内存泄漏分析器-memory-tracker

[guanhui07]

内存泄漏分析器

常驻内存 分析内存泄漏还是非常有必要的，比如使用workerman swoole 等 cli 应用程序 很多人多少都会遇到内存泄漏
而一般大多人选择解决方法就是定期 重启。简单粗暴解决。。

memory-tracker

Swoole Tracker 是由上海识沃科技公司开发的一款PHP性能分析、调用统计分析、链路追踪软件。
该软件已于2023年正式下线。在此项目下线后，有很多PHP开发者向我们反馈需要用其
分析cli守护进程程序下的内存泄漏问题。在2024年11月我们将内存泄漏分析器从Swoole Tracker
剥离出来，更名为php-memory-tracker并作为新的单独扩展，提供给开发者来使用。
另外我们也对此工具进行了重构，新的4.0版本使用更简单可靠，还增加了泄漏点调用栈的输出，更加强大。

新的php-memory-tracker扩展，既可用于swoole协程环境，也可用于非协程环境，
例如workerman或其他cli常驻进程程序。


支持PHP的7.3以上版本 
仅支持cli环境加载，避免php-fpm误加载
增加了泄漏点调用栈的输出

下载 安装

https://doc.swoole.com/@memory-tracker/download.html
忽略

下载扩展后，修改php.ini加入extension=memory_tracker即可，
可使用php -m和php --ri memory_tracker命令查看扩展是否安装成功。


php --ri memory_tracker

memory_tracker

memory_tracker support => enabled
Copyright => 上海识沃网络科技有限公司
Email => [email protected]
Website => https://www.swoole.com/
Version => 4.0.0

Directive => Local Value => Master Value
memory_tracker.enable => Off => Off

使用

使用时只需要加入-d memory_tracker.enable=1，并且在常驻进程的
主循环中加入memory_tracker_leak_check函数调用即可。

demo.php

class ClassA
{
    public array $arr = [];
    public string $str = '';
}

function foo(ClassA $obj)
{
    $str = str_repeat("big string", 1024);
    $obj->arr[] = $str;
    $obj->str .= $str;
}

$obj = new ClassA();
$usage = memory_get_usage();
$n = 100;
while ($n--) {
    foo($obj);
}

var_dump(strlen($obj->str));
var_dump(memory_get_usage() - $usage);
memory_tracker_leak_check();

执行：

# 不开启内存检测，不会有性能消耗
php cli.php 
int(1024000)
int(2259616)

# 开启检测
php -d memory_tracker.enable=1 cli.php 

int(1024000)
int(2264608)
[Round#0] leak 1000.03 KB bytes, alloc 99 times at /home/swoole/workspace/ext/memory_tracker/examples/cli.php:13
#0 /home/swoole/workspace/ext/memory_tracker/examples/cli.php(20): foo(Object(ClassA))

[Round#0] leak 1003.12 KB bytes, alloc 100 times at /home/swoole/workspace/ext/memory_tracker/examples/cli.php:11
#0 /home/swoole/workspace/ext/memory_tracker/examples/cli.php(11): str_repeat('big string', 1024)
#1 /home/swoole/workspace/ext/memory_tracker/examples/cli.php(20): foo(Object(ClassA))

Swoole 协程环境

class Test
{
    public $arr = [];

    function run()
    {
        $locals = '';
        $this->run2($locals);
    }

    function run2(&$locals)
    {
        global $global1, $global2;
        $http = new \Swoole\Http\Server("0.0.0.0", 9501, SWOOLE_BASE);
        $http->set([
            'worker_num' => 1
        ]);
        $http->on("start", function ($server) {

        });
        $http->on("request", function ($req, $resp) use (&$global1, &$global2, &$locals) {
            $global2 .= "2222222222";
            $locals .= "333333333333";
            $global1[] = random_bytes(random_int(256, 4096));
            $this->arr[] = "444444444";
            $resp->end("hello world");

            memory_tracker_leak_check(128);
        });

        $http->start();
    }
}

(new Test())->run();

执行：

php -d memory_tracker.enable=1 co_server.php
发起请求：

ab -c 5 -n 5000 http://127.0.0.1:9501/
检测结果：

[Round#2913] leak 275.73 KB bytes, alloc 128 times at /home/swoole/workspace/ext/memory_tracker/examples/co_server.php:47
#0 [internal function]: Test->{closure}(Object(Swoole\Http\Request), Object(Swoole\Http\Response))

[Round#2944] leak 34.54 KB bytes, alloc 128 times at /home/swoole/workspace/ext/memory_tracker/examples/co_server.php:46
#0 [internal function]: Test->{closure}(Object(Swoole\Http\Request), Object(Swoole\Http\Response))

[Round#2944] leak 28.79 KB bytes, alloc 128 times at /home/swoole/workspace/ext/memory_tracker/examples/co_server.php:45
#0 [internal function]: Test->{closure}(Object(Swoole\Http\Request), Object(Swoole\Http\Response))

循环引用

const N = 200;
class testA
{
    public $pro;
}
function foo()
{
    var_dump(memory_get_usage());
    for ($i = 0; $i < N; $i++) {
        $obj = new testA();
        $obj->pro = $obj;
        unset($obj);

        memory_tracker_leak_check(64);
    }
    var_dump(memory_get_usage());
}
foo();

执行：
php -d memory_tracker.enable=1 gc.php 
int(2109824)
[Round#63] leak 3.50 KB bytes, alloc 64 times at /home/swoole/workspace/ext/memory_tracker/examples/gc.php:12
#0 /home/swoole/workspace/ext/memory_tracker/examples/gc.php(20): foo()

[Round#96] leak 3.50 KB bytes, alloc 64 times at /home/swoole/workspace/ext/memory_tracker/examples/gc.php:12
#0 /home/swoole/workspace/ext/memory_tracker/examples/gc.php(20): foo()

[Round#129] leak 3.50 KB bytes, alloc 64 times at /home/swoole/workspace/ext/memory_tracker/examples/gc.php:12
#0 /home/swoole/workspace/ext/memory_tracker/examples/gc.php(20): foo()

[Round#161] leak 3.50 KB bytes, alloc 64 times at /home/swoole/workspace/ext/memory_tracker/examples/gc.php:12
#0 /home/swoole/workspace/ext/memory_tracker/examples/gc.php(20): foo()

[Round#194] leak 3.50 KB bytes, alloc 64 times at /home/swoole/workspace/ext/memory_tracker/examples/gc.php:12
#0 /home/swoole/workspace/ext/memory_tracker/examples/gc.php(20): foo()

int(2131392)

可以看到无论是复杂的循环引用，还是普通的数组、字符串无限扩容导致的内存泄漏，无论是普通的cli脚本，
亦或者是Swoole协程服务器环境，memory_tracker都可以正常工作，
除了打印申请内存的脚本文件和行数之外，还会打印申请内存时的调用栈。

https://doc.swoole.com/@memory-tracker/download.html

https://doc.swoole.com/@memory-tracker/usage.html