Thread guarantee ???

[ankur rathi]

At any time running thread can't have less priority than the thread which are in runnable state .

It will happen only if JVM is following priority based algorithem or time slicing algorithem .

So if any questiion come in exam related to first statement & nothing is specify about JVM , then what should be the answer ?

I hope question is clear .

thanks a lot .

[shandilya popuru]

i would select an answer which says behaviour is not guaranteed or that says something like "may print x or xx or xxx"

[Jeroen Wenting]

in multithreading nothing is guaranteed except that all threads will get a chance to run (providing there's no deadlock and the JVM doesn't crash of course) at some point in time unless one thread enters an infinite loop and the JVM uses cooperative multitasking (hmm, is that a guarantee . )

[Henry Wong]

At any time running thread can't have less priority than the thread which are in runnable state

Not true... threads are subjected to the underlying threading model. For example, windows will try hard to give each thread a chance to execute that lower priority threads will run, even if a higher priority thread is in a runnable state.

in multithreading nothing is guaranteed except that all threads will get a chance to run

Not true... it is possible to starve a thread via using priority levels, under certain operating systems.

Henry

[ankur rathi]

I should have put an example for my question . Anyways here is the program :

public class ThreadTest {

public static void main(String[] args) {

HasRun h  = new HasRun();
Thread t1 = new Thread(h,"A");
Thread t2 = new Thread(h,"B);
t2.setPriority(Thread.MAX_PRIORITY);
t1.setPriority(Thread.MIN_PRIORITY);
t1.start();
t2.start();
}
 
}
 
class HasRun implements Runnable {

public void run() {
for(int i=0; i<=1000; i++) {
System.out.println(Thread.currentThread().getName()+" "+i);
}
}

}

I have executed this code 10 times , I am getting output the same ( first B 1000 times & then A 1000 times ) . Although I know that this is because my JVM is based on priority based algorithem . But the confusion is , in exam it will not be specified about JVM ( definately ) so what should be the answer .

I hope the question is clear .

thanks a lot .

[navneet shrivastava]

---
i would select an answer which says behaviour is not guaranteed
---

adding to it: See we should make it clear SUN is going to conduct the exam to check ur proficiency for their JVM.

hope it makes sense
Thanks,

[Jeroen Wenting]

Originally posted by Henry Wong:


Not true... it is possible to starve a thread via using priority levels, under certain operating systems.

Henry

But it would still run when the higher priority thread is somehow terminated with extreme prejudice