Some query about synchronized

[Gobi]

public class SyncTest {
	
    public static void main (String[] args) {

    MysyncTest runna = new MysyncTest();
    Thread t1 = new Thread(runna);
    Thread t2 = new Thread(runna);	
    
    t1.start();
    t2.start();
    
    }	
}


class MysyncTest implements Runnable{
	int data = 0 ;
	int count = 1 ;
	
	synchronized public int getData()
	{
	    data  = data + count ;
	    try {
			Thread.currentThread().sleep(5000);
		} catch (InterruptedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return data;
	}
	
	public void setData(int a )
	{
		data = a ;
	}

	
	public void syncBlock()
	{
		synchronized (this) {
			// do something
			
		}
	}
	
	@Override
	public void run() {
		// TODO Auto-generated method stub
        	    ++count;
		if(count%2 == 0 )
		{
			getData();
		}
		else
		{
			setData(count);
		}
	
	}
}

Query 1 : Very first time , t1 control will enter in getData() since it is a sync function ,it will acquire lock (object lock ) and this will go to sleep ... Now t2 gets cycle to execute and it will enter in to setData() .. I wanna know since t1 has the lock for the same object how t2 is using that object ??


Query 2 : what is the diff between synchronised function and synchorized(this)

	synchronized public void fn1(){
		
	}
	
	public void fn2(){
		synchronized (this) {
                 // Do something here 			
		}
	}

Query 3 : I understood static synchronized , but I dont the know where it can be used .. can anyone help me out ?

[Gobi]

In addition to the above query , I have one more ..
when you say synchronized(this) -> a additional lock byte allocated in the heap along with the object
what abt static synchronized fn1() -> how the lock mechanism works , where the lock byte is ?