Apache::Session::Lock::MySQL - Provides mutual exclusion using MySQL

 use Apache::Session::Lock::MySQL;

 my $locker = Apache::Session::Lock::MySQL->new();

 $locker->acquire_read_lock($ref);
 $locker->acquire_write_lock($ref);
 $locker->release_read_lock($ref);
 $locker->release_write_lock($ref);
 $locker->release_all_locks($ref);

Apache::Session::Lock::MySQL fulfills the locking interface of Apache::Session. Mutual exclusion is achieved through the use of MySQL's GET_LOCK and RELEASE_LOCK functions. MySQL does not support the notion of read and write locks, so this module only supports exclusive locks. When you request a shared read lock, it is instead promoted to an exclusive write lock.

The module must know how to connect to your MySQL database to acquire locks. You must provide a datasource name, a user name, and a password. These options are passed in the usual Apache::Session style, and are very similar to the options for Apache::Session::Store::MySQL. Example:

 tie %hash, 'Apache::Session::MySQL', $id, {
     LockDataSource => 'dbi:mysql:database',
     LockUserName   => 'database_user',
     LockPassword   => 'K00l'
 };

Instead, you may pass in an already opened DBI handle to your database.

 tie %hash, 'Apache::Session::MySQL', $id, {
     LockHandle => $dbh
 };

This module was written by Jeffrey William Baker <jwbaker@acm.org>.

Apache::Session