Merge "Fix the infinite loop bug for AndroidFuture.ThenCombine." (1ccbddad) · Commits · e / os / android_frameworks_base

core/java/com/android/internal/infra/AndroidFuture.java

+8 −1

Original line number	Diff line number	Diff line
		@@ -455,7 +455,14 @@ public class AndroidFuture<T> extends CompletableFuture<T> implements Parcelable
		if (mSourceU != null) {
		// T done
		mResultT = (T) res;
		mSourceU.whenComplete(this);

		// Subscribe to the second job completion.
		mSourceU.whenComplete((r, e) -> {
		// Mark the first job completion by setting mSourceU to null, so that next time
		// the execution flow goes to the else case below.
		mSourceU = null;
		accept(r, e);
		});
		} else {
		// U done
		try {

core/tests/coretests/src/com/android/internal/infra/AndroidFutureTest.java

+32 −0

Original line number	Diff line number	Diff line
		@@ -29,6 +29,7 @@ import org.junit.runner.RunWith;

		import java.util.concurrent.CountDownLatch;
		import java.util.concurrent.ExecutionException;
		import java.util.function.BiFunction;

		/**
		* Unit test for {@link AndroidFuture}.
		@@ -154,4 +155,35 @@ public class AndroidFutureTest {
		expectThrows(ExecutionException.class, future1::get);
		assertThat(executionException.getCause()).isInstanceOf(UnsupportedOperationException.class);
		}

		@Test
		public void testThenCombine() throws Exception {
		String nearFutureString = "near future comes";
		AndroidFuture<String> nearFuture = AndroidFuture.supply(() -> nearFutureString);
		String farFutureString = " before far future.";
		AndroidFuture<String> farFuture = AndroidFuture.supply(() -> farFutureString);
		AndroidFuture<String> combinedFuture =
		nearFuture.thenCombine(farFuture, ((s1, s2) -> s1 + s2));

		assertThat(combinedFuture.get()).isEqualTo(nearFutureString + farFutureString);
		}

		@Test
		public void testThenCombine_functionThrowingException() throws Exception {
		String nearFutureString = "near future comes";
		AndroidFuture<String> nearFuture = AndroidFuture.supply(() -> nearFutureString);
		String farFutureString = " before far future.";
		AndroidFuture<String> farFuture = AndroidFuture.supply(() -> farFutureString);
		UnsupportedOperationException exception = new UnsupportedOperationException(
		"Unsupported operation exception thrown!");
		BiFunction<String, String, String> throwingFunction = (s1, s2) -> {
		throw exception;
		};
		AndroidFuture<String> combinedFuture = nearFuture.thenCombine(farFuture, throwingFunction);

		ExecutionException thrown = expectThrows(ExecutionException.class,
		() -> combinedFuture.get());

		assertThat(thrown.getCause()).isSameInstanceAs(exception);
		}
		}