/*
* Copyright (c) 2004, 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
* @bug 5047639
* @summary Check that the "java-level" APIs provide a consistent view of
* the thread list
*/
import java.lang.management.ManagementFactory;
import java.lang.management.ThreadMXBean;
import java.util.Map;
public class ThreadLists {
public static void main(String args[]) {
// get top-level thread group
ThreadGroup top = Thread.currentThread().getThreadGroup();
ThreadGroup parent;
do {
parent = top.getParent();
if (parent != null) top = parent;
} while (parent != null);
// get the thread count
int activeCount = top.activeCount();
Map<Thread, StackTraceElement[]> stackTraces = Thread.getAllStackTraces();
ThreadMXBean threadBean = ManagementFactory.getThreadMXBean();
int threadCount = threadBean.getThreadCount();
long[] threadIds = threadBean.getAllThreadIds();
System.out.println("ThreadGroup: " + activeCount + " active thread(s)");
System.out.println("Thread: " + stackTraces.size() + " stack trace(s) returned");
System.out.println("ThreadMXBean: " + threadCount + " live threads(s)");
System.out.println("ThreadMXBean: " + threadIds.length + " thread Id(s)");
// check results are consistent
boolean failed = false;
if (activeCount != stackTraces.size()) failed = true;
if (activeCount != threadCount) failed = true;
if (activeCount != threadIds.length) failed = true;
if (failed) {
throw new RuntimeException("inconsistent results");
}
}
}