How to modify the execution time of a script in php? 3 introductions

With the continuous development and use of web applications, we often need to perform some important tasks in PHP. In order to ensure the execution time and quality of these tasks, we need to optimize the script execution time. This article will introduce how to modify the script execution time to improve the performance and stability of the script.

1. View the php.ini configuration file

php.ini is the PHP system configuration file, which contains some PHP parameter configuration information. In php.ini, there is a parameter called max_execution_time, which is used to specify the maximum execution time of the script. By default, this parameter is set to 30 seconds. If the script execution time exceeds this time, the script will be terminated and a Fatal error will be prompted.

We can extend the execution time of the script by modifying the max_execution_time parameter in the php.ini file. Search for max_execution_time in php.ini, find the corresponding line, and then modify its value. For example, set it to 60 seconds:

max_execution_time = 60

After modifying the php.ini file, you need to restart the Apache or PHP service for it to take effect.

2. Modify the execution time in the script

If we don’t want to modify the global max_execution_time parameter, we can also temporarily modify the execution time in the script. PHP provides a set_time_limit function for setting the execution time of the script. The parameter of this function represents the maximum running time of the script in seconds. If we set the parameter to 0, there is no limit on the execution time of the script.

The following is a sample code:

<?php
// 设置脚本的最大执行时间为60秒
set_time_limit(60);

// 执行些重要的任务
...

// 恢复脚本的最大执行时间为默认值（按照php.ini中的配置）
set_time_limit(0);
?>

Be careful when using the set_time_limit function in a script. This function can only be used when the version of PHP is lower than 5.3.0. In 5.3.0 and It has been deprecated in the above version. In addition, whether you use the set_time_limit function in a script or modify the max_execution_time parameter of php.ini, you must ensure that the execution time is set reasonably, otherwise it may cause a waste of server resources, thus affecting the stability of the system.

3. Use PCNTL extension

PCNTL (Process Control) is an extension in PHP used to handle processes and can be used to control the execution of scripts Time and process. In PCNTL, we can use the pcntl_alarm function to set the maximum running time of the script. The parameter of this function is an integer representing the number of seconds. When the timer time reaches, a SIGALRM signal will be sent to the current process, and the script will be interrupted.

The following is a sample code:

<?php
// 函数定义
function my_alarm_handler()
{
// 执行中断代码
...
exit;
}

// 设置定时器
pcntl_alarm(60); // 设置为60秒

// 安装信号处理器
pcntl_signal(SIGALRM, &#39;my_alarm_handler&#39;);

// 执行重要的任务
...

// 关闭定时器
pcntl_alarm(0);
?>

Notes on using PCNTL extension: First of all, PCNTL extension is not a standard extension of PHP and needs to be explicitly enabled at compile time. Secondly, this extension can only be used in the PHP CLI environment and cannot be used in the web environment. Finally, since PCNTL extensions are related to system signal handlers and processes, special care needs to be taken when using them to avoid unpredictable results.

Summary

Modifying the script execution time is one of the keys to improving PHP performance and stability. This article introduces 3 methods to modify the script execution time, including modifying the max_execution_time parameter in the php.ini configuration file, temporarily modifying the execution time in the script, and using PCNTL extension to control the execution time of the script. We can choose the appropriate method according to actual needs to ensure the high performance and stability of PHP applications.

The above is the detailed content of How to modify the execution time of a script in php? 3 introductions. For more information, please follow other related articles on the PHP Chinese website!