Resource Request Algorithm

Duration: 6 min

This video lesson is available to enrolled students.

Return to /learn/DSSSB-TGT-COMPUTER-SCIENCE-PAPER-2/operating-system/deadlock/avoidance-bankers-algo/asset-resource-request-algorithm after enrolling

Inside: a video lesson and guided study material.

Module outline

  1. About Course: About the Course
  2. Programming, Data Structures, OOP & Java: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling, Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, Java, OOPS with C++, Java Fundamentals, Array, String, IO & References, Language Design, Intro to Compilers, Visual Basics, Syntax Analysis: Bottom-Up, Object Oriented Technology
  3. Computer Networks, TCP/IP & Network Security: Introduction to CN, Data Communication, DLL: Flow Control, DLL: Access Control, DLL: Error Control, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware basics, Network Access Technologies, Network Security, Society, Law & Ethics, Cloud Computing, Mobile Computing, Net Layer:Routing Protocol, Cyber Safety and Security
  4. Teaching Methodology: Child Development, Concept of Pedagogy, Theories, Inclusive Education, Experiential Pedagogy, Assessment & Evaluation, Curriculum Framework & Reforms, National Education Policy (NEP) 2020, Psychology, Teaching-Learning Process, Personality Development, Teaching Methods & Strategies, Learning and Motivation, Learners & Learning Process, Factors Affecting Teaching, Methods of Teaching, Nature, Objectives & Characteristics of Teaching, Teaching-Learning Aids & ICT Integration, Classroom Management & Communication, Evaluation, Assessment & Measurement, Curriculum & School Environment, Inclusive Education & Special Needs, Professional Development & Ethics
  5. Digital Electronics / Boolean Logic: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation, Analog-Digital Conversion
  6. Operating Systems & Linux: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, File Management, Disc Scheduling, Unix OS, Linux OS, Distributed Systems, Windows OS
  7. Data Base Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, Relational Algebra, SQL, File Organization & Indexing, Transaction Management, Concurrency Control, Database Security & Authorization, Database Recovery, Data Warehousing & Mining
  8. Internet & Web Technologies: Website, Browser & Services, Internet Fundamentals, Web Design & Development, Protocols & Services, Web Publishing & Hosting, Server Side & Security, HTML Basics, CSS, Emerging Technologies, JavaScript-Basics, .Net Programming, Electronic Data Interchange and E-Commerce, XML
  9. Computer Fundamentals, IT Basics & Architecture: Basics of COA, Cache Memory Organization, Input Output Organisation, Register Transfer and Microoperations, Control Unit Design, Programming the Basic Computer, Terms & Abbreviations, MS Office Applications, Instr Formats & Modes, Floating Point Rep
  10. Python Language: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis
  11. Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management, extras, Fundamentals of Systems and Information Systems
  12. Design & Analysis of Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos, Advanced Algorithms
  13. Mathematics - I, II, III, IV: Permutation and Combination, Logarithm, Linear Algebra, Algebra, Calculus, Trigonometry, Vectors, Set Theory, Functions, Relations, Propositional and Predicate Logic, Research Process Steps, Graph Theory
  14. Computer Graphics, Multimedia & Mobile Computing: Basics of Computer Graphics, 2-D Geometrical Transforms and Viewing, 3-D Object Representation, Geometric Transformations and Viewing, Multimedia
  15. Emerging Trends: Emerging Tech Trends, Knowledge Representation, Natural Language Processing
  16. Statistical Techniques: Probability, Statistics
  17. Interpolation - DI: Data Interpretation
  18. Basis of Physics: Physics
  19. Previous Year Paper:
  20. Business Studies and Management: Business Communication, Business Organization and Management, Financial Accounting, Business Economics, Management Information System (MIS), Knowledge Management & New Economy
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This academic lecture focuses on deadlock avoidance mechanisms within operating systems, specifically detailing the Resource-Request Algorithm and the Safety Algorithm. The instructor explains the procedural steps a system takes when a process requests resources. The core concept involves verifying if a request is within the process's maximum claim and if sufficient resources are available. Crucially, the system simulates the allocation to check if the resulting state remains 'safe,' meaning all processes can eventually complete. If the simulated state is unsafe, the request is denied, and the system reverts to its previous state to prevent potential deadlock. This ensures the system remains in a safe state at all times.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The instructor begins by defining the Resource-Request Algorithm. The slide text states, 'Let Request_i be the request vector for process P_i. If Request_i[j] = k, then process P_i wants k instances of resource type R_j.' He explains the first validation step: 'If Request_i <= Need_i, go to step 2. Otherwise, raise an error condition, since the process has exceeded its maximum claim.' This ensures that a process cannot request more resources than it originally declared it would need during its lifetime. The instructor points to the text to emphasize the condition.

  2. 2:00 – 5:00 02:00-05:00

    The lecture continues with the second and third steps. The slide reads, 'If Request_i <= Available, go to step 3. Otherwise, Pi must wait, since the resources are not available.' The instructor then details the simulation in step 3: 'Have the system pretend to have allocated the requested resources to process Pi by modifying the state as follows: Available = Available - Request_i; Allocation_i = Allocation_i + Request_i; Need_i = Need_i - Request_i.' He emphasizes that this is a temporary modification. If the resulting state is safe, the transaction is completed. However, if the new state is unsafe, 'Pi must wait for Request_i, and the old resource-allocation state is restored.' This rollback mechanism is critical for preventing the system from entering a deadlock state.

  3. 5:00 – 6:10 05:00-06:10

    The topic transitions to the Safety Algorithm. The slide title changes to 'Safety Algorithm'. The instructor explains the initialization: 'Let Work and Finish be vectors of length m and n, respectively. Initialize Work = Available and Finish[i] = false for i = 0, 1, ..., n - 1.' He describes the iterative process: 'Find an index i such that both Finish[i] == false and Need_i <= Work.' If such an index exists, the system updates `Work = Work + Allocation_i` and sets `Finish[i] = true`. The algorithm concludes by checking if `Finish[i] == true` for all `i`, indicating a safe state. The slide notes this may require an order of m*n^2 operations. The instructor gestures towards the equations to show how Work accumulates resources from finished processes.

The video provides a comprehensive walkthrough of the Banker's Algorithm logic. It starts by validating individual requests against process claims and system availability. It then simulates the allocation to test for safety. Finally, it details the Safety Algorithm used to perform this test. This progression ensures that resource allocation decisions are made conservatively to guarantee that the system never enters an unsafe state where deadlock could occur, maintaining system stability and reliability. The instructor effectively bridges the gap between request handling and state verification. This structured approach allows the operating system to make informed decisions about resource distribution.

Loading lesson…