NAME

Gestinanna::POF::Lock - Base class for locking mechanisms

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SYNOPSIS

 package My::ObjectClass;

 use base qw(
    Gestinanna::POF::Secure::Type
    Gestinanna::POF::Lock::Type
    Gestinanna::POF::Type
 );

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DESCRIPTION

** The lock protocol is still in development and may change in the next few releases. **

Deriving a locking implementation from this base class and including it in the inheritance of a data object provides a generic way to add (advisory) locking semantics to any data object.

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METHODS

The following methods are expected in any implementation.

$object -> lock

This method should try to obtain a lock on the object. If unable to, it should return undef. Otherwise, it should return a true value such as the number of unlocks needed to completely release the object. An object may be locked multiple times by the same process, requiring the same number of unlocks. This makes some algorithms more efficient and allows them not to make assumptions regarding the locked state of any objects they may need.

$object -> unlock

This method should release the lock on the object. Calls to unlock and lock should be balanced, though it is safer to have more unlocks than locks.

$object is_locked

This method should return the identifier of the object that ownes the lock if there is a lock. Otherwise, it should return undef.

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AUTHOR

James Smith, <jsmith@cpan.org>

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COPYRIGHT

Copyright (C) 2003 Texas A&M University.  All Rights Reserved.

This module is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.

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