UML Statechart semantics

1
UML Statechart semantics

• Speaker Fei Mo
• Tutor Priv.-Doz. Dr. Thomas Noll

Lehrstuhl für Informatik 2 RWTH Aachen SS 07
2
Contents

• Introduction
• Fundamentals
• Semantik of UML Statechart
• Extended Hierarchical Automata
• Statechart with STATEMATE
• Summary

3
Introduction

• formulate the semantics of UML Statechart
• We show how the Extended hierarchical Automata
  represent statecharts
• We show the Statechart in STATEMATE

4
Contents

• Introduction
• Fundamentals
• Semantik of UML Statechart
• Extended Hierarchical Automata
• Statechart with STATEMATE
• Summary

5
Fundamentals

• HierarchyHumans not capable to understand
  systems containing more than 5 objects. Most
  actual systems require more objects
• Behavioral hierarchy
• Structural hierarchy
• Timing behavior.

6
Introducing hierarchy
super-state S
sub-states
7
Contents

• Introduction
• Fundamentals
• Semantik of UML Statechart
• Extended Hierarchical Automata
• Statechart with STATEMATE
• Summary

8
Semantik of UML Statechart

• State
• a condition during the life of an object or an
  interaction
• Simple State
• rectangle with rounded corners
• The name tab
• The action label
• entry
• exit
• do
• include

9
Composite State

• State
• Composite State

10
Composite states

• Composite states
• concurrent substates - using -and-
  relationship
• each substate separated from others by dotted
  line
• disjoint substates - using -or- relationship
• transitions between substates
• Example of concurrent substates

11
Configuration

• A maximum set of states (C) that the system can
  be simultaneously in
• C contains root state
• If C contains OR-state A, it must contain only
  one of As substates
• If C contains AND-state A, it must contain all of
  As substates
• Basic configuration is a maximal set of basic
  states that the system can be in simultaneously
• Subconfiguration

12
Semantik of UML Statechart

• Event
• Triggers the transition
• Can be either internally or externally generated
• Conditions
• Guards the transition from being taken unless it
  is true when event occurs

13
Semantik of UML Statechart

• Transition
• Simple transition
• a relationship between two states
• source state of t1 is a directly or transitively
  nested substate of the source state of t2 -gt t1
  is higher than t2
• Start and end transitions

14
Semantik of UML Statechart

• Transition
• The exact sequence of actions
• first the exit actions of all states left by
  the transition are executed
• starting the deepest one in the hierarchy
• next the action associated to the transition is
  performed
• finally the entry actions of states entered by
  the transition
• starting with the highest one in the hierarchy

15
Semantik of UML Statechart

• Transition
• Transitions to and from Concurrent States
• multiple source states and target states

16
Semantik of UML Statechart

• example
• s0 refined s1, s2, and s3
• composite state s0, s1, s4 s5 concurrent state
  s1
• Configurations "System states s1 s6 s8
  s2 s3

Transition fire source state is in the current
configuration trigger is offered by the external
environment the guard is satisfied
17
Semantik of UML Statechart

• Initial subconfiguration n8, n6
• b -gt t6 next subconfiguration n5, n6
  sequence ltd.egt
• a -gt t3, t2 n9, n7 ltb, dgt if s8 active no
  t1 (s8 lower than s4)

e ? ?\a, b, No transtion, configuration does
not change
18
Contents

• Introduction
• Fundamentals
• Semantik of UML Statechart
• Extended Hierarchical Automata
• Statechart with STATEMATE
• Summary

19
Extended hierarchical Automata

• Definition Sequential Automaton
• A sequential automaton A is a 4-tuple
• is a finite set of states
• is the initial state
• is a finite set of transition labels
  (labels have a particular structure)
• is the transition relation

20
Extended hierarchical Automata

• Definition Extended hierarchical Automata
• An EHA consists of a set of sequential automata
• An EHA is a 5-tuple
• F is a finite set of sequential automaton
• E is a finite set of events
• V is the set of variables
• ? is refinement function

21
Extended hierarchical Automata

• UML Statechart example

22
Extended hierarchical Automata

• Extended hierarchical Automata example

Extended Hierarchical Automata can represent
statecharts
23
Extended hierarchical Automata

• the refinement function ?
• ?(S) TV, USER,
• ?(OFF) POWER,
• ?(ON) IMAGE,SOUND
• ?(s) Ø for any other state sin EHA dotted
  arrows.
• Initial states indicated by thick boxes.
• Non-inter-level transitions represented in the
  obvious way.

24
Extended hierarchical Automata

• The source restriction of transition on STB
• Join transitions a set of states
• target determinator (TD)
• transition from ON to STB -gt off 1
• TD of the transition off1 STB
• TD of the transition on SHW, SND.

25
Contents

• Introduction
• Fundamentals
• Semantik of UML Statechart
• Extended Hierarchical Automata
• Statechart with STATEMATE
• Summary

26
Statechart with STATEMATE
STATEMATE system
structure
function
Action
Module-charts
Activity-charts
Statecharts
27
Statechart with STATEMATE

• In Conf. S,S1,A,B,D,E
• Event a trigers a/b
• Event b trigers b/c?
• what with Event d?

28
Contents

• Introduction
• Fundamentals
• Semantik of UML Statechart
• Extended Hierarchical Automata
• Statechart with STATEMATE
• Summary

29
UML Statechart Semantics

• Can describe the behavior of instances of a model
  element.
• Describe sequences of states (rounded boxes) and
  transitions (arrows).
• Can describe behavior of use cases and
  subsystems.
• Extended Hierarchical Automata can represent
  statecharts
• Can be used in STATEMATE to descript separated
  actions as a more universal design methodology

30
References

• 1 Unified Modeling Language Document Set.
  Version1. 1, Rational Software Corporation, 1997.
• 2 OMG Unified Modeling Language Specification,
  version 2.1.1, Object Management Group, Inc.,
  2005.
• 3 Mikk E, Lakhnech Y, Petersohn C, Siegel M. On
  formal semantics of Statecharts as supported by
  STATEMATE. In Duke D, 1997
• 4 Evans A, eds. Proceedings of the 2nd BCS-FACS
  Northern Formal Methods Workshop. London
  Springer-Verlag, 1997.
• 5 Harel D, Naamad A. The STATEMATE semantics of
  statechartsJ. ACM Transactions on Software
  Engineering and Methodology, 1996.

31
Thanks!