Question 1:
A process is a program under execution and as it executes, it changes state. The state of a process is defined in part by the current activity of that process.
a) Explain the five states in which a process can be, including an explanation of the various transitions between the different states.
b) Each process is represented in the operating system by a Process Control Block (PCB). Describe five piece of information which can be found the Process Control Block.
c) In terms of process management, the kernel has to take care of Context Switching.
i. Describe the term context switch.
ii. Describe how context switching takes place. (use a diagram, with two processes)
iii. Why is context-switch time considered as overhead?
Question 2:
In a deadlock, processes never finish executing and system resources are tied up, preventing other jobs from starting. Deadlocks will be characterised by a set of conditions.
a) Explain the four necessary conditions that must hold simultaneously in a system for a deadlock situation to arise.
b) One way of handling deadlock situations is by using a deadlock-avoidance algorithm: Consider that a system always require additional information about how resources are being requested for each process before making a decision on whether to grant the request or not to grant the request. One possible reason for not granting the request is because it can put the system in an unsafe state.
What is the difference between a safe state and an unsafe state in a deadlock-avoidance system?