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/*
* Copyright (c) 2004, 2018, 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.graal.enabled
* @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 -Xmx80m 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
* -Xmx80m -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("<array size> " + as + "\n"
+ "<OOM's> " + cnt + "\n"
+ "<work units> " + 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 ");
}
}
}
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