def process_sys_p p
            if p.action==Edoors::SYS_ACT_ADD_LINK
                add_link Edoors::Link.from_particle p
            elsif p.action==Edoors::SYS_ACT_ADD_ROOM
                Edoors::Room.from_particle p, self
            end
            @spin.release_p p
        end
def process_sys_p p
            if p.action==Edoors::SYS_ACT_ADD_LINK
                add_link Edoors::Link.from_particle p
            elsif p.action==Edoors::SYS_ACT_ADD_ROOM
                Edoors::Room.from_particle p, self
            end
            @spin.release_p p
        end
process the given system Particle

 @param [Particle] p the Particle to be processed

 @note the Particle is automatically released