Description
(5 marks) Question 1. Briefly outline the evolution of Operating Systems from those used by the
earliest stored program computers of the 1940s to their modern counterparts.
(5 marks) Question 2. In the following piece of C code, how many processes are created when it is
executed? Explain your answer.
int main() {
fork();
fork();
fork();
exit(1);
}
(5 marks) Question 3. If an Operating System assigns an unsigned 32bit integer to store current
time as the number of seconds elapsed since 00:00 on January 1 1970, is this likely to be a
problem? Explain your answer.
(5 marks) Question 4. Describe how a web server might leverage multi-threading to improve
performance. Include diagrams if you feel this will make your answer clearer.
(5 marks) Question 5. (a) In a multiprogrammed environment with 16MB of memory where all
processes require 1MB of unshared memory and spend 60% of their time in I/O wait, calculate how
much memory will remain unused when approximately 99% CPU utilization is achieved. (b) In the
same multiprogrammed environment, if each process now requires 3MB of unshared memory,
calculate the maximum achievable CPU utilization. Show all your work.
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