Operating System Services
An operating system provides an environment for the execution of the program. It provides some services to the programs. The various services provided by an operating system are as follows:
• Program Execution:
The system must be able to load a program into memory and to run that program. The program must be able to terminate this execution either normally or abnormally.
• I/O Operation:
A running program may require I/O. This I/O may involve a file or a I/O device for specific device. Some special function can be desired. Therefore the operating system must provide a means to do I/O.
• File System Manipulation:
The programs need to create and delete files by name and read and write files. Therefore the operating system must maintain each and every files correctly.
The communication is implemented via shared memory or by the technique of message passing in which packets of information are moved between the processes by the operating system.
• Error detection:
The operating system should take the appropriate actions for the occurrences of any type like arithmetic overflow, access to the illegal memory location and too large user CPU time.
• Research Allocation:
When multiple users are logged on to the system the resources must be allocated to each of them. For current distribution of the resource among the various processes the operating system uses the CPU scheduling run times which determine which process will be allocated with the resource.
The operating system keep track of which users use how many and which kind of computer resources.
The operating system is responsible for both hardware as well as software protection. The operating system protects the information stored in a multiuser computer system.