PHP development: Interpretation of the internal principles of PHP extension development

As a popular development language, PHP generally not only uses its basic syntax and functions, but also involves extended development. Extension development provides PHP with more function extensions and performance optimization, which can be said to be a great tool for PHP.

However, most PHP developers do not actually understand the internal principles of PHP extension development. In this article, we will explain in detail the internal principles of PHP extension development, hoping to help developers who want to have a deeper understanding of PHP extension development.

1. What are PHP extensions?

Before understanding the internal principles of PHP extension development, you first need to understand PHP extensions. To put it simply, a PHP extension is a piece of binary code that can be used by PHP. By extending it, we can add PHP features or optimize PHP performance.

PHP extensions can be divided into two categories: built-in extensions and PECL extensions.

Built-in extensions are compiled and generated in the PHP source code and are part of PHP itself. Generally includes some very basic libraries and modules, the more commonly used ones are curl, mysqli, fileinfo, etc.

PECL extensions are some extensions maintained by the PHP community and written by external developers. PECL extensions can be compiled and generated independently of PHP source code and can be installed and uninstalled at any time.

2. How PHP extensions work

Next, let’s take a look at how PHP extensions work.

First of all, PHP loads some built-in extensions and configuration files when it starts. These files will set up some of PHP's core functions, such as memory management, string operations, etc.

Next, when PHP encounters an extension that needs to be loaded, it will find the corresponding binary code file (.so, .dll) based on the extension name. If it is found, it will enter the extension loading stage. The PHP extension will be written in C language. PHP will call the corresponding function and compile it into a data structure in memory to complete the loading of the extension.

When the extension is loaded into PHP, it can be called by PHP. At this time, PHP can implement new features or performance optimizations by calling functions exposed in the extension.

3. Introduction to PHP extension development

The above is the basic working principle of PHP extension, so how to start writing PHP extension? The following are simple PHP extension development steps:

• Install the tools and libraries required for extension development, such as php-dev, phpize, build-essential, etc.
• Enter the directory where you want to write the extension on the command line and use phpize to generate the extension code template.
• Write your extension code and add the corresponding code and library file compilation link in config.m4.
• Run ./configure to generate the Makefile, and use the sudo make && make install command on the command line to install the extension.
• Test your new extension in PHP.

Before starting PHP extension development, it is recommended to learn some basics of C language to improve your ability and understanding of writing extensions.

4. Some points of PHP extension development

In order to better develop PHP extensions, here are some points that need to be paid attention to when developing extensions:

• Avoid using global variables as they are not thread-safe.
• You can use thread safety managers, such as global data manager (TSRM) and multi-thread extension (MTS), to ensure the thread safety of the extension.
• When developing PHP extensions, you need to understand PHP's internal API in detail.
• It is recommended to use ZEND_PARSE_PARAMETERS_START or parameter parser to manage the input parameters of the function, which will increase security and stability.

Summary

This article introduces how PHP extensions work and provides some introductory steps and considerations for PHP extension development. Mastering these basic knowledge can help developers better understand and develop PHP extensions, and provide more options for code performance optimization and function expansion.

The above is the detailed content of PHP development: Interpretation of the internal principles of PHP extension development. For more information, please follow other related articles on the PHP Chinese website!