Understanding Bankers Algorithm

Duration: 11 min

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Inside: a video lesson and guided study material.

Module outline

  1. General Intelligence & Reasoning: Analogy, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Blood Relations, Directions (Direction Test), Ranking, Order and Sequence, Logical Sequence Of Words, Syllogisms, Venn Diagram, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Selection Decision Table (Decision Making), Data Sufficiency, Puzzle Solving (Puzzles), Data Arrangement, Cubes & Dices, Calendar, Clock, Arithmetic, Number System, HCF LCM, Verbal Analogy (Word Based Analogy), Visual Recognition and Figure Completion, Paper Folding and Cutting, Transformation of Shapes, Clocks and Calendars, Direction Sense, Cubes and Dice, Patterns in Two-Dimensional Figures, Seating Arrangements, Analogy and Classification, Logical Deduction and Induction, Alphabet and Word Tests, Mathematical Operations, Series Completion, Simplification and Approximation, Coding and Decoding, Numerical Reasoning, Assembling and Grouping of Shapes, Three-Dimensional Patterns and Visualization, Vocabulary, Number System, Averages, Mixtures and Alligation, Simple and Compound Interest, Percentages, Algebra, Speed, Time and Distance, Seating and Arrangement Puzzles, Traverse Surveying, Order, Ranking and Sequence, Constraint Puzzles, Syllogisms and Venn Diagrams, Reading Comprehension, Critical Reasoning, Permutations and Combinations, Narrative Sequencing, Project Monitoring, Resources and Safety, Profit, Loss and Discount, Ratio and Proportion, Time and Work, Mensuration, Data Interpretation, Powers, Surds and Logarithms, Sequences and Series, Articles and Determiners, Sentence Completion, Data Sufficiency, Blood Relations, Simple Interest and Compound Interest, Mixture and Alligation, Sequence and Series (Series), Speed Time and Distance, Algebra, Profit and Loss, Powers and Exponents (Surds and Indices), Permutation and Combination
  2. General Awareness: Physics, Chemistry, Biology, History, Geography, Polity, Indian Economy, Environment, Static General Knowledge, GK- Current Affairs, Artificial Intelligence, MS Office Applications, Terms & Abbreviations, Keyboard Shortcuts, Evolution of Indian Banking (Banking & Financial Awareness), Emerging Tech Trends
  3. Engineering Mathematics: Set Theory, Relations, Functions, Graph Theory, Group Theory, Propositional and Predicate Logic, Linear Algebra, Calculus, Probability, Statistics, Signal Space and Optimum Detection, Probability, Statistics
  4. Digital Logic: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation, Floating Point Rep, Number Systems and Codes, Registers and Counters, Boolean Algebra and Logic Gates, Microprocessors and Microcontrollers, Logic Families and CMOS Logic, Microprocessors, Logic Gates and Boolean Algebra, Minimization of Boolean Functions, Timing, Hazards and Testing, Logic Families, Combinational Logic Design, Arithmetic Circuits, Waveform Generators and Timer Circuits, Semiconductor Memories and Programmable Logic Devices, Combinational Logic Circuits, Latches and Flip-Flops, Finite State Machines, Sequential Circuits and State Machines, Minimization of Boolean Functions, Arithmetic Circuits, Latches and Flip-Flops, Number Systems and Codes, Registers and Counters
  5. Computer Organisation & Architecture: Basics of COA, Cache Memory Organization, Input Output Organisation, Pipelining, Instr Formats & Modes, Control Unit Design, Programming the Basic Computer, Register Transfer and Microoperations, Semiconductor Memories and Programmable Logic, Processor Organization and Instructions, Memory Hierarchy and Input/Output, Registers and Counters
  6. Programming & Data Structures: 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, HTML Basics, OOPS with C++, Java, Object Oriented Technology
  7. Databases: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, SQL, Relational Calculus, Transaction Management, Concurrency Control, Database Recovery, Database Security & Authorization
  8. Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos
  9. 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, Complexity Theory
  10. Compiler Design: Intro to Compilers, Lexical Analysis, Grammar & CFG, Syntax Analysis: Top-Down, Syntax Analysis: Bottom-Up, Semantic Analysis & SDT, Intermediate Code Gen, Code Optimization, Run Time Environment
  11. Operating System: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, Disc Scheduling, File Management, Security, Windows OS, Distributed Systems, Unix OS, Linux OS
  12. Computer Networks: Introduction to CN, 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, Hardware Basics, Data Communication, Website, Browser & Services, Web Design & Development, Network Security, Cyber Threats and Malware Attacks, Cyber Safety and Security
  13. Full Length Mock Tests:
  14. Sectional Tests:
  15. Paper 2 - Full-length Mock Tests:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This video is a comprehensive lecture on the Banker's Algorithm, a resource allocation and deadlock avoidance strategy used in operating systems. The instructor demonstrates how to determine if a system is in a safe state by calculating resource needs and available resources. He walks through a specific example with four processes (P0-P3) and three resource types (E, F, G), filling out tables for Max Need, Allocation, and Current Need. He then performs the safety algorithm to find a safe sequence of process execution. Finally, he introduces the theoretical concept of safe states and avoidance algorithms, explaining how systems can prevent deadlock by ensuring resources are only allocated if the system remains in a safe state.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The instructor begins by setting up the problem parameters for the Banker's Algorithm. He displays a whiteboard with several tables: Max Need, Allocation, Current Need, System Max, and Available. He starts filling the Max Need table, which represents the maximum resource demand for each process. For process P0, he writes 4, 3, 1 for resources E, F, G. For P1, he writes 2, 1, 4. For P2, he writes 1, 3, 3. For P3, he writes 5, 4, 1. He also defines the System Max (total resources in the system) as 8, 4, 6. This establishes the initial constraints and total capacity of the system before any allocation logic is applied. He points to the System Max table to emphasize that the sum of all resources in the system is fixed.

  2. 2:00 – 5:00 02:00-05:00

    Next, the instructor populates the Allocation table, indicating the resources currently held by each process. He writes P0 has 1, 0, 1; P1 has 1, 1, 2; P2 has 1, 0, 3; and P3 has 2, 0, 0. He then calculates the Current Need table using the formula Need = Max - Allocation. For instance, for P0, he subtracts the allocation (1,0,1) from the max need (4,3,1) to get a need of 3, 3, 0. He performs this calculation for all processes. Finally, he calculates the Available resources by subtracting the sum of all allocated resources from the System Max. The sum of allocations is 5, 1, 6. Subtracting this from System Max (8, 4, 6) leaves an initial Available vector of 3, 3, 0. He writes these values in the Available table.

  3. 5:00 – 10:00 05:00-10:00

    The core of the lecture involves executing the safety algorithm to determine if the system is in a safe state. The instructor checks if any process's Current Need is less than or equal to the Available resources (3, 3, 0). He identifies P0 (Need 3, 3, 0) as a candidate. He simulates P0 completing its execution and releasing its resources back to the system. He updates the Available vector by adding P0's allocation (1, 0, 1) to the current Available (3, 3, 0), resulting in a new Available of 4, 3, 1. He continues this process, finding P2 (Need 0, 3, 0) can now run. After P2 finishes, Available becomes 5, 3, 4. He then finds P1 and P3 can run. He writes the safe sequence on the board: P0 -> P2 -> P1 -> P3. He also draws a diagram illustrating the boundary between safe and unsafe states, noting that deadlock occurs in the unsafe region. He circles the safe sequence to highlight it.

  4. 10:00 – 11:02 10:00-11:02

    The lecture concludes with a theoretical overview of deadlock avoidance. A slide appears with the text 'Given the concept of a safe state, we can define avoidance algorithms that ensure that the system will never deadlock.' The instructor explains that the goal is to keep the system in a safe state at all times. He states that whenever a process requests resources, the system must check if the allocation leaves the system in a safe state. If it does, the resource is granted; otherwise, the process must wait. This ensures the system never enters an unsafe state where deadlock could occur. The slide text is clearly visible and serves as a summary of the algorithm's purpose.

The video effectively bridges the gap between theoretical definitions and practical application. It starts with data setup, moves to calculation of needs and availability, executes the safety check step-by-step to find a valid sequence, and ends with the broader context of deadlock avoidance algorithms. The instructor uses a clear, step-by-step approach, writing down every calculation on the board to ensure students understand how the Available vector changes as processes complete. The final diagram and slide reinforce the importance of maintaining a safe state to avoid the deadlock region.

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