Question

Simple java question

Consider the following statements related to AtomicInteger's compareAndSet(int expect, int update) method: LcompareAndSet sets the AtomicInteger's value to the given updated value, if its current value equals the expected value II. compareAndSet is a blocking call II. it is safe to call compareAndSet concurrently (from more than one thread) Which of the above statements are true? Select one a. All of I, I, and III b.Only I and III C. Only I and || d. None or only one of I, I, or III X e. Only l and II Which of the following is not a condition that will temporarily suspend a thread's execution: Select one: a. The thread's time allotment has expired. b. The thread calls Thread.sleep(period) c. The thread callsThread.yield() d. A higher priority thread becomes available e. The thread enters a busy-waiting loop.

Answer 1

The answer for first question is b)Only I and III

compareAndSet method expects two parameters to be passes which are expected value and value to be expected. If the atomic integer value is equal to expected value, then it update the value of atomic integer with the value passed to be updated. compareAndSet method is a non-blocking call and can be run concurrently from different threads(more than one thread).

The answer for second question is a)the thread's time allotment has expired.

• when Thread.sleep(period) is called, the thread will be put to sleep for a "period" of time.
• when Thread.yield() is called, the thread gives a hint to the thread scheduler that it is ready to pause its execution. Then thread scheduler will check whether any higher priority thread is available.
• When a higher priority thread becomes available, the thread will give way for higher priority thread to be executed.
• When thread enters a busy waiting loop such as getting input from user, the thread will temporarily suspend its execution and keeps waiting for future action.