Software system

software system functional role

operating system tasks and functions

operating system is to manage hardware and software resources, the control program execution, improving the man-machine interface, computer rational organization workflow software and a system to provide a good operating environment for the user to use the computer. The operating system is located above the hardware layer, all software

An essential layer beneath, the most basic is the most important type of system software. All hardware and software computer systems and data resources of its unified control, scheduling and management.

From the user's point of view, it is the hardware interface to the user and the computer system; from a resource management point of view, it is the manager of the computer system resources. Its main role and purpose is to improve the utilization of system resources; provide a user-friendly interface; create a good working environment, allowing users the flexibility to easily use a computer, so the entire computer system to run efficiently.

operating system's task is to manage all good computer hardware and software resources, improve the utilization of the computer; as an interface between the user and the computer, allowing users through a menu command or the operating system provides easy to use computer .

software system role

operating system resources for running the control program and the management computer. Language processing system software is software for processing language such as compiler and the like. The system software is used to support database management and access to data, including databases, database management systems. Resident database is a set of data within a computer system, the relationship between them to define the data model, and the data definition language to describe; database management system allows the user to access the data item as a shaft, and the use of modify the software. Distributed software systems including distributed operating systems, distributed programming systems, distributed file systems, distributed database systems. Interactive system is a software system providing information interaction between the user and the computer system in accordance with certain conventions, providing a friendly man-machine interface for the user. Operating system functions include processor management, memory management, file management, device management and job management, and its main contents including the operating system structure, process (task) scheduling, synchronization mechanisms to prevent deadlocks, memory allocation, device allocation, parallelism, fault tolerance and recovery mechanisms.

software system function

language processing system is a processing function of software programs for various languages, of which the user writes the software source code is converted into a variety of languages ​​may be recognized by the computer and run the target program to obtain the desired results. The main contents include: construction methods and tools of language translation technology and translation process. In addition, it involves text editing techniques, editing techniques and connected load technology.

database system database including the definition and manipulation of, the concurrency control of shared data, data security and confidentiality. Divided by the data definition module, the database system can be divided into a relational database, hierarchical databases and network database. Press control mode can be divided into a centralized database system, database systems, and distributed parallel database systems. The main contents of the database system including: database design, data model, data definition and manipulation language, relational database theory, data integrity and compatibility, database recovery and fault tolerance, and prevent deadlock control, data security and so on.

distributed software management system is to run a distributed computer system resources, and control distributed program provides distributed programming languages ​​and tools, providing a distributed file system management and distributed database management relations . The main contents distributed software systems including distributed operating systems and network operating systems, distributed programming, distributed file systems and distributed database systems.

The main function of human-computer interaction system is to provide a friendly human-machine interface between humans and computers. The main contents include the principles of human-computer interaction, human-machine interfaces and analysis of the statute, cognitive complexity theory, data input, display and search interface, computer control interface.

Main features of the operating system

1. Concurrency

concurrency (Concurrence) refers to two or more programs running at the same time interval while performing within the segment.

2. Sharing

to share the operating system's resources (including hardware and information resources) can be concurrently executing a plurality of processes to be used.

3. Asynchrony

In the multi-channel programming environment that allows concurrent execution of multiple processes, due to the limited resources of many processes, the implementation of the majority of cases, the process is not always in the end, and a "stop and go."

Classification OS

1. Single-user operating system

2. Batch OS

3. Real-time operating system < / p>

4. sharing operating system

5. network operating system

6. distributed operating system

7. computer operating system < / p>

distributed software systems

(distributed software systems) to support distributed processing system software, is executed by the multiprocessor system architecture of a communication network interconnection tasks. It includes a distributed operating systems, distributed programming language and its compiler (interpretation) systems, distributed file systems and distributed database systems.

Distributed operating system is responsible for the management and control of distributed processing distributed system resources to run. It is a centralized operating system and the difference is that the aspects of resource management, interprocess communication, and system structure.

distributed programming language for writing distributed programs running on a distributed computer system. A program distributed by a number of program modules can be independently performed, which are distributed over multiple computers in a distributed processing system are performed simultaneously. Compared with centralized programming language has three characteristics: distribution, communication and soundness.

distributed file systems have the capability to perform remote file access, file and transparently distributed on the network and access management.

distributed database system is composed of a plurality of computers distributed over a plurality of nodes composed of database system, it provides efficient means to access the database operon on these nodes. Distributed database in use can be regarded as a complete database, but in fact it is distributed among the nodes geographically dispersed. Of course, the sub-database distributed among the nodes are logically related.