Homework 3
cs550 Operating Systems
5 points
Due Monday, Oct. 20, 2014 at midnight
1. (3 points) Draw a resource allocation graph for
the following situations and determine if deadlock exists or
not. Justify your answer using the principles of
deadlock. You may assume that processes will not relinquish
their hold on resources until they receive all the resources they
have requested. You may also assume that processes will not
be interrupted to release their resources and that multiple
processes may not utilize the same resource at the same time.
a)
The dining philosophers problem using three philosophers and three
chopsticks.
b) There are 4 processes, W, X, Y, and Z.
There are 3 resources
of type I.
There are 2 resources of type II.
There is one resource of type III.
There are 2 resources of type IV.
Process X owns one resource of type II and requests one resource
of type I.
Process Y owns one resource each of type I and III and requests
one of type IV.
Process Z owns one resource each of type II and IV and requests
one of type III.
There are 2 resources
of type CPU.
There are 3 resources of type I/O.
There are 4 resources of type Memory.
There are 2 resources of type Network.
2. (2 points) Using the banker's algorithm, determine
if a safe state can be achieved. Assume
each process can complete its work once it receives its maximum
claim.
a) (0.5 points) There are four resource types
with the total number of system resources expressed as the tuple
(2, 3, 2, 1). There
are three processes with current allocations of (0, 1, 0, 1),
(1, 1, 0, 0), and (0, 0, 1, 0).
The maximum claim of each process is (2, 1, 0, 1), (1, 3,
0, 0), and (1, 3, 2, 1).
b) (0.5 points)There are three resource types
with the total number of system resources expressed as the tuple
(3, 2, 2). There
are three processes with current allocations of (0, 0, 0), (1,
1, 1), and (2, 0, 1). The
maximum claim of each process is (2, 0, 1), (3, 2, 1), and (3,
0, 2).
c) (1 point) There are four resource types
with the total number of system resources expressed as the tuple
(5, 4, 7, 2). There
are four processes with current allocations of (1, 2, 0, 1), (1,
1, 4, 0), (1, 1, 0, 1), and (0, 0, 2, 0). The maximum claim of
each process is (2, 2, 2, 2), (2, 3, 4, 1), (1, 3, 0, 1), and
(1, 3, 2, 1).