Architectural Patterns for Real-time

Systems

Software Engineering 10

Architectural patterns

Stereotypical ways of organizing the

architecture of a particular type of

software system

Observe and React

Environmental Control

Process Pipeline

Observe and React

This pattern is used when a set of

sensors are routinely monitored and

displayed. .

Environmental Control

This pattern is used when a system

includes sensors, which provide

information about the environment

and actuators that can change the

environment .

Process Pipeline

This pattern is used when data has

to be transformed from one

representation to another before it

can be processed.

Observe and reactThe input values of a set of sensors of the same types are

collected and analyzed. These values are displayed in some

way.

If the sensor values indicate that some exceptional

condition has arisen, then actions are initiated to draw the

operator’s attention to that value and, in certain cases, to

take actions in response to the exceptional value.

Real-time systems architectures are

process architectures

The system is composed of a

number of concurrent processes

Observe and React process structure

Burglar alarm system

Environmental controlThe system analyzes information from a

set of sensors that collect data from the

system’s environment. Further

information may also be collected on the

state of the actuators that are connected

to the system.

Based on the data from the sensors

and actuators, control signals are

sent to the actuators that then cause

changes to the system’s

environment.

Information about the sensor values

and the state of the actuators may be

displayed.

Environmental control

Anti-skid braking system

Process pipeline

An architecture for rapid data

collection that collects data from

sensors for later processing.

The end of the pipeline is a process

that transforms the data into a

representation that can be stored

and further processed.

Process Pipeline process structure

If the producer process runs faster

than the consumer process, a large

intermediate buffer is required

Neutron flux data acquisition

04/12/2014 Chapter 21. Real-time Software Engineering

20

Hybrid patternsLarge real-time systems often use a

combination of these patterns in different

parts of the system

For example, Process Pipeline could

be used to collect sensor information

for Observe and React pattern

Observe and React

Environmental Control

Process Pipeline