Bissoy.com
Doctors Medicines MCQs Q&A

  1. r1(x); r2(x); w1(x); r3(x); w2(x)
  2. r2(x); r1(x); w2(x); r3(x); w1(x)
  3. r3(x); r2(x); r1(x); w2(x); w1(x)
  4. r2(x); w2(x); r3(x); r1(x); w1(x)
4 views

1 Answers

Option 4 : r2(x); w2(x); r3(x); r1(x); w1(x)

Concept:

A schedule is called conflict serializable if it can be transformed into a serial schedule by swapping non-conflicting operations.

For a schedule to be conflict serializable, there should be no cycle present in its precedence graph.

Explanation: 

Option_1 – Not conflict serializable

T1

T2

T3

r(x)

 

 

 

r(x)

 

w(x)

 

 

 

 

r(x)

 

w(x)

 

 

[ alt="F2 R.S 15.7.20 Pallavi D1" src="//storage.googleapis.com/tb-img/production/20/07/F2_R.S_15.7.20_Pallavi_D1.png" style="width: 147px; height: 127px;">

  • Cycle between T1 and T2.
  • Cycle between T1->T3->T2


Option_2 – Not conflict serializable

T1

T2

T3

 

r(x)

 

r(x)

 

 

 

w(x)

 

 

 

r(x)

w(x)

 

 

 

[ alt="F2 R.S 15.7.20 Pallavi D2" src="//storage.googleapis.com/tb-img/production/20/07/F2_R.S_15.7.20_Pallavi_D2.png" style="width: 146px; height: 127px;">

  • Cycle between T1 and T2.
  • Cycle between T1->T2->T3

 

Option-3 - Not conflict serializable

T1

T2

T3

 

 

r(x)

 

r(x)

 

r(x)

 

 

 

w(x)

 

w(x)

 

 

 

[ alt="F2 R.S 15.7.20 Pallavi D3" src="//storage.googleapis.com/tb-img/production/20/07/F2_R.S_15.7.20_Pallavi_D3.png" style="width: 148px; height: 119px;">

  • Cycle between T1 and T2.

 

Option-4 - Conflict serializable

T1

T2

T3

 

r(x)

 

 

w(x)

 

 

 

r(x)

r(x)

 

 

w(x)

 

 

 

[ alt="F2 R.S 15.7.20 Pallavi D4" src="//storage.googleapis.com/tb-img/production/20/07/F2_R.S_15.7.20_Pallavi_D4.png" style="width: 142px; height: 118px;">

  • No cycle


Hence, Option_4 is a conflict serializable schedule

4 views

Related Questions

Consider the following solution to the producer-consumer synchronization problem. The shared buffer size is . Three semaphores empty, full and mutex are defined with respective initial values of 0, and 1. Semaphore empty denotes the number of available slots in the buffer, for the consumer to read from. Semaphore denotes the number of available slots in the buffer, for the producer to write to. The placeholder variables, denoted by P, Q, R, and S, in the code below can be assigned either empty or full. The valid semaphore operations are: wait ( ) and signal ( ). Producer: Consumer: do {         wait (P) ;         wait (mutex) ;         //Add item to buffer         signal (mutex) ;         signal (Q) ; } while (1) ; do {          wait (R) ;          wait (mutex) ;          //Consume item from buffer          signal (mutex) ;          signal (S) ; } while (1) ;   Which one of the following assignments to P, Q, R and S will yield the correct solution?
1 Answers 6 Views
In the following question the 1st and the last part of the sentence/passage are numbered 1 and 6. The rest of the sentence/ passage is split into four parts and named P, Q, R and S. These four parts are not given in their proper order. Read the sentence/passage and find out which of the four combinations is correct.. 1. Industrially raised chicken can be abnormally forceful, and are regularly kept in obscured sheds to avoid them pecking at each other. P. The feathered creatures invested much a greater amount of their energy—up to a third—pecking at the lifeless things in the pens, as opposed to fowls in different pens which invested a considerable measure of time assaulting others. Q. In low light conditions, they carry on less pugnaciously, yet are more inclined to ophthalmic scatters and respiratory issues. R. In an examination, forceful head-pecking was everything except killed among fowls in the improved condition. S. Modifying the birds’ condition, by adding parcels of wood-shavings to their pens, can work wonders. 6. Bundles could lessen forcefulness and decrease wounds; they may even enhance efficiency, since a glad chicken is a profitable chicken.?
1 Answers 4 Views
In the following question, the 1st and the last part of the sentence/passage are numbered 1 and 6. The rest of the sentence/ passage is split into four parts and named P, Q, R and S. These four parts are not given in their proper order. Read the sentence/ passage and find out which of the four combinations is correct. 1. More than half of the world’s population lives in urban areas. P. Due to the ongoing urbanisation and growth of the world’s population, there will be about 2.5 billion more people added to the urban population by 2050. Q. The world’s urban areas are highly varied, but many cities and towns are facing problems such as a lack of jobs, R. homelessness and expanding squatter settlements, inadequate services and infrastructure, poor health and educational services and high levels of pollution. S. This will mainly happen in Africa and Asia. 6. The situation is expected to get worse.?
1 Answers 4 Views