Research Topics in Software and
Reasoning Systems
Bharat Jayaraman
University at Buffalo (SUNY)
Collaborators:
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Fall 2014
Jan Chomicki, University at Buffalo
Venu Govindaraju, University at Buffalo
Kishore Ramachandran, Georgia Tech
Luke Ziarek, University at Buffalo
CSE Research Overview
Three Current Topics
1. Unobtrusive Smart Spaces
2. Modeling Complex Systems
3. Dynamic Analysis & Visualization
Research Methodology:
- Start with Theoretical Foundations
- Develop Practical Models/Languages
- Implement, Apply, Learn, Improve
Fall 2014
CSE Research Overview
1. Unobtrusive Smart Spaces
Fall 2014
CSE Research Overview
Research Topics
1. Large Camera Networks
2. Distributed State Transition System
3. Practical Deployment and Experiments
4. Smart Space Analytics
Three R’s of Cyber-Physical Spaces, V. Menon, B. Jayaraman, V. Govindaraju
IEEE Computer, 44(9): 73-89, 2011
A Distributed Framework for Spatio-Temporal Analysis on Large-scale Camera
Networks, K Hong, M Voelz, V Govindaraju, B Jayaraman, U Ramachandran,
Proc. Distributed Computing Systems Workshops (ICDCSW), 2013
Fall 2014
CSE Research Overview
2. Modeling Complex Systems
Grand Challenge in Information Systems (www.cra.org)
“We need a mathematical model that relates the global
behavior of complex systems to the local behaviors
and interaction patterns of the individual elements …
Whatever form such a model takes, it must permit us to
define and control emergent behavior using
declarative, not imperative, techniques.”
Motivating Domains: Engineering, Biological, …
Common Features:
Complex Assembly, Laws of Behavior,
…
Visualization
.
Fall 2014
CSE Research Overview
Constrained Objects
Constraints:
“The load on a wall ≤ its load bearing capacity.”
“The sum of the forces at a joint should be zero.”
etc.
Load
Sum of Forces = 0
class joint {
attributes
bar [ ] Bars;
load [ ] Loads;
constraints
(sum X in Bars : X.B.F * sin(X.A)) +
(sum L in Loads : L.F * sin(L.A)) =
0;
(sum Y in Bars : Y.B.F * cos(Y.A)) +
(sum M in Loads : M.F * cos(M.A)) = 0;
constructor joint(B1, L1) { Bars = B1; Loads = L1; }
}
Research Topics
• Translation to Efficient Low-level
Representations
• Inconsistency Detection and Failure Analysis
• Visualization for Dynamic Behavior
• From Constrained Objects to Constraintbased Design
Modeling Engineering Structures with Constrained Objects, B. Jayaraman
and P. Tambay, Proc. Practical Aspects of Declarative Languages,
Lecture Notes in Computer Science (2257), pp. 28-46, 2002
Compositional semantics for diagrams using constrained objects, B. Jayaraman, P.
Tambay, Proc. Diagrammatic Representation and Inference, pp. 94-96, 2003
3. Dynamic Analysis & Visualization
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Towards Better Program Comprehension
Run-time Visualization, Query-based Debugging
Execution Analysis, Summarization
JIVE: Java Interactive Visualization Environment
Extensions for Real-time, Concurrency, etc.
Temporal Data Model for Program Debugging. D. Lessa, B. Jayaraman, J.
Chomicki, Proc. Database Programming Languages, 2011.
JI. FI: Visual Test and Debug Queries for Hard Real‐Time, E. Blanton, D.
Lessa, P. Arora, L. Ziarek, B. Jayaraman, Concurrency and Computation:
Practice and Experience, 2013.
Source Code Static – Behavior Obscure
JIVE Interface
Processes
Enhanced
Object
Diagram
Source
Code
Sequence
Diagram
Query Result
JIVE Visualization:
Objects as Environments
JIVE object
diagram showing
objects as well as
method activations
in the object
contexts
Fall 2014
CSE Research Overview
JIVE Objects: Detailed View
JIVE object
diagram showing
internal details of
objects and
method activations
Fall 2014
CSE Research Overview
Objects as Environments:
Call-Path View
JIVE object
diagram focusing
on the calling
path, or the call
stack.
Fall 2014
CSE Research Overview
Flexible Views
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CSE Research Overview
Viewing Execution History:
Multi-Threaded Programming
Fall 2014
CSE Research Overview
Visualization clarifies Program Behavior
F1
F2
Fall 2014
F3
F4
F5
P1
P2
P3
JIVE sequence diagram clarifies
thread interactions
P4
P5
CSE Research Overview
F1
F2
F3
F4
F5
P1
P2
P3
P4
P5
JIVE sequence diagram at point of deadlock
Fall 2014
CSE Research Overview
Concurrency Bug Analysis:
JIVE + Java Path Finder
Java Path Finder is a special JVM that explores all
possible choices in scheduling with the goal of
identifying a concurrency bug, such as deadlock,
if one exists.
The output of JPF is also an execution sequence
that can be input to JIVE, which not only shows
the tree of possible scheduling choices, but also
the path leading to the error.
5/28/2016
CSE Research Overview
Coupling with Java Path Finder
5/28/2016
Android Workshop
5/28/2016
CSE Research Review
5/28/2016
CSE Research Overview
3. Query Based Debugging
• Traditional debugging is more like “web browsing” –
you have to manually look for the error.
• QBD is more akin to “web searching”, e.g.:
- show all changes to a variable
-
when did a variable become negative
when was an invariant violated
when did concurrent update occur
show all contended monitors
show all priority inversion
• Common queries can be form-based, but custom
queries are necessary.
Fall 2014
CSE Research Overview
Form-based Query Interface
When was ‘value’ assigned to an int less than 100?
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Query Result
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JIVE’s Overall Architecture
Fall 2014
CSE Research
Overview
Eclipse/JIVE Two-Process Model
Fall 2014
CSE Research Overview
Important Property of JIVE – 1
JIVE does not represent
program states directly,
but infers
(and reconstructs)
states from events that occur.
Fall 2014
CSE Research Overview
Important Property of JIVE – 2
Queries and Visualization
work in a synergistic way:
Queries help focus on
what is of interest.
Visualization provides a canvas
on which to report answers to queries.
Fall 2014
CSE Research Overview
JIVE Demo
www.cse.buffalo.edu/jive
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CSE Research Overview
Scalable Visualizations:
Vertical Compaction
compactify
Fall 2014
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Execution Summarization: From
Sequence to State Diagrams
(View 1)
Fall 2014
CSE Research Overview
From Sequence to State Diagrams
(View 2)
CSE Research Overview
Fall 2014
Summary and Conclusions
• JIVE has useful features not found in modern
IDEs: visualizing object states and execution
history; query-based debugging; dynamic
slicing; reverse stepping
• Declarative Queries and Visualization work in a
synergistic manner to provide an effective runtime environment for OO Languages.
• JIVE can be used for teaching and learning, and
also has features for understanding and
debugging in industrial setting.
Fall 2014
CSE Research Overview
Further Work
• Incorporate full Temporal Queries and State
Diagram construction into JIVE interface.
• Verification through Testing: the database
approach to debugging facilitates analysis over
multiple runs, checking invariants, etc.
• Model Checking in JIVE: The State Diagram
resembles a Kripke Structure, and we can
perform model-checking of such structures with
respect to temporal-logic formula.
Fall 2014
CSE Research Overview