1, concurrent:

However, there are many programs in the computer system. From a macro perspective, these plans are moving forward at the same time. On a single CPU, these concurrent programs run alternately on the CPU. ?

Program concurrency is reflected in two aspects: concurrent execution between user programs and user programs. Concurrency between user programs and operating system programs.

2. Share:

Resource sharing refers to operating system programs and multiple user programs sharing resources in the system.

3. Randomness:

Randomness means that the operating system runs in a random environment. A device may send an interrupt request to the processor at any time, and the system cannot know when and what the running program will do.

4. Virtual

It refers to turning a physical entity into several logical counterparts through technology. Virtualization is realized in the operating system mainly by time-sharing method. Obviously, if n is the number of virtual logical devices corresponding to physical devices, then the speed of virtual devices must be 1/n of the speed of physical devices.

5. Asynchronous: that is, uncertainty. Multiple runs of the same program and data may result in different results; The running time and sequence of the program are also uncertain; It is difficult to predict when external input requests and operations fail. These are all manifestations of uncertainty.

Extended data:

1, the main task of the operating system:

Manage and configure memory, determine the priority of supply and demand of system resources, control input and output devices, operate networks, and manage file systems.

The types of operating systems are very diverse, and the operating systems installed on different machines can range from simple to complex, from embedded systems of mobile phones to large operating systems of supercomputers.

2, the main functions of the operating system:

1, process management (process management)

2. Memory management

3. File system

4. Build a working network

5, Security mechanism (security)

6. User interface

7. Driver (Device Driver)

Baidu Encyclopedia-Operating System