LegORB, the 2K Component-Based Lightweight ORB

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LegORB, the 2K Component-Based Lightweight ORB

• Software Research Group
• UIUC

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Introduction

• Ubiquitous computing requires integration of
  heterogeneous devices.
• Heterogeneity must be analyzed from different
  points of view
• Different architectures.
• Different OSes.
• Different programming languages.
• Different device configurations.

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CORBA and Heterogeneity

• CORBA provides the glue to hide some aspects of
  heterogeneity
• Different architectures.
• Different OSes.
• Different programming languages.
• CORBA fails to hide some other aspects of
  heterogeneity
• Different device configurations.

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CORBA Implementations

• Static approach.
• Monolithic design and/or implementation.
• Big size.

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Reflective ORBs

• Export their internal status and offer an
  interface to modify their architecture.
• Changing execution environments can take benefit
  of reflection.

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LegORB

• Reflective component-based ORB.
• Only required functionality is offered.
• LegORB can be dynamically customized for
  different device configurations.

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LegORB

• Based on the Component Configurator pattern.
• Component Configurator keeps dependencies among
  different objects consistent.
• By combining different components, different
  functionality can be achieved.

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LegORB and CORBA compatibility

• Two approaches to CORBA compatibility
• Functional (low-level).
• Application development (high-level).
• LegORB focuses on the functional compatibility
  (GIOP).
• Application development compatibility can be
  built on top of the functional one.

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LegORB architecture

• It is based in three component configurators
• LegORB Configurator.
• Client Side Configurator.
• Server Side Configurator.
• The LegORB Configurator is the entry point to the
  ORB.

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LegORB architectureLegORB Configurator
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LegORB architectureClient-Side Configurator
IIOP
MIOP
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LegORB architectureServer-Side Configurator
GIOP Writer
GIOP Reader
Marshaler
Demarshaler
Acceptor
Object Adapter
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LegORB usage example
Client
Server
TCP
TCP
Host B
Host A
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LegORB usage example
Client
Server
TCP
IPC
TCP
IPC
Process B
Process A
Host A
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Conclusion

• LegORB offers a WYNIWYG architecture.
• LegORB can be customized for different device
  configurations (Minimal PalmPilot client-side
  functionality requires 6KB).
• LegORB is ideal for devices with limited
  resources (Mobile Phones, PDAs, etc.).

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Contact

• e-mail address
• mroman1_at_cs.uiuc.edu
• Web page
• http//choices.cs.uiuc.edu/2k