An OS offers services to both the users and as well as to the programs.
It offers programs with an environment to execute.
It offers users the services to run and execute the programs conveniently.
Given are a couple of common services provided by an OS −
- Program execution
- I/O operations
- File System manipulation
- Communication
- Error Detection
- Resource Allocation
- Protection
Program execution
OS (Operating system) manage multiple categories of services from operator specified programs to system programs like printer spooler, name attendants, digital devices and many more. Each of those activities is encapsulated as a process.
A procedure involves the complete implementation context (code to execute, data to operate, registers, OS/ Operating Systems assets in usage). Following are the main activities of an OS concerning program management −
- Loads a program into memory.
- Executes the program.
- Handles program's execution.
- offers a mechanism for process synchronization.
- offers a mechanism for process communication.
- offers a mechanism for deadlock handling.
I/O Operation
An I/O subsystem includes I/O devices and their identical driver software. Drivers conceal the characteristics of particular hardware devices from the operator.
An OS controls the communication between the operators and device drivers.
I/O operation intends to read or write operation with any file or any particular I/O(input or output) device.
The OS offers access to the particular I/O device when asked for.
File system manipulation
A file represents a set of related information. Computers can save files on the hard disk (secondary storage), for long-term storage goals. instances of storage media include mag tape, magnetic disc and optical disc drives like CDs, DVDs. Each of those media has its properties like speed, capacity, data transfer rate and data access methods.
A filing system is generally organized into directories for straightforward navigation and usage. These folders can hold data and other directions. Following are the main activities of an OS concerning file management −
- The program must read a file or write a file.
- The OS permits the program for operation on the file.
- Permission varies from read-only, read-write, denied then on.
- Operating System offers an interface for the user so, he can create or delete files and directories as per his/her requirement.
- Operating System offers an interface to create the backup of the filing system.
Communication
In the case of distributed systems which are a set of processors that don't share a memory, peripheral devices, or a clock, the OS manages communications between all the processes. Multiple processes communicate with each other through communication lines within the network.
The OS controls routing and attachment procedures, and since the difficulties of dispute and security. Given are the major activities of an OS concerning communication −
- Two processes usually want the information to be shared between them,
- Both the processes are often on one computer or different computers but are connected through a network.
- Communication could also be implemented by two methods, either by Shared Memory or by Message Passing.
Error handling
Errors can occur anytime and anywhere. a mistake may occur within the CPU, in I/O devices or the memory hardware.
Given are the main activities of an OS concerning error handling −
- The OS constantly checks for possible errors.
- The OS takes applicable legal action to make sure accurate and reliable computing.
Resource Management
In case if there are multi-user or multi-tasking environment, assets like main memory, CPU (Central processing Unit) cycles and files storing are to be supplied to each user or job.
Given are the major activities of an OS concerning resource management −
- The OS handles all sorts of assets using schedulers.
- CPU scheduling algorithms are utilized for better use of CPU (Central processing unit).
security
Considering a computing system having multiple users and multiprogramming of multiple processes, the varied processes must be shielded from each other's activities.
Security refers to a mechanism or how to improve the access of software, processes, or operators to the assets specified by a computing system.
Given are the major activities of an OS concerning protection −
- The OS guarantees that access to system resources is controlled.
- The OS guarantees that external I/O devices are shielded from illogical access attempts.
- The OS offers verification features for each user using passwords.
