Round Robin Scheduling

Duration: 12 min

This video lesson is available to enrolled students.

Return to /learn/BIHAR-STET-COMPUTER-SCIENCE-COMPLETE-COURSE/unit-5-operating-system/cpu-scheduling/round-robin-scheduling/asset-round-robin-scheduling after enrolling

Inside: a video lesson and guided study material.

Module outline

  1. About the course: About the Course
  2. Mathematical Aptitude: Number System, HCF LCM, Divisibility Rules, Percentage, Ratio and Proportion (Ratios), Average, Profit and Loss, Time and Work, Mensuration and Geometry, Simple Interest and Compound Interest, Speed Time and Distance, Age Problems, Mixture and Alligation, Algebra, Powers and Exponents (Surds and Indices), Pipe and Cistern, Trigonometry, Statistics, Data Interpretation, Arithmetic
  3. Logical Reasoning: Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Analogy, Blood Relations, Directions (Direction Test), Ranking, Order and Sequence, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Seating Arrangements, Syllogisms, Venn Diagram, Puzzle Solving (Puzzles), Logical Sequence Of Words, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Analytical Reasoning (Counting Figures Reasoning), Cubes & Dices, Calendar, Clock
  4. General Knowledge: Physics, Chemistry, Biology, History, Geography, Polity, Indian Economy, GK- Current Affairs, Static General Knowledge
  5. Art of Teaching: Nature, Objectives & Characteristics of Teaching, Learners & Learning Process, Factors Affecting Teaching, Methods of Teaching, Classroom Management & Communication, Teaching-Learning Aids & ICT Integration, Evaluation, Assessment & Measurement, Professional Development & Ethics, Policies, Acts & Contemporary Issues, Curriculum & School Environment, Guidance, Counselling & Mental Health, Inclusive Education & Special Needs, Micro-Teaching & Teaching Skills, Lesson Planning
  6. Environmental Science: Environment
  7. Unit 1 | Digital Electronics: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation
  8. Unit 2 | COA: Basics of COA, Floating Point Rep, Cache Memory Organization, Input Output Organisation, Instr Formats & Modes, Control Unit Design, Register Transfer and Microoperations, Programming the Basic Computer
  9. Unit 3 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
  10. Unit 3 | Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
  11. Unit 4 | Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos, Advanced Algorithms
  12. Unit 5 | Operating System: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, Disc Scheduling, File Management
  13. Unit 6 | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, SQL, Transaction Management, Concurrency Control
  14. Unit 7 | Computer Networks: Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, DLL: Error Control, DLL: Framing, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Net Layer:Routing Protocol, Transport Layer Services, TL: Congestion & UDP, Application Layer
  15. Unit 8 | Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management
  16. Unit 9 | Object Oriented Programming: OOPS with C++
  17. Unit 10 | Web Development: HTML Basics, CSS, JavaScript-Basics, XML
  18. Unit 11 | Theory Of Computation: Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Grammar, Regular Language Properties, Moore & Mealy Machines, Pushdown Automata & CFG, Turing Machines
  19. Unit 12 | IoT: Emerging Tech Trends, Cloud Computing
  20. Unit 13 | Artificial Intelligence: Approaches to AI, Search Algorithms, Game Playing, Knowledge Representation, Natural Language Processing, Artificial Neural Networks, Genetic Algorithms
  21. Unit 14 | E-Commerce: Electronic Data Interchange and E-Commerce, Role of Internet and Web Services, Security in Mobile and Wireless Computing, Physical Security and Cryptography Basics, Cyber Safety and Security
  22. Unit 15 | Multimedia: Multimedia
  23. Unit 16 | Python: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis, DSA using Python
  24. Full Length Mock Tests — General Paper:
  25. Full Length Mock Tests — Computer Science (Paper II):
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

The video is an educational lecture on the Round Robin CPU scheduling algorithm presented by Sanchit Jain Sir from Knowledge Gate. The lesson begins with a conceptual introduction using a visual analogy of children playing on a merry-go-round to explain the cyclic nature of the algorithm. The instructor explains that Round Robin is specifically designed for time-sharing systems where responsiveness is prioritized over completing one process entirely before starting another. Key theoretical points include the treatment of the ready queue as a circular queue (FIFO) and the introduction of pre-emption to switch between processes. The lecture then transitions into a practical numerical problem involving six processes (P0 through P5) with specific arrival and burst times. The instructor sets a time quantum (TQ) of 2 units and demonstrates the scheduling sequence by drawing a Gantt chart. Finally, he calculates the Completion Time (CT), Turn Around Time (TAT), and Waiting Time (WT) for each process using the formulas TAT = CT - AT and WT = TAT - BT, filling out a detailed table to summarize the performance metrics.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The instructor introduces the Round Robin algorithm using a slide titled 'Round robin' featuring an image of children on a merry-go-round. He explains that this algorithm is designed for time-sharing systems where it is not necessary to complete one process before starting another, but rather to be responsive and divide CPU time among processes in the ready state. The slide text explicitly states that the ready queue is treated as a circular queue (FIFO). The instructor emphasizes the concept of fairness and responsiveness in this scheduling method, noting that it allows multiple processes to share the CPU effectively without waiting for a long process to finish.

  2. 2:00 – 5:00 02:00-05:00

    The slide displays bullet points detailing the mechanics of Round Robin. The instructor explains that the algorithm is similar to FCFS (First Come First Serve) scheduling but adds pre-emption to enable the system to switch between processes. He highlights that the ready queue is treated as a circular queue where the CPU scheduler goes around allocating the CPU to each process for a time interval equivalent to 1 Time quantum (TQ). The slide notes that the value of TQ can be anything, establishing the core parameter for the scheduling logic. He also mentions that if a process has a CPU burst less than the time quantum, it releases the CPU voluntarily, preventing unnecessary context switches.

  3. 5:00 – 10:00 05:00-10:00

    The instructor begins solving a numerical problem on a whiteboard. A table is shown with columns for P. No, Arrival Time (AT), and Burst Time (BT). The processes are P0 to P5 with arrival times 0, 1, 2, 3, 4, 6 and burst times 4, 5, 2, 1, 6, 3 respectively. He writes 'TQ = 2' on the board. He constructs a Gantt chart sequence: P0, P1, P2, P0, P3, P4, P1, P5, P4, P1. He marks the time points on the chart, showing the progression from time 0 to 21. The sequence shows how processes are interrupted and re-queued after their time quantum expires. He specifically writes the sequence P0 P1 P2 P0 P3 P4 P1 P5 P4 P1 on the board to visualize the execution order and timing.

  4. 10:00 – 12:00 10:00-12:00

    The instructor completes the table by filling in the Completion Time (CT), Turn Around Time (TAT), and Waiting Time (WT) columns. He calculates TAT using the formula TAT = CT - AT and WT using WT = TAT - BT. For example, for P0, CT is 8, so TAT is 8 - 0 = 8, and WT is 8 - 4 = 4. He points to the calculated values in the table, such as P1 having a TAT of 17 and WT of 12. The final table summarizes the performance of all processes under the Round Robin scheduling with a time quantum of 2. He also calculates the average waiting time at the bottom of the table, providing a final metric for system efficiency.

The video effectively bridges the gap between theoretical concepts and practical application of the Round Robin scheduling algorithm. By starting with a relatable analogy and moving to a step-by-step numerical solution, the instructor clarifies how time quantum affects process execution and waiting times. The detailed calculation of TAT and WT provides students with a clear method for evaluating scheduling efficiency in time-sharing systems. The use of a Gantt chart helps visualize the pre-emptive nature of the algorithm, showing exactly when processes are switched and how the circular queue operates in practice.

Loading lesson…