thread state

[abalfazl hossein]

 
class FooRunnable implements Runnable {
       public void run() {
             for(int x =1; x < 6; x++) {
                System.out.println("Runnable running");
             }
       }
}


public class Main {

    /**
     * @param args the command line arguments
     */
           public static void main (String [] args) {
             FooRunnable r = new FooRunnable();
             Thread t = new Thread(r);
             Thread.State e = t.getState();
             Thread.State[] ts = e.values();
             for(int i = 0; i < ts.length; i++){
             System.out.println(ts[i]); }
             t.start();
        }


}   

output is:


WAITING
TIMED_WAITING
TERMINATED
Runnable running
Runnable running
Runnable running
Runnable running
Runnable running


I didn't use wait() or join() or..

why does print WAITING?

[Christophe Verré]

I'm surprised it doesn't print more than that. e.values() returns all the values of the Thread.State enum. It has nothing to do with the current state of your thread. What you want to do is :

public static void main (String [] args) {
             FooRunnable r = new FooRunnable();
             Thread t = new Thread(r);
             Thread.State e = t.getState();
             System.out.println(e);
             t.start();
        }

[amitabh mehra]

Thread.State[] ts = e.values();

would return you an array of enum of Thread.State, and you are printing the same. These are not your "current thread" states.
Please check http://java.sun.com/j2se/1.5.0/docs/api/java/lang/Thread.State.htmlfor more info.

[abalfazl hossein]

After the bold statement has been executed, clockThread is in the New Thread state. When a thread is a New Thread, it is merely an empty Thread object; no system resources have been allocated for it yet. When a thread is in this state, you can only start the thread. Calling any method besides start when a thread is in this state makes no sense and causes an IllegalThreadStateException. (In fact, the runtime system throws an IllegalThreadStateException any time a method is called on a thread and that thread's state does not allow for that method call.)

http://www.lkn.ei.tum.de/arbeiten/faq/man/JAVA-tutorial/essential/threads/lifecycle.html

  public class Main {

    /**
     * @param args the command line arguments
     */
           public static void main (String [] args) {
             FooRunnable r = new FooRunnable();
             Thread t = new Thread(r);
             Thread.State e = t.getState();
             System.out.println(e);
             t.setName("A");
             t.start();
             
        }


}  

I run this code without any problem.Then the above statement is wrong.Right?

[abalfazl hossein]

If I wanted to see other state of thread,How could I do in that code?

[Ireneusz Kordal]

abalfazl hossein wrote:If I wanted to see other state of thread,How could I do in that code?

class FooRunnable implements Runnable {

    Object monitor;

    FooRunnable(Object monitor) {
        this.monitor = monitor;
    }

    public void run() {
        for (long x = 1; x < 6000000000l; x++) {
        }
        try {
            Thread.sleep(2000);
        } catch (InterruptedException ex) {
        }
        try {
            synchronized (monitor) {
                monitor.wait();
            }
        } catch (InterruptedException ex) {
        }
        try {
            synchronized (monitor) {
                monitor.wait(2000);
            }
        } catch (InterruptedException ex) {
        }
        System.out.println("Exit");
    }
}

public class ThreadState {

    public static void main(String[] args) {
        Object monitor = new Object();
        FooRunnable r = new FooRunnable(monitor);
        Thread t = new Thread(r);
        Thread.State e = t.getState();
        System.out.println("State = " + e);
        t.start();
        while (true) {
            Thread.State e1 = t.getState();
            if (!e1.equals(e)) {
                e = e1;
                System.out.println("State = " + e);

                try {
                    Thread.sleep(500);
                } catch (InterruptedException ex) {
                }
            }
            if (e.equals(Thread.State.WAITING)) {
                synchronized (monitor) {
                    monitor.notify();
                }
            }
            if (e.equals(Thread.State.TERMINATED)) {
                break;
            }
        }
    }
}

.......
run:
State = NEW
State = RUNNABLE
State = TIMED_WAITING
State = RUNNABLE
State = WAITING
State = BLOCKED
State = TIMED_WAITING
State = RUNNABLE
Exit
State = TERMINATED