Odd even number printing using thread

Question

Odd even number printing using thread.Create one thread class, two instance of the thread. One will print the odd number and the other will print the even number.

Answer 1

I have implemented in such a way, based on the argument, no of threads will be spawned and will the respective no in round robin manner. i.e., If thread count is 3, thread 1 will print 1,4 ...; thread 2 will print 2,5,... and thread 3 will print 3,6...

public class ThreadSynchronizer
{

    public static void main(String[] args)
    {
    // BASED ON THE ARGUMENT MULTIPLE THREADS WILL BE CREATED AND EACH WILL PRINT ITS RESPECTIVE NO
    // IE, IF THREAD COUNT IS 3, THREAD 1 WILL PRINT 1,4 ..., THREAD2 WILL PRINT 2,5,... AND THREAD3 WILL PRINT 3,6...
    // LIMITED THE DISPLAY TO 1000 NOS
    int threadCnt = Integer.parseInt(args[0]);

    ReentrantLock lckArray[] = new ReentrantLock[threadCnt + 1];

    for (int i = 0; i < threadCnt + 1; i++)
    {
        ReentrantLock lck = new ReentrantLock();
        lck.lock();
        lckArray[i] = lck;
    }

    for (int i = 0; i < threadCnt; i++)
    {
        Thread th = new Thread(new Printer(lckArray, i + 1));
        th.start();
    }

    for (int i = 1; i < threadCnt + 1; i++)
    {
        lckArray[i].unlock();

        while (!lckArray[i].isLocked())
        {

        }
    }
    lckArray[0].unlock();
    }
}

class Printer implements Runnable
{

    private ReentrantLock[] lckArray;
    private int index;

    Printer(ReentrantLock[] lckArray, int startValue)
    {
    this.lckArray = lckArray;
    this.index = startValue;
    }

    @Override public void run()
    {
    ReentrantLock prevLock = null;
    int printCounter = index;

    for (int counter = 0; printCounter <= 1000; counter++)
    {
        int remCounter = counter % lckArray.length;
        int incCounter = lckArray.length - remCounter;
        int indexPostion = index + incCounter;
        int curElementIndex = indexPostion % lckArray.length;

        lckArray[curElementIndex].lock();
        if (prevLock != null)
        prevLock.unlock();
        prevLock = lckArray[curElementIndex];

        if (curElementIndex == 0)
        {
        System.out.println("Printed by Thread " + index + " " + printCounter);
        printCounter = printCounter + lckArray.length - 1;
        }

    }

    if (prevLock != null)
    {
        if (prevLock.isHeldByCurrentThread())
        prevLock.unlock();
    }

    }

}