletedNormally(f, v);
3721 +
3722 +        checkIncomplete(g);
3723 +        assertTrue(g.cancel(true));
3724 +    }
3725 +
3726      //--- tests of implementation details; not part of official tck ---
3727  
3728      Object resultOf(CompletableFuture<?> f) {
3729 +        SecurityManager sm = System.getSecurityManager();
3730 +        if (sm != null) {
3731 +            try {
3732 +                System.setSecurityManager(null);
3733 +            } catch (SecurityException giveUp) {
3734 +                return "Reflection not available";
3735 +            }
3736 +        }
3737 +
3738          try {
3739              java.lang.reflect.Field resultField
3740                  = CompletableFuture.class.getDeclaredField("result");
3741              resultField.setAccessible(true);
3742              return resultField.get(f);
3743 <        } catch (Throwable t) { throw new AssertionError(t); }
3743 >        } catch (Throwable t) {
3744 >            throw new AssertionError(t);
3745 >        } finally {
3746 >            if (sm != null) System.setSecurityManager(sm);
3747 >        }
3748      }
3749  
3750      public void testExceptionPropagationReusesResultObject() {
# Line 3284 | Line 3767 | public class CompletableFutureTest exten
3767          funs.add((y) -> m.applyToEither(y, incomplete, new IncFunction(m)));
3768  
3769          funs.add((y) -> m.runAfterBoth(y, v42, new Noop(m)));
3770 +        funs.add((y) -> m.runAfterBoth(v42, y, new Noop(m)));
3771          funs.add((y) -> m.thenAcceptBoth(y, v42, new SubtractAction(m)));
3772 +        funs.add((y) -> m.thenAcceptBoth(v42, y, new SubtractAction(m)));
3773          funs.add((y) -> m.thenCombine(y, v42, new SubtractFunction(m)));
3774 +        funs.add((y) -> m.thenCombine(v42, y, new SubtractFunction(m)));
3775  
3776 <        funs.add((y) -> m.whenComplete(y, (Integer x, Throwable t) -> {}));
3776 >        funs.add((y) -> m.whenComplete(y, (Integer r, Throwable t) -> {}));
3777  
3778          funs.add((y) -> m.thenCompose(y, new CompletableFutureInc(m)));
3779  
3780 +        funs.add((y) -> CompletableFuture.allOf(new CompletableFuture<?>[] {y}));
3781          funs.add((y) -> CompletableFuture.allOf(new CompletableFuture<?>[] {y, v42}));
3782 +        funs.add((y) -> CompletableFuture.allOf(new CompletableFuture<?>[] {v42, y}));
3783 +        funs.add((y) -> CompletableFuture.anyOf(new CompletableFuture<?>[] {y}));
3784          funs.add((y) -> CompletableFuture.anyOf(new CompletableFuture<?>[] {y, incomplete}));
3785 +        funs.add((y) -> CompletableFuture.anyOf(new CompletableFuture<?>[] {incomplete, y}));
3786  
3787          for (Function<CompletableFuture<Integer>, CompletableFuture<?>>
3788                   fun : funs) {
# Line 3343 | Line 3833 | public class CompletableFutureTest exten
3833          }
3834      }}
3835  
3836 +    /**
3837 +     * Minimal completion stages throw UOE for all non-CompletionStage methods
3838 +     */
3839 +    public void testMinimalCompletionStage_minimality() {
3840 +        if (!testImplementationDetails) return;
3841 +        Function<Method, String> toSignature =
3842 +            (method) -> method.getName() + Arrays.toString(method.getParameterTypes());
3843 +        Predicate<Method> isNotStatic =
3844 +            (method) -> (method.getModifiers() & Modifier.STATIC) == 0;
3845 +        List<Method> minimalMethods =
3846 +            Stream.of(Object.class, CompletionStage.class)
3847 +            .flatMap((klazz) -> Stream.of(klazz.getMethods()))
3848 +            .filter(isNotStatic)
3849 +            .collect(Collectors.toList());
3850 +        // Methods from CompletableFuture permitted NOT to throw UOE
3851 +        String[] signatureWhitelist = {
3852 +            "newIncompleteFuture[]",
3853 +            "defaultExecutor[]",
3854 +            "minimalCompletionStage[]",
3855 +            "copy[]",
3856 +        };
3857 +        Set<String> permittedMethodSignatures =
3858 +            Stream.concat(minimalMethods.stream().map(toSignature),
3859 +                          Stream.of(signatureWhitelist))
3860 +            .collect(Collectors.toSet());
3861 +        List<Method> allMethods = Stream.of(CompletableFuture.class.getMethods())
3862 +            .filter(isNotStatic)
3863 +            .filter((method) -> !permittedMethodSignatures.contains(toSignature.apply(method)))
3864 +            .collect(Collectors.toList());
3865 +
3866 +        CompletionStage<Integer> minimalStage =
3867 +            new CompletableFuture<Integer>().minimalCompletionStage();
3868 +
3869 +        List<Method> bugs = new ArrayList<>();
3870 +        for (Method method : allMethods) {
3871 +            Class<?>[] parameterTypes = method.getParameterTypes();
3872 +            Object[] args = new Object[parameterTypes.length];
3873 +            // Manufacture boxed primitives for primitive params
3874 +            for (int i = 0; i < args.length; i++) {
3875 +                Class<?> type = parameterTypes[i];
3876 +                if (parameterTypes[i] == boolean.class)
3877 +                    args[i] = false;
3878 +                else if (parameterTypes[i] == int.class)
3879 +                    args[i] = 0;
3880 +                else if (parameterTypes[i] == long.class)
3881 +                    args[i] = 0L;
3882 +            }
3883 +            try {
3884 +                method.invoke(minimalStage, args);
3885 +                bugs.add(method);
3886 +            }
3887 +            catch (java.lang.reflect.InvocationTargetException expected) {
3888 +                if (! (expected.getCause() instanceof UnsupportedOperationException)) {
3889 +                    bugs.add(method);
3890 +                    // expected.getCause().printStackTrace();
3891 +                }
3892 +            }
3893 +            catch (ReflectiveOperationException bad) { throw new Error(bad); }
3894 +        }
3895 +        if (!bugs.isEmpty())
3896 +            throw new Error("Methods did not throw UOE: " + bugs.toString());
3897 +    }
3898 +
3899 +    static class Monad {
3900 +        static class ZeroException extends RuntimeException {
3901 +            public ZeroException() { super("monadic zero"); }
3902 +        }
3903 +        // "return", "unit"
3904 +        static <T> CompletableFuture<T> unit(T value) {
3905 +            return completedFuture(value);
3906 +        }
3907 +        // monadic zero ?
3908 +        static <T> CompletableFuture<T> zero() {
3909 +            return failedFuture(new ZeroException());
3910 +        }
3911 +        // >=>
3912 +        static <T,U,V> Function<T, CompletableFuture<V>> compose
3913 +            (Function<T, CompletableFuture<U>> f,
3914 +             Function<U, CompletableFuture<V>> g) {
3915 +            return (x) -> f.apply(x).thenCompose(g);
3916 +        }
3917 +
3918 +        static void assertZero(CompletableFuture<?> f) {
3919 +            try {
3920 +                f.getNow(null);
3921 +                throw new AssertionFailedError("should throw");
3922 +            } catch (CompletionException success) {
3923 +                assertTrue(success.getCause() instanceof ZeroException);
3924 +            }
3925 +        }
3926 +
3927 +        static <T> void assertFutureEquals(CompletableFuture<T> f,
3928 +                                           CompletableFuture<T> g) {
3929 +            T fval = null, gval = null;
3930 +            Throwable fex = null, gex = null;
3931 +
3932 +            try { fval = f.get(); }
3933 +            catch (ExecutionException ex) { fex = ex.getCause(); }
3934 +            catch (Throwable ex) { fex = ex; }
3935 +
3936 +            try { gval = g.get(); }
3937 +            catch (ExecutionException ex) { gex = ex.getCause(); }
3938 +            catch (Throwable ex) { gex = ex; }
3939 +
3940 +            if (fex != null || gex != null)
3941 +                assertSame(fex.getClass(), gex.getClass());
3942 +            else
3943 +                assertEquals(fval, gval);
3944 +        }
3945 +
3946 +        static class PlusFuture<T> extends CompletableFuture<T> {
3947 +            AtomicReference<Throwable> firstFailure = new AtomicReference<>(null);
3948 +        }
3949 +
3950 +        /** Implements "monadic plus". */
3951 +        static <T> CompletableFuture<T> plus(CompletableFuture<? extends T> f,
3952 +                                             CompletableFuture<? extends T> g) {
3953 +            PlusFuture<T> plus = new PlusFuture<T>();
3954 +            BiConsumer<T, Throwable> action = (T result, Throwable ex) -> {
3955 +                try {
3956 +                    if (ex == null) {
3957 +                        if (plus.complete(result))
3958 +                            if (plus.firstFailure.get() != null)
3959 +                                plus.firstFailure.set(null);
3960 +                    }
3961 +                    else if (plus.firstFailure.compareAndSet(null, ex)) {
3962 +                        if (plus.isDone())
3963 +                            plus.firstFailure.set(null);
3964 +                    }
3965 +                    else {
3966 +                        // first failure has precedence
3967 +                        Throwable first = plus.firstFailure.getAndSet(null);
3968 +
3969 +                        // may fail with "Self-suppression not permitted"
3970 +                        try { first.addSuppressed(ex); }
3971 +                        catch (Exception ignored) {}
3972 +
3973 +                        plus.completeExceptionally(first);
3974 +                    }
3975 +                } catch (Throwable unexpected) {
3976 +                    plus.completeExceptionally(unexpected);
3977 +                }
3978 +            };
3979 +            f.whenComplete(action);
3980 +            g.whenComplete(action);
3981 +            return plus;
3982 +        }
3983 +    }
3984 +
3985 +    /**
3986 +     * CompletableFuture is an additive monad - sort of.
3987 +     * https://en.wikipedia.org/wiki/Monad_(functional_programming)#Additive_monads
3988 +     */
3989 +    public void testAdditiveMonad() throws Throwable {
3990 +        Function<Long, CompletableFuture<Long>> unit = Monad::unit;
3991 +        CompletableFuture<Long> zero = Monad.zero();
3992 +
3993 +        // Some mutually non-commutative functions
3994 +        Function<Long, CompletableFuture<Long>> triple
3995 +            = (x) -> Monad.unit(3 * x);
3996 +        Function<Long, CompletableFuture<Long>> inc
3997 +            = (x) -> Monad.unit(x + 1);
3998 +
3999 +        // unit is a right identity: m >>= unit === m
4000 +        Monad.assertFutureEquals(inc.apply(5L).thenCompose(unit),
4001 +                                 inc.apply(5L));
4002 +        // unit is a left identity: (unit x) >>= f === f x
4003 +        Monad.assertFutureEquals(unit.apply(5L).thenCompose(inc),
4004 +                                 inc.apply(5L));
4005 +
4006 +        // associativity: (m >>= f) >>= g === m >>= ( \x -> (f x >>= g) )
4007 +        Monad.assertFutureEquals(
4008 +            unit.apply(5L).thenCompose(inc).thenCompose(triple),
4009 +            unit.apply(5L).thenCompose((x) -> inc.apply(x).thenCompose(triple)));
4010 +
4011 +        // The case for CompletableFuture as an additive monad is weaker...
4012 +
4013 +        // zero is a monadic zero
4014 +        Monad.assertZero(zero);
4015 +
4016 +        // left zero: zero >>= f === zero
4017 +        Monad.assertZero(zero.thenCompose(inc));
4018 +        // right zero: f >>= (\x -> zero) === zero
4019 +        Monad.assertZero(inc.apply(5L).thenCompose((x) -> zero));
4020 +
4021 +        // f plus zero === f
4022 +        Monad.assertFutureEquals(Monad.unit(5L),
4023 +                                 Monad.plus(Monad.unit(5L), zero));
4024 +        // zero plus f === f
4025 +        Monad.assertFutureEquals(Monad.unit(5L),
4026 +                                 Monad.plus(zero, Monad.unit(5L)));
4027 +        // zero plus zero === zero
4028 +        Monad.assertZero(Monad.plus(zero, zero));
4029 +        {
4030 +            CompletableFuture<Long> f = Monad.plus(Monad.unit(5L),
4031 +                                                   Monad.unit(8L));
4032 +            // non-determinism
4033 +            assertTrue(f.get() == 5L || f.get() == 8L);
4034 +        }
4035 +
4036 +        CompletableFuture<Long> godot = new CompletableFuture<>();
4037 +        // f plus godot === f (doesn't wait for godot)
4038 +        Monad.assertFutureEquals(Monad.unit(5L),
4039 +                                 Monad.plus(Monad.unit(5L), godot));
4040 +        // godot plus f === f (doesn't wait for godot)
4041 +        Monad.assertFutureEquals(Monad.unit(5L),
4042 +                                 Monad.plus(godot, Monad.unit(5L)));
4043 +    }
4044 +
4045 +    /**
4046 +     * A single CompletableFuture with many dependents.
4047 +     * A demo of scalability - runtime is O(n).
4048 +     */
4049 +    public void testManyDependents() throws Throwable {
4050 +        final int n = 1_000;
4051 +        final CompletableFuture<Void> head = new CompletableFuture<>();
4052 +        final CompletableFuture<Void> complete = CompletableFuture.completedFuture((Void)null);
4053 +        final AtomicInteger count = new AtomicInteger(0);
4054 +        for (int i = 0; i < n; i++) {
4055 +            head.thenRun(() -> count.getAndIncrement());
4056 +            head.thenAccept((x) -> count.getAndIncrement());
4057 +            head.thenApply((x) -> count.getAndIncrement());
4058 +
4059 +            head.runAfterBoth(complete, () -> count.getAndIncrement());
4060 +            head.thenAcceptBoth(complete, (x, y) -> count.getAndIncrement());
4061 +            head.thenCombine(complete, (x, y) -> count.getAndIncrement());
4062 +            complete.runAfterBoth(head, () -> count.getAndIncrement());
4063 +            complete.thenAcceptBoth(head, (x, y) -> count.getAndIncrement());
4064 +            complete.thenCombine(head, (x, y) -> count.getAndIncrement());
4065 +
4066 +            head.runAfterEither(new CompletableFuture<Void>(), () -> count.getAndIncrement());
4067 +            head.acceptEither(new CompletableFuture<Void>(), (x) -> count.getAndIncrement());
4068 +            head.applyToEither(new CompletableFuture<Void>(), (x) -> count.getAndIncrement());
4069 +            new CompletableFuture<Void>().runAfterEither(head, () -> count.getAndIncrement());
4070 +            new CompletableFuture<Void>().acceptEither(head, (x) -> count.getAndIncrement());
4071 +            new CompletableFuture<Void>().applyToEither(head, (x) -> count.getAndIncrement());
4072 +        }
4073 +        head.complete(null);
4074 +        assertEquals(5 * 3 * n, count.get());
4075 +    }
4076 +
4077 + //     static <U> U join(CompletionStage<U> stage) {
4078 + //         CompletableFuture<U> f = new CompletableFuture<>();
4079 + //         stage.whenComplete((v, ex) -> {
4080 + //             if (ex != null) f.completeExceptionally(ex); else f.complete(v);
4081 + //         });
4082 + //         return f.join();
4083 + //     }
4084 +
4085 + //     static <U> boolean isDone(CompletionStage<U> stage) {
4086 + //         CompletableFuture<U> f = new CompletableFuture<>();
4087 + //         stage.whenComplete((v, ex) -> {
4088 + //             if (ex != null) f.completeExceptionally(ex); else f.complete(v);
4089 + //         });
4090 + //         return f.isDone();
4091 + //     }
4092 +
4093 + //     static <U> U join2(CompletionStage<U> stage) {
4094 + //         return stage.toCompletableFuture().copy().join();
4095 + //     }
4096 +
4097 + //     static <U> boolean isDone2(CompletionStage<U> stage) {
4098 + //         return stage.toCompletableFuture().copy().isDone();
4099 + //     }
4100 +
4101   }

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