Kĩ thuật lập trình - Chapter 12: The koala component model

Chapter 12The Koala Component Model Page Building Reliable Component-based Systems Chapter 12 - The Koala Component Model OverviewRequirements for Koala Koala Interfaces Binding, Gluing and Switches The Product Line Architecture Managing Versions and Variants Subtyping Summary Page Building Reliable Component-based Systems Chapter 12 - The Koala Component Model KoalaKoala is architectural description language component model for development of embedded software for consumer electronics products.Is used to build a large diversity of products from a repository of components.Page Building Reliable Component-based Systems Chapter 12 - The Koala Component Model Requirements for KoalaOriginal requirements:Devise a technique with which components can be ‘freely’ composed into products.The technique must work in resource-constrained environments.Make the product architectures as explicit as possible.Additional requirements:Let components make as few assumptions as possible about their environment.Allow for parameterized components that are as efficient as dedicated components.Allow for various ways of connecting components.Page Building Reliable Component-based Systems Chapter 12 - The Koala Component Model Koala InterfacesProvide:Like interfaces in COM and java.Require:Communication with components environment.Multiple:Handle evolution and diversity.Optional:Fine tune.Page Building Reliable Component-based Systems Chapter 12 - The Koala Component Model Binding and Bind Time in KoalaBasic binding scheme:Usage of symbolic names.Architectural description language.Compiler generates #define.Can be used as long as we build closed systems.Page Building Reliable Component-based Systems Chapter 12 - The Koala Component Model Principle of Binding ABPAB’P’Page Building Reliable Component-based Systems Chapter 12 - The Koala Component Model Koala ComponentsKoala component:Implementation in C.Component definition.Koala configuration:List of components.Top-level component.Koala component definition:Describes template for instantiating component.Resembles a class in java.Page Building Reliable Component-based Systems Chapter 12 - The Koala Component Model CCC2C1C3msA Koala ComponentA moduleA switchInterfacesSubcomponentPage Building Reliable Component-based Systems Chapter 12 - The Koala Component Model Composing Koala ComponentsConnect:Requires interfaces to provides interfaces;Provides interfaces to provides interfaces;Requires interfaces to requires interfaces.Does not fit?Connect a wider type.’Normal’ glue code.Switch.Page Building Reliable Component-based Systems Chapter 12 - The Koala Component Model Architectural RulesInitializationInitialization interface MultithreadingPumpsNotificationsLarge number of asynchronous activitiesPage Building Reliable Component-based Systems Chapter 12 - The Koala Component Model Overall ArchitectureSeparated into three layers:Computing platformAudio/video/data platformService and applicationLayer contains a set of subsystems Subsystems contain may componentsPage Building Reliable Component-based Systems Chapter 12 - The Koala Component Model Computing HardwaretvplfinfraA/VPlatformAPIuimstxtepgdealfactComputingPlatformtvsvcappsComputing Platform API Audio / Video HardwareA/V and Data PlatformApplications & ServicesProduct Line ArchitecturePage Building Reliable Component-based Systems Chapter 12 - The Koala Component Model Managing Versions and VariantsDiversity in a product line should not be handled by a CM system, because:It keeps diversity outside scope of the architects and,CM systems only handle compile-time variation.CM used for:Maintaining full version history.Temporary branches.Safeguarding product in final testing phase.Koala used for permanent diversity.Page Building Reliable Component-based Systems Chapter 12 - The Koala Component Model SummaryInterfacesBinding and bindtimesComponents compositionArchitectural rulesOverall architectureVersion managementPage Building Reliable Component-based Systems Chapter 12 - The Koala Component Model