Thread scheduling question(Marcus Green's NO2)

[Bin Zhao]

Again I encountered this problem.
Again I got it wrong.
Question 22)
What can cause a thread to stop executing?
1) The program exits via a call to System.exit(0);
2) Another thread is given a higher priority
3) A call to the thread's stop method.
4) A call to the halt method of the Thread class
I always think 2) is incorrect but everytime I am wrong.
I think in time-slicing system,even when a thread with higher priority gets runnable,the thread scheduler won't let it to run until the original running thread finishes its time-slice.
Please help me with this.I am appearing the test in 3 days.
If I encounter this question again in real test,should I choose it or not?

[saumil shukla]

Bin,
low or normal priority threads are nothing but us driving on the street. If emergency vehical wants to travel on the same street at the same time then we have to yield.
Hope this will help.

[Rob Acraman]

I think the question has to be concerned with what is GUARANTEED behaviour by the JVM. How threads with differing priorities behave is left upto the OS. An applet with threads of differing priorities run (for example) on a Netscape browser and on MSIE will behave differently - and (I hope) you won't get a question whose answer is so platform-dependent.

[Bob Moranski]

I think even threads with higher priorities will not be guaranteed to run. Sometimes, JVM will choose threads of lower priorities over higher priorities to avoid starvation. I hope the exam will not ask a badly made question like this.

[Jane Griscti]

Hi Bin,
The question is "What can cause a thread to stop executing?". Java is implemented on systems that use either pre-emptive scheduling, time-slicing or a combination of both. On some systems a higher-priority thread can preempt a running thread with lower priority.
From other comments I've seen by people taking the real exam you need to watch out for questions wording. In this can cause implies you must take all possible situations into account.
Hope that helps. Best of luck on the exam.
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Jane
The cure for boredom is curiosity.
There is no cure for curiosity.
-- Dorothy Parker