如何阻止 PHP 中的无限递归函数吃掉所有可用内存并最终导致笔记本电脑崩溃?

2022-01-12 00:00:00 递归 memory-management segmentation-fault php

我这里有一个简单的无限递归代码:

I have a simple infinite recursive code here:

<?php
    function test() {
        test();
    }

    test();

当我尝试运行相同的程序时，它会耗尽所有内存，最终我的笔记本电脑会挂起.我正在寻找一种方法来捕捉它并阻止机器挂起.PHP中是否有任何错误处理程序?

When I try to run the same, it eats up all the memory and eventually my laptop hangs. What I am looking for is a way to catch this and stop the machine from hanging. Is there any error handler in PHP for the same?

我已阅读并尝试过的内容:将 max_execution_time 设置为，比如说 5 秒，然后捕获错误行号.这没有按建议工作.

Things I have read and tried: setting max_execution_time to, let’s say, 5 seconds and catch the error line number. This didn’t work as proposed.

还有其他方法可以捕捉和阻止这种情况吗?

Is there another way to catch and stop this?

我正在使用 Ubuntu 16.04.1 LTS (Xenial Xerus).

I am using Ubuntu 16.04.1 LTS (Xenial Xerus).

推荐答案

限制shell子进程内存使用:

Limit the shell subprocess memory usage:

由于您声明您使用的是 Ubuntu，因此您可以限制进程的内存:

Since you state you use Ubuntu, you can limit the memory for your processes:

$ ulimit -v 500000
$ php -r 'function test() { test(); } test();'
mmap() failed: [12] Cannot allocate memory
mmap() failed: [12] Cannot allocate memory
PHP Fatal error:  Out of memory (allocated 304087040) (tried to allocate 262144 bytes) in Command line code on line 1

您可以在 PHP 中设置配置选项memory_limit:

From PHP you can set the configuration option memory_limit:

$ php -r 'ini_set("memory_limit", "500MB"); function test() { test(); } test();'
PHP Fatal error:  Allowed memory size of 2097152 bytes exhausted (tried to allocate 262144 bytes) in Command line code on line 1

现在您还可以编辑默认 php.ini 文件中的 memory_limit，或者您可以为您的脚本制作一个特定的.

Now you can also edit the memory_limit in the default php.ini file or you can make a specific one for your script.

$ echo 'memory_limit = 500MB' > test.ini
$ php --php-ini test.ini -r 'function test() { test(); } test();'
Fatal error: Allowed memory size of 2097152 bytes exhausted (tried to allocate 262144 bytes) in Command line code on line 1

您可能想要复制默认选项，而不是只提供一个选项.

You might want to copy the default one instead of having one just providing that one option.

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