UML for Realtime Modeling Constructs and Notation

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UML for Real-time Modeling Constructs and Notation

• Judy Dizon

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Presentation Outline

• Modeling Structure
• Capsules
• Ports
• Connectors
• Modeling Behavior
• Protocols
• State Machines
• States
• Transitions
• Time Service

• Application Example
• Air Condition (Heating System)
• References

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Capsules UML Modeling

• Stereotype of Class concept capsule with
  specialized (executable) semantics
• represent independent flow of control (active
  classes)
• used to represent the architecture of a system
• Class diagram representation

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Capsules Composition
Relay port
FaxCall

• Alternative representation more abstract

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Capsules Notation
Since a capsule is a stereotype of a class, the
stereotype icon appears in the name compartment
of the class rectangle.
Class diagram view
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Capsules Communication

• Capsules receive messages through public ports
  which understand protocols.

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Capsules Attributes

• Capsules only have private attributes to enforce
  encapsulation.

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Capsules Behavior

• Optional hierarchical state machine
• Defined by state machines which run in response
  to the arrival of signals.

transitionS1toS2 port2.send(m1)
port3.send(m2)
message arrival on port1 triggers transition S1
to S2
S1
S1
S1
S2
S3
S2
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Ports UML Modeling

• Stereotype of Class concept ltltportgtgt
• Boundary objects for a capsule instance.
• Unlike an interface (which is a behavioral
  thing), a port includes both structure and
  behavior.
• Each port plays a specific role in a protocol.
• The protocol defines the valid flow of
  information (signals) between connected ports of
  capsules.

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Ports Types

• Viewed from the outside, ports present the same
  object interface, and they cannot be
  distinguished except by their identity and
  protocol role.
• Viewed from inside the capsule, they can be one
  of two kinds
• relay ports - connected to sub-capsules
• end ports directly connected to the capsules
  state machine

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Ports Boundary Objects

• Fully isolate a capsules implementation from its
  environment (in both directions)

Ports are created and destroyed along with their
capsule
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Ports Notation
b) Capsule role view (only public ports are
shown)
a) Class diagram
Note. All the ports shown here implement the base
role of their protocol.
c) Capsule structure diagram (all ports are shown)
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Connectors

• Modeled by an association that exist between 2 or
  more ports of the corresponding capsule classes
• No required UML extensions exist to represent it
• No notational extensions are present because it
  does not entail any special stereotype

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Protocols

• A protocol is a specification of desired behavior
  to take place over a connector.
• It is pure behavior and does not specify any
  structural properties.

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Protocols UML Modeling

• Collaboration stereotype protocol
• Classifier Role stereotype protocolRole

protocolRolecaller
protocolOperatorAssistedCall
protocolRolecallee
protocolRoleoperator
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Protocols Binary Protocols

• Binary protocols, involving only two
  participants, are the most common.
• For binary protocols, only one role, called the
  base role, needs to be specified.
• The conjugate role can be derived from the base
  role by transposing incoming and outgoing signal
  sets

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Protocol
ltltprotocolgtgt BinaryProtocolA
Incoming
signal1 signal2 signal3
Outgoing
signal1 signal4 signal5
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State Machines States

• A state machine is a graph of states and
  transitions that describes the response of an
  object of a given class to the receipt of outside
  stimuli.
• The states are represented by state symbols and
  the transitions are represented by arrows
  connecting the state symbols.
• States may also contain sub-diagrams, or other
  state machines which represent different
  hierarchical state levels.

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States external and internal view
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State actions entry and exit actions
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Junction Points
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State Machines Transitions
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Initial Point and Initial Transition
Initial transition (connects initial point with
start state)
Initial point (one per state machine)
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State machine without initial transition
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Time Service

• Can be accessed through a standard port (service
  access point)
• Converts time into events that can be handled in
  the same way as other signal-based events

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Time Service

• No UML extensions or special notations designed
• Service access points for accessing timing
  service are indicated by protected end ports
  whose type is defined as TimeServiceSAP (a
  system defined protocol)

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Application Example Heating System

• Consists of 2 heating subsystems and 2 heating
  levels
• Level1 only standard heating system is active
• Level2 additional heating system is active
• Motor is cold in the start phase additional
  heating system needs to be on (if user selects
  higher temp that actual temp)
• Then can it only be that the standard heating is
  sufficient (it must be on only)

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Heating System (2)

• An incoming temp event changes the heating
  systems status from off to level1 and from start
  to level2
• Heating system automatically changes its status
  from start to off after 10 minutes (after the
  standard heating system delivers enough heat)
• Low/high voltage, cold ignition key status
  cause temporary deactivations of the heating
  system

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Heating System (3)

• As soon as there are no more exceptions, the
  heating system should continue operating on the
  selected level
• The heating system is switched off if the
  ignition key status is cold for more than 5
  minutes or if it is removed

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Heating System UML RT Model

• Structure diagram for Air Condition Control

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Heating System UML RT Model (2)

• Structure Diagram for heating system control

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Heating System UML RT Model (3)

• State diagram for basic heating controller

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Heating System UML RT Model (4)

• Class diagram of heating controller

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References

• Neilsen, M., CIS 721 Lecture Slides. Spring 2005.
• A UML Profile for Modeling Complex Real-Time
  Architectures. Database on-line. Available from
  www.omg.org/news/meetings/workshops/presentations/
  realtime 2001/6-3_Selic.presentation.pdf.
  Accessed on 26 April 2005. 
• Formal Verification of UML Statecharts with
  Real-Time Extensions. Database on-line. Available
  from www.brics.dk/omoeller/papers/fase02.pdf.
  Accessed on 26 April 2005.
• Unified Modeling of Real-Time Control Systems and
  their Physical Environments Using UML. Database
  on-line. Available from www.ida.liu.se/jakax/Publ
  ications/ ecbs01.pdf. Accessed on 26 April 2005.
• UML for Real-Time Overview. Database on-line.
  Available from www.uml.org.cn/UMLApplication/pdf/u
  mlrt_overview.pdf. Accessed on 19 April 2005.

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References (2)

• Using UML for Modeling Complex Real-Time Systems.
  Database on-line. Available from
  www-28.ibm.com/developerworks/rational/library/con
  tent/03July/1000/1155/1155_umlmodeling.pdf.
  Accessed on 19 April 2005.
• Embedded UML A Merger of Real-Time UML and
  Co-Design. Database on-line. Available from
  www.gigascale.org/pubs/101/EmbeddedUML.whitepaper.
  v7. External.pdf. Accessed on 26 April 2005.
•  
• A Survey of Real-Time Management in Common
  Object-Oriented Methods. Database on-line.
  Available from www.irisa.fr/Convergence/LivrablesP
  ublics/ D13_Irisa.doc. Accessed on 26 April 2005.
• Integrating Data Flow Equations with UML /
  Real-Time. Database on-line. Available from
  www.es.tu-darmstadt.de/english/research/publicatio
  ns/download/ BichlerRadermacherSchuerr-rtj.pdf.
  Accessed on 19 April 2005.