Essay On Multiprogramming

An operating system is a program that acts as an intermediary between the user of a computer and the computer hardware. It is an essential part of the computer system and provides an environment in which the user can execute programs. The main functions of an operating system are: 1) To provide an environment where a computer user can execute programs on computer hardware in a convenient and efficient way. 2) To allocate the different resources of the computer as and when needed to solve a given problem. The allocation made should fair and as efficient as possible. 3) As a control program it serves two major functions: (1) To supervise the execution of user programs so as to prevent errors and improper use of the computer, and (2) To manage

The term multiprogramming is defined, in a uni-processor system, as the ability to execute more than one application concurrently. This can be achieved by time-slicing the processor among multiple applications in the system, giving the illusion that each application possesses its own processor. In a multiprogramming system, multiple processes are stored and maintained in main memory. The objective of multiprogramming is to have some process running at all times, to maximize CPU utilization [7]. Each process can be defined by the portion of memory that contains the program which is being executed by the process (along with its associated data), and by the contents of the Central Processing Unit (CPU) registers used by the process.. Each process also alternates between processor usage and input/output (I/O) event occurrences. The latter could wait for an I/O to be performed or for some other external event to occur. The processor will execute one process at a time, but will switch to another process, if the latter is waiting for an event. The processor will thus be kept busy by executing a specific process, while all other system processes are in queue (either for the processor or for an