What are operating system services? Get know more about Operating system.

OPERATING SYSTEM SERVICES

As discussed earlier, the main purpose of operating system is to provide environment for the execution of programs. Thus, an operating system provides certain services to programs and the users of those programs.

However, different operating systems can provide different set of services. Some of the basic services provided by operating system are :

1.      Program Execution

·        Operating system provides a convenient environment where users can run their programs.

·        The operating system performs memory allocation to programs, load them into appropriate location so that they can execute. The users need not to worry about all these tasks.

2.      I/o Operations

·        In order to execute a program, it usually requires an I/O operations. For example, it may need to read a file and print the output.

·        When all these l/O operations are performed users cannot control I/O devices.

·        All I/O are performed under the control of operating system.

3.      File System Manipulation

·        The execution of a program may involve reading data from a file or writing data to a file. It may also require to create or delete a certain file.

·        The operating system provides all these operations and performs secondary storage management.

·        The users just give commands to read or write a particular file, the rest of work is done by an operating system .

4.      Communication

·        The various processes executin g on a system may need to communicate inorder to exchange data or information.

·        Operating system provides this communication by using a facility of message passing. In message passing packets of information are moved between processes by the operating system.

5.      Error Detection

·        When various programs are executing on a system involving various resources, an error may occur

·        Error may occur in CPU and memory hardware (such as a memory error or a power failure), in I/O devices and in user programs (such as stack overflow an attempt to access an illegal memory location.)

·        In such a situation, the operating system constantly monitors the system for detecting the errors.

·        For each type of error, the operating system takes the appropriate actio ensdre correct and consistent computing .

6.      Resource Allocation

·        When multiple processes are running on a system or multiple users are logged on, large variety of resources may be used by each process or a user.

·        These resources may be CPU cycles, main memory, files, I/O devices etc.

·        The operating system manages all these resources and uses different algorithms to satisfy the requirements of different processes or users.

7.      Accounting  

·        When multiple resources are allocated to different processes in multiprogramming, the operating system keeps track of which user or process has how many resources and of which kind.

·        This kind of record eeping by an OS is known as accounting.

8.      Protection

·        When several processes are executing concurrently, it is important that s should not interfere with each other. Moreover, these different processe processes should not also interfere with operating system.

·        Thus, an operating system provides protection to ensure that all the access to system resources is controlled.

·        An operating system also provides security to the system by authenticating different users by means of passwords, artifacts or biometrics. Only the authorized users are allowed to access the system.

·        The operating system also defends the external VO devices, including modems and network adapters from invalid access attempts.