How can another waiter thread enter the synchronized block, if a waiter thread is already waiting in that block waiting for the notify call?
I have tested with other examples and all other threads seem to wait to enter the synchronized block when one of the threads is in synchronized block and the new thread enters the synchronized block right after the old one leaves the block:
class ThreadClassNotifier implements Runnable {
private Message msg;
public ThreadClassNotifier(Message msg) {
this.msg = msg;
}
@Override
public void run() {
String name = Thread.currentThread().getName();
System.out.println(name+" started");
try {
Thread.sleep(1000);
synchronized (msg) {
msg.setMsg(name+" Notifier work done");
msg.notify();
// msg.notifyAll();
}
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
class ThreadClassWaiter implements Runnable {
private Message msg;
public ThreadClassWaiter(Message m){
this.msg=m;
}
@Override
public void run() {
String name = Thread.currentThread().getName();
synchronized (msg) {
try{
System.out.println(name+" waiting to get notified at time:"+System.currentTimeMillis());
Thread.sleep(10000);
msg.wait();
}catch(InterruptedException e){
e.printStackTrace();
}
System.out.println(name+" waiter thread got notified at time:"+System.currentTimeMillis());
//process the message now
System.out.println(name+" processed: "+msg.getMsg());
}
}
}
public class ThreadMain {
public static void main(String[] args) throws InterruptedException {
Message msg = new Message("process it");
ThreadClassWaiter waiter = new ThreadClassWaiter(msg);
new Thread(waiter,"waiter").start();
ThreadClassWaiter waiter1 = new ThreadClassWaiter(msg);
new Thread(waiter1, "waiter1").start();
System.out.println("All the threads are started");
}
}
