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POWhy does the php garbage collection (gc) throw an error if SESSION and COOKIE data is used
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  1. POWhy does the php garbage collection (gc) throw an error if SESSION and COOKIE data is used
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    copied!<p>I sometimes need to use both $_SESSION and $_COOKIE as well as <strong><a href="http://de3.php.net/manual/en/function.setcookie.php" rel="nofollow noreferrer">setcookie()</a></strong> inside some php script. They both work fine. <strong>But ...</strong></p> <h1>The problem:</h1> <p>Every now and then the <strong><a href="http://de3.php.net/manual/en/features.gc.php" rel="nofollow noreferrer">php garbage collector</a></strong> fires and throws an error on pages that run scripts with both $_SESSION and $_COOKIE usage. The error being:</p> <blockquote> <p>session_start() [function.session-start]: ps_files_cleanup_dir: opendir(/var/lib/php5) failed: Permission denied (13)</p> </blockquote> <p><strong>By the way</strong><br> I use these php.ini settings:</p> <pre><code>session.gc_probability = 1 session.gc_divisor = 100 session.gc_maxlifetime = 1800 </code></pre> <p><strong>Considerations</strong><br> There is much discussion on the net about this phenomena, but the only relevant idea comes from the <strong><a href="https://bugs.php.net/bug.php?id=19029" rel="nofollow noreferrer">php bug report forum</a></strong>. Scroll to the very end of the page and find:</p> <blockquote> <p>The cause of it was that I used sessions AND cookies in one script. I commented all the 'setcookie' lines and all other cookie functions in my script and ... the problem vanished!</p> </blockquote> <p><strong>The hack</strong><br> Well, splitting $_SESSION and $_COOKIE use to two scripts was not an option as of now, but I manualy disable the garbage collector for each script concerned via @<strong><a href="http://de3.php.net/manual/en/function.gc-disable.php" rel="nofollow noreferrer">gc_disable()</a></strong>. But a hack, is a hack, is a hack, <a href="http://en.wikipedia.org/wiki/Rose_is_a_rose_is_a_rose_is_a_rose" rel="nofollow noreferrer">is a hack</a> ;)</p> <p><strong>Suggestions?</strong><br> Use the php.ini setting <code>session.gc_probability=0</code> to kill off the garbage collection altogether as discussed in <strong><a href="https://stackoverflow.com/questions/2904862/issues-with-php-5-3-and-sessions-folder">this answer</a></strong> or <a href="http://vvv.tobiassjosten.net/php/php-session-garbage-collection" rel="nofollow noreferrer">here</a> and <a href="http://somethingemporium.com/2007/06/obscure-error-with-php5-on-debian-ubuntu-session-phpini-garbage" rel="nofollow noreferrer">here</a><br> <em>Result:</em> Does not prevent the gc from running on my site, oddly enough. Why? I don't know.</p> <h1>Solution:</h1> <p>After setting a <a href="http://de3.php.net/manual/en/session.configuration.php#ini.session.save-path" rel="nofollow noreferrer">session.save_path</a> the garbage collection stopped throwing errors. I'm also using the default "session.gc_" directives now. PHP-version 5.4.9</p> <pre><code>session.save_path = /website/sessions </code></pre>
 

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