System Call

Duration: 3 min

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Module outline

  1. HPSC Interview Preparation: Interview Preparation
  2. Python Language: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis, DSA using Python
  3. Data Structure & Algorithms: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, Algorithm Analysis, Sorting Algorithms, Minimum Spanning Trees, Time Complexity Analysis, Graph Theory, Shortest Path Algos
  4. Computer Networks: Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware basics, Network Security
  5. Computer System & Organisation: Basics of COA, Cache Memory Organization, Input Output Organisation, Pipelining, Instr Formats & Modes, Control Unit Design, Programming the Basic Computer
  6. Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, SQL, File Organization & Indexing, Transaction Management, Concurrency Control
  7. Operating Systems: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling
  8. Digital Logic & Circuits: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation
  9. Theory Of Computation: Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Grammar, Regular Language Properties, Pushdown Automata & CFG, Turing Machines, Moore & Mealy Machines
  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. Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management, Data Warehousing & Mining
  12. Introduction to Emerging Trends: Emerging Tech Trends
  13. Digital Society & Cyber Law: Society, Law & Ethics
  14. HPSC PGT Previous Year Paper:
  15. HPSC Assistant Professor Previous Year Paper:
  16. Live Sessions: HPSC Live Sessions, EMRS TGT/PGT Live Class
  17. Full Mock Test:
  18. HPSC PGT - MOCK Test Series:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

The lecture introduces the fundamental concept of system calls within operating systems, defining them as the critical interface between user programs and the kernel. It explains that system calls provide the means for a user program to request services reserved for the operating system to perform on its behalf. The instructor details the role of the Application Programming Interface (API) in specifying available functions, parameters, and return values. The presentation then transitions to categorizing system calls into six major groups: process control, file manipulation, device manipulation, information maintenance, communications, and protection. Specific examples for process control and file management are provided to illustrate these categories, highlighting the practical application of these theoretical concepts in software development.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The instructor begins by defining system calls using a slide titled 'System call'. He explains that system calls provide the means for a user program to ask the operating system to perform tasks on its behalf. The slide notes that these calls are generally routines written in C and C++. A diagram illustrates the flow from 'User Programs' through 'System Calls' to the 'Kernel' and finally 'Hardware'. The instructor emphasizes that the API specifies the set of functions available to programmers, including parameters and return values. He mentions common APIs like Windows API, POSIX API, and Java API, noting that the caller need only obey the API without knowing the implementation details. He highlights that the API is the interface to the services made available by the operating system.

  2. 2:00 – 2:58 02:00-02:58

    The lecture shifts to 'Types of System Calls', grouping them into six categories: process control, file manipulation, device manipulation, information maintenance, communications, and protection. The instructor focuses on 'Process control', listing examples such as end, abort, load, execute, create process, terminate process, and memory allocation. He then briefly shows a slide on 'File management', listing operations like create file, delete file, open, close, read, write, and reposition. This section provides concrete examples of how system calls are categorized based on the services they provide to the user program. The instructor uses checkmarks to indicate the items being discussed on the slide.

The video effectively bridges the gap between high-level programming concepts and low-level OS operations. By defining system calls as the essential interface and then categorizing them, the lecture provides a structured understanding of how user applications interact with the kernel. The progression from definition to API details to specific types (process control, file management) creates a comprehensive overview of system call mechanisms. This structured approach helps students understand the hierarchy and purpose of system calls in managing system resources.

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