###### Programming-for-Output-Problems

October 6, 2023###### Computer-Organization

October 6, 2023# Operating-Systems

Question 9 |

Consider the following snapshot of a system running n concurrent processes. Process i is holding X_{i} instances of a resource R, 1 ≤ i ≤ n. Assume that all instances of R are currently in use. Further, for all i, process i can place a request for at most Y_{i} additional instances of R while holding the X_{i} instances it already has. Of the n processes, there are exactly two processes p and q such that Y_{p} = Y_{q} = 0. Which one of the following conditions guarantees that no other process apart from p and q can complete execution?

Min (X _{p}, X_{q}) ≥ Min {Y_{k} | 1 ≤ k ≤ n, k ≠ p, k ≠ q} | |

X _{p} + X_{q} < Max {Y_{k} | 1 ≤ k ≤ n, k ≠ p, k ≠ q} | |

Min (X _{p}, X_{q}) ≤ Max {Y_{k} | 1 ≤ k ≤ n, k ≠ p, k ≠ q} | |

X _{p} + X_{q} < Min {Y_{k} | 1 ≤ k ≤ n, k ≠ p, k ≠ q} |

Question 9 Explanation:

{P

P

P

Given two process p & q such that their additional requests are zero.

Y

{Y

For p & q to complete first, accordingly

X

Option D is correct.

There are exactly two process p and q which do not need any additional instances of resources.

So, p and q will complete their execution and will release X

Now to guarantee that no other process apart from p and q can complete execution, the no. of instances of resources available must be less than the minimum no. of instances of resources required by any other process, i.e.,

X

_{1}, P_{2}, …, P_{n}}P

_{i}holds X_{i}instances.P

_{i}can request additional Y_{i}instances.Given two process p & q such that their additional requests are zero.

Y

_{p}= Y_{q}= 0{Y

_{k}| 1 ≤ k ≤ n, k ≠ p, k ≠ q} means that out of ‘n’ processes, we are left with (n-2) process (except p&q), i.e., Y_{k}indicates additional request of all the processes (n-2) except p & q.For p & q to complete first, accordingly

X

_{p}+ X_{q}< Min {Y_{k}}Option D is correct.

There are exactly two process p and q which do not need any additional instances of resources.

So, p and q will complete their execution and will release X

_{p}and X_{q}instances of resources.Now to guarantee that no other process apart from p and q can complete execution, the no. of instances of resources available must be less than the minimum no. of instances of resources required by any other process, i.e.,

X

_{p}+ X_{q}< Min {Y_{k}| 1 ≤ k ≤ n, k ≠ p, k ≠ q}.Correct Answer: D

Question 9 Explanation:

{P

P

P

Given two process p & q such that their additional requests are zero.

Y

{Y

For p & q to complete first, accordingly

X

Option D is correct.

There are exactly two process p and q which do not need any additional instances of resources.

So, p and q will complete their execution and will release X

Now to guarantee that no other process apart from p and q can complete execution, the no. of instances of resources available must be less than the minimum no. of instances of resources required by any other process, i.e.,

X

_{1}, P_{2}, …, P_{n}}P

_{i}holds X_{i}instances.P

_{i}can request additional Y_{i}instances.Given two process p & q such that their additional requests are zero.

Y

_{p}= Y_{q}= 0{Y

_{k}| 1 ≤ k ≤ n, k ≠ p, k ≠ q} means that out of ‘n’ processes, we are left with (n-2) process (except p&q), i.e., Y_{k}indicates additional request of all the processes (n-2) except p & q.For p & q to complete first, accordingly

X

_{p}+ X_{q}< Min {Y_{k}}Option D is correct.

There are exactly two process p and q which do not need any additional instances of resources.

So, p and q will complete their execution and will release X

_{p}and X_{q}instances of resources.Now to guarantee that no other process apart from p and q can complete execution, the no. of instances of resources available must be less than the minimum no. of instances of resources required by any other process, i.e.,

X

_{p}+ X_{q}< Min {Y_{k}| 1 ≤ k ≤ n, k ≠ p, k ≠ q}. Subscribe

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