objective interface systems...embedded systems are constrained swap – size, weight and power...

REAL-TIME AND EMBEDDED MIDDLEWARE PRODUCTS

© 2004 Objective Interface Systems, Inc.

CORBA/e CORBA for embedded

OBJECTIVE INTERFACE SYSTEMS



Why CORBA for Embedded Systems

Common Object Request Broker Architecture – CORBAOpen standard maintained by Object Management Group consortiumHigh performance, low footprint implementations

Why middleware?Standalone systems are a thing of the pastPlatform flexibility is essentialSoftware is becoming larger part of embedded systems

Why CORBA?Distribution – integrate into “system of systems” and enterprise management environmentPortability – migrate across processors, operating systems, communications infrastructuresInteroperability – interoperate with older models and new enterprise systems



CORBA/e

Embedded systems are constrainedSWaP – size, weight and powerHigher unit counts – different economics

Different processing infrastructuresProcessors PeripheralsCommunications

CORBA/e – “CORBA for embedded”Standalone specification Proven performance and utility in the embedded marketRetains interoperability



CORBA/e Overview

Purpose – to reduceResource usage – to extend CORBA’s applicability to systems constrained by

FootprintCPU

Complexity of implementation – higher assuranceComplexity of specification – fewer choices

Result - two profiles containing “static” parts of CORBACompact profile – embedded 32-bit µprocessorsMicro profile – smaller µprocessors, high-end DSPs



CORBA/e Profiles Overview

CORBA/e Compact ProfileReplaces “minimum CORBA” profileIncludes

“Static” parts of CORBAEssential parts of Real-time CORBABasic services – Naming, Events, Logging

CORBA/e Micro Profile Restricts typesFurther simplifies serversReal-time predictability



CORBA/e Table of Contents

1. CORBA Overview2. Object Model 3. OMG IDL Syntax and

Semantics4. Repository IDs 5. ORB Interface 6. Object Interfaces7. Policies8. The Portable Object Adapter9. Real-time

10. Naming Service11. Event Service12. Lightweight Logging13. General Inter-ORB Protocol14. CDR Transfer Syntax15. GIOP Messages16. Internet Interoperability

Protocol (IIOP)A. OMG IDL Tags and

ExceptionsB. Legal Information



CORBA/e Compact Profile

1. CORBA Overview2. Object Model3. OMG IDL Syntax and Semantics

Full grammar must be accepted (parsed)Can ignore

context clauses (in errata)abstract interfacesvalue boxescustom valuetypesvalue “supports” interfaceimport




4. Repository IDs – OMG IDL formats only5. ORB Interface

No dynamic TypeCode creationNo domain managersAdded back: shutdown, destroy

6. Object Interfaces Object - added back: is_a, nonexistentValueType Semantics

Lightweight valuetypeNo “polylithic” valuetype instances



CORBA/e Compact ProfileLightweight Value Types

Syntactically eliminates Value boxesAbstract interfacesDerivation from interfaces

Semantically eliminate “polylithic” valuetypes containingOther valuetypesType Any – which could contain other value typeAny other components (structs,unions, etc.) transitively containing

Other valuetypesType Any

Eliminates need for garbage collection (complexity, unpredictability)




7. Policies Policy objectsEffectivenessMessaging QoS Policies

Rebind supportSyncScope supportRoundTrip Timeout support




8. The Portable Object Adapter “Static parts” of POA specification

A la MinCORBANo servant managersNo default servantsNo POA policies to support above




9. Real-time Features “Hard real-time” parts of RTCORBA

Priorities DefinitionMappingClient propagated model

MutexesBindingBandingInvocation timeout




Services10.Naming Service11.Event Services – Untyped only12.Lightweight Log Service




Interoperability13.General Inter-ORB Protocol (GIOP)14.CDR Transfer Syntax15.GIOP Messages16.Internet Interoperability Protocol (IIOP)

AnnexesA. OMG IDL Tags and ExceptionB. Legal Information



CORBA/e Micro Profile

1. CORBA Overview2. Object Model3. OMG IDL Syntax and Semantics

Full grammar must be accepted (parsed)Can ignore

context clauses (in errata)abstract interfacesvalue typestype Anyimport (in errata)




4. Repository IDs – OMG IDL formats only5. ORB Interface

All sub-clauses requiredNo dynamic TypeCode creationNo domain managersAdded back shutdown, destroy

6. Object Interfaces Object - added back: is_a, nonexistentNo ValueType Semantics




7. Policies All sub-clauses requiredPolicy objectsEffectivenessMessaging QoS Policies

Rebind supportSyncScope supportRoundTrip Timeout support




8. The Portable Object Adapter Single root POA – default policies“Static parts” of POA specification

Ala MinCORBANo servant managersNo default servantsNo POA policies to support above

9. Real-timeMutexes only

Services – not required




Interoperability (common with CORBA/i)- all sub-clauses13.General Inter-ORB Protocol (GIOP)14.CDR Transfer Syntax15.GIOP Messages16.Internet Interoperability Protocol (IIOP)

AnnexesA. OMG IDL Tags and ExceptionB. Legal InformationC. Acknowledgement



Summary

CORBA/e Compact ProfileCompact, yet powerful – targeted to resource-constrained 32-bit µpDeterministic

Combines static core of CORBA with core of Real-time CORBAPriority propagation, priority banding

Server options – transient or persistent retained servantsCORBA Services – Naming, Events, LoggingInteroperable – native IIOP

CORBA/e Micro ProfileTruly micro – mobile or low-power µp, high-end DSPDeterministic core – real-time internalsCompact server-sideInteroperable – native IIOP



Further Information

CORBA/e Specificationhttp://www.omg.org/cgi-bin?doc/realtime/2006-02-02

PIDL & IDL for profiles http://www.omg.org/cgi-bin?doc/realtime/2006-01-03

http://www.omg.org/cgi-bin?doc/realtime/2006-02-02

http://www.omg.org/cgi-bin?doc/realtime/2006-01-03

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