Constraint Programming: What is behind? Roman Barták Charles University, Prague [email protected].
SW Components in Resource Constraint...
Transcript of SW Components in Resource Constraint...
CHARLES UNIVERSITY IN PRAGUE
http://d3s.mff.cuni.cz
faculty of mathematics and physics
SW Components in Resource Constraint
Environments
Tomas Pop [email protected]
Resource Constraint Environment
Tomas Pop | Res Informatica Seminar | 2.11.2010 Components in Resouce Constraint Environments 2
Embedded devices
Control systems
Mobile devices
Very important domain
Anywhere
Plenty of constraints
Memory, CPU
Timing (RT systems)
Battery consumption…
Why NOT to Use Monolithic Approach?
Tomas Pop | Res Informatica Seminar | 2.11.2010 Components in Resouce Constraint Environments 3
Control systems
Mission critical
Complexity is growing exponentially
Hard to validate and test
Specific hardware
Hard to reuse
=> Component based approach
How Can Components Help?
Tomas Pop | Res Informatica Seminar | 2.11.2010 Components in Resouce Constraint Environments 4
System Verification
Single components
System composition
Reuse
Specific components for specific hardware
Repository
Model lines
Overcoming system limitations
Code migration
Two Approaches
Tomas Pop | Res Informatica Seminar | 2.11.2010 Components in Resouce Constraint Environments 5
1. Systems with low requirements
Low memory footprint & CPU consumption
Association with properties (e.g. timing)
=> SOFA HI
2. Component migration
If resource is not available here, run component on server
Memory footprint
Battery consumption
SOFA HI
Tomas Pop | Res Informatica Seminar | 2.11.2010 Components in Resouce Constraint Environments 6
Profile of SOFA 2
Explicit support for real-time applications
Active and passive component
~ tasks and the others
Tool support
SOFA HI IDE
Next Steps – Executional Modes
Tomas Pop | Res Informatica Seminar | 2.11.2010 Components in Resouce Constraint Environments 7
Typical for control systems
Calibration, run, clean-up, error recovery, …
Support in existing tools (e.g. Scade)
Protocols for mode switches
Next Steps – System Models
Tomas Pop | Res Informatica Seminar | 2.11.2010 Components in Resouce Constraint Environments 8
Lot of code is generated
On another idea level than development
=> Models and simulations
Give a quick view how constructed system works
Component Migration - Motivation
Tomas Pop | Res Informatica Seminar | 2.11.2010 Components in Resouce Constraint Environments 9
Targeted to cell phones and tablets
Conditions there are changing rapidly
Lot of users, often connected to internet via wifi…
Limit is not memory and CPU anymore
Limit is battery consumption
Processor is consuming major portion of energy
Wide range of application similar architecture
SENSOR – COMPUTATION – DISPALYER
Component Migration - Usage
Tomas Pop | Res Informatica Seminar | 2.11.2010 Components in Resouce Constraint Environments 10
Lets migrate processor intensive parts to a server
If sufficient network connection is available
Only parts not bounded to hardware
In network is not available, executed locally
Different to cloud computing
Component Migration - Example
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Voice recognition
Microphone driver component stays on the phone
Recognition executed on remote server
Text displayed/saved on the phone
Component migration – Plan
Tomas Pop | Res Informatica Seminar | 2.11.2010 Components in Resouce Constraint Environments 12
Measurements
Simple component model
Metrics for code offload decisions
Implementation
Evaluation
Thank You
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