Server-side listening port with PHP emulation

Reference: http://www.cnblogs.com/thinksasa/archive/2013/02/26/2934206.html

http://blog.csdn.net/alongken2005/article/details/8056910

Socket_accept () is the server accepts client requests, and once a client link comes up, the function returns a new socket resource that is the resource that communicates with the client.

socket_accept () is blocked and will remain stuck there.

Discovery: Once the client disconnects, it affects the main process on the server. How to avoid this effect?

A normal server should be a new child process to process the request.

Socket_connect () is to link a socket to go. is used by the client.

C Language Introduction:Connect, send, recv are synchronous blocking mode of operation.

Then, it can be concluded that Socket_connect () is also obstructive.

Using the coprocessor in PHP:

Http://www.laruence.com/2015/05/28/3038.html

Socket_recv and Socket_read ($msgsock, 2048, Php_normal_read)

What difference does it have?

Stream_select ()

Accepts a socket stream, can be multiple, an array form.

Wait for these flows to change the state. A value greater than 0 is returned when the state is changed



<?php
/* Prepare the Read array */
$read = Array ($stream 1, $stream 2);//two sockets created
$write = NULL;
$except = NULL;
if (false = = = ($num _changed_streams = Stream_select ($read, $write, $except, 0))) {
/* Error Handling */
} elseif ($num _changed_streams > 0) {
/* At least on one of the streams something interesting happened */
}
?>


To use a reference pass, the value is modified.

PHP multiplexing Reference: http://blog.csdn.net/phphot/article/details/2020269

Summarize

If the socket extension is not installed, the following related functions are used: Stream_socket_client, Fread (), fwrite (), Stream_select (), fclose ()

If the Sokcet extension is installed , you can replace the extended function:

Stream_socket_client equivalent to Socket_create ()

Socket_select () equivalent to Stream_select ()

Socket_close () equivalent to fclose ()

Socket_write () equivalent to fwrite ()

Socket_read () equivalent to Fread ()

Stream_socket_client () is actually calling the connect () function of the Linux system.

Socket_select (), Stream_select () are all called the Select () functions provided by the operating system.

Thinking: What is the difference between stream and socket nature?

Don't know, think about to think about Socket_accept and Socket_listen () difference, perhaps can find the answer.

I always confuse socket_accept and Socket_listen ().

Socket_accept is the link that begins to accept the client, and if there is a client link, the function returns a handle to the socket, which is a handle specifically to the client. Socket_listen is starting to listen to this socket channel, just listening, not accepting the client's connection request.

Server-side listening port with PHP emulation