在两个 foreach 循环中使用 "continue 2"时，php 5.5 内存泄漏？

Question

我刚刚遇到一个奇怪的内存泄漏问题。我设法将问题追溯到以下代码:

<?php
$data=array();
for($c=0; $c<32768; $c++)
    $data[$c]=array(1, 2, 3);
$filter=array(1, 2, 3);

for($kc=0; $kc<25600; $kc++)
{
    $cm=memory_get_usage(true);
    $pm=memory_get_peak_usage(true);
    echo "<b>loop $kc: current_memory: $cm, peak_memory: $pm...</b><br>";
    flush();

    foreach($data as $entry)
        foreach($filter as $pattern)
            continue 2;
}
?>

输出:

loop 0: current_memory: 12582912, peak_memory: 12582912...
loop 1: current_memory: 20709376, peak_memory: 20709376...
loop 2: current_memory: 28835840, peak_memory: 28835840...
loop 3: current_memory: 36962304, peak_memory: 36962304...
loop 4: current_memory: 45088768, peak_memory: 45088768...
loop 5: current_memory: 53215232, peak_memory: 53215232...
loop 6: current_memory: 61341696, peak_memory: 61341696...
loop 7: current_memory: 69468160, peak_memory: 69468160...
loop 8: current_memory: 77594624, peak_memory: 77594624...
loop 9: current_memory: 85721088, peak_memory: 85721088...
loop 10: current_memory: 93847552, peak_memory: 93847552...
loop 11: current_memory: 101974016, peak_memory: 101974016...
loop 12: current_memory: 110100480, peak_memory: 110100480...
loop 13: current_memory: 118226944, peak_memory: 118226944...
loop 14: current_memory: 126353408, peak_memory: 126353408...
loop 15: current_memory: 134479872, peak_memory: 134479872...
loop 16: current_memory: 142606336, peak_memory: 142606336...
loop 17: current_memory: 151257088, peak_memory: 151257088...
loop 18: current_memory: 159383552, peak_memory: 159383552...
loop 19: current_memory: 167510016, peak_memory: 167510016...
loop 20: current_memory: 175636480, peak_memory: 175636480...
loop 21: current_memory: 183762944, peak_memory: 183762944...
loop 22: current_memory: 191889408, peak_memory: 191889408...
loop 23: current_memory: 200015872, peak_memory: 200015872...
loop 24: current_memory: 208142336, peak_memory: 208142336...
loop 25: current_memory: 216268800, peak_memory: 216268800...
loop 26: current_memory: 224395264, peak_memory: 224395264...
loop 27: current_memory: 232521728, peak_memory: 232521728...
loop 28: current_memory: 240648192, peak_memory: 240648192...
loop 29: current_memory: 248774656, peak_memory: 248774656...
loop 30: current_memory: 256901120, peak_memory: 256901120...
loop 31: current_memory: 265027584, peak_memory: 265027584...
Fatal error: Allowed memory size of 268435456 bytes exhausted (tried to allocate 40 bytes) in xxx

当我删除“继续 2”语句并使用简单的“中断”或“继续”时，内存使用量保持不变。任何人都可以证实这种奇怪的行为吗？我在 php 5.5 中发现内存泄漏错误吗？使用 php-cli 不会显示这种奇怪的行为。仅在 apache 内使用 php 作为 mod_php 才会显示此行为。

我的系统:

$ php --version
PHP 5.5.11-2 (cli) (built: Apr  8 2014 11:42:22) 
Copyright (c) 1997-2014 The PHP Group
Zend Engine v2.5.0, Copyright (c) 1998-2014 Zend Technologies
    with Zend OPcache v7.0.4-dev, Copyright (c) 1999-2014, by Zend Technologies

$ apache2ctl status
Apache Server Status for localhost (via ::1)

   Server Version: Apache/2.4.9 (Debian)
          mod_fastcgi/mod_fastcgi-SNAP-0910052141 PHP/5.5.11-2
          mod_perl/2.0.8 Perl/v5.18.2

   Server MPM: prefork
   Server Built: Mar 29 2014 21:52:01

我正在进行当前的 Debian 测试 (Jessie)。

感谢您的帮助!

Answer 1

等等!!

您不应禁用 opcache:除了缓存之外，opcache 还会执行优化。

优化意味着 opcache 更改编译的操作码。

我确信调整优化会告诉您错误是在哪里引入的，这意味着您可以在 bugs.php.net 上创建错误报告，我们有机会为每个人解决问题。

请花点时间执行此操作。

调优优化

Opcache 有多个优化阶段，https://gist.github.com/krakjoe/962e54c38b155f896b00

配置运行的过程只需更改配置中的 opcache.optimization_level，这是一个位掩码，默认为 0xffffffff。

如果您需要调试帮助，请访问 EFnet 上的#php.pecl。

注意:要在 php-cli 中启用 opcache，请将 opcache.enable_cli 更改为 1，这将允许您在控制台中测试相同的行为应该显示自己