Lecture Notes: Process States and OS Components

Question-and-answer flashcards covering processes, states, modes, interrupts, OS architecture, and key Windows/Linux UNIX terms from the notes.

A program in execution; an instance of a program running on a computer that can be assigned to and executed on a processor.

Process

A data structure that stores all information about a process, enabling interruption and resumption.

Process Control Block (PCB)

A state where the process is prepared to execute but is waiting to be assigned to a processor by the OS dispatcher.

Ready State

The state where the process is currently being executed by the processor.

Running State

A state where a process cannot execute until a specific event occurs, such as the completion of an I/O operation.

Blocked/Waiting State

A process that is not immediately available for execution, placed in this state by itself, a parent process, or the OS, independent of being blocked.

Suspended Process

A privileged mode of execution where the OS kernel has complete control over the processor, its instructions, and memory.

Kernel Mode

A less-privileged mode of execution where user programs run, with restricted access to certain instructions and memory regions.

User Mode

An external event, independent of the currently running process, that alerts the OS and can cause a process switch.

Interrupt

An internal event related to an error or exception condition generated within the currently running process, which can cause a process switch.

Trap

Software that manages a computer's hardware resources and provides services to users and application programs.

Operating System (OS)

The core, most privileged part of a operating system that controls processes, manages memory, and handles low-level hardware interaction.

Kernel

An early form of computing where programmers interacted directly with hardware without an OS, leading to scheduling issues and significant setup time.

Serial Processing

A system that improves processor utilization by processing jobs in bulk using a monitor program to automatically sequence them.

Batch Processing

A system where several jobs are kept in memory at once, allowing the processor to switch between them to increase overall efficiency.

Multiprogramming

An OS that allows multiple users to access a system simultaneously through terminals, with the CPU time split into small quanta for each user.

Time-sharing System

A set of functions that allows application programs to access the hardware resources and services of a system.

Application Program Interface (API)

The core component of the Windows OS that contains base OS services and provides an API for user-mode software.

Windows Executive

A layer of code that isolates the OS kernel from platform-specific hardware differences.

Hardware Abstraction Layer (HAL)

A family of multitasking, multiuser computer operating systems originally developed at Bell Labs, known for its portability and modular design.

UNIX

The central component of an OS that manages system resources and facilitates communication between hardware and software components.

System Kernel

An object file whose code can be dynamically linked and unlinked from the kernel at runtime, used for adding features like device drivers.

Loadable Module (Linux)

A Linux-based operating system originally designed for mobile devices, consisting of a software stack including a modified Linux kernel, middleware, and apps.

Android

A unique numeric identifier assigned by the OS to each process for management and cross-referencing.

Process Identifier

A register that holds the memory address of the next instruction to be executed for a specific process.

Program Counter

The data present in a processor's registers during the execution of a process, which must be saved during an interrupt.

Context Data

A Windows Executive component that provides a framework for applications to access input/output devices.

I/O Manager

An OS component that manages the mapping of virtual addresses to physical memory and disk-based paging files.

Virtual Memory Manager

A Windows Executive component that enforces access validation and audit rules for all protected objects like files and processes.

Security Reference Monitor

A Windows Executive component that creates, manages, and deletes objects that represent system resources like processes and threads.

Object Manager

The state of a process that has just been created but not yet admitted by the OS to the pool of executable processes.

New State

The state of a process that has been released from the pool of executable processes, either because it halted or was aborted.

Exit State

The act of the OS saving the context of the currently running process and loading the saved context of a new process to run.

Process Switching

The conclusion of a process's execution, initiated by the process itself, a parent process, or the OS, freeing its resources.

Process Termination

The fundamental program in early batch processing systems that controlled the automatic sequencing of jobs.

Monitor (Resident Monitor)