Thread not starts while other is too busy

Question

Thread not starts while other is too busy

I have multi thread application. I'm analyzing workflow of two threads. Thread_1 has cycle for(...) . Thread_2 has some small job. In some cases Thread_2 not starts it's job while cycle for(...) not finished in Thread_1 . Is it possible that system decides to put all resources for Thread_1 ? How to give possibility to start Thread_2 while Thread_1 is in for(...) . Should I put something like Thread.sleep(100) there? Everything is in Java 1.4.

Answer 1

It will be great if you share some code piece, it's difficult to debug the code without looking logic. Ideally thread_1 and thread_2 should run independently. thread_2 can't wait to finish for loop in thread_1. Example:

class RunnableDemo implements Runnable {
   private Thread t;
   private String threadName;

   RunnableDemo( String name){
       threadName = name;
       System.out.println("Creating " +  threadName );
   }
   public void run() {
      System.out.println("Running " +  threadName );
      try {
         for(int i = 4; i > 0; i--) {
            System.out.println("Thread: " + threadName + ", " + i);
            // Let the thread sleep for a while.
            Thread.sleep(50);
         }
     } catch (InterruptedException e) {
         System.out.println("Thread " +  threadName + " interrupted.");
     }
     System.out.println("Thread " +  threadName + " exiting.");
   }

   public void start ()
   {
      System.out.println("Starting " +  threadName );
      if (t == null)
      {
         t = new Thread (this, threadName);
         t.start ();
      }
   }

}

public class TestThread {
   public static void main(String args[]) {

      RunnableDemo R1 = new RunnableDemo( "Thread-1");
      R1.start();

      RunnableDemo R2 = new RunnableDemo( "Thread-2");
      R2.start();
   }   
}

Output:

Creating Thread-1
Starting Thread-1
Creating Thread-2
Starting Thread-2
Running Thread-1
Thread: Thread-1, 4
Running Thread-2
Thread: Thread-2, 4
Thread: Thread-1, 3
Thread: Thread-2, 3
Thread: Thread-1, 2
Thread: Thread-2, 2
Thread: Thread-1, 1
Thread: Thread-2, 1
Thread Thread-1 exiting.
Thread Thread-2 exiting.

Answer 2

you can make the first thread for loop pause for after a given number of iterations and set the static var th2_done to false to not waist Thread_1 time once the Thread_2 is done

Thread_1: for (...){ if(num_it % cycle && th2_done==false) sleep(100);}

Thread_2: for (...){} th2_done = true