It allows programs to use a set of operations that

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Unformatted text preview: ter system is used to simultaneously handle several applications, there may be many, possibly conflicting, requests for resources. In such a situation, the operating system must decide which requests are allocated resources to operate the computer system efficiently and fairly (providing due attention to all users). The efficient and fair sharing of resources among users and/or programs is a key goal of most operating systems. Main Functions of an Operating System We saw that an operating system provides certain services to programs and to the users of those programs. The; specific services provided will, of course, differ from one operating system to another, but there are some common types of functions that we can identify. The main functions provided by most operating systems of today are as follows: 1. Process Management. A process is a program in execution. During execution, a process needs certain resources such as CPU time, memory space, files, and I/O devices. At a particular instance of time, a computer "system normally consists of a collection of processes. The process management module of an operating system takes care of the creation and deletion of processes, scheduling of various system resources to the different processes requesting them, and providing mechanisms for synchronization and communication among processes. 2. Memory Management. To execute a program, it must be loaded, together with the data it accesses, in the main memory (at least partially). To improve CPU utilization and to provide better responses time to its users, a computer system normally keeps several programs in main memory. The memory management module of an operating system takes care of the allocation and deal location of memory space to the various programs in need of this resource. 3. File Management. All computer systems are used for storage, retrieval and sharing of information. A computer normally stores such information in units called files. Processes can read information from files and can create new files for storing newly generated information. Information stored ii files is made persistent by storing them on a secondary storage media s...
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