8068432: Inconsistent exception handling in CompletableFuture.thenCompose
Reviewed-by: psandoz, chegar, martin
--- a/jdk/src/java.base/share/classes/java/util/concurrent/CompletableFuture.java Tue Jan 20 11:23:03 2015 -0800
+++ b/jdk/src/java.base/share/classes/java/util/concurrent/CompletableFuture.java Wed Jan 21 09:46:21 2015 +0000
@@ -978,7 +978,15 @@
}
try {
@SuppressWarnings("unchecked") T t = (T) r;
- return f.apply(t).toCompletableFuture();
+ CompletableFuture<V> g = f.apply(t).toCompletableFuture();
+ Object s = g.result;
+ if (s != null)
+ return new CompletableFuture<V>(encodeRelay(s));
+ CompletableFuture<V> d = new CompletableFuture<V>();
+ UniRelay<V> copy = new UniRelay<V>(d, g);
+ g.push(copy);
+ copy.tryFire(SYNC);
+ return d;
} catch (Throwable ex) {
return new CompletableFuture<V>(encodeThrowable(ex));
}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/java/util/concurrent/CompletableFuture/ThenComposeExceptionTest.java Wed Jan 21 09:46:21 2015 +0000
@@ -0,0 +1,112 @@
+/*
+ * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import org.testng.Assert;
+import org.testng.annotations.DataProvider;
+import org.testng.annotations.Test;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.CompletionException;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.function.BiFunction;
+import java.util.function.Consumer;
+
+
+/**
+ * @test
+ * @bug 8068432
+ * @run testng ThenComposeExceptionTest
+ * @summary Test that CompletableFuture.thenCompose works correctly if the
+ * composing future completes exceptionally
+ */
+@Test
+public class ThenComposeExceptionTest {
+
+ static final BiFunction<CompletableFuture<String>, CompletableFuture<String>, CompletableFuture<String>>
+ THEN_COMPOSE = (f, fe) -> f.thenCompose(s -> fe);
+
+ static final BiFunction<CompletableFuture<String>, CompletableFuture<String>, CompletableFuture<String>>
+ THEN_COMPOSE_ASYNC = (f, fe) -> f.thenComposeAsync(s -> fe);
+
+ static final Consumer<CompletableFuture<String>>
+ COMPLETE_EXCEPTIONALLY = f -> f.completeExceptionally(new RuntimeException());
+
+ static final Consumer<CompletableFuture<String>>
+ NOP = f -> { };
+
+ static Object[][] actionsDataProvider;
+
+ @DataProvider(name = "actions")
+ static Object[][] actionsDataProvider() {
+ if (actionsDataProvider != null) {
+ return actionsDataProvider;
+ }
+
+ List<Object[]> data = new ArrayList<>();
+ data.add(new Object[]{"thenCompose and completeExceptionally", NOP, THEN_COMPOSE, COMPLETE_EXCEPTIONALLY});
+ data.add(new Object[]{"thenComposeAsync and completeExceptionally", NOP, THEN_COMPOSE_ASYNC, COMPLETE_EXCEPTIONALLY});
+ data.add(new Object[]{"completeExceptionally and thenCompose", COMPLETE_EXCEPTIONALLY, THEN_COMPOSE, NOP});
+ data.add(new Object[]{"completeExceptionally and thenComposeAsync", COMPLETE_EXCEPTIONALLY, THEN_COMPOSE_ASYNC, NOP});
+
+ return actionsDataProvider = data.toArray(new Object[0][]);
+ }
+
+ @Test(dataProvider = "actions")
+ public void testThenCompose(
+ String description,
+ Consumer<CompletableFuture<String>> beforeAction,
+ BiFunction<CompletableFuture<String>, CompletableFuture<String>, CompletableFuture<String>> composeFunction,
+ Consumer<CompletableFuture<String>> afterAction) throws Exception {
+ CompletableFuture<String> f = new CompletableFuture<>();
+ CompletableFuture<String> fe = new CompletableFuture<>();
+
+ // Ensure pre-composed stage is completed to trigger
+ // processing the composing future
+ f.complete("");
+
+ beforeAction.accept(fe);
+
+ CompletableFuture<String> f_thenCompose = composeFunction.apply(f, fe);
+ Assert.assertNotSame(f_thenCompose, fe, "Composed CompletableFuture returned directly");
+
+ AtomicReference<Throwable> eOnWhenComplete = new AtomicReference<>();
+ f_thenCompose.whenComplete((r, e) -> eOnWhenComplete.set(e));
+
+ afterAction.accept(fe);
+
+ Throwable eOnJoined = null;
+ try {
+ f_thenCompose.join();
+ }
+ catch (Throwable t) {
+ eOnJoined = t;
+ }
+
+ Assert.assertTrue(eOnWhenComplete.get() instanceof CompletionException,
+ "Incorrect exception reported on whenComplete");
+ Assert.assertTrue(eOnJoined instanceof CompletionException,
+ "Incorrect exception reported when joined");
+ }
+}