IO multiplexing of PHP+Socket series and implementation of web server

This article brings you relevant knowledge about php socket, which mainly introduces IO multiplexing and how php socket implements web server? Friends who are interested can take a look below. I hope it will be helpful to everyone.

php native socket IO multiplexing and web server implementation

Multiplexing

## Previous articleSimple server-client communication is implemented through native sockets, but when multiple clients are connected, the server can only handle the request of the first client and cannot serve subsequent clients

• Multiple processes, that is, multiple processes are started on the server to monitor

• IO multiplexing mechanism, which simply implements the use of N clients One network cable simultaneously accesses

selectandepoll, common In the software,Apacheuses theselectmodel, andnginxuses theepollmodel. Theselectmodel is built into php, and the corresponding function issocket_select. Multiplexing is the basis for implementing the http server.

socket_selectfunction that implements theselectmodel. Its syntax is as follows:

socket_select( array &$read, array &$write, array &$except, int $seconds [, int $microseconds = 0]): int|false

• read

  The socket resource monitored by the server, when it changes (that is, a new message is received or a client is connected or disconnected),

  The socket_selectfunction will return (otherwise it will continue to block), and at the same time modify the variable to the socket resource list of the current event (received message or client connection or disconnection), and continue to execute downwards.

• write

  #Monitor whether there is a client writing data. Passing in

  nullmeans that you don’t care whether there are any write changes.

• except

  The elements to be excluded in the socket, passing in

  nullis "listening" All

• seconds

  Seconds and microseconds together form the timeout parameter. If

  nullis passed in, it will block, and if it is 0, it will be non-blocking. If it is >0, it will be the maximum blocking time

• microseconds

last articlewe simply implemented the socket server-side monitoring connection with the client. Next, we build the basis of the server-side monitoring code. Optimize the code through multiplexing:

        

         Copy after login
        
       

socket_selectfunction will block the current process. When the$tmp_socketssocket resource in the array has new When the client connects or disconnects or receives a new message, it will modify the$tmp_socketsarray to the currently active socket resource, and then process the business logic by traversing the array

Use socket to implement a simple http server

socket_writeWhen sending data according to the format, the browser can respond to the request normally

this is php worker'; $len = strlen($output); $response = "HTTP/1.1 200 OK\r\n"; $response .= "content-type: text/html\r\n"; $response .= "server: php socket\r\n"; $response .= "Content-Length: {$len}\r\n\r\n"; $response .= $output; socket_write($sock, $response); } } }

ip:8888in the browser, you can see the following:

GET / HTTP/1.1 Host: 124.222.**.**:8888 Connection: keep-alive Cache-Control: max-age=0 Upgrade-Insecure-Requests: 1 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/101.0.0.0 Safari/537.36 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9 Accept-Encoding: gzip, deflate Accept-Language: zh-CN,zh;q=0.9 Cookie: jenkins-timestamper-offset=-28800000; _ga=GA1.1.1403944751.1652010033; _ga_2GM6102E19=GS1.1.1652802985.7.1.1652803014.0

file_get_contentRead the content of the specified file and return it to the browser

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