Processes Pt.2 - Lec.7

Question 1

Context Switching

Answer 1

Context switching is the CPU switching from one process to another, involves storing and restoring the CPU’s state(context).

Question 2

Context Switching Triggers MIK

Answer 2

Multitasking(switching between processes/threads), Interrupts( e.g. handling external events), Kernel/User Mode transitions( e.g. accessing system resources).

Question 3

Hardware vs Software context switching

Answer 3

Some CPUS like Intelx86 support hardware switching, but modern OSes often use software-based switching for portability and performance.

Question 4

Process Creation[PID, Tree Structures, Resource Sharing, Execution] PTRE

Answer 4

PID- processes are dynamically created and identified by a process id(pid), Tree Structures- processes form a tree structure with parent processes creating child processes, Resource Sharing- Can be shared fully, partially or not at all between parent and child, Execution- Parent and child can run concurrently or the parent can wait until the child has finished.

Question 5

Process Address Space

Answer 5

Child processes may- 1. Duplicate the parent process(same program/data), or 2. Load a new program(using exec() after fork()).

Question 6

POSIX Process Creation Commands( fork(), exec(), exit() and wait() )

Answer 6

fork() creates a new process(child), exec() replaces the process memory with a new program, exit() terminates a process, wait() allows parent process to wait for child termination.

Question 7

Process termination( zombie and orphan processes)

Answer 7

Processes terminate with exit(), releasing resources. Zombie process is a terminated process whose parent hasn’t called wait(). Orphan process is a process whose parent terminates without waiting, reparented to init in Linux.