educative.io

AtomicReference code example is not correct

Courses
,
#1

It seems like this code is not correct:

class Demonstration {

static Thread firstThread = null;
public static void main( String args[] ) throws Exception {
    ExecutorService executor = Executors.newFixedThreadPool(50);
    try {
        for (int i = 0; i < 25; i++) {
            executor.submit(new Runnable() {
                @Override
                public void run() {
                    synchronized (this) {
                        if (firstThread == null) {
                            firstThread = Thread.currentThread();
                            System.out.println(Thread.currentThread().getName() + " takes first turn");
                        }
                    }
                }
            });
        }
    } finally {
        executor.shutdown();
        executor.awaitTermination(1, TimeUnit.HOURS);
    }
}

}

To work as expected it should be synchronized not on THIS which is an instance of each submitted runnable itself, but on some shared object like Deonsytation.class.

#2

Hi @Zakhar,
Please provide the lesson link for this query, Thanks.

#3
1 Like