Question

suppose i want to make two threads . one thread A to be accessed multiple times by different processes and one time B to be accessed only one at a time.

please explain the concept and code by using synchronized() method keyword

Answer 1

Thread synchronization is the concurrent execution of two or more threads that share critical resources.

Synchronized Method: Includes the synchronized keyword in its declaration. When a thread invokes a synchronized method, synchronized method automatically acquires the intrinsic lock for that method's object and releases it when the method returns, even if that return was caused by an uncaught exception.

CODE

class Table{

synchronized void printTable(int n){ // synchronized method  

   for(int i=0;i<5;i++){  

     System.out.println(n*i);  

     try{  

      Thread.sleep(500);  

     }catch(Exception e){System.out.println(e);}  

   }  

   }  

}  

class Addition{

void printAddition(){ /

int x=6,y=9,z;

z = x+y;

System.out.println(z);  

     try{  

      Thread.sleep(500);  

     }catch(Exception e){System.out.println(e);}  

   }  

}  

  class ThreadA extends Thread{  

Table t;  

Addition ad;

ThreadA(Table t){  

this.t=t;  

}

ThreadA(Addition ad){  

this.ad=ad;  

}

public void run(){  

t.printTable(5);

ad.printAddition();

}  

}  

class ThreadB extends Thread{  

Table t;  

ThreadB(Table t){  

this.t=t;  

}  

public void run(){  

t.printTable(100);  

}  

}  

  

public class SynchronizationMethod{  

public static void main(String args[]){  

Table obj = new Table(); //only one object

Addition obj1 = new Addition();   

ThreadA a = new ThreadA(obj);  

ThreadB b = new ThreadB(obj);  

   ThreadA an = new ThreadA(obj1);

a.start();  

b.start();  

an.start();

}  

}