PPOOA
provides the following types of components
as building block of the architecture,namely:
-Algorithmic Component.
Algorithmic components or utilities are elements of the architecture
that perform
calculations or transform data from one type to another but separated from
its structural
abstraction . Data classification
components, Unix filters or data processing algorithms
typically represent them.
-Domain Component. The
domain component is an element of the architecture that responds directly to
the modeled problem. This component
does not depend on hardware or user interface. Its instances are similar to the
classic object in object oriented
design.
-Process. The process is
a building element of the architecture that implements an activity or group of
activities that can be executed at the same time as other processes. Its execution can be scheduled. The
PPOOA vocabulary supports two different types of processes: periodic and
aperiodic. Each of them is described in PPOOA profile and their real-time
attributes are also considered.
-Structure. A structure
is a component that denotes an object or class of objects characterized as an
abstract state machine or an abstract data type. Typical examples are:
stack, queue, list, ring and others.
-Controller Object. The
controller object is responsible for initiating and managing directly a group of activities
that can be repetitive, alternative or parallel. These activities can be
executed depending on a set of events or conditions. Typically, a controller
object receives an event. An event is something that can happen, like a Posix signal, a hardware interrupt or it represents a
computed event, like
an airplane entering a conflict volume or an alarm. Where one of these events
occurs, the system schedules associated event handlers.
Coordination
mechanisms are supported also: Semaphore, bounded buffer, mailbox, transporter and
rendezvous