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/*
* Copyright (c) 2013, 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.Test;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.CountDownLatch;
/**
* @test
* @bug 8029164
* @run testng ThenComposeAsyncTest
* @run testng/othervm -Djava.util.concurrent.ForkJoinPool.common.parallelism=0 ThenComposeAsyncTest
* @summary Test that CompletableFuture.thenCompose works correctly if the
* composing task is complete before composition
*/
@Test
public class ThenComposeAsyncTest {
public void testThenComposeAsync() throws Exception {
// Composing CompletableFuture is complete
CompletableFuture<String> cf1 = CompletableFuture.completedFuture("one");
// Composing function returns a CompletableFuture executed asynchronously
CountDownLatch cdl = new CountDownLatch(1);
CompletableFuture<String> cf2 = cf1.thenCompose(str -> CompletableFuture.supplyAsync(() -> {
while (true) {
try {
cdl.await();
break;
}
catch (InterruptedException e) {
}
}
return str + ", two";
}));
// Ensure returned CompletableFuture completes after call to thenCompose
// This guarantees that any premature internal completion will be
// detected
cdl.countDown();
String val = cf2.get();
Assert.assertNotNull(val);
Assert.assertEquals(val, "one, two");
}
}
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