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This article mainly shows you "what is the use of Libevent extension in PHP", the content is simple and clear, and I hope it can help you solve your doubts, so let me lead you to study and learn "what is the use of Libevent extension in PHP".

1. Libevent introduction

Libevent is an event-triggered network library, which is suitable for windows, linux, freebsd and other platforms. It uses select, poll, epoll, kqueue and other system calls to manage event mechanisms internally. Libevent is cross-platform and has extraordinary performance. Event-driven like nodejs; official website: http://libevent.org/

The latest stable version

Https://github.com/downloads/libevent/libevent/libevent-2.0.16-stable.tar.gz

Main modules:

Event handling framework

Event engine module

Buffer management module

Signal processing module

Php itself does not support multithreading, and php does not implement the concurrency mechanism very well. Pecl provides pcntl (process control), libevent extensions, socket packages, stream system functions, you can easily use php to develop high-performance, high-concurrency network applications.

Simple application example: Pcntl fork n worker. After the master process receives the request, the processing information is sent to the worker program, and the worker is processed and sent back to client. Master process can follow the concurrency to set the number of worker, that is, the size of n, and monitor (monitor) worker data to start more processes when insufficient. Same as nginx principle.

Attached: Php network programming framework

Http://code.google.com/p/swoole/downloads/list

2. Why learn libevent

Http server can be said to be a classic application of libevent. The standard way to write http can be found in libevent, non-blocking http server, that is, socket processing and http protocol processing winding.

Learning libevent helps to improve programming skills. In addition to network programming, Libevent code has many useful design skills and basic data structures, such as information hiding, function pointers, polymorphic support of c language, linked lists and heaps, etc., all help to improve their programming skills [1].

Three types of processing of requests:

1 、 connection input fork a new process

2 、 connection input pthread_create

3 、 connection input throw an Event-based array; main process do nonblocking things

3. Php libevent expansion module installation

Curl-O https://github.com/downloads/libevent/libevent/libevent-2.0.16-stable.tar.gz

Tar-zxvf libevent-2.0.16-stable.tar.gz

Cd libevent-2.0.16-stable

/ usr/local/php/bin/phpize

. / configure

Make

Make install

Vi / usr/local/php/etc/php.ini

Extension_dir= ""

Extension=libevent.so

Php-m | grep lib

Installation succeeded

The above is all the content of the article "what is the use of Libevent extensions in PHP". Thank you for reading! I believe we all have a certain understanding, hope to share the content to help you, if you want to learn more knowledge, welcome to follow the industry information channel!

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