Java Thread working correctly only when using println in run method

Asked Jan 02 '14 at 22:35

Active Feb 04 '14 at 19:58

Viewed 87 times

I was trying to implement autoscrolling for small project of mine, where I thought of using a thread for it.

@Override
public void run() {

    while(true) {
        System.out.println("");
        if(isScrolling) {
            view.getWorkarea().autoScroll(direction);

            try {
                sleep(100);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
}

Now, I got this strange bug, where it's only working while I don't remove System.out.println(""). If I remove it, autoscrolling stops working. Does anyone know why it's happening and how to solve it?

edited Feb 04 '14 at 19:58

tshepang

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asked Jan 02 '14 at 22:35

user3155293

9

Because `println()` is a `synchronized` method. This will help : http://stackoverflow.com/questions/20786483/code-not-executed-without-a-print-statement/20786677 – Alexis C. Jan 02 '14 at 22:37
2

Change your isScrolling to volatile. – sksamuel Jan 02 '14 at 22:39

Java Thread working correctly only when using println in run method

0 Answers0