Precise and Reproducible Testing of Concurrent Software Tejasvi Aswathanarayana, Noah Watkins, Douglas Niehaus ([e-mail])

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Precise and Reproducible Testing of Concurrent
SoftwareTejasvi Aswathanarayana, Noah Watkins,
Douglas Niehaus (niehaus_at_ittc.ku.edu)
Overview
Variability of Time in Concurrency Testing

• Concurrency issues are difficult to test and
  debug
• The difficulty arises from a lack of precise
  control over the execution of computations
• This lack of control results in an inability to
  reliably reproduce problem scenarios and to
  perform verifiable testing of
  concurrent software
• Current techniques of test scenario coverage
  depend on the probabilistic assumption
  that stress testing of a software system will
  cover all scenarios
• Test results show that probabilistic stress
  testing does not always cover all relevant
  scenarios and even when it does, the time
  required is highly variable

Deterministic Control
Guided Execution of 3 Threads

• Group Scheduling under KURT-Linux creates an
• environment in which precise control of every
• computation is possible
• We can use precise and customized control to
• guide a computation through specific scenarios
• This establishes a debugging and testing
  framework providing deterministic test
  case coverage
• Waypoints describe locations in the code where
• thread execution is interleaved in some
  scenario
• Specialized scheduler controls execution
  according
• to a specified scenario schedule under group
• scheduling