wdm multiplexing

Modify the CentOS release information to bypass the operating system of the disk array multiplexing software to check the implementation of the project. The entire system uses the disk array, and then the disk array uses the form of load, multi-channel merge software is required, but multi-channel merge software needs to detect the system version. he supports Re... the CentOS release information is modified to bypass the operating system inspection im

scrambling codes of the plural values.In the downlink channel spread spectrum, in addition to the other downstream physical channels of Sch, each pair of successive two symbols are divided into I-and Q-Paths after serial and conversion. The tap principle is that even numbered symbols are divided into the I-way and the odd numbered symbols to the Q-path. The real values of I-and Q-paths are spread-spectrum, phase-adjusted, and combined, and become sequences of complex values. This sequence is sc

TCP/IP network programming (transcription Note 5) –select and IO multiplexingUsing fork () to generate a child process can reach a server-side request that can respond to multiple clients at the same time, but this has drawbacks:Requires a lot of computing and memory space, each process must have a separate memory space, data exchange is also cumbersome (IPC, such as pipelines)IO Multiplexing:Ethernet bus structure is also used multiplexing technology

1. I/O modelAn input operation typically consists of two different stages: waiting for data to be ready, copying data from the kernel to the process.Blocking I/O modelsNon-blocking I/O modelI/O multiplexing model: The kernel discovery process specifies that one or more I/O conditions are in place, and it notifies the process, supported by select and poll two functionsSignal-driven I/O model: The kernel sends a SIGIO signal notification process when th

This article to share the content is about PHP implementation of System programming network socket and IO multiplexing, has a certain reference value, the need for friends can refer to All along, PHP is rarely used for socket programming, after all, is a scripting language, efficiency will become a big bottleneck, but can not say that PHP can not be used for socket programming, and can not say that PHP socket programming performance is very low, such

Python network programming-epoll of IO multiplexing What is epoll? What is epoll? In linux network programming, select is used for event triggering for a long time. In the new linux kernel, there is a mechanism to replace it, that is, epoll. Of course, this is not only available in the 2.6 kernel. it is introduced in the 2.5.44 kernel (epoll (4) is a new API introduced in Linux kernel 2.5.44 ), it has almost all the advantages mentioned previously, an

What is epollepoll? In linux network programming, select is used for event triggering for a long time. In the new linux kernel, there is a mechanism to replace it, that is, ep what is epoll What is epoll? In linux network programming, select is used for event triggering for a long time. In the new linux kernel, there is a mechanism to replace it, that is, epoll. Of course, this is not only available in the 2.6 kernel. it is introduced in the 2.5.44 kernel (epoll (4) is a new API introduced in Li

The internal details of Linux seem to be destined to get farther away from desktop users. more and more popular desktop environments provide attractive interfaces and fancy functions to users. The internal details of Linux seem to be destined to get farther away from desktop users. the popular desktop environment is increasingly providing attractive interfaces and fancy features to users, which shows no signs of slowing down. Ubuntu, one of the popular desktop distributions, even considered rep

The function of Tmux is terminal multiplexing.1. Start a bash on the server. and execute the Tmux inside.2. telnet to the server via SSH, execute tmux attach, switch to the bash on the server, and the next action is in bash.3. You can open many other forms at this time so that you can use more than one bash at the same time as on-premisesSuppose you want to send a command. For example, the following:Tmux send-t checkpoint ls ENTERNote: Checkpoint is t

course the error message props incoming. Finally can be customized model-type, instruction style, passed in a JS object, can be customized.3.reactjsReact advocated the Web components, each part of it is a component, of course, the data is props incoming, he has to think well. This component is more reusable, it maintains its own state, a component is a state, and two components have virtually no coupling. Then the reuse is good to do. The communication of the component is through props, and the

Content directory: Python scope The multiple inheritance differences between python2.7 and python3.5 IO multiplexing Multithreading, process, and co-processes Python scopeNo block-level scopes in PythonIf 1 = = 1: name = ' Jabe ' print (name) #可以正常输出jabe # no block-scoped scope in Python # is not used in C # or Java, prompt for name undefinedFunction-scoped in Pythondef func (): name = ' Jbae ' func () print (name) #

multiplexing, where an IP can have millions of port statements used by TCP connections. The basic element of a socket is the src+s_port+dst+d_port+ protocol. A socket can be created as long as not all elements overlap at the same time.Use the following command to see how many ports are available for snip:Nsapimgr-d FreeportsFor example, query the number of ports available for each IP:[Email protected]# nsapimgr-d freeportsDisplaying All-ports of all

=" Wkiol1fptafqbn1laaaizyto-ci586.png-wh_50 "/>3. Select () mechanism analysis (1), recv, send, select ... It's all blocking functions .But here we use the blocking function--------> solve the non-blocking problem;(2), when a readable event occurs, distinguish between two situations:A, the request and the server connection, B, has been connected, the direct communication;(3), each time to reset, leaving only a client can.(4), select () is the polling mode, visit all sockets, the time is set to 0

Introduction to the Epoll modelEpoll but currently in Linux under the development of large-scale concurrent network programs popular candidates, Epoll in the Linux2.6 kernel formally introduced, and select similar, in fact, all I/O multiplexing technology, and there is no mystery.In fact, the design of concurrent network programs under Linux, there is always no lack of methods, such as the typical Apache model (Process Per Connection, abbreviated PPC)

descriptive word that identifies a set of interfaces. 7 level: The hierarchy of option definitions; Sol_socket, ipproto_tcp, Ipproto_ip, and Ipproto_ipv6 are supported. 8 optname: Options to be set. 9 optval: Pointer to the buffer that holds the option value. Ten optlen:optval the buffer length. One return value: Successfully returned 0, failure returned-1. */ A - 　　 if(SetSockOpt (SOCKFD, Sol_socket, SO_REUSEADDR, on,sizeof(ON)) 0) -Err_exit ("setsockopt so_reuseaddr"); the } - - //Port

', Data) msg_dic[r].put (data) Output_list.append (r) # into the returned connection queue except Socket.err Or:print ('Client disconnects ') break for W in Stdoutput: # The list of connections to return to the client data_to_client = Msg_dic[w].get () w.send (Data_ to_client) # Send the data to the client Output_list.remove (W) # Ensure that the next loop stdoutput not return the connection that has been processed for E in stderr:if e in O Utput_list:output_list.remove (e) input_list.remove (e

We see TCP clients processing two inputs at a time: standard input and TCP sockets. The problem we are experiencing is that the server process will be killed when the customer is blocking the (standard input) Fgets call. Server TCP sends a FIN correctly to client TCP, but since the client process is blocking the process of reading from standard input, it will not see this EOF until the socket is read (possibly over a long time). Such a process requires a capability to inform the kernel beforehan

for higher bandwidth.The emergence of the problem will inevitably lead to corresponding solutions to the problem. One of the simplest and most direct methods is to use multiple low-bandwidth 2 M lines to meet the user's needs for high-bandwidth 8 M lines. However, new problems are born again. Theoretically, four 2 m lines equals one 8 m line, but in practical application, such a mathematical equation is not true. The problem must be solved by line multiplex