made easy 2019

Question

PLS TELL ME HOW IT IS  RUNNING?? 

WHAT I KNOW IS DEKKER'S ALGO SATISFIES ALL THE 3 PROPERTIES OF CRITICAL SECTION!!

BUT HERE ANSWER IS GIVEN ONLY S1 AND S3!!

 

Comments

u are right @Shaik Masthan;

i should nt go on name!!

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 @Shaik Masthan

@Shaijal Tripathi

pls chk this

I am convinced that ME is ensured

but pls chk my reason for progress and starvation;

PROGRESS REQUIREMENT:-

i think it is not satisfied, because if p1 comes first, and after that p2 comes, then it wont be able to go to CS unless p1 comes again , so the sequence is like p1,p1,p2 or p2,p2,p1; 

means it is not a kind of ping pong situation such as p1-p2-p1-p2;

thats why progress requirement is not satisfied!!

STARVATION  :-

i guess there is no starvation because if bith p1,p2 came then one process cant go again and again;

in the options MADE EASY has marked S1 AND S3 but in the explanation they say starvation may occur;however i didnt find any case where it can occur!!

pls chk my understanding!!

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Progress is said to be not satisfied when even one case is there where when CS is empty and a process wants to go inside, it is not allowed to. Here, progress is clearly not satisfied.

Starvation occurs when we do not know the definite amount of time a process has to wait. Or we can say, definite number of processes that will go inside the CS before the concerned process gets a chance to get inside. In this case, we know that no matter how much time a process has to wait, it will definitely get a chance to execute once the other comes out. Hence, no starvation.