Operating System-Kickoff

Operating System-Kickoff
Next, I will write a series of Operating System articles. Today, I will start. The main content of this article: What is the core concept of the operating system program = Data Structure + algorithm 1, what is the operating system 1.1 operating system is the abstraction of hardware (hardware acion) one of the important functions of the operating system is to hide the hardware, and display the hardware functions with beautiful and highly abstract interfaces. The location of the OS in the entire computer system is shown in. Abstraction is the core concept of management complexity. The operating system abstracts the hardware, which frees our programmers from a variety of hardware, program applications using the youmei interface provided by the operating system. Modern people use computers every day. They feel that the operating system is intended for humans. In fact, they are wrong. The operating system is intended for applications rather than for humans. The abstraction made by the operating system reduces the complexity of the application. 1.2 The operating system is a resource manager that runs a large number of applications on the operating system at the same time. All these applications need to operate on different resources, such as I/O, CPU, and Memory. How to allocate resources to these applications, what is the allocation policy, how to ensure the integrity of these resources if resources are operated by different applications at the same time, and so on, these are all problems to be solved by the operating system. For example: who will get CPU resources and how long the memory will be protected: application A will not cause data loss of application B. 2. The core concepts of the operating system. The article begins to describe that the operating system is an abstraction of hardware, therefore, the core concepts of the operating system are the abstraction of specific physical hardware. When this series of blog posts end up with the following content. 2.1 process (thread) is the CPU abstraction of the Operating System 2.2 virtual memory (address space) virtual Memory is the abstraction of the operating system to the physical memory. 2.3 file files are the abstraction of the operating system to the physical disk. 3. program = Data Structure + algorithm. How can this problem be solved?, it can be understood through the operating system. 3.1 Data Structure is abstract. in the operating system, because of abstraction, the application only needs to focus on threads, processes, and files, rather than the implementation behind them, you don't have to worry about the possible changes in these implementations. In the usual application programming, we advocate interface-oriented programming, which is the data structure and of course abstract. There are also a variety of advanced languages, such as Java and C #, which are more abstract. The programming syntax is data structure to some extent. 3.2 algorithm algorithms are strategies, that is, trade-offs and trade-offs. We are in a world with limited resources. This is a better understanding. In the operating system, this compromise and trade-offs reflect a limited cpu: Who should get the CPU, how long should the appropriate memory be limited: When should the data be stored in the memory, when should the cache be removed? Limited: the data should be put into the cache of the CPU, level 1 or level 3. When should it be replaced? Replace the data...