Ordering Among Different Process Using Semaphore

Duration: 8 min

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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:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

The video is an educational lecture on Operating Systems, specifically focusing on the synchronization concept of "Ordering" concurrent processes using semaphores. The instructor begins by introducing the topic and uses a relatable real-world analogy involving a street food vendor making a sandwich to illustrate the necessity of sequential steps. He then transitions to a formal problem statement requiring the execution order P2 -> P3 -> P1. The lecture concludes with a step-by-step derivation of the semaphore code needed to enforce this specific ordering constraint. The instructor uses a digital whiteboard to write down the semaphore variables and operations. This approach helps students understand the abstract concept through a concrete example.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The session opens with the title "Ordering" clearly visible on the whiteboard. The instructor introduces the topic and immediately plays a video clip of a street food vendor preparing a sandwich. The vendor is shown cutting buns, spreading green chutney, and adding sliced tomatoes and onions. The instructor uses this visual to explain that just as ingredients must be added in a specific sequence to make the dish, processes in a computer system often need to execute in a defined order to function correctly. He points out that the vendor does not add the onion before the tomato, illustrating a strict ordering constraint. The video clip serves as a practical demonstration of the concept.

  2. 2:00 – 5:00 02:00-05:00

    The instructor continues to reference the sandwich video, emphasizing the sequential dependency of the actions. He then shifts focus to the academic problem displayed on the screen: "Q Using Semaphores ensure that the order of execution of there concurrent process p1, p2 and p3 must be p2 -> p3 -> p1?". A table is presented with three columns labeled P1(), P2(), and P3(), representing the code blocks for each process. The instructor explains that the goal is to fill in the semaphore operations to enforce the specific chain of execution starting with P2. He notes that the processes are concurrent but must follow a specific path. The problem requires careful placement of wait and signal operations.

  3. 5:00 – 7:39 05:00-07:39

    The instructor starts solving the problem by initializing two semaphores, writing `S1 = 0` and `S2 = 0` on the board. He explains that since P2 is the first process to run, it does not require a wait operation. He then places a `P(S1)` operation in the P3 column, indicating that P3 must wait for P2 to complete. He adds a `V(S1)` operation in the P2 column to signal P3. To handle the transition from P3 to P1, he adds a `P(S2)` operation in the P1 column and a `V(S2)` operation in the P3 column, effectively creating the chain P2 -> P3 -> P1. He writes the final code structure on the table, showing the P and V operations in their respective rows.

The lecture successfully connects a tangible real-world example with abstract computer science theory. By first visualizing the sequential steps of making a sandwich, the instructor clarifies the concept of process ordering. He then rigorously applies this logic to a standard Operating Systems problem, demonstrating the precise placement of P (wait) and V (signal) operations. The final solution shows how semaphores can be used to enforce a strict execution sequence of P2 -> P3 -> P1, ensuring that P3 waits for P2 and P1 waits for P3. This method ensures that the processes do not run in parallel but rather in a synchronized, ordered manner. The use of two semaphores allows for the chaining of three processes.

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