real time operating system

The most recent project page needs to display the server time in real time, and if the server time is loaded by Ajax every second, a lot of requests will be generated. A combination of "Javscript" and "Ajax Load Server Time" was designed to display server

-calculates the time slice. First, we will introduce the concept of a basic time slice. The static priority essentially determines the basic time slice of the process. That is, the length of the time slice that the system assigns to the process when the process has used up t

;　　Context Data : The data of the processor registers when the process executes;　　I/O status information : Includes display of i/0 requests, I/O devices assigned to processes, list of files used by the process;　　Audit Information : including the use of the processor time, the sum of the number of clocks and so on;This information is stored in a data structure called the Process Control block , which is created and managed by the

the basic time slice of the process, which is the time slice length that the system allocates to the process before the process has run out of time. The relationship between the static priority and the base time slice is determined by the following formula:As you can see, t

When using Javascript to implement interaction between the client and the server, you sometimes need to judge the operating system to achieve compatibility under different operating systems. For example, we have a website, in Windows XP, the browsing effect is good, but in Ubuntu, due to many different features, it may cause slight differences in browsing, and ev

operating system cp/m etc. The functions of this kind of operating system are mainly operation command execution, file service, support high-level programming language compiler program and control external device and so on.② time-sharing

The operating system can be classified according to different methods. For example, the number of users can be divided into single-user and multi-user systems. Based on the hardware scale on which the operating system depends, it can be divided into mainframe, middleware, minicomputer and minicomputer

) {scanf ("%s", cmd);if (!fork ()) {exec (cmd);} wait (); } }a command starts a process, returns the shell and starts another process ...Multi-process Images: How are multiple processes organized?There is a process in the executionThere are processes waiting to be executedThere are some processes waiting for an eventOrganization of multiple processes: pcb+ status + queueRun → wait; Run → Ready; Ready → run ... The graph is called the process state diagram It can give a clear descrip

In addition to displaying summary statistics, distribution, trends, and other data content relatively statically, a report can also be used to display time-related real-time information and display real-time results, for example, in the following device monitoring applicatio

What is the difference between 32-bit and 64-bit computer operating systems ?, 32-bit Operating System When using a computer, we often look at the number of digits in the system first. Although many users know the number of digits in the system, what is the difference betwe

In multiple operating systems, how does one set the default Operating System? -- Debian information of the Linux release-the following is a detailed description. In other operating environments (linux and windows2 systems) If debian or other linux versions are installed, you should set them in linux. Without a doubt

serving others, just as the entire system is exclusive to him. Timeliness means that the system responds to requests from users in a timely manner. Common general operating system is the combination of time-sharing system and bat

work. After the work is completed, the thread is sleep, rather than destroying the thread. The process pool is the same as the thread pool. Memory Pool: the memory pool is used by the program to apply for a large enough memory from the operating system in advance. After that, when the program needs to apply for memory, it does not apply directly to the operating

request releases, processes, thread-creation destruction, and so on.Thread pool: The thread pool principle is very simple, similar to the concept of buffer in the operating system, its flow is as follows: Start a number of threads, and let these threads are asleep, when a need to open a thread to do specific work, it will wake up a thread pool of a sleep thread, let it do the specific work, When the work i

considered. Generally speaking, there is a certain regularity in the number of movies. Usually for n movies, the hit rate of the nth movie is usually c / n where n is N,c is a constant. Meet C /1+C /2+C /3+...+C /N =1 Such a condition.In general, file storage on a video server satisfies the organ distribution. This allows the head to remain in the center of the disk in practice to reduce the time of movement.7.7.5

interface, convenient for users to use the computer. It has a connecting position in the whole computer system.Classification of operating systems:There are DOS, OS/2, UNIX, Xenix, LINUX, Windows, NetWare and so on, which are common on microcomputer. But all operating systems have four basic features of concurrency, sharing, virtualization, and uncertainty.The operatin