Integer value not increment every time

Question

I declare an int value that tries to increment every button click but some time value not increment and some after 2 or 3 click increment working. I always get log so click event no issue, already tried without static but still not working.

public static int TotalScore = 0;

btnsubmit.setOnClickListener(new View.OnClickListener() 
{
            @Override
            public void onClick(View view) {
                initScoreSubmit();
            }
 });

public void initScoreSubmit()
{

        TotalScore++;
        txtTotalPoint.setText("Total Point: " +   String.valueOf(TotalScore));

        settings.set(AppSettings.Key.UserTotalPoint, TotalScore);

        Log.d(TAG, "Total_point "+TotalScore);
}

Answer 1

Can you please tell me why not static value or only int not working.

Because of the Java memory model.

If one thread writes a variable and another reads the variable, the only ways to guarantee that the second thread sees the value written by the first are:

• declare the variable as a volatile ,
• synchronize the two threads, or
• replace the bare variable with reference to a thread safe class; eg an AtomicInteger . The variable should be final .

You need to read the Oracle Tutorial on Concurrency, and specifically the sections on synchronization:

• https://docs.oracle.com/javase/tutorial/essential/concurrency/sync.html