| /* |
| * Copyright (c) 2015, 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.concurrent.TimeUnit; |
| import java.util.concurrent.locks.Condition; |
| import java.util.concurrent.locks.ReentrantLock; |
| |
| import java.lang.reflect.Method; |
| import java.lang.reflect.Field; |
| |
| /* |
| * @test |
| * @summary Unit test for FinalizerHistogram |
| * @modules java.base/java.lang.ref:open |
| * @run main FinalizerHistogramTest |
| */ |
| |
| public class FinalizerHistogramTest { |
| static ReentrantLock lock = new ReentrantLock(); |
| static volatile int wasInitialized = 0; |
| static volatile int wasTrapped = 0; |
| static final int objectsCount = 1000; |
| |
| static class MyObject { |
| public MyObject() { |
| // Make sure object allocation/deallocation is not optimized out |
| wasInitialized += 1; |
| } |
| |
| protected void finalize() { |
| // Trap the object in a finalization queue |
| wasTrapped += 1; |
| lock.lock(); |
| } |
| } |
| |
| public static void main(String[] argvs) { |
| try { |
| lock.lock(); |
| for(int i = 0; i < objectsCount; ++i) { |
| new MyObject(); |
| } |
| System.out.println("Objects intialized: " + objectsCount); |
| System.gc(); |
| while(wasTrapped < 1); |
| |
| Class<?> klass = Class.forName("java.lang.ref.FinalizerHistogram"); |
| |
| Method m = klass.getDeclaredMethod("getFinalizerHistogram"); |
| m.setAccessible(true); |
| Object entries[] = (Object[]) m.invoke(null); |
| |
| Class<?> entryKlass = Class.forName("java.lang.ref.FinalizerHistogram$Entry"); |
| Field name = entryKlass.getDeclaredField("className"); |
| name.setAccessible(true); |
| Field count = entryKlass.getDeclaredField("instanceCount"); |
| count.setAccessible(true); |
| |
| System.out.println("Unreachable instances waiting for finalization"); |
| System.out.println("#instances class name"); |
| System.out.println("-----------------------"); |
| |
| boolean found = false; |
| for (Object entry : entries) { |
| Object e = entryKlass.cast(entry); |
| System.out.printf("%10d %s\n", count.get(e), name.get(e)); |
| if (((String) name.get(e)).indexOf("MyObject") != -1 ) { |
| found = true; |
| } |
| } |
| |
| if (!found) { |
| throw new RuntimeException("MyObject is not found in test output"); |
| } |
| |
| System.out.println("Test PASSED"); |
| } catch(Exception e) { |
| System.err.println("Test failed with " + e); |
| e.printStackTrace(System.err); |
| throw new RuntimeException("Test failed"); |
| } finally { |
| lock.unlock(); |
| } |
| } |
| } |