process synchronization

Question

DOES STRICT ALTERNATION APPROACH SATISFY BOUNDED WAITING CONDITION??

INT TURN;(RANDOMLY ASSIGNED)

---P1----     

WHILE(TURN !=0);

CRITICAL SECTION...

TURN=1;

---P2---

WHILE(TURN!=1);

CRITICAL SECTION

TURN=0;

PS: Though this methods has strict alternation but if the process which has its turn to enter CS, doesnt want to enter the critical section , it will never ever give a chance to another process to enter CS, hence progress violated. But what about bounded wait condition ?? It also fails right??

Comments

Progress and Bounded Waiting are independent of each other.

 

Answer 1

Bound and waiting is independent of progress. Strict alteration definitely satisfy the bound and waiting and even the bound and waiting will be 1.

Comments

i understand ur point but what if a process is made to wait forever because the other process never enters a CS?

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That's progress. Bound and waiting does not say anything about progress it only say the number of process which can go before it get a chance, In this case it is 1. means at most 1 process can go to cs before I get the turn.  0 IS surely les than 1

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OOhhhhhhhhhhh now i got it. Really thanx a lot.

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can u please tell me the same thing for the snchronozation mechanism in which we take two flags flag[0] and flag[1] for two processes?? we know that deadlock can happen in this scenario if both processes set their flags to true? now will this violate bounded wait or not??

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For all your needs
http://www.csl.mtu.edu/cs3331.ck/common/05-Sync-Basics.pdf

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thanx.

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what is the relation of strict alteration and progress, bounded wait ?

Answer 2

I THINK  STRICT ALTERNATION APPROACH DOES NOT SATISFY BOUNDED WAITING CONDITION

Answer 3

If process 1 gets the turn and enters into critical section and after completion if it's preempted then when P2 tries to enter then it can't right .so from this point  P2 don't know how much time to wait .so ,i think we can conclude that strict alteration  enters into UNBOUNDED WAITING