No Pre-Emption

Duration: 3 min

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Inside: a video lesson and guided study material.

Module outline

  1. Quantitative Aptitude: Number System, Percentage, Profit and Loss, Ratio and Proportion (Ratios), Average, Time and Work, Speed Time and Distance, Simple Interest and Compound Interest, Mixture and Alligation, Data Interpretation, Permutation and Combination, Probability, Logarithm, Powers and Exponents (Surds and Indices), Age Problems, Divisibility Rules, Partnership, HCF LCM, Algebra, Pipe and Cistern
  2. Logical Reasoning: Series (Number and Letter Series) (Numerical Relations and Reasoning), Analogy, Coding Decoding, Blood Relations, Directions (Direction Test), Syllogisms, Logical Sequence Of Words, Data Sufficiency, Seating Arrangements, Puzzle Solving (Puzzles), Calendar, Clock, Cubes & Dices, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Data Arrangement
  3. English Language: Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Vocabulary, Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Active Passive Voice (Voice), Direct and Indirect Speech, Cloze Test (Cloze Passage), Tenses, Subject Verb Agreement (Verb Noun Agreement), Preposition, Articles, Conjunction, Adverb
  4. Written English Test: English Writing Ability
  5. Coding: Coding Questions by Yash Sir, C Programming by Yash Sir, Programming in C++, Java, Python for Placements by Yash Sir
  6. Communication Round: Communication Assessment
  7. DBMS (Technical Interview): 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, Big Data Systems, NoSQL, Data Warehousing & Mining
  8. SQL (Technical Interview): SQL
  9. Operating Systems (Technical Interview): 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
  10. Computer Networks (Technical Interview): 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
  11. OOPs (Technical Interview): Object Oriented Programming (OOPS)
  12. HR Interview: MR & HR Interview Preparation
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

The video lecture focuses on the 'No pre-emption' condition in deadlock handling strategies within operating systems. The instructor, Sanchit Jain Sir, breaks down the specific rules governing resource allocation when pre-emption is not strictly forbidden but managed under certain conditions. He explains the step-by-step logic a system follows when a process requests resources: checking availability, checking if another waiting process holds them, and handling the waiting state. The lecture includes visual aids on the slide and hand-drawn diagrams to clarify the flow of resource pre-emption between processes.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The instructor begins by analyzing the slide titled 'No pre-emption'. He reads the first bullet point: 'if a process requests some resources, we first check whether they are available. If they are, we allocate them.' He then moves to the second point, explaining that if resources are not available, the system checks if they are allocated to another process waiting for additional resources. If this condition is met, the system pre-empts the resources from the waiting process and allocates them to the requesting process. To illustrate this, he draws a diagram on the screen with 'R' representing a resource and 'P' representing a process, showing an arrow indicating the transfer of resources from one to the other.

  2. 2:00 – 3:18 02:00-03:18

    The lecture proceeds to the third bullet point: 'If the resources are neither available nor held by a waiting process, the requesting process must wait.' The instructor emphasizes that while waiting, the process's own resources may be pre-empted if another process requests them. He then explains the final condition: a process can only be restarted when it is allocated the new resources it requested and recovers any resources that were pre-empted while it was waiting. He gestures to emphasize the recovery aspect of the process restart, ensuring the student understands that the process must regain its lost resources before continuing execution.

The video provides a detailed walkthrough of the 'No pre-emption' condition in deadlock handling. It clarifies that pre-emption is conditional. The system first checks availability. If unavailable, it looks for a waiting process holding the resource to pre-empt from. If no such process exists, the requester waits. During this wait, the requester is vulnerable to having its own resources taken by others. The process only resumes execution once it secures the requested resources and regains any previously held resources that were taken away. This structured approach ensures that resources are managed efficiently without causing indefinite blocking, balancing the needs of multiple processes in the system effectively.

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