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
Your task is to replace the round robin CPU scheduling scheme you developed in Practical 6 with a priority-based scheduling algorithm. To simplify matters, you can maintain the ori

whta is an operating system ? what sorts services are provided by an operating system ?

Q. What are the major differences between capability lists and access lists? Answer: An access list is a list for each object consisting of the domains with a nonempty set of

Q. Why is it significant to balance file system I/O among the disks as well as controllers on a system in a multitasking environment? Answer: A system can perform mere

Problem: a) Define the term ‘process' and what are the different constituents of a process. b) In the three-state process model, what does each of the three states signify?

Explain the general structure of a typical process? There are basically four main sections through which each of the process has to pass through.The universal algorithm is:-

Q. Some untimely computers protected the operating system by placing it in a memory partition that couldn't be modified by either the user job or the operating system itself. Expl

Define the features are needed to implement top down parsing                      Source string marker, Prediction making mechanism and Matching and Backtracking mechanism

Problem: Within a corporate environment, there are usually many servers located across various departments. Naming of servers is often a tedious task. In many circumstances, w

Difference between threads and processes 1. Thread is flow of implementation. Process is group of instruction which is alike to that of a program except which may be stopped an