3704e204-410e-4bab-a7e6-3d5445948200.pptx

Operating system

1. Department of Applied Computational Science & Engineering Course Code: BCS401 Course Name: Operating System

2. Topics to be Covered Introduction to the operating system : Introduction : Operating system and functions, Classification of Operating systems- Batch, Interactive, Time sharing, Real-Time Systems, Multiprocessor Systems, Multiuser Systems, Multiprocessor Systems, Multithreaded Systems, Operating System Structure- Layered structure, System Components, Operating System services, Reentrant Kernels, Monolithic, and Microkernel Systems.

3. Introduction to Operating Systems Operating systems are the essential software that manage the hardware and software resources of a computer. They act as the intermediary between users and the computer's components, enabling seamless interaction and efficient utilization of system resources. Department of Applied Computational Science & Engineering

4. Definition and Purpose of Operating Systems An operating system (OS) is the software that manages a computer's hardware and software resources, providing a platform for applications to run. It serves as the intermediary between users, programs, and the underlying computer components. The primary purpose of an OS is to ensure efficient and reliable operation of a computer system, allowing users to interact with the hardware and execute various tasks and programs. Department of Applied Computational Science & Engineering

5. Evolution of Operating Systems 1 Early Computing In the 1940s and 1950s, early computers relied on batch processing and required manual operator intervention to execute programs. 2 Mainframe Era The 1960s saw the rise of mainframe computers, which introduced concepts like time-sharing and multiprogramming to improve resource utilization. 3 Personal Computing The 1970s and 1980s brought the personal computer revolution, with the development of graphical user interfaces and affordable home systems. Department of Applied Computational Science & Engineering

6. Example of Operating Systems Windows The most widely used desktop operating system, Windows offers a familiar and user-friendly graphical interface. It powers a vast ecosystem of software and devices, making it a popular choice for both personal and enterprise use. macOS Developed by Apple, macOS is known for its sleek design, tight integration with Apple hardware, and robust security features. It is a popular choice among creative professionals and those who prefer a streamlined computing experience. Linux Linux is a open-source operating system that offers a high degree of customization and flexibility. It is widely used in servers, supercomputers, and embedded systems, and is gaining popularity among developers and IT professionals. Mobile OSes Mobile operating systems, such as iOS and Android, are designed for smartphones and tablets. They offer a touch-based interface and a wide range of apps and services optimized for on-the-go use. Department of Applied Computational Science & Engineering

7. Key Functions of Operating Systems 1 Process Management Coordinates the execution of multiple programs and allocates system resources like CPU, memory, and I/O devices. 2 Memory Management Efficiently allocates and manages the computer's limited memory resources to ensure optimal performance. 3 File Management Organizes files and folders, provides access control, and manages the storage and retrieval of data. 4 Input/Output Management Handles the communication between the computer and external devices like keyboards, mice, printers, and displays. Department of Applied Computational Science & Engineering

8. Process Management Process management is a key function of operating systems. It involves creating, scheduling, and managing the execution of individual processes, which are instances of running programs. The operating system allocates system resources to processes, such as CPU time, memory, and I/O access, ensuring efficient and fair utilization of the hardware. Department of Applied Computational Science & Engineering

9. Memory Management Memory management is a crucial function of operating systems, responsible for efficiently allocating and controlling the computer's memory resources. It ensures that programs and data are loaded and executed correctly. Key aspects of memory management include virtual memory, paging, and segmentation, which allow the OS to provide each process with its own protected address space. Department of Applied Computational Science & Engineering

10. File Management File management is a critical function of modern operating systems, allowing users to organize, access, and manipulate digital files and directories. This includes creating, deleting, modifying, and searching for files and folders across the system's storage devices. Effective file management enables efficient data organization, retrieval, and backup, allowing users to seamlessly work with their digital content. Operating systems provide intuitive file management interfaces, empowering users to manage their files and directories with ease. Department of Applied Computational Science & Engineering

11. Input/Output Management Operating systems play a crucial role in managing the flow of data between computers and external devices. This includes managing input from keyboards, mice, and other input peripherals, as well as directing output to displays, printers, and storage devices. Efficient I/O management ensures data is seamlessly transferred, with the OS handling communication protocols, buffering, and error handling to provide a smooth user experience. Department of Applied Computational Science & Engineering

12. Security and Protection Mechanisms Implement access control policies to restrict unauthorized access to system resources. Utilize encryption techniques to protect sensitive data during storage and transmission. Implement firewalls to monitor and control network traffic, blocking potential threats. Employ antivirus and malware protection software to detect and remove malicious code. Regularly backup critical data and maintain secure offsite storage for disaster recovery. Department of Applied Computational Science & Engineering

13. Introduction to Operating Systems Operating systems are the fundamental software that manage a computer's hardware and software resources, providing a platform for applications to run. They play a crucial role in determining how a computer functions and interacts with users and other devices. Department of Applied Computational Science & Engineering

14. Batch Processing Systems Batch processing systems are a type of operating system where tasks are executed in a predetermined order, without user interaction. Programs are submitted in groups or "batches" and processed automatically, with no immediate feedback to the user. Efficient for high-volume, repetitive tasks like payroll or billing Allows for optimized resource utilization and scheduling of jobs Ideal for large-scale, non-interactive tasks that can be executed overnight or during off-peak hours Department of Applied Computational Science & Engineering

15. Characteristics of Batch Processing Systems Batch processing systems are designed to handle large volumes of data and tasks in a sequential, non-interactive manner. They execute jobs in a predefined order, with no user intervention required during runtime. Batch systems are highly efficient for repetitive, high-volume tasks such as payroll processing, inventory management, and report generation. They minimize human interaction and provide consistent, reliable results. Department of Applied Computational Science & Engineering

16. Interactive Systems Interactive systems are computer programs that allow direct user interaction and immediate response. Users can input data, make selections, and receive output in real-time. These systems provide a more engaging and efficient user experience compared to batch processing. Examples include web browsers, graphic design software, and video games. Department of Applied Computational Science & Engineering

17. Characteristics of Interactive Systems Interactive systems allow users to directly input commands and receive immediate feedback. They enable real-time interaction, enabling users to control and manipulate the system dynamically. These systems are designed for individual users, providing a personalized experience. They facilitate prompt responses and enable users to make on-the-fly adjustments based on the system's output. Department of Applied Computational Science & Engineering

18. Time-Sharing Systems Time-sharing systems allow multiple users to access a single computer simultaneously. They divide the computer's resources, such as CPU time and memory, among the users, providing each with the illusion of having the system to themselves. This enables efficient utilization of computing power and allows for interactive, multi-user applications. Enables concurrent access to a single computer by multiple users Divides system resources like CPU time and memory among users Provides the perception of exclusive access for each user Allows for interactive, multi-user applications and efficient resource utilization Department of Applied Computational Science & Engineering

19. Characteristics of Time-Sharing Systems Time-sharing systems allow multiple users to access a single computer simultaneously, dividing processing time and resources among them. This enables efficient and interactive usage, with users able to run programs and access data in real-time. These systems often feature advanced scheduling algorithms, virtual memory management, and robust security measures to ensure fair and secure access for all users. Department of Applied Computational Science & Engineering

20. Real-Time Systems Real-time systems are designed to process data and respond within a specified time frame, often in milliseconds. These systems prioritize immediate and predictable responses, making them critical for applications like flight control, medical monitoring, and industrial automation. Real-time systems must have the ability to: Respond to events within a guaranteed time period Maintain a high degree of reliability and availability Prioritize critical tasks to ensure the most important operations are executed first Department of Applied Computational Science & Engineering

21. Characteristics of Real-Time Systems Real-time systems are designed to handle time-critical tasks, ensuring immediate response to events. They prioritize responsiveness over efficiency, with strict deadlines for task completion. These systems feature deterministic behavior, guaranteed execution times, and the ability to handle interrupts and task preemption. Reliability and fault tolerance are crucial, as real-time systems are often used in safety-critical applications. Department of Applied Computational Science & Engineering

22. Comparison and Conclusion Batch Processing Batch systems are best suited for repetitive, high-volume tasks that can be processed without user interaction. They offer efficient resource utilization but lack flexibility and responsiveness. Interactive Systems Interactive systems provide immediate user feedback and allow for real-time decision-making. They are well-suited for tasks requiring user input and dynamic responses, but may have higher resource requirements. Time-Sharing Systems Time-sharing systems enable multiple users to access a single computer system concurrently, improving efficiency and resource utilization. However, they may suffer from longer response times compared to dedicated systems. Real-Time Systems Real-time systems are designed to respond to events within strict time constraints, ensuring critical tasks are completed on time. They are essential for applications where timing is crucial, such as medical devices and industrial control systems. Department of Applied Computational Science & Engineering

23. Introduction to Multiprocessor, Multiuser, Multiprocess, and Multithreaded Systems Explore the diverse world of modern computing systems, where multiple processors, users, processes, and threads harmoniously converge to unlock unprecedented levels of performance and efficiency. Aa Department of Applied Computational Science & Engineering

24. Multiprocessor Systems: Architecture and Advantages Parallel Processing Multiprocessor systems leverage multiple CPUs working in parallel to tackle complex computational tasks, dramatically increasing processing power and efficiency. Fault Tolerance If one processor fails, the system can continue operating by redistributing the workload across the remaining functional processors, ensuring high availability. Scalability Multiprocessor architectures can be easily scaled by adding more processors, allowing the system to adapt to growing computational demands. Resource Sharing Processors in a multiprocessor system share access to common memory and I/O resources, enabling efficient data exchange and coordination. Department of Applied Computational Science & Engineering

25. Multiuser Systems: Resource Sharing and Access Control In multiuser systems, multiple users share common system resources, such as processor time, memory, and storage. Effective resource allocation and access control mechanisms are crucial to ensure fair and secure usage. Access control policies define which users can perform specific actions on resources, preventing unauthorized access and protecting sensitive information. User authentication, permission levels, and audit trails are essential components of a robust access control system. Department of Applied Computational Science & Engineering

26. Multiprocess Systems: Process Management and Scheduling Multiprocess systems involve the concurrent execution of multiple independent processes, each with its own address space and resources. Efficient process management and scheduling are crucial for optimizing system performance and ensuring fair resource allocation. Process Creation and Termination: Processes are dynamically created and terminated to handle user requests and system tasks. Process Scheduling: Advanced scheduling algorithms, such as round-robin , priority-based , and multilevel feedback , are used to determine the order of process execution. Inter-Process Communication (IPC): Processes communicate and coordinate using mechanisms like pipes , shared memory , and message queues . Department of Applied Computational Science & Engineering

27. Multithreaded Systems: Concurrency and Synchronization 1 Concurrency Multithreaded systems allow multiple tasks to execute concurrently, improving efficiency and responsiveness. However, this introduces challenges around shared resources and race conditions. 2 Synchronization Synchronization mechanisms like locks, semaphores, and monitors are used to coordinate access to shared resources and ensure data integrity in multithreaded environments. 3 Deadlocks and Livelocks Careful thread management is crucial to avoid deadlocks, where threads are indefinitely blocked, and livelocks, where threads continually interfere with each other without making progress. Department of Applied Computational Science & Engineering

28. Memory Management in Multiprocessor and Multiuser Systems In multiprocessor and multiuser systems, efficient memory management is critical to ensure optimal resource utilization and prevent conflicts. This involves dynamic allocation, virtual memory techniques, and advanced caching strategies to balance the needs of multiple concurrent processes and users. Careful memory partitioning, page replacement algorithms, and seamless memory paging are essential for maintaining high performance and preventing thrashing or deadlocks in these complex environments. Department of Applied Computational Science & Engineering

29. Input/Output and Device Management in Multiprocessor and Multiuser Systems Storage Management Efficient management of storage devices like hard drives, SSDs, and network storage to meet the demands of multiple users and processes. Printer and Peripheral Control Coordinating access and priority for shared printer and peripheral devices to ensure fair and reliable usage across the system. Network Integration Seamless integration of network interfaces and protocols to enable data transfer and communication between multiprocessor and multiuser systems. I/O Bandwidth Optimization Techniques to maximize I/O throughput and minimize latency to support the high-performance demands of multiprocessor and multiuser environments. Department of Applied Computational Science & Engineering

30. Security Considerations in Multiprocessor and Multiuser Systems Access Control Implement robust user authentication and authorization mechanisms to restrict access to sensitive resources and prevent unauthorized actions. Isolation and Sandboxing Utilize virtualization and containerization technologies to isolate processes and users, limiting the impact of security breaches. Secure Communications Ensure secure communication channels between system components and users to prevent eavesdropping and data tampering. Monitoring and Auditing Implement comprehensive logging and auditing systems to detect and respond to security incidents in a timely manner. Department of Applied Computational Science & Engineering

31. Performance Optimization and Benchmarking 1 Workload Analysis Analyze the system's workload to identify bottlenecks and opportunities for optimization. Understand the resource demands and patterns of your applications and users. 2 Resource Tuning Optimize the allocation and utilization of system resources like CPU, memory, storage, and network. Fine-tune configurations to match the workload and maximize efficiency. 3 Benchmark Testing Conduct comprehensive benchmark tests to measure and analyze the system's performance under various loads and conditions. Use industry-standard tools and methodologies. 4 Iterative Improvements Apply learnings from benchmarking to refine the system's configuration and architecture. Continuously monitor performance and make incremental improvements over time. Department of Applied Computational Science & Engineering

32. Emerging Trends and Future Developments As technology continues to evolve, the landscape of multiprocessor, multiuser, multiprocess, and multithreaded systems is poised to undergo transformative changes. Advancements in quantum computing , artificial intelligence , and edge computing are expected to revolutionize the way these systems are designed and deployed. The rise of 5G and 6G networks will enable faster, more reliable data transmission, paving the way for real-time, mission-critical applications that require low latency and high bandwidth. Neuromorphic computing and programmable hardware will also play a crucial role in enhancing the efficiency and flexibility of these systems. Department of Applied Computational Science & Engineering

33. Operating System Structure The operating system is the foundation of a computer system, providing a structure that manages hardware resources and facilitates interaction between software and hardware. This layered architecture ensures stability, security, and efficient use of system components. Department of Applied Computational Science & Engineering

34. Layered Structure Abstraction Layers The operating system employs a layered architecture, where each layer provides a specific set of services and abstractions to the layers above it. This modular design promotes isolation, flexibility, and efficient resource management. Kernel and User Mode The kernel layer, the core of the OS, operates in a privileged 'kernel mode', handling critical system tasks. The user applications run in a less privileged 'user mode', accessing system resources through well-defined interfaces. Hardware Abstraction Lower layers of the OS abstract away the complexities of the underlying hardware, presenting a consistent and standardized interface to the upper layers. This allows applications to run seamlessly across diverse hardware platforms. Interoperability The layered structure facilitates interoperability, as each layer can be independently updated or replaced without affecting the overall system functionality, enabling the OS to evolve and adapt to changing requirements. Department of Applied Computational Science & Engineering

35. System Components Hardware The physical components of a computer system, such as the processor, memory, storage devices, and input/output devices. Software The programs and data that control the hardware, including the operating system, applications, and system utilities. Firmware Low-level software that is embedded in the hardware, providing basic control and functionality for the system. Drivers Software that enables the operating system to communicate with and control the various hardware components. Department of Applied Computational Science & Engineering

36. Operating System Services Operating systems provide a variety of essential services to users and applications. These include process management, memory management, file management, I/O management, and security and protection services. Process Management: Handles the creation, execution, and termination of processes , ensuring efficient resource allocation and scheduling. Memory Management: Manages the allocation and deallocation of memory , providing isolation and protection for running processes. File Management: Provides a hierarchical file system for storing and retrieving data, with access control and metadata management. Department of Applied Computational Science & Engineering

37. Process Management 1 Process Creation The operating system creates and manages processes, allocating resources like CPU time, memory, and I/O to enable multiple programs to run concurrently. 2 Process Scheduling The OS uses various scheduling algorithms to determine which processes get CPU time, ensuring fair and efficient use of system resources. 3 Inter-Process Communication Processes can communicate with each other through mechanisms like shared memory, message queues, and sockets, allowing them to coordinate and collaborate. Department of Applied Computational Science & Engineering

38. Memory Management Memory management is a critical component of operating systems, responsible for efficiently allocating and controlling the use of computer memory. It ensures programs have the required memory resources while preventing conflicts and optimizing performance. Key functions include virtual memory, paging, segmentation, and memory protection, allowing the OS to provide each process with its own secure, isolated memory space. Department of Applied Computational Science & Engineering

39. File Management The file management system is a crucial component of an operating system. It provides services for creating, storing, retrieving, and organizing files in a hierarchical directory structure. This allows users and applications to efficiently manage their data, ensuring reliable and secure access to information. Key file management functions include file creation, deletion, renaming, and permissions control. The file system also handles tasks like storage allocation, access control, and file backup and recovery, ensuring the integrity and availability of user data. Department of Applied Computational Science & Engineering

40. I/O Management The operating system manages a wide range of input and output (I/O) devices, including keyboards, mice, displays, printers, storage devices, and network interfaces. It provides a consistent interface for applications to access these devices. I/O management involves controlling data flow, scheduling requests, handling interrupts, and providing device drivers to abstract the underlying hardware. This ensures efficient and reliable I/O operations for the entire system. Department of Applied Computational Science & Engineering

41. Security and Protection Robust security measures are critical to safeguarding the integrity and confidentiality of the operating system. This includes access control, encryption, and monitoring mechanisms to prevent unauthorized access, data breaches, and system disruptions. Comprehensive protection also encompasses defensive strategies against malware, intrusion attempts, and other cyber threats, ensuring the overall resilience and trustworthiness of the operating environment. Department of Applied Computational Science & Engineering

42. Conclusion In conclusion, the operating system is the foundation of a computer system, providing essential services and managing critical resources to enable applications and users to function efficiently. By understanding the layered structure, core components, and key services of an operating system, we can appreciate the complexity and importance of this vital software layer. Department of Applied Computational Science & Engineering

43. Introduction to Kernel Architectures Explore the different architectural approaches used in operating system kernels. From monolithic designs to modular microkernel systems, understanding the trade-offs is crucial for building robust and efficient systems. a Department of Applied Computational Science & Engineering

44. What is a Reentrant Kernel? Concurrency Handling A reentrant kernel is able to handle multiple threads or processes concurrently, allowing the operating system to efficiently utilize system resources. Interruptibility The reentrant design enables the kernel to be interrupted and resumed without corrupting its internal data structures or states. Thread-Safe Reentrant kernels are designed to be thread-safe, meaning they can safely execute multiple threads of control within the same address space. Department of Applied Computational Science & Engineering

45. Benefits of Reentrant Kernels 1 Improved Efficiency Reentrant kernels can efficiently handle multiple concurrent processes by allowing the kernel code to be shared, reducing memory usage and improving overall system performance. 2 Enhanced Reliability Reentrant kernels are designed to be interruptible and able to resume execution after an interrupt without corrupting data or system state, improving the overall reliability of the operating system. 3 Scalability and Flexibility Reentrant kernels can scale to support more processors and handle increased workloads without significant performance degradation, making them suitable for a wide range of computing environments. 4 Optimized Memory Usage By allowing multiple processes to share the same kernel code, reentrant kernels can reduce the overall memory footprint of the operating system, leading to more efficient use of system resources. Department of Applied Computational Science & Engineering

46. Challenges of Reentrant Kernel Design Designing a reentrant kernel poses several key challenges. Ensuring thread-safe access to shared resources, such as data structures and device drivers, is crucial but complex. Managing concurrency and avoiding race conditions requires advanced synchronization mechanisms. Additionally, the kernel must maintain a consistent state even when multiple threads are executing simultaneously. This can lead to increased code complexity and potential vulnerabilities if not implemented carefully. Department of Applied Computational Science & Engineering

47. Monolithic Kernel Architecture A monolithic kernel is a traditional operating system architecture where all core system components are tightly integrated within a single, large program. This includes the file system, device drivers, memory management, and other critical functionality. Department of Applied Computational Science & Engineering

48. Advantages of Monolithic Kernels High Performance : Monolithic kernels have a tightly integrated architecture, allowing for efficient data exchange and fast response times. Easier Debugging : Since all kernel components are in a single address space, debugging and troubleshooting issues is generally simpler. Mature and Stable : Monolithic kernels like Linux and Windows have been actively developed and refined for decades, making them robust and reliable. Department of Applied Computational Science & Engineering

49. Disadvantages of Monolithic Kernels Lack of Modularity : Monolithic kernels are tightly-coupled, making it difficult to isolate and modify individual components without affecting the entire system. Limited Scalability : As the system grows in complexity, the monolithic design can become unwieldy, leading to performance bottlenecks and increased maintenance overhead. Security Risks : A vulnerability in one part of the monolithic kernel can potentially compromise the entire system, exposing the entire system to security threats. Department of Applied Computational Science & Engineering

50. Microkernel Architecture The microkernel architecture is a design approach where the kernel is minimized to only the essential functions, with most operating system services running in user-mode processes. This modular design offers increased security and reliability. Department of Applied Computational Science & Engineering

51. Advantages of Microkernels Improved reliability and stability since core OS components are isolated and more easily debugged Increased modularity and flexibility allowing for easy customization and updates to specific OS components Better security by containing damage from vulnerabilities to specific modules rather than the entire OS Department of Applied Computational Science & Engineering

52. Comparison and Tradeoffs Performance Monolithic kernels generally offer better performance due to their tight integration and reduced overhead. Microkernels, however, can be optimized for specific tasks, trading off some overall performance. Complexity Monolithic kernels have a higher degree of complexity as they contain all core system components. Microkernels, with their modular design, are generally simpler and easier to maintain. Flexibility Microkernels provide greater flexibility, as individual components can be swapped or upgraded without affecting the entire system. Monolithic kernels have a more rigid structure. Reliability Due to their isolation, microkernels can be more reliable, as a failure in one component does not bring down the entire system. Monolithic kernels, however, can be more robust if properly designed. Department of Applied Computational Science & Engineering