Threading on different servers

Question

Hi,
I have a single client that sends same data parameters to two servers. It needs each server to complete a few runs and report the results. At the same time the client has an overall target to accomplish, say 200 runs. Servers may execute a single batch of 20 runs at a time. So it starts off with allocating 20 runs each to both servers which get busy immediately. Whichever server sends in the results first or gets free, needs to be allocated another 20 runs. This needs to happen till all 200 runs are completed.
I have written two threads calling the same constructor yet passing different IP Addresses into the constructor. Run method basically has the same code for each thread.
The problem: I start both the threads at the same time, but how do I check which server finished its batch (Will Thread.getState() help resolve the problem?) and then how do I allocate the next lot of 20 runs? Both the threads are running and there seems no way to find out which one finished first batch.
Thanks.

Answer 1

Hello Javajockey,
implementing Runnable is good practice - it makes the code a little more general:
Worker.java (revised)
class Worker extends Thread {
     private final Queue<Runnable> queue;
     Worker(Queue<Runnable> queue) {
          this.queue = queue;
          this.setDaemon(true);
     @Override
     public void run() {
          while (true) {
               try {
                    Runnable runnable = queue.getNext();
                    runnable.run();
               } catch (RuntimeException e) {
                    // in case the run() method throws an
                    // exception. if you don't catch it, the thread
                    // will be terminated and you lose a
                    // worker without wanting to.
                    // you should implement some logging mechanism
                    // ( even a System.out.println(...); will do.
                    // see: http://www.javapractices.com/Topic16.cjp )
               } /* finally {
                    // this finally block is now obsolete
                    // unless you accumulate resources
                    // somewhere in the obove try statement
}Now let's just revise the code snippet from befor:
Queue<Runnable> queue = new Queue<Runnable>();
new Worker(queue).start(); // worker one
new Worker(queue).start(); // worker two
// I don't know where you get the parameters from,
// but you'll figure it out..
queue.add(new TSP(port1, port2, ip));I noticed, that I forgot to start() the workers. That's probably why you did not get it to work.. silly me!
I commented it a little more detailed anyway.
Hopefully that's all you need. The best of luck! ;)
With kind regards
Ben