Question

This set of questions is involving multithreading in C++ and are multiple choice, choose the best answer

1) Which action will not recover a process from deadlock?

Terminate threads holding onto resources

Terminate user process and restart

Wait for the resource to be released by other threads

None of the others

2) In a boss-worker thread model, the boss must keep in constant communication with the workers to make sure they are functioning correctly.

True

False

3) Process aging is?

Decreasing the priority of a process each time the process gets to run

Increasing the priority of a process if it sits in the ready state for a long time.

decreasing the priority of a process as it gets older regardless of the queue

Increasing the priority of a resource if it becomes deadlocked

4) A race condition is _____________________

When one thread is trying to beat another to execute a region of code

When a thread cannot make progress because another one is blocking it.

When the outcome of multiple threads is dependent on the order of execution among them

A form of locking where processes coordinate for exclusive access to a critical section.

Answer 1

1) Which action will not recover a process from deadlock?

a) Terminate threads holding onto resources
--> Not correct
--> Because when you terminate threads one by one resources locked will
   be released which results in recovering from deadlock.

b) Terminate user process and restart
--> Not correct
--> Because when you terminate the user process whole resources will be released
   which results in deadlock removal.

c) Wait for the resource to be released by other threads
--> Correct
--> Because deadlock is the situation where a thread is depend on the resources used by other threads and at the same
   time other threads are depend on the resources used by this thread.
   if you do nothing then the threads will always be waiting for one another.

d) None of the others
--> Not correct.

Answer : Wait for the resource to be released by other threads

2) In a boss-worker thread model, the boss must keep in constant communication with the workers to make sure they are functioning correctly.
a) True
b) False
Answer: False
Explanation: In Boss Worker Model boss assigns works to each worker , after assigning the work boss checks if worker is available to do next task.
here boss checks if worker is ready or not to do next task but not is he working correctly.
So answer is False.

3) Process aging is?

a) Decreasing the priority of a process each time the process gets to run

b) Increasing the priority of a process if it sits in the ready state for a long time.

c) decreasing the priority of a process as it gets older regardless of the queue

d) Increasing the priority of a resource if it becomes deadlocked

Answer: Increasing the priority of a process if it sits in the ready state for a long time.
Explanation: Aging is the technique used to solve the Starvation problem in processes.
   Starvation is the situation in Priority Scheduling algorithm in which a Process
   is ready to run in the CPU but have to wait long time(may be infinite) because of
   low priority of that process.
   So your answer is b.

4) A race condition is _____________________

a) When one thread is trying to beat another to execute a region of code

b) When a thread cannot make progress because another one is blocking it.

c) When the outcome of multiple threads is dependent on the order of execution among them

d) A form of locking where processes coordinate for exclusive access to a critical section.

Answer: When the outcome of multiple threads is dependent on the order of execution among them
Explanation : A race condition is a situation where you have a data modifying code which uses by multiple thread
   and that data modified by the earlier threads overwritted by the latest thread that executes it.
   let us consider:
       thread 1 executes that code updates the value to 1
       again thread 2 executes the same code and updates it to 2.
       .... and so on.
   Hence your answer is c).