Experiences using SPARK in an Undergraduate CS Course

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Experiences using SPARK in an Undergraduate CS
Course

• Dr. Anthony S. Ruocco
• Roger Williams University
• aruocco_at_rwu.edu

Attendance made possible through the Educator
Grant Program
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Agenda

• Why this course
• Course Development
• Assessment
• Future Possibilities (some unexpected effects)

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Ada95 Course

• Needed a CS elective suitable for juniors/seniors
• Asked constituents about Ada95
• Local industry was uninterested
• One employer supported it (Navy Research Lab)
• Dean was skeptical
• More conducive to the idea of well-constructed
  software
• Planned for a software development course using
  Ada95

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High Integrity Software

• SPARK toolset available at SIGSCE2004
• Gnat Programming System (GPS) available via
  AdaCorp Academic Alliance
• Professional grade IDE
• Some SPARK tools available as drop-down menu
  items
• JGRASP
• Used in other courses
• Requires use of SPARK toolset outside the IDE

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The students

• Seven total
• 2 Juniors
• 4 Seniors
• 1 December grad
• Courses (Completed/Concurrent)

• Intro to Programming (7)
• Data Structures (7)
• Computer Organization (7)
• Programming Languages (7)
• Theory of Computation (5/2)

• Analysis of Alg (5)
• Operating Systems (2/3)
• Compiler Design (2/3)
• Senior Design I (2/3)
• Senior Design II (2)

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Course Description

• This course focuses on programming techniques
  for computer systems found in safety critical
  environments such as avionics, power plant and/or
  transportation systems. The course uses a
  specialized language (SPARK) and its tools to
  write and examine high-integrity code segments.
  Students become familiar with some of the
  differences between general programming languages
  and specialized languages. Use of the risks.comp
  news group also highlights non software-specific
  risks in large systems.

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Course Objectives

• Understand the safety/risk implications inherent
  in high integrity software systems.
• Use specialized software tools in the production
  of high integrity code segments.
• Use a specialized programming language to produce
  high integrity code segments.
• Research an issue in high integrity software and
  present a possible solution.

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Course Layout

• Ada95 / SPARK language basics (10 lessons)
• Examiner tools and software design (14 lessons)
• gtkAda tools (4 lessons target of opportunity)
• Four projects
• Two individual projects
• One group project
• One course project

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SPARK Overview

• A language fully contained within Ada95
• Syntactically, it is Ada code linked by special
  annotations to a tool-set
• Produces a series of reports of the results (but
  it is not a compiler)

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Projects

• P1 Matrix
• Individual
• IDE and SPARK familiarization
• Enforced requirement for all ranges to be
  subtypes
• P2 Extension of Project 1
• No one thought of using child-packages

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Projects (cont)

• P3 max-flow
• Given functional pascal code
• Two groups (size 3 and 4)
• This was an interesting project
• P4 Flight control simulator
• Three groups of 2 for Pitch, Roll, Yaw control
• Each group gave one person to a control team
• They were to work independently, then link their
  pieces

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Assessment Lessons Learned

• First time course was offered
• Only 7 students
• Lots of opportunity for one-to-one discussions of
  content
• Some follow-up after the course with graduates

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Course Development

• This course focuses on programming techniques
  for computer systems found in safety critical
  environments such as avionics, power plant and/or
  transportation systems. The course uses a
  specialized language (SPARK) and its tools to
  write and examine high-integrity code segments.
  Students become familiar with some of the
  differences between general programming languages
  and specialized languages. Use of the risks.comp
  news group also highlights non software-specific
  risks in large systems.

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Course Objectives

• Understand the safety/risk implications inherent
  in high integrity software systems.
• Use specialized software tools in the production
  of high integrity code segments.
• Use a specialized programming language to produce
  high integrity code segments.
• Research an issue in high integrity software and
  present a possible solution.

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Student Comments

• Students felt SPARK was a unique language (not
  just an Ada subset)
• Students felt they needed to know Ada before
  starting SPARK
• Students would like to see Ada95 as a regular
  elective and SPARK done on some cycle
• All students felt the most important pre-req for
  this course was Programming Languages (a survey
  course)
• Students were surprised by how much the OS and
  compiler removes from the programmer
• All students were able to link some aspect of
  every previous course they had to this course

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Lessons learned

• Had to do parallel development of Ada as SPARK
  constructs were covered
• The GPS IDE with SPARK drop down menu helped
  instill habit of running SPARK tools prior to
  compilation
• Pay attention to SPARK license, it expires in
  September (after the semester was underway)

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Future possibilities(FIE 2006 paper)

• SPARK supports a number of concepts from other
  courses
• Five categories from CAC
• Algorithms, software design, computer
  organization architecture, data structures,
  programming languages
• Algorithms understanding all variables, as well
  as the operating space of the algorithm, tools to
  support formal proof
• Software Design strong focus on design by
  contract. All the parts need to be completely
  understood to integrate them

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• Computer Org and Architecture Use of config
  files allows for various target machines
• Data structures Reduced operating space enforces
  careful data structure design and links to
  algorithm
• Programming languages SPARK itself
• Consider SPARK as an overall educational tool,
  not just a language

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Thanks to

• Adacore
• www.gnat.com/academic_overview.php
• Rod Chapman at Praxis
• www.praxis-his.com/sparkada/universities.asp