Authors: russell@unturf.com · brackishbert@gmail.com · foxhop.net · TimeHexOn.com Patches, unit tests, benchmarks, whitepaper, and outreach briefs. Public domain — no copyright claimed. Use freely.
118 lines
4.2 KiB
Java
118 lines
4.2 KiB
Java
/*
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* Copyright (c) 2015, 2025, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*/
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import jdk.test.whitebox.WhiteBox;
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import java.util.concurrent.atomic.AtomicInteger;
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import java.util.concurrent.locks.ReentrantLock;
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import java.lang.reflect.Method;
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import java.lang.reflect.Field;
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/*
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* @test
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* @summary Unit test for FinalizerHistogram
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* @modules java.base/java.lang.ref:open
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* @library /test/lib
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* @build jdk.test.whitebox.WhiteBox
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* @run driver jdk.test.lib.helpers.ClassFileInstaller jdk.test.whitebox.WhiteBox
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* @run main/othervm
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* -Xbootclasspath/a:.
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* -XX:+UnlockDiagnosticVMOptions
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* -XX:+WhiteBoxAPI
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* FinalizerHistogramTest
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*/
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public class FinalizerHistogramTest {
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static ReentrantLock lock = new ReentrantLock();
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static final AtomicInteger initializedCount = new AtomicInteger(0);
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static final int OBJECTS_COUNT = 1000;
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static WhiteBox wb;
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static class MyObject {
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public MyObject() {
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// Make sure object allocation/deallocation is not optimized out
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initializedCount.incrementAndGet();
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}
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protected void finalize() {
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// Trap the object in a finalization queue
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lock.lock();
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}
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}
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public static void main(String[] argvs) throws InterruptedException {
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try {
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lock.lock();
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for(int i = 0; i < OBJECTS_COUNT; ++i) {
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new MyObject();
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}
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System.out.println("Objects intialized: " + initializedCount.get());
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wb = WhiteBox.getWhiteBox();
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wb.fullGC();
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boolean refProResult;
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do {
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refProResult = wb.waitForReferenceProcessing();
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System.out.println("waitForReferenceProcessing returned: " + refProResult);
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} while (refProResult);
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Class<?> klass = Class.forName("java.lang.ref.FinalizerHistogram");
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Method m = klass.getDeclaredMethod("getFinalizerHistogram");
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m.setAccessible(true);
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Object entries[] = (Object[]) m.invoke(null);
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Class<?> entryKlass = Class.forName("java.lang.ref.FinalizerHistogram$Entry");
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Field name = entryKlass.getDeclaredField("className");
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name.setAccessible(true);
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Field count = entryKlass.getDeclaredField("instanceCount");
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count.setAccessible(true);
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System.out.println("Unreachable instances waiting for finalization");
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System.out.println("#instances class name");
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System.out.println("-----------------------");
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boolean found = false;
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for (Object entry : entries) {
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Object e = entryKlass.cast(entry);
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System.out.printf("%10d %s\n", count.get(e), name.get(e));
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if (((String) name.get(e)).indexOf("MyObject") != -1 ) {
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found = true;
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}
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}
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if (!found) {
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throw new RuntimeException("MyObject is not found in test output");
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}
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System.out.println("Test PASSED");
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} catch(Exception e) {
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System.err.println("Test failed with " + e);
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e.printStackTrace(System.err);
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throw new RuntimeException("Test failed");
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} finally {
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lock.unlock();
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}
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}
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}
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