Automated Software Engineering with Concurrent Class Machines

1
Automated Software Engineering with Concurrent
Class Machines
Radu Grosu SUNY at Stony Brook joint work with Y.
Liu, S. Smolka, S.Stoller, J. Yan SUNY at Stony
Brook
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Motivation (ASE)

• Automated OO software development method
• OO language for req.specification/modeling/implem
  ,
• transition semantics capturing OO constructs,
• trace semantics supporting compositional
  refinement,
• analysis exploiting OO structure,
• generation of optimized (and monitored) code.

• Close the gap between
• object oriented methods (UML,OMT,),
• formal methods (Model Checking, Static
  Analysis,).

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Concurrent Class Machines (CCM)

• Modeling language for concurrent OO systems
• classes, inheritance, objects, object creation
• methods, exceptions, multithreading,
• abstract collection types, nondeterminism.

• 2. Observational trace semantics
• class machine refinement,
• modular reasoning.

• 3. Code generation and analysis
• prototype code generation.
• exploits the hierarchy information (in progress),

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Readers/Writers Problem
Resource
Class Diagram
res
m
Monitor
1

1
m

Client
WrCap
5
Classes
attributes
Monitor
Call entry point
return exit point
methods
Method signature
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Transitions
Monitor
transition (atomic)
guard (blocking)
assignments (parallel)
method can be declared atomic
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Call Hierarchy (Boxes)
RdCap
local variables
return expression
choice point (nondeterminism)
return variable
method invocation box
object creation box
exception exit point
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Concurrency
Client extends Thread
-m Monitor
main() void r Resource c Client
new Resource
r
m
c.start
new Monitor(r)
run() void
thread start box
thread run method
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Operational Semantics
Transition system A (S, s0, ?)
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Method Invocation Box
Client
-m Monitor
run() int r Resource i int
i
b
v
v
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Method Invocation Box (Call)
Client
-m Monitor
run() int r Resource i int
i
b
v
v
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Method Invocation Box (Return)
Client
-m Monitor
run() int r Resource i int
i
b
v
v
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Environment (Interface) Objects
Static vars, streams
Allow compositional modeling reasoning

• Their body is not known and not part of ?
• Allow any update of public objects. The latter
  are
• determined via an escape analysis.

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Denotational Semantics

• Execution of CCM m
• s0-gt s1-gt s2-gt -gt sn
• si-gt si1 is a CCM transition in ? or
• si-gt si1 is an environment transition.
• Set of Traces Lm of m
• Projection of executions on global variables.
• Object escape analysis is necessary.
• Refinement m lt n
• Inclusion of the sets of traces Lm ? Ln
• Compositional w.r.t. beh/arch hierarchies.

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Modular Reasoning
lt
N
N
N
N
lt
N
N
lt
M
M
M
M
Sub-CCM refinement
Super-CCM refinement
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Wrap Up

• Modeling language for concurrent OO systems
• classes, inheritance, objects, object creation
• methods, exceptions, multithreading,
• abstract collection types, nondeterminism.

• 2. Observational trace semantics
• class machine refinement,
• modular reasoning.

• 3. Code generation and analysis
• prototype code generation.
• exploits the hierarchy information (in progress),