LockFreeList Example
/*
* Copyright (c) 2008 IBM Corporation
*
* 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.
*/
package org.amino.examples;
/* The list contains the given types of items.
* This example shows the mainly interfaces of LockFreeList.
* Including : add(), remove(), isEmpty(), size(), iterator().
*
* The ListAdder class will add different items of String from "1" to "ELEMENT_NUM".
* The ListRemover class will remove no more than ELEMENT_NUM items.
* The main thread will wait for all the threads in pool to finish.
* 2009/05/22
*/
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.Iterator;
import org.amino.ds.lockfree.LockFreeList;
public class ListExample {
public static final int ELEMENT_NUM = 100;
private static final int TASKS_NUM = 4;
public static void main(String[] argvs) {
ExecutorService exec = Executors.newFixedThreadPool(TASKS_NUM);
final List<String> listStr = new LockFreeList<String>();
for (int i = 0; i < TASKS_NUM; ++i) {
exec.submit(new ListAdder(listStr));
exec.submit(new ListRemover(listStr));
}
exec.shutdown();
// Wait until all the threads in pool to finish.
try {
while(!exec.awaitTermination(600, TimeUnit.SECONDS));
} catch (InterruptedException e) {
e.printStackTrace();
}
// If the List is empty now, the program will exit.
if (listStr.isEmpty())
{
System.out.println("The List is empty, so I will exit!");
System.exit(1);
}
// Print all the elements in List.
for (String str : listStr)
System.out.println(str);
System.out.println("List size before clearing: "+ listStr.size());
listStr.clear();
System.out.println("List size after clearing: "+ listStr.size());
}
}
/*
* The ListAdder class will add elements to the given List.
*/
class ListAdder implements Runnable {
List<String> taskLst;
private static AtomicInteger count = new AtomicInteger();
public ListAdder(List<String> taskList)
{
taskLst = taskList;
}
public void run(){
while (taskLst.size() < ListExample.ELEMENT_NUM)
{
if (taskLst.add(Integer.toString(count.incrementAndGet()))) {
System.out.println(Thread.currentThread()+ " Added " + count.get());
}
}
Thread.yield();
}
}
/*
* The ListRemover class will remove the existed elements from the given List.
*/
class ListRemover implements Runnable {
List<String> taskLst;
private static AtomicInteger count = new AtomicInteger();
public ListRemover(List<String> taskList)
{
taskLst = taskList;
}
public void run(){
int times = 0;
while (times < ListExample.ELEMENT_NUM)
{
if (taskLst.remove(Integer.toString(count.incrementAndGet()))) {
System.out.println(Thread.currentThread()+ "Removed: " + count.get());
}
times++;
}
Thread.yield();
}
}
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