EQUIP, components and MASSIVE3

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EQUIP, components and MASSIVE-3

• Chris Greenhalgh
• SHAPE workshop, 30 April 2001

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Contents

• Introducing EQUIP
• EQUIP URLs
• EQUIP dataspaces
• EQUIP MASSIVE-3 components
• Map table example
• Using and extending EQUIP
• More information

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Introducing EQUIP

• C and Java compatible
• CORBA IDL (valuetypes) specify cross-language
  types (classes)
• Adds Java-like facilities to C
• Limited type introspection
• Serialisation
• Dynamic class loading (using Bamboo)
• Adds general value equals and matches ops.
• Cross-platform build environment (Bamboo)

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EQUIP URLs

• C.f. Java RMI URLs
• Specify services
• Directlyequip//hostport/
• Via EQUIP traderequip//traderhosttraderport/se
  rvicename
• Defaultequip//LOCALHOST7883/
• LOCALHOST is 127.0.0.1 or value of environment
  variable LOCALHOST

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EQUIP dataspaces

• General-purpose data-sharing service, combines
• Data item semantics from MASSIVE-3
• Tuple-space operations
• in, out, read, collect, copycollect
• Pattern-matching (a la tuplespaces/ELVIN/)
• One server one dataspace
• Identified by EQUIP URL

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Dataspace usage

• Server forwards events/data items to connected
  clients (uses code loading)
• Clients may
• Publish information by creating data items
• Adverts, input and sensor data, reporting,
• Be controlled via data matching persistent
  patterns
• Activation, output, translators,
• Remove items from the dataspace representing jobs
• traditional tuplespace usage less efficient

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EQUIP MASSIVE-3 components

• MASSIVE-3 Management server (MgmtServer)
• Mouse input (from graphical window)
• Keyboard input (from graphical window)
• View control (world, position)
• Entity reporting (avatars and objects -gt EQUIP)
• EntityGenerator
• Creates MASSIVE-3 entities

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Component operation activation

• Advertise in a discovery or activation
  dataspace
• equip.service.ServiceAvailable with
• Unique service instance name
• Service capability (string)
• Respond to ServiceRequest by activating
• Specified application dataspace
• Specified application name

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Component operation ongoing (1)

• Generic publishers (mouse, keyboard)
• Multiple activation
• Create update specific item(s) representing
  input
• Specialised publisher (entreq)
• Single activation
• Pattern match to determine requirement (world,
  entities of interest)
• Dynamically creates updates items to represent
  each entity

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Component operation ongoing (2)

• Specialised controlled (view)
• Single activation
• Specific patterns (named) to determine view
  requirement (world, position, )
• Generic controlled/translator (EntityGenerator)
• Multiple activation
• Generic pattern to identify current requests
  (multiple)

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Map table example
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Ghostbuster example
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Using and extending EQUIP

• Create new Java applications
• Just use existing shared data types
• Can be components/ services or applications
• Create new shared data types
• New module, IDL specification, C Java
  compilation
• Create new Applications
• New module, possible IDL (better in separate
  module), C compilation and initialisation

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More Information

• http//www.crg.cs.nott.ac.uk/cmg/Equator
• MRL /mrl/src/Equator/docs
• MRL /mrl/src/Equator/shared
• CVS TBA