The Complete Codes

Software Software is a collection of sets of programs, which are used to execute all kinds of specific instruction. It consists of a number of machine instructions, and arrays in a specific order to perform a particular task. Software is used to describe all the programs and their associated documents which run on a computer. So, a computer needs both software and hardware for its proper functioning. Software means computer instructions or data. Anything that can be stored electronically is software. Firmware is software (programs or data) that has been permanently written onto read-only memory (ROM) All software falls into two general types or categories: System Software and Application Software. System software consists of low-level programs that interact with the computer at a very basic level. This includes operating systems, compilers, and utilities for managing resources. On the other hand, application software includes database programs, word processors, and spreadsheets. Typ

The Purpose of The System Call The interface between a process and an operating system is provided by system calls. In general, system calls are available as assembly language instructions. They are also included in the manuals used by the assembly-level programmers. System calls are usually made when a process in user mode requires access to a resource. Then it requests the kernel to provide the resource via a system call. In general, system calls are required in the following situations: If a file system requires the creation or deletion of files. Reading and writing from files also require a system call. Creation and management of new processes. Network connections also require system calls. This includes sending and receiving packets. Access to a hardware device such as a printer, scanner, etc. requires a system call. Types of System Calls There are mainly five types of system calls. These are explained in detail as follows: Process Control These system calls deals with p

C-LOOK Disk Scheduling Algorithm- Circular-LOOK Algorithm is an improved version of the LOOK Algorithm. Head starts from the first request at one end of the disk and moves towards the last request at  the other end servicing all the requests in between. After reaching the last request at the other end, head reverses its direction. It then returns to the first request at the starting end without servicing any request in between. The same process repeats.

Look Disk Scheduling Algorithm LOOK Algorithm is an improved version of the SCAN Algorithm. Head starts from the first request at one end of the disk and moves towards the last request at the other end servicing all the requests in between. After reaching the last request at the other end, the head reverses its direction. It then returns to the first request at the starting end servicing all the requests in between. The same process repeats.

Introduction to SSTF disk scheduling : SSTF stands for Shortest Time First which very uses full of learning about how the disk drive manages the data having the shortest seek time.

Introduction to  First Come First Serve ( FCFS) disk scheduling :                     The simplest form of disk scheduling is, of course, the first-come, first-served (FCFS) algorithm. This algorithm is intrinsically fair, but it generally does not provide the fastest service. Consider, for example, a disk queue with requests for I/O to blocks on cylinders 98, 183, 37, 122, 14, 124, 65, 67. If the disk head is initially at cylinder 53, it will first move from 53 to 98, then to 183, 37, 122, 14, 124, 65, and finally to 67, for a total head movement of 640 cylinders.

Introduction to SCAN disk scheduling :                    In the SCAN algorithm, the disk arm starts at one end of the disk and moves toward the other end, servicing requests as it reaches each cylinder, until it gets to the other end of the disk. At the other end, the direction of the head movement is reversed, and servicing continues. The head continuously scans back and forth across the disk. The SCAN algorithm is sometimes called the elevator algorithm, since the disk arm behaves just like an elevator in a building, first servicing all the requests going up and then reversing to service requests the other way.

Introduction to C-SCAN disk scheduling :                     Circular SCAN (C-SCAN) scheduling is a variant of SCAN designed to provide a more uniform wait time.  Circular-SCAN The algorithm is an improved version of the  SCAN Algorithm .