Remove ThreadCommon.java file from dcae-pgaasHEADmaster

Change-Id: I0a1279976f25447dfab63e73bd6e1b3974fb2487
Signed-off-by: Tony Hansen <tony@att.com>
Issue: DCAEGEN2-77

3 files changed, 90 insertions, 120 deletions

diff --git a/cdf/src/cdf-prop-value/cdf-util/src/main/java/makefile b/cdf/src/cdf-prop-value/cdf-util/src/main/java/makefile
index af2f0b0..9f04d67 100644
--- a/cdf/src/cdf-prop-value/cdf-util/src/main/java/makefile
+++ b/cdf/src/cdf-prop-value/cdf-util/src/main/java/makefile
@@ -22,7 +22,7 @@ JAVA=	org/openecomp/dcae/cdf/util/common/Classify.java \
 	org/openecomp/dcae/cdf/util/config/Configurable.java \
 	org/openecomp/dcae/cdf/util/config/ConfigurationRegistry.java \
 	org/openecomp/dcae/cdf/util/threads/TaskThread.java \
-	org/openecomp/dcae/cdf/util/threads/ThreadCommon.java
+	org/openecomp/dcae/cdf/util/threads/ThreadUtils.java
 
 CLASSES=$(JAVA:.java=.class)
 
diff --git a/cdf/src/cdf-prop-value/cdf-util/src/main/java/org/openecomp/dcae/cdf/util/threads/ThreadCommon.java b/cdf/src/cdf-prop-value/cdf-util/src/main/java/org/openecomp/dcae/cdf/util/threads/ThreadCommon.java
deleted file mode 100644
index fd9f3c1..0000000
--- a/cdf/src/cdf-prop-value/cdf-util/src/main/java/org/openecomp/dcae/cdf/util/threads/ThreadCommon.java
+++ /dev/null
@@ -1,119 +0,0 @@
-/*
-    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.openecomp.dcae.cdf.util.threads;
-
-/**
- *    Some functions to manipulate thread info. Based on
- *	http://nadeausoftware.com/articles/2008/04/java_tip_how_list_and_find_threads_and_thread_groups
- *	which is licensed under LGPL 2
- */
-
-import java.lang.management.*;
-// import java.util.Arrays;
-
-public final class ThreadCommon {
-    /**
-     * ThreadCommon is not to be instantiated.
-     */
-    private ThreadCommon() { }
-
-    private static ThreadGroup rootThreadGroup = null;
-
-    /**
-     * Get the root thread group in the thread group tree.
-     * Since there is always a root thread group, this
-     * method never returns null.
-     *
-     * @return		the root thread group
-     */
-    public static synchronized ThreadGroup getRootThreadGroup() {
-	if ( rootThreadGroup != null )
-	    return rootThreadGroup;
-	ThreadGroup tg = Thread.currentThread().getThreadGroup();
-	ThreadGroup ptg;
-	while ( (ptg = tg.getParent()) != null )
-	    tg = ptg;
-	return tg;
-    }
-
-    /**
-     * Get a list of all threads.  Since there is always at
-     * least one thread, this method never returns null or
-     * an empty array.
-     *
-     * @return		an array of threads
-     */
-    public static Thread[] getAllThreads() {
-	final ThreadGroup root = getRootThreadGroup();
-	final ThreadMXBean thbean = ManagementFactory.getThreadMXBean();
-	int nAlloc = thbean.getThreadCount();
-	int n = 0;
-	Thread[] threads;
-	do {
-	    nAlloc *= 2;
-	    threads = new Thread[ nAlloc ];
-	    n = root.enumerate( threads, true );
-	} while ( n == nAlloc );
-	return copyOf( threads, n );
-    }
-
-    /**
-     * Get the thread with the given name.  A null is returned
-     * if no such thread is found.  If more than one thread has
-     * the same name, the first one found is returned.
-     *
-     * @param	name	the thread name to search for
-     * @return		the thread, or null if not found
-     * @throws	NullPointerException
-     * 			if the name is null
-     */
-    public static Thread getFirstThread( final String name ) {
-	if ( name == null )
-	    throw new NullPointerException( "Null name" );
-	final Thread[] threads = getAllThreads();
-	for ( Thread thread : threads )
-	    if ( thread.getName().equals( name ) )
-		return thread;
-	return null;
-    }
-
-    /**
-     * Get a list of all threads with a given thread name.
-     *
-     * @param	name	the name to look for
-     * @return		an array of threads in that state
-     */
-    public static Thread[] getAllThreads( final String name ) {
-	if ( name == null )
-	    throw new NullPointerException( "Null name" );
-	final Thread[] allThreads = getAllThreads();
-	final Thread[] found = new Thread[allThreads.length];
-	int nFound = 0;
-	for ( Thread thread : allThreads )
-	    if ( thread.getName().equals(name) )
-		found[nFound++] = thread;
-	return copyOf( found, nFound );
-    }
-
-    // return java.util.Arrays.copyOf( found, nFound );
-    private static Thread[] copyOf( Thread[] threads, int n ) {
-	Thread[] nthreads = new Thread[ n ];
-	for (int i = 0; i < n; i++) {
-	    nthreads[i] = threads[i];
-	}
-	return nthreads;
-    }
-}
diff --git a/cdf/src/cdf-prop-value/cdf-util/src/main/java/org/openecomp/dcae/cdf/util/threads/ThreadUtils.java b/cdf/src/cdf-prop-value/cdf-util/src/main/java/org/openecomp/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/openecomp/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());
+    }
+}