OPERATING SYSTEM EXAM

Collection of software (e.g., Windows, Linux, macOS, Android) needed for a computer or phone to function

Operating System

Refers to the queuing system where the first one in line is served first (queueing system)

FIFO

FUNCTIONS OF OS————————-

Creates, schedules, pauses, and terminates processes for smooth multitasking and fair CPU use

Process Management

FUNCTIONS OF OS————————-

Tracks RAM, decides which data/programs go where, and allocates/deallocates space as tasks start and finish

Memory Management

MEMORY MANAGEMENT———————

Refers to primary memory that needs the PC on and is cleared when the PC turns off

Random Access Memory (RAM)

MEMORY MANAGEMENT———————

Refers to permanent, built-in storage that works even when the PC is off

Read-Only Memory (ROM)

MEMORY MANAGEMENT———————

Software that lets OS communicate with outside devices

Drivers

FUNCTIONS OF OS————————-

Organizes files and directories on storage; handles creation, deletion, reading, writing, and access controls

File Management

FUNCTIONS OF OS————————-

OS function that communicates with hardware peripherals through device drivers to handle input and output

Device Management

USB, mouse, keyboard, scanners, microphones, webcams, biometric devices

Input Devices

Speakers, monitors, projectors, printer (printer can be both input and output)

Output Devices

FUNCTIONS OF OS————————-

Manages user accounts, passwords, and permissions to protect system data from unauthorized access

Security and Access Control

Uses predefined roles to restrict system access

Role-Based Access Control

FUNCTIONS OF OS————————-

Manages the computer's connection to the outside world; packages data and sends it over Wi-Fi or cables

Networking

FUNCTIONS OF OS————————-

Measures how fast, efficiently, and reliably the kernel and system software manage CPU, memory, storage, and I/O; viewable in the taskbar/Task Manager

System Performance

Converting one thing to another (e.g., into another data type)

Parse

File type that is the actual program

Exe

COMPONENTS OF OS———-———

Central core of the OS that resides in memory and manages system resources; main bridge between hardware and software

Kernel

COMPONENTS OF OS———-———

Handles creation, scheduling, execution, synchronization, and termination of processes

Scheduler (OS Component)

COMPONENTS OF OS———-———

Tracks, allocates, and deallocates RAM and virtual memory for active programs

Memory Manager

COMPONENTS OF OS———-———

Organizes, creates, deletes, maps, and secures files and directories on storage drives

File System Management

COMPONENTS OF OS———-———

Translates user commands into system actions through a CLI or GUI

User Interface

A program that is currently being executed by the computer; a combination of tasks that executes

Process

PROCESS and COMPONENTS———-

Compiled, read-only executable machine instructions of the program

Code (Text Section)

PROCESS and COMPONENTS———-

Global and static variables, initialized or uninitialized before execution

Data Section

PROCESS and COMPONENTS———-

Dynamically allocated memory that grows or shrinks at run time (via malloc or new)

Heap

COMPONENTS of PROCESS———

Temporary data: local variables, function parameters, and return addresses

Stack

COMPONENTS of PROCESS———

Accumulators, index registers, and general-purpose registers that store the live state of the CPU when a process is paused

CPU Registers (Process)

Turns a raw program on disk into a running instance with the illusion of dedicated hardware

Process Abstraction

PROCESSING ABSTRACTION ALLOWS———

Multiple apps open at once

Multitasking

PROCESSING ABSTRACTION ALLOWS———

Holds data and information

Resource Management

PROCESSING ABSTRACTION ALLOWS———

Separates tasks from one another

Process Isolation

PROCESSING ABSTRACTION———

Tasks set to run at a particular time or trigger; also what starts up apps

Scheduling

A process in an operating system concept that turns a raw program on disk into a running, living instance with the illusion of dedicated hardware.

Process States

PROCESS STATES———————

The process is being created; the operating system allocates resources and sets up its Process Control Block (PCB).

New

PROCESS STATES———————

The process is loaded into main memory (RAM) and waits in the ready queue for the CPU scheduler to assign it a processor core.

Ready

PROCESS STATES———————

The CPU instructions for the process are actively being executed (only one process runs per core at a time).

Running

PROCESS STATES———————

The process cannot run because it is waiting for an external event, such as I/O completion or a locked resource.

Blocked / Waiting

PROCESS STATES———————

The process finishes execution or is aborted, and the OS deletes its PCB and frees its allocated resources.

Terminated / Exit

Also known as a task control block or process descriptor, it is a data structure used by an operating system kernel to store all necessary information about a specific process.

Process Control Block (PCB)

COMPONENTS PCB———-——

A unique number is assigned to identify the process, along with the Parent Process ID (PPID) and User ID (UID).

PROCESS INDENTIFICATION (PID)

COMPONENTS PCB———-——

The current phase of the process, such as new, ready, running, waiting (blocked), or terminated.

PROCESS STATE

COMPONENTS PCB———-——

The memory address of the next instruction that the CPU needs to execute for the process

PROGRAM COUNTER

COMPONENTS PCB———-——

Accumulators, index registers, stack pointers, and general-purpose registers that must be saved when a process is paused and restored when it resumes.

CPU REGISTERS

COMPONENTS PCB———-——

Details like process priority, pointer to scheduling queues, and time-slice or quantum values.

CPU SCHEDULING INFORMATION

COMPONENTS PCB———-——

Page tables, segment tables, or base and limit registers used by the operating system's memory subsystem.

MEMORY MANAGEMENT INFORMATION

COMPONENTS PCB———-——

A list of open files, allocated input/output devices, and pending I/O requests.

I/O and FILE STATUS

COMPONENTS PCB———-——

CPU time used, time limits, and account or job numbers.

ACCOUNTING INFORMATION