Circular Wait

Duration: 6 min

This video lesson is available to enrolled students.

Return to /learn/AMCAT-PREPARATION/operating-systems/deadlock/deadlock-prevention/asset-circular-wait after enrolling

Inside: a video lesson and guided study material.

Module outline

  1. Quantitative Ability: Percentage, Profit and Loss, Ratio and Proportion (Ratios), Average, Time and Work, Speed Time and Distance, Simple Interest and Compound Interest, Age Problems, Number System, Divisibility Rules, HCF LCM, Algebra, Permutation and Combination, Probability, Data Interpretation, Logarithm, Sequence and Series (Series), Powers and Exponents (Surds and Indices), Speed Mathematics and Basic Mathematics
  2. Logical Reasoning: Seating Arrangements, Puzzle Solving (Puzzles), Data Arrangement, Coding Decoding, Blood Relations, Directions (Direction Test), Ranking, Order and Sequence, Data Sufficiency, Venn Diagram, Inequality, Series (Number and Letter Series) (Numerical Relations and Reasoning), Logical Sequence Of Words, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Selection Decision Table (Decision Making), Analogy, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning)
  3. Verbal Ability: Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Subject Verb Agreement (Verb Noun Agreement), Tenses, Articles, Preposition, Conjunction, Modals, Active Passive Voice (Voice), Direct and Indirect Speech, Vocabulary, Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Sentence Completion (Fill in the blanks), Sentence Correction (Error Correction), Cloze Test (Cloze Passage), Facts, Inference and Judgements
  4. Programming Fundamentals (Technical): C Fundamentals
  5. Data Structures (Technical): Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
  6. Algorithms (Technical): Algorithm Analysis, Sorting Algorithms, Greedy Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos, Time Complexity Analysis, Advanced Algorithms
  7. OOPs (Technical): Object Oriented Programming (OOPS)
  8. DBMS (Technical): Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, Relational Calculus, Transaction Management, Concurrency Control, Database Recovery, ORDBMS, Database Security & Authorization, Query Processing & Optimization, Enhanced Data Models, Data Warehousing & Mining, Big Data Systems, NoSQL
  9. SQL (Technical): SQL
  10. Operating Systems (Technical): Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Windows OS, Linux OS, Security, Distributed Systems, Virtual Machines
  11. Computer Networks (Technical): 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, Hardware basics, Network Security, Mobile Technology, Cloud Computing and IoT, Cyber and Info Security
  12. Software Engineering (Technical): Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management
  13. Coding/Automata Round: Coding Questions by Yash Sir, C Programming by Yash Sir, Programming in C++, Java, Python for Placements by Yash Sir, Pseudo Codes
  14. Personality / Behavioral Assessment: Behavioral Assessment (Behavioral Competency Profiling) (Psychometric Test)
  15. Writing Assessment: English Writing Ability
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…