Circular Wait

Duration: 6 min

This video lesson is available to enrolled students.

Return to /learn/MPPSC-ASSISTANT-PROFESSOR-COMPUTER-SCIENCE-PAPER-2/operating-system/deadlock/deadlock-prevention/asset-circular-wait after enrolling

Inside: a video lesson and guided study material.

Module outline

  1. About Course: About the Course
  2. Paper 1 | General Studies: State Wise GK
  3. Paper 1 | Information and Communication Technology: Role of Internet and Web Services, Security in Mobile and Wireless Computing
  4. Paper 1 | Current Affairs: GK- Current Affairs
  5. Paper 2 | Discrete Mathematical Structure: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Set Theory, Relations, Functions, Graph Theory, Group Theory, Propositional and Predicate Logic, Probability
  6. Paper 2 | Digital Computer Organization And Architecture: Number System, Number Representation, Sequential Circuits, Combinational Circuit, Basics of COA, Floating Point Rep, Cache Memory Organization, Input Output Organisation, Pipelining, Instr Formats & Modes, Register Transfer and Microoperations, Control Unit Design, Programming the Basic Computer
  7. Paper 2 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
  8. Paper 2 | Programming Languages & Object-Oriented Programming Concepts: Java, OOPS with C++, Java Fundamentals, Array, String, IO & References
  9. Paper 2 | Python: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis
  10. Paper 2 | Data Structure And Algorithms: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Minimum Spanning Trees, Advanced Algorithms
  11. Paper 2 | Operating System: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Unix OS
  12. Paper 2 | 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
  13. Paper 2 | 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
  14. Paper 2 | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, Relational Algebra, SQL, Transaction Management, Concurrency Control, Database Recovery, Database Security & Authorization, Enhanced Data Models
  15. Paper 2 | Computer Network And Information Security: Introduction to CN, Data Communication, Application Layer, Hardware basics, Cyber Threats and Malware Attacks, Network Security, 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
  16. Paper 2 | Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management
  17. Paper 2 | Current Trends & Technologies: Emerging Tech Trends, Approaches to AI, Search Algorithms, Game Playing, Knowledge Representation, Planning, Multi Agent Systems, Fuzzy Sets, Natural Language Processing, Artificial Neural Networks, Genetic Algorithms, Artificial Intelligence, Data Warehousing & Mining, Electronic Data Interchange and E-Commerce, Terms & Abbreviations
  18. Paper 2 | Full Length Mock Tests:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This video is a lecture on the topic of 'Circular wait', a condition in operating systems that can lead to deadlock. The instructor, Sanchit Jain, explains a method to eliminate the circular wait condition by enforcing a strict ordering on resource requests. The core concept is to assign a natural number to each resource and require all processes to request resources in increasing order of their numbers. If a process needs a resource with a lower number than one it already holds, it must first release all resources with higher numbers before making a new request. The lecture uses a whiteboard to illustrate this with diagrams showing processes (P1, P2) and resources (R1, R2), first depicting a scenario where circular wait can occur and then showing how the ordering rule prevents it. The video is part of a series by Knowledge Gate Educator.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video opens with a slide titled 'Circular wait' which presents a text-based solution to eliminate the circular wait problem. The text states: 'We can eliminate circular wait problem by giving a natural number mapping to every resource and then any process can request only in the increasing release order and if a process wants a lower number, then process must first release all the resource larger than that number and then give a fresh request.' The instructor, Sanchit Jain, begins to explain this concept, writing 'P1' and 'P2' on the whiteboard to represent processes, and 'R1' and 'R2' to represent resources, setting up the context for a diagrammatic explanation.

  2. 2:00 – 5:00 02:00-05:00

    The instructor draws a diagram to illustrate the circular wait condition. On the left side of the whiteboard, he draws a process P1 requesting resource R1, and a process P2 requesting resource R2. He then draws arrows to show that P1 is holding R1 and waiting for R2, while P2 is holding R2 and waiting for R1, creating a circular dependency. He explains that this is a classic example of a deadlock. He then draws a vertical line to separate this scenario from the solution, and on the right side, he begins to draw a new diagram to show how the problem is solved by enforcing a resource ordering.

  3. 5:00 – 6:06 05:00-06:06

    The instructor completes the diagram on the right side of the whiteboard to demonstrate the solution. He shows that if processes must request resources in increasing order, then P1 can only request R1 before R2. He draws a diagram where P1 requests R1, then R2, and P2 requests R2, then R1. He explains that this ordering prevents the circular wait because a process cannot hold a higher-numbered resource and then request a lower-numbered one. He also draws a circle around the resources R1 and R2 to emphasize the concept of a resource hierarchy. The video ends with the instructor summarizing the method.

The video provides a clear, step-by-step explanation of how to prevent the circular wait condition, a necessary condition for deadlock. It starts by defining the problem with a textual rule and then uses a visual, diagrammatic approach to contrast a problematic scenario with a solution. The core teaching point is the enforcement of a total ordering on resource requests, which breaks the circular dependency. The instructor effectively uses the whiteboard to build the concept from a simple definition to a complex, illustrative diagram, making the abstract concept of deadlock prevention more concrete for the viewer.

Loading lesson…