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2
Outline
• Setting the stage
• UML 2.0
– RFPs
– Influences
– Issues
• Real-time UML
• On the horizon
3
Application domains
• Soft real-time systems
– event-driven
– asynchronous
– concurrent
– distributed
• Application areas
– telecom
– automotive
– aerospace
4
The Unified Modeling Language™
• UML is managed by the Object Management Group (OMG)
– the language makes no provisions for real-time
• The real-time analysis and design working group
– promotes real-time issues for UML
– uses profiles to tailor the capabilities of UML
standardization work
5
Application
Some concerns
ArchitectureArchitecture
PerformancePerformance
ConcurrencyConcurrency
SchedulingScheduling
TimeTime
ResourcesResources
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Real-time profiles of the UML
UMLUML
PerformancePerformance
SchedulingSchedulingTimeTime
Fault toleranceFault tolerance
QoSQoS Large-scale systemsLarge-scale systems
UML 2.0UML 2.0
- SDL
- UML-RT (ROOM)
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UML 2.0
InfrastructureInfrastructure
OCLOCL Diagram InterchangeDiagram Interchange
- Kernel language (core)
- Extensions (profiles)
SuperstructureSuperstructure
- Architecture (scalability and component-based-development)
- Workflow (state machines and activity graphs)
- Interaction (augmentation with Message Sequence Charts)
- Action semantics (integration)
- Collaboration (simplification)
- Relationships
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Inspiration sources for UML 2.0
• SDL (Specification and Description Language)
– architecture
– state machines
– executability
• MSC (Message Sequence Charts)
– decomposition
– variations (inline expressions)
– references
– organization
• ROOM (Real-time Object-Oriented Modeling)
– architecture (UML-RT)
UML 2.0UML 2.0
SDLSDL
MSCMSC
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Visual modeling
1. Round-trip engineering
– consistency between models, code, and application
– maintenance• code is king
2. Models with code inserted
– fragmentation
– target language dependent• portability
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Add executability
3. Executable models
• Visual modeling
• Behavioral modeling
– action language
– data model
• Run-time semantics
• Configuration
– build scripts
– realization mappings• deployment
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Visual software engineering
• Express functionality in the model– check the correctness of the model
• validation
• simulation
• verification
• testing
• Transform the model into code– forward engineering
• round-trip superfluous
• reverse engineering required to capture legacy and integrations
– automatic and complete• configurable
– target language independent• transport mechanisms selectable
– the documentation is the model is the code
iteration
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• A logical component (agent, capsule)– is an active class
– provides encapsulation• a ”black box”
• hierarchical decomposition
• internal structure
• behavior
– has interfaces
• Used as building blocks– top down
• divide and conquer
– bottom up• like lego
Logical components
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Encapsulation
• Logical components use connection points (gate, port)
– to provide bi-directional access points without exposing the internal structure
– each connection point provides its own view of the logical component
• The connection points specify contracts in the form of interfaces (interface, protocol, protocol role)
– implemented interfaces• services that are realized by the
logical component
– required interfaces• services that others must implement
ATM
«interface»
Display «interface»
Keyboard «interface»
Log
Display
CustomerKeyboard
OperatorLog, Verify, Transaction
Display, Shutdown
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Connection requirements
• Connection points specify how instances of logical components may be connected to each other (channel, connector)
– it it only possible to connect logical components that have matching required and implemented interfaces
• The connections describe communication paths
:ATM
Operator
Visa:Bank
Terminal
C1
Bank
Terminal Log, Transaction
Display
MC:Bank
Operator
Terminal
C2
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Internal structure and behavior
Bank
Bank
S1
S2
e2 e3e1
Terminal Log, Transaction
Display
Bank
Terminal Log, Transaction
Display
ctrl(1..1):Controller
db(1..1):DataBase
LogATM
Log
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Dynamic decomposition aspects
• A state machine controls the internal structure
– may be implicit
– interacts with contained logical components as well as external logical components
• Initialization of internal structure
– start configuration
• Life-cycle dependencies– creation
– termination
• Multiplicity constraints
Switch
Switch
basic(0..*):Call
service(1..1):Library
Initiate
Trigger
Control
Setup
Phone
Phone
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Communication mechanisms
• To-based communication
– relies on object-references
– interfaces provide typed object references to logical components
– object references may be obtained through
• creation of logical components
• parameters of received messages
• naming service (or similar)
• Via-based communication
– relies on structure
– usually via connection points
// pseudo code: to
Client aClient = ...;
send sig1 to aClient;
aClient.send(sig1);
// pseudo code: via
Port aPort = ...;
send sig1 via aPort;
aPort.send(sig1);
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Transition-centric state machines
Dummy
S1
S2
e2 e3e1
state-centric view
S1
S2
e1 e2
S2
e3
S1
i = i + 1
e1
e1
Dummy
e2
i = 0
e3
i[5] [else]
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Sequence diagrams
• Decomposition
– collapsed views
• Variations (inline expressions)
– parallelism, alternatives
– loops, optionality, exceptions
• Sequence diagram references
• High-level sequence diagrams
– organizing sequence diagrams
seq
init
a b c
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Performance, scheduling, and time
• The first of the real-time UML profiles
– Initial submission August 2000
– Revised (final) submissions due this summer
• Major areas of concern
– Schedulability analysis• the ability of a system to meet its deadlines
– Performance analysis• the response of the system under different conditions
– Time
– Concurrency
– Realization mappings• deployment
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Realization mappings
Functions
Logical
view
Engineering
view
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Quantitative aspects
• There are many quantitative concerns when a logical viewpoint is mapped on top of an engineering viewpoint
– Will we get the right performance?
– How much memory can we afford to use?
– Is the throughput sufficient?
– Do we need additional resources?
• Should we add resources or cut functionality?
• These quantitive aspects are captured as Quality of Service (QoS)
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On the horizon: Embedded UML
• A UML profile for hardware and software co-design
• Delay implementation decisions
– virtual integration by focusing on functionality
• Several system-level design languages could be brought together by UML
– SystemC, SpecC, etc.• These languages primarily provide abstractions of existing programming languages
to model ports, interfaces, channels, state machines, etc.
– require additions/modifications to the UML• abstractions
• communication mechanisms (buses, broadcasts, synchronization)
• realization mappings (deployment)
• non-functional requirements ($)
• Visual Systems Engineering
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On the horizon: Testing
• A UML profile for testing
– UML notation (primarily sequence diagrams)• strong relationship to TTCN-3, which is a language dedicated to testing
• conformance, robustness, regression, system, and integration testing
– Verification of functionality of object-oriented/component-based systems, primarily from a conformance point of view
– Definition of test cases, and how they are collected in test suites
– Setting up, executing, and evaluating tests
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Now it is your turn
• Questions
