select function

Ways to avoid zombie processes on the server side:1 ) by ignoring SIGCHLD signal to resolve zombie processesSignal (SIGCHLD, sig_ign) 2 ) by Wait method to resolve the zombie processSignal (SIGCHLD, HANDLE_SIGCHLD);Wait (NULL)

I/O multiplexing uses a mechanism that can monitor multiple descriptors and, once a descriptor is ready (usually read-ready or write-ready), notifies the program to read and write. The I/O multiplexing technique is designed to address the technology

Directory First, understand the operating system Ii. Type of Task Third, Socket module 四、一个 Simple c/S program V. Using blocking IO for concurrency Scenario One: Blocking io+ multi-process Scenario Two:

Non-blocking connect () and accept () A. Select () functionThe criteria for the Select () function to read:1> The set interface has data readable2>. The read half of the connection closes (that is, the TCP connection that received the Fin). A read

Topic: Select the bottom of the database.First, from the database query data angle, probably the framework (premise: The client needs to send query statements to the server side)1. Receive statement lookup SQL plan cacheIf there is no-_-| |2. Check

Advanced IO non-blocking IO allows us to call IO operations such as open, read, and write without permanent blocking. Advanced I/O non-blocking IO Non-blocking I/O allows us to call I/O operations such as open, read, and write without permanent

Server-Side Backend code:1 private string getmodelnames () {2 return @ "[3 {4 ' value ': ' jquery ', 5 ' label ': ' jquery ', 6 ' desc ': ' The Write less, does more,

This article mainly introduces considerations for writing JavaScript text box scripts and helps you better compile javascript form scripts. For more information, see in HTML, there are two ways to express the text box: One is a single line text

Mysql Study Notes (single table data record query) Querying data records refers to obtaining required data records from database objects. Mysql provides various data query methods.1. Simple data record Query  Select field1, field2,..., fieldn

C_select Call1. Select System CallThe select system call is used to let our program monitor the state changes of multiple file descriptors. The program stops at select to wait until one or more of the monitored file descriptors has changed state.The

11th. The first section of network programming client-server programming model Each network application is based on the client-server model. With this model, an application is a service provided by a server's client. The server manages a

#defineHost_server_ip "192.168.3.35"#defineHost_port 9501#defineSleep_time 1#defineLoop_time 3#defineData_size 80intjudge_socket_exist () {intLoop_time =0; Fd_set Send_data_flag; Static intSOCKET_FD =-1; while(1) { if(SOCKET_FD 0)

For multiple non-blocking I/O instances, how can I/O be read or writable? If you use a loop to call write/read until the return is successful, this method becomes polling ). Most of the time I/O is not ready, so such Round Robin is a waste of CPU. A

Original Text Reprinted from Ghost. In the high-performance I/O design, there are two well-known modes: reactor and proactor. The reactor mode is used to synchronize I/O, while the proactor is used for asynchronous I/O operations. Before comparing

1. Non-blocking I/O Non-blocking I/O allows us to call I/O operations that are not always blocked, such as open, read, and write. If this operation cannot be completed, an error is returned immediately, indicating that the operation will continue to

In the high-performance I/O design, there are two well-known modes: reactor and proactor. The reactor mode is used to synchronize I/O, while the proactor is used for asynchronous I/O operations.   Before comparing these two modes, we should first

Socket-related functions 1. Read the current error value: When an error occurs, if you want to handle the problem, you should call this function to obtain the error code. int WSAGetLastError(void ); #define h_errno

Winsock I/O operations: Select model: You can call the select function to determine the status of one or more sockets and determine whether there is data on the socket, or Is it possible to write data to a socket. Int select (INT NFDs, fd_set far *

Select function: The system provides the select function to achieve multiplexing of input/output models. Prototype: # Include # Include Select function:The system provides the select function to achieve multiplexing of input/output models.

With the development and popularization of Intenet, networks are widely used in embedded systems. More and more embedded devices use Linux operating systems. Linux is a free operating system with open source code and is highly portable. Therefore,