wdm multiplexing

When the program is IO, the IO is blocked if the data is not ready. When a process has multiple open files, such as a socket, then all files that are ready to be read and written will be affected by blocking and cannot be manipulated. Without threading, a single process cannot serve multiple file descriptors at the same time. Non-blocking IO can be used as a solution, but not very efficient. First the process needs to constantly send IO requests, and secondly, if the program can hibernate, the C

Multiplexing Control File, creating a pfile file through the original spfile file, modifying the control file information in the pfile file through the vi editor, and then creating a spfi through the pfile File Multiplexing Control File, creating a pfile file through the original spfile file, modifying the control file information in the pfile file through the vi editor, and then creating a spfi through th

IO multiplexing: A process can monitor multiple descriptors and, once a descriptor is read-ready or written, notifies the process program to read and write accordinglyUsage scenarios:1. When the customer processes multiple descriptors (network sockets) or one customer processes multiple sockets simultaneouslyThe 2.TCP server handles both the listener socket interface and the connected socket.3. One server to handle multiple services or multiple protoc

:"Step3");Coroutine. yield ();Print(User:"Step4");Coroutine. yield ();if(user = = pass) Then Print(User:"SUCC");Else Print(User:"Fail");EndEnd-----Create two co-processes: A and BLocalCoA =Coroutine. Create (routine);LocalCoB =Coroutine. Create (routine);-----Pass the USER1,USER2 information to the login login function and simulate the event succession distribution function callPrint();Coroutine. Resume (CoA, Login, {"user1","user1"});Coroutine. Resume (CoB, Login, {"User2","Test2"

This article is mainly for the familiarity of Linux under the Network programming, and implementation of a simple network chat room program. Implement I/O Multiplexing technology with poll to simultaneously process network connections and user input, enabling multiple users to chat online at the same time.The client implements two functions: one reads the user data from the standard input and sends the user data to the server, the second: receives the

function return value, there are three kinds of possible Positive number, which indicates how many revents in a struct POLLFD struct array are not 0, in other words, which events are called poll this time. 0, which means timeout is up, and no file descriptor is ready. -1, internal error has occurred, errno will be set When the return value of poll is-1, it means poll error, errno will be set, errno's value is 4 possible Efault, the parameter struct POLLFD struct a

Preludeto copy the definition of the JTAG, SW interface,Jtag:jtag (Joint test Action Group; joint testing team) is an international standard test protocol that is used primarily for in-chip internal testing. Most advanced devices now support JTAG protocols such as DSPs, FPGA devices, and so on. The standard JTAG interface is 4 lines: TMS, TCK, TDI, TDO, mode selection, clock, data input, and data output lines, respectively.SWD:SW (Serial wire mode Interface), serial interface pattern. In serial

In the previous article, I talked about some basic concepts of network programming. In the real use, the most used is I/O multiplexing, is nothing more than select,poll,epollMany people refer to the Internet as saying epoll that epoll efficiency is the highest. In fact, it is biased. Epoll is efficient, but it is how to be efficient, it is better than Select or poll excellent where?We simply analyze it by invoking the process.First Take select as an e

The commonly used net development multiplexing technology is divided into three kinds1. master Page2. User Controls3. Web Services (webserver)Ways to create webserver under vs2012Create a serviceCreate Project-Select Web service, server. CS is located under App_Code, extension. asmxReferencing a Web service in a real projectAdd a Web reference under the Web site root, and the URL fills in the URL of the Web service. Then fill in the Add Web reference

The following are from Wikipedia. The principle of radio technology is that changes in the current strength in the conductor will generate radio waves. With this phenomenon, information can be loaded onto radio waves through modulation. When the radio waves pass through the space to the receiver, the electromagnetic field changes caused by the radio waves will generate currents in the conductor.Information is transmitted by extracting information from current changes through demodulation. The

Synchronous blocking Io takes too much time while waiting for data to be ready. Although traditional non-blocking synchronous IO does not block the processRound RobinTo determine whether the data is ready will still consume a lot of CPU time. Multi-channel Io multiplexing provides a high-performance solution to check the readiness of a large number of file descriptors. Select Select was born on 4.2bsd and is supported on almost all platforms. Its goo

There is more http/ssh multiplexing on the web, but in the real world, with IIS load Balancing using Haproxy, 80 ports are required to use the Remote Desktop Management Server.Recently through the Wireshark grab packet, found the TPKT header field, finally successfully implemented RDP protocol multiplexing:Note: RDP typically uses TPKT as its transport protocol, and TPKT runs on top of TCP. When used to transmit RDP, the TCP port used is 3389, not the

1, Epoll ()Epoll () is a Linux-specific I/O multiplexing function, and its implementation differs greatly from the use and select (), poll ().Epoll () uses a set of functions to accomplish a task, not a single function, and secondly, epoll () places the file description in the kernel event table with an additional file descriptor that identifies the unique event table in the kernel.The API to use:int epoll_create (int size);int epoll_ctl (int epfd, in

Synchronous blocking IO spends too much time waiting for data to be ready, while traditional synchronous non-blocking IO does not block processes, but combining polling to determine whether data is ready still consumes a lot of CPU time. Multi-Path IO multiplexing provides a high-performance solution for a large number of file descriptors to be ready for inspection. Select Select was born in 4.2BSD and is supported on almost all platforms, and its go

synchronous asynchronous blocking non-blocking: nonsense do not say, Lao Zhang Love tea, boiled water, there are two kettle, ordinary kettle, Ring kettle (water meeting tips) (quoted) synchronization is ordinary kettle boiling water, to do nothing to come to see Open; Obstruction is the process of boiling water, you can not do other things (that is, you are blocked), non-blocking is the process of boiling water to do other things. For example, go out and chat with old flame, go to the living roo

analysis of high performance IO model Server-side programming often requires the construction of a high-performance IO model, with four of common IO models: (1) Synchronous blocking IO (Blocking io): The traditional IO model. (2) Synchronous non-blocking IO (non-blocking io): The socket created by default is blocked and non-blocking IO requires the socket to be set to Nonblock. Note that the NIO mentioned here is not a Java NiO (New IO) library. (3) IO mul