Tutorial Point Study

A Process Control Block is a data structure maintained by the Operating System for every process. The PCB is identified by an integer process ID (PID). A PCB keeps all the information needed to keep track of a process as listed below:  Process State: The current state of the process i.e., whether it is ready, running, waiting, or whatever. ...

System call is Programming interface to the services provided by the OS Typically written in a high-level language (C or C++) Mostly accessed by programs via a high-level Application Programming Interface (API) rather than direct system call use Three most common APIs are Win32 API for Windows, POSIX API for POSIX- based systems (including...

It is a module whose responsibility is to give control of a CPU to a process selected by short term scheduler for execution. It is invoked by short-term scheduler. The time taken by dispatcher to switch from one process to another is called as dispatch latency. To keep this switching overhead to minimum dispatcher should be as fast as possible. The...

The process scheduling is the activity of the process manager that handles the removal of the running process from the CPU and the selection of another process on the basis of a particular strategy. Process scheduling is an essential part...

A process is a program in execution. A program by itself is not a process. Program is a passive entity whereas process is an active entity. A thread is a lightweight process which is a basic unit of CPU utilization. Differences between process and thread. 1. Threads share the address space of the process that created it; whereas each process has...

Following are some of important functions of an operating System. Booting: Booting is a process of starting the computer. It checks the computer and makes it ready to work. Memory Management: Operating System does the following activities for memory management:  Keeps tracks of primary memory, i.e., what part of it are in use by whom,...

Interactivity refers to the ability of users to interact with a computer system. An Operating system does the following activities related to interactivity:  Provides the user an interface to interact with the system.  Manages input devices to take inputs from the user. For example, keyboard.  Manages output devices to show outputs to...

Network operating system is an operating system that provides features such as file sharing across the network and that includes the communication scheme that allows different processes on different computers to exchange messages. Example: Microsoft Windows Server 2003, Microsoft Windows Server 2008, UNIX, Linux, Mac OS X, Novell NetWare,...

Distributed system is a collection of physically separate, possibly heterogeneous, computer systems that are networked to provide the users with access to the various resources that the system maintains. Access to a shared resource increases computation speed, functionality, data availability, and reliability. In contrast to the tightly...

Following are a few common services provided by an operating system: Program execution: The system must be able to load a program in memory into memory and to run that program. The program must be able to end its execution either normally or abnormally. I/O operations: A running program may require I/O. OS must provide a means to access...

From the computer's point of view, the operating system is the program most intimately involved with the hardware. In this context, we can view an operating system as a resource allocator. A computer system has many resources that may be required to solve a given problem: to name the few the resources can be CPU time, memory space, file-storage...