ExecutorService java可能的线程泄漏

Question

我正在尝试运行这个简单的类，并且对于每个cicle，我正在计算java进程线程的数量。

ps huH p pid wc-l。

对于每个cicle，线程数是availableProcessors（）数的增加。

当ExecutorService在其他线程中运行时，garbace收集器似乎不会释放僵尸线程。

如果我创建了一个静态ExecutorService,它就不会发生

import java.util.ArrayList;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;

public class ExecutorTest implements Runnable{

private ExecutorService executor = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors());
private static final int CICLE_NUMBERS=100;
private static final int WAIT_SECONDS=20;

@Override
public void run() {
    try{
    ArrayList<Future<DummyThread>> responses = new ArrayList<>();
    for(int i=0;i<CICLE_NUMBERS;i++)
        responses.add((Future<DummyThread>) executor.submit(new DummyThread()));
    for (Future<DummyThread> future : responses)
        future.get(WAIT_SECONDS, TimeUnit.SECONDS);
    }
    catch(Exception e){
        e.printStackTrace();
    }
    System.gc();
}

public static void main(String[] args) throws InterruptedException {
    for(;;){
        new Thread(new ExecutorTest()).start();
        Thread.sleep(2000);
    }
}
}

class DummyThread implements Runnable{

@Override
public void run() {
    System.out.println("Hello World!");
}

}

Answer 1

在run（）方法中添加try/finally块，并在finally块中的executor上调用shutdownNow()。