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6. 

What will be the output of the program? 

class s implements Runnable 
{ 
    int x, y; 
    public void run() 
    { 
        for(int i = 0; i < 1000; i++) 
            synchronized(this) 
            { 
                x = 12; 
                y = 12; 
            } 
        System.out.print(x + " " + y + " "); 
    } 
    public static void main(String args[]) 
    { 
        s run = new s(); 
        Thread t1 = new Thread(run); 
        Thread t2 = new Thread(run); 
        t1.start(); 
        t2.start(); 
    } 
}

A. DeadLock
B. It print 12 12 12 12
C. Compilation Error
D. Cannot determine output.
7. 

What will be the output of the program? 

public class ThreadDemo 
{ 
    private int count = 1; 
    public synchronized void doSomething() 
    { 
        for (int i = 0; i < 10; i++) 
            System.out.println(count++); 
    } 
    public static void main(String[] args) 
    { 
        ThreadDemo demo = new ThreadDemo(); 
        Thread a1 = new A(demo); 
        Thread a2 = new A(demo); 
        a1.start(); 
        a2.start(); 
    } 
} 
class A extends Thread 
{ 
    ThreadDemo demo; 
    public A(ThreadDemo td) 
    { 
        demo = td; 
    } 
    public void run() 
    { 
        demo.doSomething(); 
    } 
}

A. It will print the numbers 0 to 19 sequentially
B. It will print the numbers 1 to 20 sequentially
C. It will print the numbers 1 to 20, but the order cannot be determined
D. The code will not compile.
8. 

What will be the output of the program? 

public class SyncTest 
{
    public static void main (String [] args) 
    {
        Thread t = new Thread() 
        {
            Foo f = new Foo();
            public void run() 
            {
                f.increase(20);
            }
        };
    t.start();
    }
}
class Foo 
{
    private int data = 23;
    public void increase(int amt) 
    {
        int x = data;
        data = x + amt;
    }
}
and assuming that data must be protected from corruption, what—if anything—can you add to the preceding code to ensure the integrity of data?
A. Synchronize the run method.
B. Wrap a synchronize(this) around the call to f.increase().
C. The existing code will cause a runtime exception.
D. Synchronize the increase() method
9.  

class Test 
{
    public static void main(String [] args) 
    {
        printAll(args);
    }

    public static void printAll(String[] lines) 
    {
        for(int i = 0; i < lines.length; i++)
        {
            System.out.println(lines[i]);
            Thread.currentThread().sleep(1000);
        }
    }
}
the static method Thread.currentThread() returns a reference to the currently executing Thread object. What is the result of this code?
A. Each String in the array lines will output, with a 1-second pause.
B. Each String in the array lines will output, with no pause in between because this method is not executed in a Thread.
C. Each String in the array lines will output, and there is no guarantee there will be a pause because currentThread() may not retrieve this thread.
D. This code will not compile.
10. 

What will be the output of the program? 

class MyThread extends Thread 
{
    public static void main(String [] args) 
    {
        MyThread t = new MyThread(); /* Line 5 */
        t.run();  /* Line 6 */
    }

    public void run() 
    {
        for(int i=1; i < 3; ++i) 
        {
            System.out.print(i + "..");
        }
    }
}

A. This code will not compile due to line 5.
B. This code will not compile due to line 6.
C. 1..2..
D. 1..2..3..