jdk-24/test/hotspot/jtreg/runtime/Thread/ThreadCountLimit.java
2020-10-27 14:25:34 +00:00

114 lines
3.4 KiB
Java

/*
* Copyright (c) 2020, 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.
*/
/**
* @test
* @summary Stress test that reaches the process limit for thread count, or time limit.
* @key stress
* @run main ThreadCountLimit
*/
import java.util.concurrent.CountDownLatch;
import java.util.ArrayList;
public class ThreadCountLimit {
static final int TIME_LIMIT_MS = 5000; // Create as many threads as possible in 5 sec
static class Worker extends Thread {
private final int index;
private final CountDownLatch startSignal;
Worker(int index, CountDownLatch startSignal) {
this.index = index;
this.startSignal = startSignal;
}
@Override
public void run() {
if ((index % 250) == 0) {
System.out.println("INFO: thread " + index + " waiting to start");
}
try {
startSignal.await();
} catch (InterruptedException e) {
throw new Error("Unexpected: " + e);
}
setName(String.valueOf(index));
Thread.yield();
if (index != Integer.parseInt(getName())) {
throw new Error("setName/getName failed!");
}
if ((index % 250) == 0) {
System.out.println("INFO: thread " + getName() + " working");
}
}
}
public static void main(String[] args) {
CountDownLatch startSignal = new CountDownLatch(1);
ArrayList<Worker> workers = new ArrayList<Worker>();
int count = 1;
long start = System.currentTimeMillis();
try {
while (true) {
Worker w = new Worker(count, startSignal);
w.start();
workers.add(w);
count++;
long end = System.currentTimeMillis();
if ((end - start) > TIME_LIMIT_MS) {
// Windows path or a system with very large ulimit
System.out.println("INFO: reached the time limit " + TIME_LIMIT_MS + " ms, with " + count + " threads created");
break;
}
}
} catch (OutOfMemoryError e) {
if (e.getMessage().contains("unable to create native thread")) {
// Linux, macOS path
long end = System.currentTimeMillis();
System.out.println("INFO: reached this process thread count limit at " + count + " [" + (end - start) + " ms]");
} else {
throw e;
}
}
startSignal.countDown();
try {
for (Worker w : workers) {
w.join();
}
} catch (InterruptedException e) {
throw new Error("Unexpected: " + e);
}
}
}