Can indefinite blocking take place, Operating System

Consider the subsequent resource-allocation policy. Requests as well as releases for resources are allowed at any time. If a request for resources can't be satisfied because the resources aren't available then we check any processes that are blocked waiting for resources. If they have the desired resources after that these resources are taken away from them and are given to the requesting process. The vector of the resources for which the process is waiting is increased to include the resources that were taken away. For instance consider a system with three resource types and the vector Available initialized to (4,2,2). If process P0 asks for (2, 2, 1) it gets them. If P1 asks for (1,0,1) it gets them. After that if P0 asks for (0, 0, 1), it is blocked (resource not available). If P2 now asks for (2, 0, 0) it gets the available one (1,0,0) in addition to one that was allocated to P0 (since P0 is blocked). P0's Allocation vector goes down to (1, 2, 1) and its Need vector goes up to (1, 0, 1).

a. Can deadlock take place? If you answer "yes" give an instance and If you answer "no," specify which necessary condition cannot occur.

b. Can indefinite blocking take place? Describe your answer.

Answer:

a. Deadlock cannot take place because pre-emption exists.

b. Yes A process may never obtain all the resources it needs if they are continuously pre-empted by a series of requests such as those of process C.

Posted Date: 7/27/2013 5:04:08 AM | Location : United States







Related Discussions:- Can indefinite blocking take place, Assignment Help, Ask Question on Can indefinite blocking take place, Get Answer, Expert's Help, Can indefinite blocking take place Discussions

Write discussion on Can indefinite blocking take place
Your posts are moderated
Related Questions
Consider a setting where processors are not associated with unique identifiers but the total number of processors is known and the processors are organized along a bidirectional ri

Differentiate between sequential access and direct access method?

What is the main function of the memory-management unit? The runtime mapping from virtual to physical addresses is done by a hardware device known as a memory management unit (

What are the three main activities of an operating system in regard to memory management? Keep track of which parts of memory are now being used and by whom. Decide which pr

The term thread-safe in computer programming describes that routine or portion of the program that may be called from multiple programming threads without uncalled for interactions

Q. Define the difference among pre-emptive and non pre-emptive scheduling. Answer: Pre-emptive scheduling permits a process to be interrupted in the midst of its execution ta

What is the information associated with an open file? Various pieces of information are associated with  an open file which may be: File pointer Disk location of th

1. Problem Domain You will be considering the Wumpus world introduced in Russell and Norvig (2009) Chapter 7. For this programming assignment you'll use Prolog's ability to do in

Give a brief introduction about the operation of your program and show that you understand the idea behind threads and mutual exclusion variable. Why do we need to use mutual exclu

explain how response time are reduced by allowing time sharing on top of multiprogramming