Classify each of the following statements as TRUE or FALSE with brief justificat
ID: 3885825 • Letter: C
Question
Classify each of the following statements as TRUE or FALSE with brief justification: The OS creates a single process if two users execute the same program. A Process Control Block holds information of currently running all processes. After handling an event, the kernel need not perform scheduling before dispatching if none of the process states has changed. When a user-level thread of a process makes a system call that leads to blocking, all threads of the process becomes blocked. Kernel-level threads provide more concurrency than user-level threads in both uniprocessor and multiprocessor systems. When a process terminates, its threads still continue their tasks.Explanation / Answer
1) The OS creates a single process if two users execute same program :
False .
OS creates separate process for each user if two or more users want to run same program.
2) A process control block holds information of currently running all processes.
False.
Process control block stores information about particular process that is currently running.
For each running process, new process control block is created.
3) After handling an event, the kernel need not perform scheduling before dispatching if none of the process states has changed.
true.
When event occurs, there is some process which is running, at that time, the processor stops execution of currently running process and starts executing routine for handling an event that has occurred.
So after routine has been perform, it will continue with execution of old process as no other process has changed the state.
So no need to perform scheduling.
4) When a user-level thread of a process makes a system call that leads to blocking, all threads of the process becomes blocked.
True
When only one thread is blocked, Kernel is unaware of the situation, as it is user level thread and kernel sees it as a single thread.
So kernel will not execute other thread of same process.
5) Kernel-level thread provides more concurrency than user level threads in both uniprocessor and multiprocessor system.
Kernel level thread provides more concurrency with multiprocessors
but with uniprocessor it has overhead as kernel has to manage process and thread data both.
6) When a process terminates, its thread still continue their tasks.
False.
In user mode, with user-level threads, thread can not exist without process.
So thread dies after process terminates.
if you have any doubts then you can ask in comment section.