diff --git a/src/java.base/share/classes/java/util/stream/GathererOp.java b/src/java.base/share/classes/java/util/stream/GathererOp.java index 24b42fb28ad..096ac4ea3a5 100644 --- a/src/java.base/share/classes/java/util/stream/GathererOp.java +++ b/src/java.base/share/classes/java/util/stream/GathererOp.java @@ -1,5 +1,5 @@ /* - * Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2023, 2024, 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 @@ -142,6 +142,7 @@ final class GathererOp extends ReferencePipeline { private final Integrator integrator; // Optimization: reuse private A state; private boolean proceed = true; + private boolean downstreamProceed = true; GatherSink(Gatherer gatherer, Sink sink) { this.gatherer = gatherer; @@ -173,12 +174,12 @@ final class GathererOp extends ReferencePipeline { @Override public boolean cancellationRequested() { - return cancellationRequested(proceed); + return cancellationRequested(proceed && downstreamProceed); } private boolean cancellationRequested(boolean knownProceed) { // Highly performance sensitive - return !(knownProceed && (!sink.cancellationRequested() || (proceed = false))); + return !(knownProceed && (!sink.cancellationRequested() || (downstreamProceed = false))); } @Override @@ -194,12 +195,12 @@ final class GathererOp extends ReferencePipeline { @Override public boolean isRejecting() { - return !proceed; + return !downstreamProceed; } @Override public boolean push(R r) { - var p = proceed; + var p = downstreamProceed; if (p) sink.accept(r); return !cancellationRequested(p); diff --git a/test/jdk/java/util/stream/GathererShortCircuitTest.java b/test/jdk/java/util/stream/GathererShortCircuitTest.java new file mode 100644 index 00000000000..059d90a6e7f --- /dev/null +++ b/test/jdk/java/util/stream/GathererShortCircuitTest.java @@ -0,0 +1,65 @@ +/* + * Copyright (c) 2024, 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 java.util.List; +import java.util.stream.Collectors; +import java.util.stream.Gatherer; + +import org.junit.jupiter.api.Test; +import static org.junit.jupiter.api.Assertions.*; +import static org.junit.jupiter.api.Assumptions.*; + +/** + * @test + * @bug 8328316 + * @summary Testing Gatherer behavior under short circuiting + * @enablePreview + * @run junit GathererShortCircuitTest + */ + +public class GathererShortCircuitTest { + @Test + public void mustBeAbleToPushFromFinisher() { + Integer expected = 8328316; + List source = List.of(1,2,3,4,5); + + Gatherer pushOneInFinisher = + Gatherer.of( + (_, element, downstream) -> false, + (_, downstream) -> downstream.push(expected) + ); + + var usingCollect = + source.stream().gather(pushOneInFinisher).collect(Collectors.toList()); + var usingBuiltin = + source.stream().gather(pushOneInFinisher).toList(); + var usingCollectPar = + source.stream().parallel().gather(pushOneInFinisher).collect(Collectors.toList()); + var usingBuiltinPar = + source.stream().parallel().gather(pushOneInFinisher).toList(); + + assertEquals(List.of(expected), usingCollect); + assertEquals(List.of(expected), usingBuiltin); + assertEquals(List.of(expected), usingCollectPar); + assertEquals(List.of(expected), usingBuiltinPar); + } +}