join() method

[dennis zined]

Hi all.
In the code snippet below, how can I get t2 join t1? thanks.

Transaction transaction = new Transaction(); 
Thread t1 = new Thread(transaction);
Thread t2 = new Thread(transaction);

[Vad Fogel]

Hi Dennis, if I get your question right, a possible solution with minor modifications can look like this:

class JoinThreads{
    static Thread t1, t2;   //to make threads objects accessible without JoinThreads instance
    public static void main(String[] args){
        Transaction transaction = new Transaction(); 
        t1 = new Thread(transaction, "t1");   //to assign a descriptive name
        t2 = new Thread(transaction, "t2");  
        t1.start();
        t2.start();
    }
}
class Transaction implements Runnable{
    public void run() {
        String name=Thread.currentThread().getName();
        try{
            if(name.equals("t2")){
                JoinThreads.t1.join();
            }
            System.out.println(Thread.currentThread().getName() + " is done.");
        }catch(InterruptedException ie){}
    }
    
}

Hope this helps.
[ December 24, 2003: Message edited by: Vad Fogel ]

[venkatesh rajmendram]

Hi,
The code looks good, but just one thing that poped into my mind...
What if t2 never gets chance to run before t1, meaning there won't be actual join... ? or what if t1 will never get chance to run....and t1 goes ahead and finishes....
I might not sure but how about this code ...

  
class JoinThreads {
static Thread t1, t2;
//to make threads objects accessible without object instance   
public static void main(String[] args) {
Transaction transaction = new Transaction();
t1 = new Thread(transaction, "t1");
//to assign a descriptive name      
t2 = new Thread(transaction, "t2");
t2.start();
}
}
class Transaction implements Runnable {
public void run() {
String name = Thread.currentThread().getName();
try {
if (name.equals("t2")) {
JoinThreads.t1.start();
JoinThreads.t1.join();
}
System.out.println(Thread.currentThread().getName() + " is done.");
} catch (InterruptedException ie) {
}
}
}

Just that t2 starts t1 and joins itself...
Thanks
Venkatesh

[Vad Fogel]

If a call to the thread's isAlive() method returns false, you can still join a currently executing thread to it. isAlive() returns false if a thread hasn't been started or its run() has completed. In this event, t.join() returns immediately to allow the current thread to continue executing.
[ December 24, 2003: Message edited by: Vad Fogel ]

[dennis zined]

Thanks Vad, Venkatesh. I love this place!