Chapter 12

Question 1

What kill -l do

Answer 1

It displays the signals supported by system and their numbers

Question 2

Why we create threads

Answer 2

Process is expensive. Multiple threads can run simultaneously. A thread can be independent unit in CPU.

Question 3

Does each thread has its own thread Id, stack, CPU context, priority and errno

Answer 3

Yes

Question 4

What are 2 levels of threads

Answer 4

1. User level thread

2. Kernel level thread

Question 5

What are similarities between threads and processes

Answer 5

• States are same (new, terminated, blocked, run, ready, blocked)
• A thread can create another thread

Question 6

What are differences between threads and processes

Answer 6

• Multiple threads can operate within same address space
• No automatic protection mechanism is in place for threads. OS does not provide such support that one time there should be only one writing mechanism in thread. We do it by code.

Question 7

What is example of multi threaded server

Answer 7

Web browser

Question 8

What are advantages of threads

Answer 8

• Multi threading
• Resource sharing
• Economy
• Performance