/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* Running concurrent gc and doing some System.arraycopy
* Several threads is created in order to increase the probability
* of thread switches at critical points. Without creating several
* threads the test case usually passed even when there were bugs.
* Size of array and amount of garbage created is based on experimental
* numbers and is a tradeoff between time that the test takes when
* it succeeds and the probability that the test discovers a problem.
*/
public class Main {
public static void main(String args[]) {
new ObjectCreatorThread(true).start();
new ObjectCreatorThread(false).start();
new ObjectCreatorThread(false).start();
}
static class ObjectCreatorThread extends Thread {
boolean mDoLog;
public ObjectCreatorThread(boolean doLog) {
mDoLog = doLog;
}
@Override
public void run() {
new Main().stressArray(mDoLog);
}
}
Object [] array = new Object[10000];
void stressArray(boolean doLog) {
// We want many references in the array
// We also want elements close to each other to have large
// diff in address so lets skip every 2:nd address so it is null
if (doLog) {
System.out.println("Initializing...");
}
for (int i = 0; i < array.length; i+=2) {
array[i] = new String("Creating some garbage" + i);
}
if (doLog) {
System.out.println("Starting the test");
}
for (int j = 0; j < array.length; j++) {
Object obj = array[array.length - 1];
System.arraycopy(array, 0, array, 1, array.length - 1);
array[0] = obj;
new String("Creating some garbage" + Math.random());
new String("Creating some garbage" + Math.random());
new String("Creating some garbage" + Math.random());
new String("Creating some garbage" + Math.random());
}
for (int j = 0; j < array.length; j++) {
Object obj = array[0];
System.arraycopy(array, 1, array, 0, array.length - 1);
array[array.length - 1] = obj;
new String("Creating some garbage" + Math.random());
new String("Creating some garbage" + Math.random());
new String("Creating some garbage" + Math.random());
new String("Creating some garbage" + Math.random());
}
if (doLog) {
System.out.println("Test OK");
}
}
}