QUESTION 2 Assume that there are : • 3 processes P1, P2, & P3 o 3 Resources R1( two instances), R2 (one instance), & R3 (two instances) And the processes make the requests for resources in the following order: o Pl requests R1 o P2 requests R2 o Pl requests R2 o P3 request R3 o P3 Request R2 o P2 request R3 Draw the resource allocation graph and find wybether deadlock evists? Justify vour answer

QUESTION 2 Assume that there are : • 3 processes P1, P2, & P3 o 3 Resources R1( two instances), R2 (one instance), & R3 (two instances) And the processes make the requests for resources in the following order: o Pl requests R1 o P2 requests R2 o Pl requests R2 o P3 request R3 o P3 Request R2 o P2 request R3 Draw the resource allocation graph and find wybether deadlock evists? Justify vour answer

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

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A system has three processes (P1,P2, P3) and three resources (R1,R2, R3). There is one instance of R1 and R2. There are three instances of R3. P1 holds an R1 and is requesting an R3. P2 holds an R3 and is requesting an R1. P3 holds two instances of R3 and an R2. Does a deadlock exist? Justify your answer.
50. Match the following.i) Mutual exclusion a) A process may hold allocated resources while waiting assignment.ii) Hold and wait b) No resource can be forcibly removed from a process holding it.iii) No preemption c) Only one process may use a resource at a time. a. i-a, ii-b, iii-c b. i-a, ii-c, iii-b c. i-b, ii-c, iii-a d. i-c, ii-a, iii-b
a) Consider 4 processes P0, P1, P2 and P3 that need to share 3 resource types A (10 instances), B (6 instances) and C (7 instances). The allocation of resources and the maximum need for 4 processes as mentioned in the table. Process Allocation Max A B C A B CP0 0 1 0 7 5 3P1 2 0 0 3 2 2P2 3 0 2 9 0 2P3 2 1 1 2 2 2 Does the sequence of processes < P1, P3, P2, P0> satisfy the safety criteria?Note: Provide the working for each step.
7. 'm' processes share 'n' resources of the same type. The maximum need of each process doesn't exceed 'n' and the sum all the their maximum needs is always less than m + n. In this set up a. deadlock can never occur b. deadlock may occur c. deadlock has to occur d. none of these
Hey, I have already received a good answer to this question but I am looking for greater detail to be provided. There are three processes P1, P2 and P3 are running in a system with 3 instances of a resource R1, 2 instances of a resource R2, and 2 instances of a resource R3. At a given time the allocation matrix is: A = [{1, 1, 1} { 0, 1, 0} { 1, 0, 0 }] Assume that the maximum matrix is M = [ {2,2,1} {1,1,1} {3,1,0}] While in this state, a new process P4 is created which requires at most 2 instances of R1 and one instance of R2. This process initially requests one instance of R1 to be allocated to it. Using the Banker’s algorithm, determine whether this request can be granted or must be refused.
Suppose a system has 5 processes, P = {P1, P2, P3, P4, P5}, and 4 resources, R = {R1, R2, R3, R4}, where there are 2 instances of R1, 1 instance of R2, 3 instances of R3, and 3 instances of R4. The current state of the system is defined by the following requests and assignments: P1 is requesting an instance of R3 and has been assigned an instance of R2; P2 is requesting an instance of R1 and has been assigned an instance of R3; P3 is requesting an instance of R4 and has been assigned an instance of R1 and an instance of R3; P4 is requesting an instance of R3; P5 is requesting an instance of R2 and has been assigned an instance of R4. Is there deadlock in this system? (Explicitly state yes, there’s deadlock or no, there isn’t.) If applicable, draw a wait-for graph or resource-allocation graph, and use the appropriate graph to justify your answer. If you conclude there is no deadlock, your justification should contain a sequence of execution for the processes which shows that…
Consider 4 processes P0, P1, P2 and P3 that need to share 3 resource types A (10 instances), B(6 instances) and C (7 instances). The allocation of resources and the maximum need for 4processes as mentioned in the table.
A deadlock occurs when a group of processes is stalled because one process is holding a resource and waiting for another process to obtain it. Consider the situation when two trains are approaching each other on the same track and there is only one track: once they are in front of each other, neither train can proceed. In operating systems, a similar scenario happens when two or more processes possess certain resources while waiting on resources owned by other processes (s). In the picture below, Process 1 is holding Resource 1 and waiting for Process 2 to acquire Resource 2, while Process 2 is waiting for Resource 1. Give an example of a realistic deadlock avoidance approach and describe the basic strategy behind it.
Processes P1, P2, and P2 are queued to run. The arrival time of P1 is t = 0, the arrival time of P2 is t = 1, and the arrival time of P3 is t = 2. According to the first come first serve (FCFS) algorithm, processes are run by the operating system. P1 operates 7 time units, P2 4 time units, P3 operates 1 time unit. So what is the average waiting time (in time units) for this system? 0 5 3 7
Suppose processes P1-P4 with the given priorities and resource allocations. 1 is the highest priority and 4 is the lowest priority. Let us also assume that the "no preemption" condition is now relaxed by allowing preemption of resources by processes of higher priority. For example, P3 may preempt P2 or P4 if it needs a resource which they are holding. If P3 preempts one of these processes, say P4, then P4 release all the resources it is holding. Show one sequence of events in which resources are allocated to the 4 processes and the resulting preemptions, if any, until all new requests are serviced. Current allocations are shown below. Each resource has 4 instances. Try to minimize the preemptions as they are expensive. Process ID Process Priority Current allocation New request R1 R2 R1 R2 P1 1 2 1 2 1 P2 3 0 1 1 0 P3 2 1 1 0 1 P4 4 1 1 2 1
In the following resource allocation graph, are the processes deadlocked? If “yes” explain why and state which processes are involved in deadlock. If “not" explain why. I believe there is no deadlock but I need help with explanation.
b.Start from the resource allocation state in Q 13. If a request from a process P3 arrives for (1, 2, 3), can the request be immediately granted ? Why or why not ? c.Start from the resource allocation state in Q 13. Suppose that P4 asks for 2 instances of resource B. Can the system grant this if it wants to avoid deadlock ? Explain.