diff options
Diffstat (limited to 'cdf/src/cdf-prop-value/cdf-util/src/main/java/org/onap/dcae/cdf/util/threads/ThreadUtils.java')
-rw-r--r-- | cdf/src/cdf-prop-value/cdf-util/src/main/java/org/onap/dcae/cdf/util/threads/ThreadUtils.java | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/cdf/src/cdf-prop-value/cdf-util/src/main/java/org/onap/dcae/cdf/util/threads/ThreadUtils.java b/cdf/src/cdf-prop-value/cdf-util/src/main/java/org/onap/dcae/cdf/util/threads/ThreadUtils.java new file mode 100644 index 0000000..34afebe --- /dev/null +++ b/cdf/src/cdf-prop-value/cdf-util/src/main/java/org/onap/dcae/cdf/util/threads/ThreadUtils.java @@ -0,0 +1,89 @@ +/* + Copyright (C) 2017 AT&T Intellectual Property. All rights reserved. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this code 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. + +*/ +package org.onap.dcae.cdf.util.threads; + +import java.util.LinkedList; +import java.util.List; + +/** + * Various utility functions dealing with threads + */ +public class ThreadUtils { + /** + * Get a list of all threads. + * + * @return an array of threads + */ + public static Thread[] getAllThreads() { + ThreadGroup rootGroup = getRootGroup(); + int noThreads = rootGroup.activeCount(); // returns an estimated count of active threads + Thread[] threads = new Thread[noThreads + 1]; + rootGroup.enumerate(threads); + + while ( rootGroup.enumerate( threads, true ) == threads.length ) { // iterate if we filled up the array + threads = new Thread[ threads.length + noThreads ]; + } + // remove null threads + LinkedList<Thread> lthreads = new LinkedList<Thread>(); + for (Thread thread: threads) + if (thread != null) + lthreads.push(thread); + return lthreads.toArray(new Thread[0]); + } + + /** + * Get a list of all threads with a given thread name. + * + * @param name the name to look for + * @return an array of threads with that name + */ + public static Thread[] getNamedThreads(final String name) { + Thread[] allThreads = getAllThreads(); + LinkedList<Thread> lthreads = new LinkedList<Thread>(); + for (Thread thread: allThreads) + if (thread.getName().equals(name)) + lthreads.push(thread); + + return lthreads.toArray(new Thread[0]); + } + + /** + * Get the ultimate root of the threads + * + * @return the root thread + */ + public static ThreadGroup getRootGroup() { + ThreadGroup rootGroup = Thread.currentThread( ).getThreadGroup( ); + ThreadGroup parentGroup; + while ( ( parentGroup = rootGroup.getParent() ) != null ) { + rootGroup = parentGroup; + } + return rootGroup; + } + + public static void main(String args[]) throws Exception { + System.out.println("==== get Root Threads ===="); + System.out.println("Root thread = " + getRootGroup().getName()); + System.out.println("==== get All Threads ===="); + Thread[] threads = getAllThreads(); + for (int i = 0; i < threads.length; i++) + System.out.println("Thread No:" + i + " = " + threads[i].getName()); + System.out.println("==== getNamedThreads(main) ===="); + threads = getNamedThreads("main"); + for (int i = 0; i < threads.length; i++) + System.out.println("Thread No:" + i + " = " + threads[i].getName()); + } +} |