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>.