CS CS Operating Systems & Memory Management

Question 1

What is a deadlock in operating systems?

Accepted Answer

A situation where two or more processes wait indefinitely for resources held by each other

Answer

Deadlock occurs when a set of processes are each waiting for a resource held by another process in the set, so none can proceed.

Question 2

Which page replacement algorithm replaces the page that will not be used for the longest time in the future?

Accepted Answer

OPT (Optimal)

Answer

The Optimal (OPT) algorithm is theoretically perfect but impractical because it requires future knowledge of which pages will be accessed next.

Question 3

What is the difference between a process and a thread?

Accepted Answer

A process is an independent execution unit with its own memory space, while threads share memory within a process

Answer

A process has its own isolated memory space, while threads within the same process share the same heap and data segments, making inter-thread communication faster but requiring synchronization.

Question 4

What does a context switch entail in an operating system?

Accepted Answer

Saving the state of a running process and restoring the state of another so the CPU can switch tasks

Answer

A context switch saves the CPU registers and process state of the current process to its PCB and loads the saved state of the next scheduled process.

Question 5

In virtual memory, what is a 'page fault'?

Accepted Answer

An interrupt triggered when a process accesses a page not currently loaded in physical memory

Answer

A page fault occurs when a process references a virtual memory page that is not currently mapped to a physical frame, causing the OS to load it from disk.

(CS) Computer Science Practice Test

(CS) Computer Science Practice Test

CS CS Operating Systems & Memory Management