--- /dev/null Wed Feb 3 17:15:59 2016 +++ new/test/gc/cms/TestBubbleUpRef.java Wed Feb 3 17:17:21 2016 @@ -0,0 +1,186 @@ +/* + * Copyright (c) 2004, 2016, 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.ref.ReferenceQueue; +import java.lang.ref.WeakReference; +import java.util.LinkedList; +import java.util.ListIterator; + +/* + * @test + * @requires vm.gc=="ConcMarkSweep" | vm.gc == "null" + * @key cte_test + * @bug 4950157 + * @summary Stress the behavior of ergonomics when the heap is nearly full and + * stays nearly full. + * @run main/othervm + * -XX:+UseConcMarkSweepGC -XX:-CMSYield -XX:-CMSPrecleanRefLists1 + * -XX:CMSInitiatingOccupancyFraction=0 -Xmx8m TestBubbleUpRef 16000 50 10000 + */ + +/** + * Test program to stress the behavior of ergonomics when the + * heap is nearly full and stays nearly full. + * This is a test to catch references that have been discovered + * during concurrent marking and whose referents have been + * cleared by the mutator. + * Allocate objects with weak references until the heap is full + * Free the objects. + * Do work so that concurrent marking has a chance to work + * Clear the referents out of the weak references + * System.gc() in the hopes that it will acquire the collection + * Free the weak references + * Do it again. + * + * Use the following VM options + * -Xmx8m -XX:-CMSYield [-XX:+UseConcMarkSweepGC] -XX:-CMSPrecleanRefLists1 + * -XX:CMSInitiatingOccupancyFraction=0 + * + * Use parameter: + * args[0] - array size (16000) + * args[1] - iterations (50) + * args[2] - work (10000) + */ +class MyList extends LinkedList { + + int[] a; + + MyList(int size) { + a = new int[size]; + } +} + +class MyRefList extends LinkedList { + + WeakReference ref; + + MyRefList(Object o, ReferenceQueue rq) { + ref = new WeakReference(o, rq); + } + + void clearReferent() { + ref.clear(); + } +} + +public class TestBubbleUpRef { + + MyList list; + MyRefList refList; + ReferenceQueue rq; + int refListLen; + int arraySize; + int iterations; + int workUnits; + + TestBubbleUpRef(int as, int cnt, int wk) { + arraySize = as; + iterations = cnt; + workUnits = wk; + list = new MyList(arraySize); + refList = new MyRefList(list, rq); + } + + public void fill() { + System.out.println("fill() " + iterations + " times"); + int count = 0; + while (true) { + try { + // Allocations + MyList next = new MyList(arraySize); + list.add(next); + MyRefList nextRef = new MyRefList(next, rq); + refList.add(nextRef); + } catch (OutOfMemoryError e) { + // When the heap is full + try { + if (count++ > iterations) { + return; + } + System.out.println("Freeing list"); + while (!list.isEmpty()) { + list.removeFirst(); + } + System.out.println("Doing work"); + int j = 0; + for (int i = 1; i < workUnits; i++) { + j = j + i; + } + System.out.println("Clearing refs"); + ListIterator listIt = refList.listIterator(); + while (listIt.hasNext()) { + MyRefList next = (MyRefList) listIt.next(); + next.clearReferent(); + } + System.gc(); + System.out.println("Freeing refs"); + while (!refList.isEmpty()) { + refList.removeFirst(); + } + } catch (OutOfMemoryError e2) { + System.err.println("Out of Memory - 2 "); + continue; + } + } catch (Exception e) { + System.err.println("Unexpected exception: " + e); + return; + } + } + } + + /** + * Test entry point. + * args[0] - array size (is the size of the int array in a list item) + * args[1] - iterations (is the number of out-of-memory exceptions before exit) + * args[2] - work (is the work done between allocations) + * @param args + */ + public static void main(String[] args) { + // Get the input parameters. + if (args.length != 3) { + throw new IllegalArgumentException("Wrong number of input argumets"); + } + + int as = Integer.parseInt(args[0]); + int cnt = Integer.parseInt(args[1]); + int work = Integer.parseInt(args[2]); + + System.out.println(" " + as + "\n" + + " " + cnt + "\n" + + " " + work + "\n"); + + // Initialization + TestBubbleUpRef b = new TestBubbleUpRef(as, cnt, work); + + // Run the test + try { + b.fill(); + } catch (OutOfMemoryError e) { + b = null; // Free memory before trying to print anything + System.err.println("Out of Memory - exiting "); + } catch (Exception e) { + System.err.println("Exiting "); + } + } +} +