multiplexer demultiplexer

The Linux kernel sees all external devices as a single file, and read and write to a file invokes the system commands provided by the kernel., returns a file descriptor (FD, filename descriptor). and read and write to a socket will have a corresponding descriptor, become SOCKETFD(socket descriptor), a descriptor is a number that points to a struct in the kernel (file path, data area, and so on).Based on the classification of the I/O model by UNIX programming, UNIX provides 5 I/O models, namely:(

compiling the source code, and then the machine code is run by the machine .Word has two bytes, one byte is 8 bit (bit)Complement, the original code is reversed by a bit and added 116 complement, the original number, the bitwise 15 minus the number in this position, and the last plus 1But the decimal number needs to be converted into binary and complementQuestion 7: If a Boolean function has 4 inputs, how many rows does its truth table need?Answer: There are title 5 and title 6 can be seen, 2 i

between the service name and the port number. Many system programs need to use this file. The following are the first lines of the default/etc/services during RedHat installation: Tcpmux 1/tcp # TCP port service multiplexer Echo 7/tcp Echo 7/udp Discard 9/tcp sink null Discard 9/udp sink null Listen at 11/tcp users The leftmost column is the host service name, the middle column is the port number, "/" is followed by the port type, either TCP or UDP

/tcp # TCP port service multiplexer Echo 7/tcp Echo 7/udp Discard 9/tcp sink null Discard 9/udp sink null Listen at 11/tcp users Daytime 13/tcp Daytime 13/udp Netstat 15/tcp Qotd 17/tcp quote Msp 18/tcp # message send protocol 2.3/etc/hostname The host name configuration file, which has only one line and records the Host Name of the local machine. File Format: Host Name $ Cat/etc/hostname Tonybox 2.4/etc/host. conf When both DNS domain name

handler execution, always by the I/O thread nioeventloop responsible, it is unexpectedly the entire process does not switch thread context, The data also does not face the risk of being modified concurrently, and for the user it is not even necessary to know the thread details of the Netty, which is really a very good design concept, and it works as follows:Figure 6-4 Netty 4 serialization design conceptA nioeventloop aggregates a multiplexer selecto

1 PackageCom.slp.nio;2 3 Importorg.junit.Test;4 5 Importjava.io.IOException;6 Importjava.net.InetSocketAddress;7 ImportJava.nio.ByteBuffer;8 ImportJava.nio.channels.SelectionKey;9 ImportJava.nio.channels.Selector;Ten ImportJava.nio.channels.ServerSocketChannel; One ImportJava.nio.channels.SocketChannel; A ImportJava.time.LocalDateTime; - Importjava.util.Date; - ImportJava.util.Iterator; the ImportJava.util.Scanner; - - /** - * Created by SANGLP on 2017/3/2. + * I. Three cores to complete netwo

idle mechanism for Netty is to have a timeout exception and close the connection, but we can customize its time-out implementation mechanism to support different user scenarios.The timeout interface for Writetimeouthandler is as follows:Figure 2-22 Write timeoutThe timeout interface for Readtimeouthandler is as follows:Figure 2-23 Read timeoutRead and write idle interfaces are as follows:Figure 2-24 Read and write idleWith the link idle detection mechanism provided by Netty, it is very flexible

handler. The reactor class is used to manage EventHandler (registration, deletion, and so on) and uses handle_events to implement event loops, constantly invoking a multi-separator select for a synchronous event multiplexer (typically the kernel), as long as a file handle is activated (readable/writable, etc.). Select returns (blocks), and Handle_events invokes the handle_event of the event handler associated with the file handle.Figure 5 IO Multiple

1, the design of each component module includes 3 parts: 1) Circuit Module Design 2) test Module design 3) design document preparation and collation.Among them, 2, 3 steps is particularly important. Whether the test module is rigorous and complete has set the success or failure of the system design, the complete and accurate design document for the future commissioning and maintenance brought great convenience.**************************************************************************************

In fact, learning single-chip computer This kind of thing is not what single-chip computer learning Forum, first look at the information books, and then practice, if you encounter any problem can not solve the online search for information, on the network on the single-chip microcomputer frequently asked questions are very many, how to pick out the answer you need to cultivate the ability.Single Chip microcomputer is an integrated circuit chip, using large scale integrated circuit technology wil

(obtained through Get_handle), and handle_event (read/write, etc.) for the handle operation. Subclasses that inherit from EventHandler can customize the behavior of the event handler. The reactor class is used to manage EventHandler (registration, deletion, and so on) and uses handle_events to implement event loops, constantly invoking a multi-separator select for a synchronous event multiplexer (typically the kernel), as long as a file handle is act

: Select, read or test service group (Fax:select, RE AD OR TEST SERVICE CLASS) At+fmi Telex: report produced identification (Fax:report manufactured ID) AT+FMM Telex: Reporting mode ID (Fax:report model ID) AT+FMR Telex:The report amends the identification (Fax:report REVISION ID) at+vtd (TONE DURATION) At+vts DTMF and the generation of the dial tone (DTMF and TONE GENERATION) At+cmux multi-channel control ( Multiplexer CONTROL) at+cnum User (subscrib

; (4) "Full-parallel", XST that the conditional statement is complete and does not have a branch inside, and does not use a latch and a priority encoder."RAM Extraction": Memory extension. This parameter is valid only for the FPGA and is used to enable and disable the RAM macro interface. The default is to allow the use of the RAM macro interface.Ram Style: The type of RAM implementation. This parameter is valid only for FPGAs and is used to choose whether to use block RAM or distributed RAM as

logic circuit such as a trigger, but it is used as an "atom". With a multi-channel selector, a multiplexer, and a trigger, you can make memory (the Random Access Unit). This step to get the largest memory is 16K, that is, the final design of the computer's memory size, in terms of the size of the computer memory now, it is incredibly small. This week in addition to memory, the design of another important circuit is the program Counter, is actually a

telnet or ssh telnet to Linux, if the connection is not normal interruption, reconnect, the system will open a new session, unable to restore the original Session.screen command can solve the problem. The screen tool is an end-multiplexer, in essence, which means you can run multi-terminal applications using a single terminal window.Syntaxscreen [-amrvx-ls-wipe][-d Additional notes:Screen is a multiple Windows management program. The so-called window,

countries, and it has developed into the best choice for connecting the WAN between North America, Europe and Asia. Internationally, S O N E T is known as S D H (synchronous data layer, synchronous Digital Hierarchy). S O N E T and T Media, I S D N, and at M technology have good interoperability, making it a good choice for long distances (even in the same country) to connect Wan and LAN.S O N E T relies on fiber-optic transmission media to achieve very high service quality and throughput. As w

API request, its main processing flow is as follows: The HTTP request is handled by a set of filter handlers defined in the Defaultbuildhandlerchain () () (Config.go) function, and related operations are performed (the relevant filtering handler functions are shown). These filtering handlers save the HTTP request to Central CTX. Requestinfo, such as the user's relevant authentication information, or the corresponding HTTP request return code. Then Multi