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Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 44 (Page No. 470)
In certain countries, when two people meet they bow to each other. The protocol is that one of them bows first and stays down until the other one bows. If they bow at the same time, they will both stay bowed forever. Write a program that does not deadlock.

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 43 (Page No. 470)
Write a program that detects if there is a deadlock in the system by using a resource allocation graph. Your program should read from a file the following inputs: the number of processes and the number of resources. ... system. In case there is, the program should print out the identities of all processes that are deadlocked.

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 42 (Page No. 470)
Write a program to implement the deadlock detection algorithm with multiple resources of each type. Your program should read from a file the following inputs: the number of processes, the number of resource types, the ... . In case there is, the program should print out the identities of all processes that are deadlocked.

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 41 (Page No. 470)
Program a simulation of the banker’s algorithm. Your program should cycle through each of the bank clients asking for a request and evaluating whether it is safe or unsafe. Output a log of requests and decisions to a file.

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 40 (Page No. 469)
Repeat the previous problem, but now avoid starvation. When a baboon that wants to cross to the east arrives at the rope and finds baboons crossing to the west, he waits until the rope is empty, but no more westward-moving baboons are allowed to start until at least one baboon has crossed the other way.

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 39 (Page No. 469)
A student majoring in anthropology and minoring in computer science has embarked on a research project to see if African baboons can be taught about deadlocks. He locates a deep canyon and fastens a rope across ... . Do not worry about a series of eastward-moving baboons holding up the westward-moving baboons indefinitely.

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 38 (Page No. 469)
Cinderella and the Prince are getting divorced. To divide their property, they have agreed on the following algorithm. Every morning, each one may send a letter to the other's lawyer requesting one item of ... vacation, the computers are still negotiating. Why? Is deadlock possible? Is starvation possible? Discuss your answer.

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 37 (Page No. 469)
A program contains an error in the order of cooperation and competition mechanisms, resulting in a consumer process locking a mutex (mutual exclusion semaphore) before it blocks on an empty buffer. The producer process ... the producer. Is this a resource deadlock or a communication deadlock? Suggest methods for its control.

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 36 (Page No. 468 - 469)
Local Area Networks utilize a media access method called CSMA/CD, in which stations sharing a bus can sense the medium and detect transmissions as well as collisions. In the Ethernet protocol, stations requesting the ... or a livelock? Can you suggest a solution to this anomaly? Can starvation occur with this scenario?

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 35 (Page No. 468)
Assume two processes are issuing a seek command to reposition the mechanism to access the disk and enable a read command. Each process is interrupted before executing its read, and discovers that the other has moved the ... . Is this a resource deadlock or a livelock? What methods would you recommend to handle the anomaly?

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 34 (Page No. 468)
Explain the differences between deadlock, livelock, and starvation.

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 33 (Page No. 468)
Main memory units are preempted in swapping and virtual memory systems. The processor is preempted in time-sharing environments. Do you think that these preemption methods were developed to handle resource deadlock or for other purposes? How high is their overhead?

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 32 (Page No. 468)
A computer science student assigned to work on deadlocks thinks of the following brilliant way to eliminate deadlocks. When a process requests a resource, it specifies a time limit. If the process blocks because the resource ... allowed to run again. If you were the professor, what grade would you give this proposal and why?

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 31 (Page No. 468)
One way to prevent deadlocks is to eliminate the hold-and-wait condition. In the text it was proposed that before asking for a new resource, a process must first release whatever resources it already holds ( ... new resource but lose some of the existing ones to competing processes. Propose an improvement to this scheme.

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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15

Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 30 (Page No. 468)
In an electronic funds transfer system, there are hundreds of identical processes that work as follows. Each process reads an input line specifying an amount of money, the account to be credited, and the account to be ... , solutions that lock one account and then release it immediately if the other is locked are not allowed.)

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 29 (Page No. 468)
A distributed system using mailboxes has two $IPC$ primitives, send and receive. The latter primitive specifies a process to receive from and blocks if no message from that process is available, even though ... no shared resources, but processes need to communicate frequently about other matters. Is deadlock possible? Discuss.

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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17

Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 28 (Page No. 468)
Two processes, $A$ and $B,$ each need three records, $1, 2,$ and $3,$ in a database. If $A$ asks for them in the order $1, 2, 3,$ and $B$ asks for them in the same order, deadlock ... or six possible combinations in which each process can request them. What fraction of all the combinations is guaranteed to be deadlock free?

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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18

Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 27 (Page No. 467)
One way to eliminate circular wait is to have rule saying that a process is entitled only to a single resource at any moment. Give an example to show that this restriction is unacceptable in many cases.

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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19

Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 26 (Page No. 467)
A system has four processes and five allocatable resources. The current allocation and maximum needs are as follows: What is the smallest value of x for which this is a safe state?

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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20

Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 25 (Page No. 467)
The banker’s algorithm is being run in a system with $m$ resource classes and $n$ processes. In the limit of large $m$ and $n,$ the number of operations that must be performed to check a state for safety is proportional to $m^{a} n^{b}.$ What are the values of $a$ and $b?$

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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21

Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 24 (Page No. 467)
Suppose that process $A$ in Fig. 6-12 requests the last tape drive. Does this action lead to a deadlock?

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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22

Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 23 (Page No. 467)
Consider the previous problem again, but now with $p$ processes each needing a maximum of $m$ resources and a total of $r$ resources available. What condition must hold to make the system deadlock free?

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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23

Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 22 (Page No. 467)
A system has two processes and three identical resources. Each process needs a maximum of two resources. Is deadlock possible? Explain your answer.

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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24

Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 21 (Page No. 467)
Take a careful look at Fig. 6-11(b). If $D$ asks for one more unit, does this lead to a safe state or an unsafe one? What if the request came from $C$ instead of $D?$

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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25

Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 20 (Page No. 467)
Can a system be in a state that is neither deadlocked nor safe? If so, give an example. If not, prove that all states are either deadlocked or safe.

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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26

Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 19 (Page No. 467)
In theory, resource trajectory graphs could be used to avoid deadlocks. By clever scheduling, the operating system could avoid unsafe regions. Is there a practical way of actually doing this?

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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27

Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 18 (Page No. 467)
Can the resource trajectory scheme of Fig. 6-8 also be used to illustrate the problem of deadlocks with three processes and three resources? If so, how can this be done? If not, why not?

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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28

Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 17 (Page No. 467)
All the trajectories in Fig. 6-8 are horizontal or vertical. Can you envision any circumstances in which diagonal trajectories are also possible?

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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29

Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 16 (Page No. 467)
Suppose that in Fig. 6-6 $C_{ij} + R_{ij} > E_{j}$ for some i. What implications does this have for the system?

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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30

Andrew S. Tanenbaum (OS) Edition 4 Exercise 6 Question 15 (Page No. 467)
Explain how the system can recover from the deadlock in previous problem using recovery through preemption. recovery through rollback. recovery through killing processes.

Lakshman Patel RJIT asked in Operating System Oct 30, 2019

by Lakshman Patel RJIT

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Recent questions tagged tanenbaum