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Input/Output Management GROUP 5 Arao Bañas Dubria Lumigue Madlos What is INPUT/OUTPUT MANAGEMENT Input/Output (I/O) Management is crucial in operating systems, bridging the gap between software and hardware. It manages data transfer between the computer and external d...

Input/Output Management GROUP 5 Arao Bañas Dubria Lumigue Madlos What is INPUT/OUTPUT MANAGEMENT Input/Output (I/O) Management is crucial in operating systems, bridging the gap between software and hardware. It manages data transfer between the computer and external devices like disks, keyboards, and printers. The OS controls data flow, making sure it's efficient and error-free. Without I/O management, applications would need to handle hardware communication directly, which would be complex and inconsistent.  I/O DEVICES: Physical components like keyboards, printers, and storage drives that interact with the computer Key BUFFERS: Components Temporary storage areas for data being transferred, which help manage speed of I/O differences between devices and software Management DEVICE DRIVERS: Specialized programs that allow the OS to communicate with specific hardware devices  examples I/O DEVICES BUFFERS DEVICE DRIVERS Keyboard Print Buffer Graphics Driver Printer Keyboard Printer Driver Storage Drives (e.g., Buffer Network Adapter SSDs, HDDs, USB Network Buffer Driver drives) Monitor Sound Card Driver Monitor Disk Cache USB Controller Network Card Driver  Enable smooth data transfer Objectives between software and of I/O hardware. Management Improve overall system performance by efficiently in OS handling device requests. Ensure security and error handling during data transfers.  SYSTEM CALLS IN I/O MANAGEMENT System Calls: Commands the OS provides for applications to perform basic file and device operations, like open(), read(), write(), and close(). open(): Opens a file or device for reading or writing. read(), write(): Transfers data to/from a file or device. close(): Closes the connection to a file or device when done. System calls create a bridge between user applications and the hardware, allowing the OS to control access and keep operations secure. ioctl(): An advanced system call on Linux, allows device-specific commands for hardware interactions (e.g., changing the display settings of a monitor).  I/O Management FILE I/O OPERATIONS File I/O operations in Python allow reading from and writing to files using the `open()` function. To write, open the file in `"w"` mode and use `write()`. To read, open the file in `"r"` mode and use `read()`. The `with` statement automatically closes the file after the operations. - -  I/O Management INTERACTING WITH DEVICE FILES ON LINUX In Linux, device files represent system resources. The code opens /dev/null in write mode and writes a message to it. Since /dev/null discards any data written to it, the message is effectively ignored, demonstrating how device files can be used like regular files, but with specific behaviors. - -  I/O Management DEVICE I/O USING IOCTL() ON LINUX The ioctl() system call in Linux is used for device-specific operations, like controlling hardware. In Python, fcntl.ioctl() is used to interact with device files. The code opens a device file with os.open(), then uses fcntl.ioctl() to send a control command to the device. After the operation, the file is closed with os.close(). The specific command and arguments depend - - on the device being accessed.  I/O SYSTEM CALLS ON DIFFERENT OPERATING SYSTEMS Windows Commands: diskpart Opens the DiskPart command-line tool for managing disk partitions. Get-Volume PowerShell command to retrieve details about volumes, such as filesystem type, size, and label. DISKPART COMMAND GET-VOLUME COMMAND  I/O SYSTEM CALLS ON DIFFERENT OPERATING SYSTEMS Linux Commands: lsblk: Lists information about block devices, such as hard drives and partitions fdisk -l: Displays the partition tables of all available disks mount: Shows currently mounted file systems (useful for checking which partitions are mounted) umount: Unmounts a file system (to safely remove or alter a mounted partition  INTERACTING WITH NETWORK DEVICES In client.py, a TCP client socket connects to the server on localhost at port 8080, receives the server's message, prints it, and then closes the connection. Client.py Server.py In server.py, a TCP server socket is created and bound to port 8080. It listens for a client connection, sends a message upon connection, and then closes the socket. I/O IN DIFFERENT OPERATING SYSTEMS Windows: Uses Windows Driver Model (WDM) for driver standardization, Device Manager for centralized control, Plug and Play (PnP) for easy device setup, and I/O Request Packets (IRPs) to manage data flow. Linux: Employs kernel and user space separation, treats devices as files in /dev, supports modular drivers (loadable without reboot), and uses the Virtual File System (VFS) for unified device access. - - I/O IN DIFFERENT OPERATING SYSTEMS macOS: Utilizes I/O Kit, an object-oriented driver framework, offers device abstraction for easy plug-and-play, and leverages its UNIX-based architecture for flexibility. Android: Based on a modified Linux kernel with a Hardware Abstraction Layer (HAL) for broad hardware support and the Binder IPC for efficient inter-process communication UNIX: Treats devices as files in /dev, supports I/O redirection for automation, and adheres to POSIX standards for compatibility across UNIX-like systems. - - HOW I/O SYSTEM CALLS INTERACT WITH HARDWARE DEVICES I/O system calls act as an intermediary between software applications and hardware or virtual devices. When a program makes an I/O request, the system call sends the request to the operating system, which then communicates with the hardware or virtual device. For physical devices, this may involve interacting with device drivers, which translate the software request into hardware-specific instructions. HOW I/O SYSTEM CALLS INTERACT WITH VIRTUAL DEVICES For virtual devices, the OS treats them as if they were physical devices, but the requests are routed through software, such as a hypervisor or virtual machine manager, which handles the interaction with the underlying physical resources. This abstraction allows programs to interact with both real and virtual devices without needing to know their specifics.  REAL-WORLD APPLICATIONS OF DEVICE AND FILE I/O OPERATIONS Real-world applications of device and file I/O operations are integral to many software systems. Operating systems use file I/O to manage user data, including reading and writing files to disk storage. Database management systems rely on file I/O to store and retrieve large amounts of data efficiently. Web servers handle file I/O to serve static content like images or HTML files to clients. Embedded systems,device I/O operations enable communication with hardware such as sensors or actuators Networking, I/O operations are crucial for sending and receiving data packets over the internet. Virtual devices like virtual disks or network interfaces in cloud computing environments use I/O operations to simulate physical resources and facilitate resource management across multiple virtual machines.  KEY TAKEAWAY System Calls for I/O: System calls like open, read, write, and ioctl enable applications to interact with files and devices, abstracting the complexity of hardware communication. Device Abstraction: The OS provides a consistent interface for interacting with physical and virtual devices, allowing applications to perform I/O operations without hardware-specific knowledge. Real-World Relevance: I/O operations support critical functionalities in applications ranging from data logging and media streaming to hardware communication in embedded systems and IoT devices.