Transcript AmOP and AmbientTalk Analysis

Middleware for Ubiquitous Computing
Students:
- Arnaud Borg
- Christian Brel
- Sandie Dupain
I) AmOP and AmbientTalk description
AmOP and AmbientTalk Analysis
AmOP : Ambient Oriented Programming
 A paradigm from the Programming Technology
Laboratory at the Vrije Universiteit Brussel, Belgium
 A paradigm to develop the ideal ambient application
 Define the features of an ideal ambient language
 Departing of a hardware phenomena
Arnaud Borg, Christian Brel, Sandie Dupain
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I) AmOP and AmbientTalk description
AmOP and AmbientTalk Analysis
Hardware phenomena (1/2)
 The connection volatility
 Not a stable connection between two devices
 Users can move out of range
 Connection re-established : tasks have to resume
 The Ambient resource
 Availability of a resource depends on the location of the
device
 Ambient resources become dynamically
available/unavailable
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I) AmOP and AmbientTalk description
AmOP and AmbientTalk Analysis
Hardware phenomena (2/2)
 The Autonomy
 Devices should have an independent running
 No “higher authority”
 The natural concurrency
 Devices don’t have to wait the responses of the other
devices.
 Is a natural phenomenon in software running on mobile
networks
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I) AmOP and AmbientTalk description
AmOP and AmbientTalk Analysis
Their solution: AmbientTalk
 Explicitly designed to satisfy the AmOP characteristics
 Experimental object-oriented distributed
programming language
 Largely influenced by the E programming language
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I) AmOP and AmbientTalk description
Our Issues
 Is it enough useful to answer the current problems of
the classical ambient languages?
 We will :
 Analyze and criticize the 4 points
 Redefine some of these points
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AmOP and AmbientTalk Analysis
II) Our synthesis
Connection volatility (1/4)
 Asynchronous messages
Device 1
Device 2
Message processed
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AmOP and AmbientTalk Analysis
II) Our synthesis
Connection volatility (2/4)
 Use of sentbox
Device 1
Device 2
Sentbox
Message processed
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AmOP and AmbientTalk Analysis
II) Our synthesis
Connection volatility (3/4)
 Use of Joinedbox to keep the references of the devices
Device 1
Device 2
Joinedbox
Device 2 reference
disjoinedbox
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AmOP and AmbientTalk Analysis
II) Our synthesis
Connection volatility (4/4)
 Mailboxes can’t stock messages eternally
 Use a lease
 How can we choose this leasing time?
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AmOP and AmbientTalk Analysis
II) Our synthesis
Ambient resource (1/2)
 Discovery : publish/subscribe protocol
 Use of tags to identify the devices
Device 1
tag2
Connection
tag1
Device 2
tag3
providedbox
providedbox
tag2
requiredbox
Arnaud Borg, Christian Brel, Sandie Dupain
requiredbox
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AmOP and AmbientTalk Analysis
II) Our synthesis
Ambient resource (2/2)
 AmbientTalk discovery protocol  UPnP discovery
protocol
 Network devices warn when they are added to the
network
 Services are provided by devices
 Control points search when they are added to the
network
 Why haven’t they used UPnP ?
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AmOP and AmbientTalk Analysis
II) Our synthesis
Autonomy
 No “higher authority” to coordinate interactions
between devices
 Goal not aimed:
 The devices need to identify themselves with tags for the
discovery
 AmbientTalk Interpreter must deliver all tags to all
devices
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AmOP and AmbientTalk Analysis
II) Our synthesis
The natural concurrency (1/2)
 The message queue : Sends an asynchronous message
 The response of the message is stocked in a future
Device 1
Device 2
Remote object
Local object
obj
?
future
res
obj<-m()
Message Queue
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AmOP and AmbientTalk Analysis
II) Our synthesis
The natural concurrency (2/2)
 The messages of the message queue are always
processed in the same order of reception
 Symbiosis between the AmbientTalk and the Java
linguistic
 Use the maturity and the functionalities of Java
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AmOP and AmbientTalk Analysis
Conclusion
 Connection volatility
 Mailboxes to stock messages
 But : lease on mailboxes
 Ambient resources
 Why not UPnP ?
 Autonomy
 AmbientTalk Interpreter doesn’t fully respond to the problem
 Natural concurrency
 Future
 Asynchronous messages
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AmOP and AmbientTalk Analysis
Thank you
Questions ?
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