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23 results

TestLambdaFormCustomization.java

  • TestLambdaFormCustomization.java 2.66 KiB
    /*
     * 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.lang.invoke.MethodHandles;
    import java.lang.invoke.VarHandle;
    import java.util.ArrayList;
    
    /**
      * @test
      * @bug 8340812
      * @summary Verify that LambdaForm customization via MethodHandle::updateForm is thread safe.
      * @run main TestLambdaFormCustomization
      * @run main/othervm -Djava.lang.invoke.MethodHandle.CUSTOMIZE_THRESHOLD=0 TestLambdaFormCustomization
      */
    public class TestLambdaFormCustomization {
    
        String str = "test";
        static final String value = "test" + 42;
    
        // Trigger concurrent LambdaForm customization for VarHandle invokers
        void test() throws NoSuchFieldException, IllegalAccessException {
            VarHandle varHandle = MethodHandles.lookup().in(getClass()).findVarHandle(getClass(), "str", String.class);
    
            ArrayList<Thread> threads = new ArrayList<>();
            for (int threadIdx = 0; threadIdx < 10; threadIdx++) {
                threads.add(new Thread(() -> {
                    for (int i = 0; i < 1000; i++) {
                        varHandle.compareAndExchange(this, value, value);
                        varHandle.compareAndExchange(this, value, value);
                        varHandle.compareAndExchange(this, value, value);
                    }
                }));
            }
            threads.forEach(Thread::start);
            threads.forEach(t -> {
                try {
                    t.join();
                } catch (Throwable e) {
                    throw new IllegalStateException(e);
                }
            });
        }
    
        public static void main(String[] args) throws Exception {
            TestLambdaFormCustomization t = new TestLambdaFormCustomization();
            for (int i = 0; i < 4000; ++i) {
                t.test();
            }
        }
    }