Model of Threading

Duration: 3 min

This video lesson is available to enrolled students.

Return to /learn/UPPSC-POLYTECHNIC-LECTURER-2025-CS/paper-2-operating-systems/threads-process-creation/threading-models/asset-model-of-threading after enrolling

Inside: a video lesson and guided study material.

Module outline

  1. About Course: UPPSC Course Overview
  2. Interview Preparation & Guidance: Interview Preparation
  3. Paper 1 | General Hindi: भाषा, लिपि, ध्वनि, वर्ण, अक्षर, स्वर, व्यंजन, मात्रा और संयुक्ताक्षर, वर्तनी, वर्ण-विन्यास, अनुस्वार, अनुनासिक, चंद्रबिंदु और ‘र’ के रूप, शब्द, पद और शब्द-भेद, संज्ञा और सर्वनाम, विशेषण और क्रिया, लिंग, वचन, पुरुष और कारक, काल, वाच्य, वाक्य और वाक्य-भेद, वर्णमाला, समास, संधि, विलोम शब्द, पर्यायवाची शब्द, सामान्य अशुद्धियाँ, अनेक शब्दों के लिए एक शब्द, मुहावरे और लोकोक्तियाँ, अपठित गद्यांश और अपठित पद्यांश, Multi-Topic Content (Cross-Concept Material)
  4. Paper 2 | General Studies: State Wise GK, Polity, Geography, History, GK- Current Affairs
  5. Paper 1 | Programming Language: Language Design, C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling, OOPS with C++
  6. Paper 1 | Database Management Systems: 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, ORDBMS, NoSQL
  7. Paper 1 | Cyber Security: Society, Law & Ethics, Cyber Threats and Malware Attacks, Role of Internet and Web Services, Security in Mobile and Wireless Computing, Electronic Data Interchange and E-Commerce, Physical Security and Cryptography Basics, Intrusion Detection Systems (IDS), Cyber Safety and Security, Ethical Hacking
  8. Paper 1 | Computer Organization and Architecture: Basics of COA, Programming the Basic Computer, Cache Memory Organization, Input Output Organisation, Instr Formats & Modes, Register Transfer and Microoperations, Control Unit Design
  9. Paper 1 | Computer Networks: 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
  10. Paper 1 | Design and Analysis of Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos, Advanced Algorithms
  11. Paper 1 | Data Structures: Introduction to DS, Array, Linked List, Stack, Queue, Tree, Graphs, Hashing
  12. Paper 1 | Discrete Structures and Theory of Logic: Permutation and Combination, Set Theory, Relations, Functions, Propositional and Predicate Logic, Graph Theory, Group Theory
  13. Paper 1 | Software Project Management: Software Project Management
  14. Paper 2 | Operating Systems: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, Disc Scheduling, File Management, Unix OS, Linux OS, Security
  15. 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, Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Pushdown Automata & CFG, Complexity Theory
  16. Paper 2 | Artificial Intelligence & High Performance Computing: Approaches to AI, Search Algorithms, Game Playing, Knowledge Representation, Planning, Multi Agent Systems, Natural Language Processing, Emerging Tech Trends
  17. Paper 2 | Image Processing: Digital Image Fundamentals, Image Enhancement, Image Restoration, Color Image Processing, Image Compression
  18. 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
  19. Paper 2 | Computer Graphics: Basics of Computer Graphics, 2-D Geometrical Transforms and Viewing, 3-D Object Representation, Geometric Transformations and Viewing
  20. Paper 2 | Web Technologies: Website, Browser & Services, Internet Fundamentals, Web Design & Development, Protocols & Services, Web Publishing & Hosting, Server Side & Security, Emerging Technologies, HTML Basics, JavaScript-Basics, Java
  21. Paper 2 | Soft Computing: Fuzzy Sets, Artificial Neural Networks, Genetic Algorithms
  22. Paper 2 | Distributed System: Distributed Systems
  23. UPPSC Live Class Recordings: UPPSC Polytechnic Lecturer 2025 (CS)
  24. Previous Year Papers:
  25. Mock Test:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

The lecture introduces the concept of multithreading models, specifically distinguishing between user threads and kernel threads. It details the Many-to-One model, highlighting its limitations regarding blocking calls and CPU utilization. The presentation then transitions to the One-to-One model, explaining its advantages in concurrency and overhead trade-offs. Finally, it covers the Many-to-Many model as a hybrid approach combining the best features of the previous two.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The lecture begins with a slide titled "Multithreading Models," defining user threads as application-level and kernel threads as OS-supported. The focus shifts to the "Many-To-One Model," where many user-level threads are mapped onto a single kernel thread. A diagram illustrates this with multiple wavy lines connecting to one 'k'. The instructor explains that if a blocking system call occurs, the entire process blocks, even if other threads could continue. He writes "T1L" and "T2L" on the diagram to label specific user threads and "P1" to denote the process. He notes that because a single kernel thread operates on only one CPU, this model cannot split processes across multiple CPUs. He mentions Green threads for Solaris as a historical example.

  2. 2:00 – 3:14 02:00-03:14

    The presentation transitions to the "One-To-One Model," creating a separate kernel thread for each user thread. The diagram changes to show four distinct 'k' circles, each linked to a wavy line. The instructor highlights that this model overcomes blocking system call issues and allows splitting across multiple CPUs. However, he points out the significant overhead involved in managing these threads. He cites Linux and Windows 95 to XP as implementations. The final segment introduces the "Many-To-Many Model," which multiplexes user threads onto an equal or smaller number of kernel threads. The diagram shows multiple user threads mapping to three kernel threads. This approach combines the best features of previous models, allowing variable allocation of kernel threads based on CPU count.

The lecture provides a comprehensive overview of multithreading architectures. It starts by establishing the fundamental difference between user and kernel threads. The Many-to-One model is critiqued for its inability to handle parallelism and blocking calls effectively. The One-to-One model is presented as a robust alternative that enables true parallelism but suffers from high overhead. Finally, the Many-to-Many model is described as a hybrid solution that balances flexibility and performance by allowing the kernel to manage a pool of threads for user-level execution efficiently and effectively. This progression illustrates the evolution of threading strategies to optimize system performance and resource management.

Loading lesson…