FUNCTION AND TYPE OF AN OS

WHAT IS A PROCESS?

A PROCESS IS A PROGRAM THAT IS BEING EXECUTED BY THE CPU.

A _____ IS A PROGRAM THAT IS BEING EXECUTED BY THE CPU.

PROCESS

WHAT IS THREAD?

A thread is a smaller unit of a process.

_____ is a smaller unit of a process.

THREAD

_____ are called “lightweight processes” because they share memory and resources, making them faster than full processes.

THREADS

THREADS

are called “lightweight processes” because they share memory and resources, making them faster than full processes.

THREADS are called _____ because they share memory and resources, making them faster than full processes.

LIGHTWEIGHT PROCESSES

_____ allows OS to handle many processes at once, making the computer do many things at the same time.

MULTITASKING

MULTITASKING

allows OS to handle many processes at once, making the computer do many things at the same time.

CORE FUNCTION OF PROCESS MANAGEMENT

PROCESS SCHEDULING, PROCESS SYNCHRONIZATION, DEADLOCK HANDLING, AND INTER-PROCESS COMMUNICATION (IPC)

The OS deciding which process/thread gets the CPU next

PROCESS SCHEDULING

PROCESS SCHEDULING

The OS deciding which process/thread gets the CPU next

Make sure that multiple processes don't interfere with each other, especially when accessing shared files/resources.

PROCESS SYNCHRONIZATION

PROCESS SYNCHRONIZATION

Make sure that multiple processes don't interfere with each other, especially when accessing shared files/resources.

• Prevents program from getting stuck

DEADLOCK HANDLING

DEADLOCK HANDLING

Prevents program from getting stuck

Allows to exchange data 

INTER-PROCESS COMMUNICATION (IPC)

INTER-PROCESS COMMUNICATION (IPC)

Allows to exchange data 

Manages how memory is used so that programs run efficiently without crashing or interfering with each other.

MEMORY MANAGEMENT

MEMORY MANAGEMENT

Manages how memory is used so that programs run efficiently without crashing or interfering with each other.

MEMORY MANAGEMENT: 2 TYPES

PRIMARY MEMORY MANAGEMENT AND SECONDARY MEMORY MANAGEMENT

PRIMARY MEMORY MANAGEMENT: 5 PARTS

MEMORY ALLOCATION, MEMORY DEALLOCATION, MEMORY PROTECTION, VIRTUAL MEMORY AND FRAGMENTATION MEMORY.

MEMORY ALLOCATION

Uses techniques like PAGING (splitting memory to fixed-size pages) or SEGMENTATION (variable-size segments)

______ (splitting memory to fixed-size pages)

PAGING

_____ (variable-size segments)

SEGMENTATION

MEMORY DEALLOCATION

When program finishes, its memory is released for others to use

When program finishes, its memory is released for others to use

MEMORY DEALLOCATION

MEMORY PROTECTION

Keeps one program from accessing another’s memory, avoiding crashes and security issues.

Keeps one program from accessing another’s memory, avoiding crashes and security issues.

MEMORY PROTECTION

Uses hard drive space as extra memory when ram is full, allowing larger programs to run

VIRTUAL MEMORY

VIRTUAL MEMORY

Uses hard drive space as extra memory when ram is full, allowing larger programs to run

Deals with unused gaps in memory. Rearrange data to free up larger blocks of memory called COMPACTION.

FRAGMENTATION MANAGEMENT

FRAGMENTATION MANAGEMENT

Deals with unused gaps in memory. Rearrange data to free up larger blocks of memory called COMPACTION.

SECONDARY MEMORY MANAGEMENT: 5 PARTS

DISK SPACE ALLOCATION, FILE SYSTEM MANAGEMENT, FREE SPACE MANAGEMENT, DISK SCHEDULING, AND BACK UP AND RECOVERY

Determines how files are saved, either in order, linked, or using indexes.

DISK SPACE ALLOCATION

DISK SPACE ALLOCATION

Determines how files are saved, either in order, linked, or using indexes.

Manages folders, file names, and file organization.

FILE SYSTEM MANAGEMENT

FILE SYSTEM MANAGEMENT

Manages folders, file names, and file organization.

Tracks available storage to prevent saving issues

FREE SPACE MANAGEMENT

FREE SPACE MANAGEMENT

Tracks available storage to prevent saving issues

DISK SCHEDULING

Optimized how storage is read/written.

Optimized how storage is read/written.

DISK SCHEDULING

Ensures that files are saved and can be restored after system failure. Protects data from being lost

BACK UP AND RECOVERY

BACK UP AND RECOVERY

Ensures that files are saved and can be restored after system failure. Protects data from being lost

FILE MANAGEMENT

• It organizes files into folders/directories

• It manages access permissions (who can read/write/execute a file)

• It hides hardware details so users don’t have to worry about where files are stored physically

FILE MANAGEMENT: 4 TYPES

FILE ATTRIBUTES, FILE TYPES, FILE OPERATIONS AND ACCESS METHODS

FILE ATTRIBUTE: 4 PARTS

FILE NAME, FILE TYPE, SIZE AND PERMISSIONS

FILE NAME

WHAT IS FILE CALLED

FILE TYPE

TYPE OF CONTENT

SIZE

HOW MUCH SPACE THE FILE TAKES

PERMISSIONS

WHO CAN READ, WRITE OR EXECUTE THE FILES

FILE TYPES: 3 PARTS

TEXT FILES, BINARY FILES AND EXECUTABLE FILES

FILE OPERATIONS

CREATE, READ, WRITE AND DELETE

ACCESS METHODS: 3 PARTS

SEQUENTIAL ACCESS, DIRECT ACCESS, AND INDEXED ACCESS

SEQUENTIAL ACCESS

READ FROM THE START TO END

DIRECT ACCESS

JUMP TO SPECIFIC PART

INDEXED ACCESS

USES INDEX TO FIND DATA QUICKLY (LIKE TABLE OF CONTENTS)

TYPE OF AN OS: 3 TYPES

BATCH OS, TIME-SHARING OS, AND DISTRIBUTED OS

BATCH OS

You group similar tasks together and run them all at once and with no interruptions or changes in between.

______ IS You group similar tasks together and run them all at once and with no interruptions or changes in between.

BATCH OS

Earliest types of OS used in computers

BATCH OS

_____ Is like doing all your chores all at once without stopping

BATCH OS

_____ means sharing CPU time among multiple users or processes

TIME-SHARING OS

Supports real-time multitasking for multiple users.

TIME-SHARING OS

connects multiple computers called nodes over network.

DISTRIBUTED OS

spreads tasks across several machines connected in a network

DISTRIBUTED OS

These computers work together and share resources like memory, files and processing power

DISTRIBUTED OS