POE manages several types of information internally. Its Resource
classes are mix-ins designed to manage those types of information
behind tidy, mostly private interfaces. This was done to facilitate
testing and a conversion to C without the need to port POE::Kernel all
POE::Resource subclasses are generally different from one another, but
there are some similarities to note.
Every resource should have an initializer and finalizer method.
Initializers set up initial data and link resources into POE::Kernel.
Finalizers clean up any remaining data and verify that each resource
subsystem was left in a consistent state.
One common theme in resource implementations is that they dont need
to perform much error checking, if any. Resource methods are used
internally by POE::Kernel and/or POE::API classes, so its up to them
to ensure correct usage.
Resource methods follow the naming convention _data_???_activity,
where ??? is an abbreviation for the type of resource it belongs to:
Finalizer methods end in _finalize.
Finalizers return true if a resource shut down cleanly, or false if
there were inconsistencies or leaks during end-of-run checking. The
t/res/*.t tests rely on these return values.