Hi friend,


Synchronozation is a mechanism which is used to provide the priority for
multiple thread programs to avoid the deadlock condition


If there is a portion of code within a method or the
complete method that can be accessed by multiple threads,
that section of code is called critical section. To make
sure that only one thread can access critical section at a
time, we synchronize critical section. Synchronization is
the keyword to avoid concurrent access to critical section
of the code.

There are two ways to synchronized the execution of code:

1. Synchronized Methods

2. Synchronized Blocks (Statements)

Synchronized Methods :

public class SynThread{
public static void main(String args[]){
Share s=new Share();
MyThread m1=new MyThread(s,"Thread1");
MyThread m2=new MyThread(s,"Thread2");
MyThread m3=new MyThread(s,"Thread3");
}
}
class MyThread extends Thread{
Share s;
MyThread(Share s,String str){
super(str);
this.s=s;
start();
}
public void run(){
s.doword(Thread.currentThread().getName());
}
}
class Share{
public synchronized void doword(String str){
for(int i=0;i<5;i++){
System.out.println("Started :"+str);
try{
Thread.sleep(100);
}catch(Exception e){}
}
}
}

Synchronized Blocks (Statements)

public class SynStatement{
public static void main(String args[]){
Share s=new Share();
MyThread m1=new MyThread(s,"Thread1");
MyThread m2=new MyThread(s,"Thread2");
MyThread m3=new MyThread(s,"Thread3");
}
}
class MyThread extends Thread{
Share s;
MyThread(Share s,String str){
super(str);
this.s=s;
start();
}
public void run(){
s.doword(Thread.currentThread().getName());
}
}
class Share{
public void doword(String str){
synchronized(this){
for(int i=0;i<5;i++){
System.out.println("Started :"+str);
try{
Thread.sleep(100);
}catch(Exception e){}
}
}
}
}

For more information on Synchronization visit to :

http://www.roseindia.net/java/thread/synchronization.shtml

http://www.roseindia.net/java/java-methods/java-method-synchronized.shtml

http://www.roseindia.net/tutorialsearch/?t=synchronized

Thanks