Description:
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On my highloaded server bbcode extension behaves very unstable. Two types of errors occur very often on the same page when i simply reload it:

1) I get "502 bag Gateway" from nginx, that means that apache process craches. And in apache error_log appears a new line:
[Sat Apr 05 20:53:52 2008] [notice] child pid 14943 exit signal Segmentation fault (11)

2) I get "Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 2843012053 bytes) in XXX on line XXX" on a random place where i use bbcode_parse();... Only when i set memory_limit to 1Gb the problem doesn't appear. But there is one very strange moment here: when i use memory_get_peak_usage at the end of the script - it returns always just 1Mb, and never more!

And some times the page loads as expexted.

And that's all, nothing more in any logs...

I thought that xcache might cause this problems, but when i turned it off nothing changed.

Looks like the problem is in callbacks because when i don't use them i my bbcode stack - everything is perfect.

Reproduce code:
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My php Configure Command: './configure' '--prefix=/usr/lib/php5' '--host=i686-pc-linux-gnu' '--mandir=/usr/lib/php5/man' '--infodir=/usr/lib/php5/info' '--sysconfdir=/etc' '--cache-file=./config.cache' '--disable-cli' '--with-apxs2=/usr/sbin/apxs2' '--with-config-file-path=/etc/php/apache2-php5' '--with-config-file-scan-dir=/etc/php/apache2-php5/ext-active' '--without-pear' '--enable-bcmath' '--with-bz2' '--disable-calendar' '--with-curl' '--with-curlwrappers' '--disable-dbase' '--enable-exif' '--without-fbsql' '--without-fdftk' '--enable-ftp' '--with-gettext' '--without-gmp' '--disable-ipv6' '--without-kerberos' '--enable-mbstring' '--with-mcrypt' '--with-mhash' '--without-msql' '--without-mssql' '--without-ncurses' '--with-openssl' '--with-openssl-dir=/usr' '--enable-pcntl' '--disable-pdo' '--without-pgsql' '--without-pspell' '--without-recode' '--disable-reflection' '--enable-shmop' '--with-snmp' '--enable-soap' '--enable-sockets' '--disable-spl' '--without-sybase' '--without-sybase-ct' '--enable-sysvmsg' '--enable-sysvsem' '--enable-sysvshm' '--without-tidy' '--disable-tokenizer' '--disable-wddx' '--with-xmlrpc' '--with-xsl' '--enable-zip' '--with-zlib' '--disable-debug' '--enable-dba' '--without-cdb' '--with-db4' '--without-flatfile' '--without-gdbm' '--without-inifile' '--without-qdbm' '--with-freetype-dir=/usr' '--with-t1lib=/usr' '--disable-gd-jis-conv' '--with-jpeg-dir=/usr' '--with-png-dir=/usr' '--without-xpm-dir' '--with-gd' '--with-imap' '--with-imap-ssl' '--with-mysql=/usr' '--with-mysql-sock=/var/run/mysqld/mysqld.sock' '--with-mysqli=/usr/bin/mysql_config' '--with-readline' '--without-libedit' '--with-mm' '--without-sqlite'

reproduce code of the class is here: http://video.interzet.ru/bbclass.php