qstn no 475 operating system NB Venkateswarulu gate csit book by tata mcgrawhill

Question

A process can have

• A. Only One critical Section
• B.Any number of critical Section
• C.Os may put some restrictions on number of critical sections
• D.None of the above

Answer 1

I think the answer will be (B).

because Critical section of a process accesses shared variables in a group of cooperating processes, at a given point of time....

Answer 2

critical section can be anything...file,resource,code anything which is shared by two processes....so any number of critical sections are possible....option B

Comments

Yes, you are correct. But then OS needs to guarantee deadlock avoidance rt? What it normally does?

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mutual exclusion sir...if one process is inside it should not allow other to enter

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but sir it is the responsibilty of OS to see about mutual exclusion.....a process can have many critical sections but whether it can access it or not should be by OS managing deadlock

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yes, it can have many. But can this many go on without a limit as like a node in a linkedlist?

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sir i think it should depend on the memory available...more memory we have more resources can be shared

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Memory is ofcourse a limit. But question is does OS put a limit?

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sir i think if  os can see through waits for graph that there is any chance of deadlock or so then it can take actions like suspending the resource or process....but beforehand there shouldn't be any restriction by os i guess

Answer 3

Critical section is a piece of a program that requires mutual exclusion of access  so a critical section at a time can allow only one process at a time and For uniprocessor system the inverse should also be true. so I think 

A process can have Only One critical Section . and ans should be (A)

Answer 4

as we knw if one process enter into it's cs no other process can enter it's cs to satisfy ME,so for sycronization a single process can have only one CS.

http://www.personal.kent.edu/~rmuhamma/OpSystems/Myos/criticalSec.htm