An Operating System offers services for users and programmes respectively.
Many kinds of tasks are performed by operating systems from user programmes to system programmes such as printer spooler, name servers, file server, etc. Any such operation is encapsulated as a process.
A process requires the full context of the execution (code to execute, deceptive data, registers, OS resources in use). Then observe the main programme activities of an operating system-
An I / O subsystem consists of I / O devices and associated driver software. Drivers mask the peculiarities of individual users hardware devices.
The communication between user and device drivers is controlled by an Operating System.
A file contains a set of information relating to it. For long-term storage purposes computers may store files on the disk (secondary storage). Examples of storage media include magnetic tape, magnetic disk, and optical disc drives such as CD, DVD. Each of these media has its own characteristics such as speed, size, data transfer rate and methods of data access.
For easy access and use a file system is usually organised into folders. These directories can include files, as well as other directions. Following are the main file management operations of an operating system-
The operating system handles communications between all processes in the case of distributed systems that are a series of processors that do not share memory, peripheral devices or a clock. Inside the network, several processes interact with each other across communication lines.
The OS manages methods for routing and communication, and the contention and security issues. The following are the main communication tasks of an operating system –
Errors can occur anywhere, anywhere. Error in CPU, I / O devices, or memory hardware can occur. Following are the core operating system activities relating to error handling −
In the case of multi-user or multi-tasking environment, each user or job must be allocated resources such as main memory , CPU cycles, and file storage. Following is the main resource management tasks of an operating system −
Considering a computer system that has multiple users and several processes run concurrently, the different processes must be protected from each other's activities.
Protection refers to a method or means of controlling the access of programmes, processes, or users to computer system-defined resources. Following are the main protections tasks of an operating system-