Computing Maximum Task Execution Times — A Graph-BasedApproach
Real-Time Systems
Refining data flow information using infeasible paths
ESEC '97/FSE-5 Proceedings of the 6th European SOFTWARE ENGINEERING conference held jointly with the 5th ACM SIGSOFT international symposium on Foundations of software engineering
Advanced compiler design and implementation
Advanced compiler design and implementation
POPL '77 Proceedings of the 4th ACM SIGACT-SIGPLAN symposium on Principles of programming languages
Principles of Program Analysis
Principles of Program Analysis
Counterexample-Guided Abstraction Refinement
CAV '00 Proceedings of the 12th International Conference on Computer Aided Verification
Automatic Derivation of Loop Bounds and Infeasible Paths for WCET Analysis Using Abstract Execution
RTSS '06 Proceedings of the 27th IEEE International Real-Time Systems Symposium
An Iterative Refinement Framework for Tighter Worst-Case Execution Time Calculation
ISORC '07 Proceedings of the 10th IEEE International Symposium on Object and Component-Oriented Real-Time Distributed Computing
The Algorithm Design Manual
FShell: Systematic Test Case Generation for Dynamic Analysis and Measurement
CAV '08 Proceedings of the 20th international conference on Computer Aided Verification
EXE: Automatically Generating Inputs of Death
ACM Transactions on Information and System Security (TISSEC)
Combining Worst-Case Timing Models, Loop Unrolling, and Static Loop Analysis for WCET Minimization
ECRTS '09 Proceedings of the 2009 21st Euromicro Conference on Real-Time Systems
Deriving the Worst-Case Execution Time Input Values
ECRTS '09 Proceedings of the 2009 21st Euromicro Conference on Real-Time Systems
KLEE: unassisted and automatic generation of high-coverage tests for complex systems programs
OSDI'08 Proceedings of the 8th USENIX conference on Operating systems design and implementation
OTAWA: an open toolbox for adaptive WCET analysis
SEUS'10 Proceedings of the 8th IFIP WG 10.2 international conference on Software technologies for embedded and ubiquitous systems
r-TuBound: loop bounds for WCET analysis (tool paper)
LPAR'12 Proceedings of the 18th international conference on Logic for Programming, Artificial Intelligence, and Reasoning
The WCET analysis tool calcwcet167
ISoLA'12 Proceedings of the 5th international conference on Leveraging Applications of Formal Methods, Verification and Validation: applications and case studies - Volume Part II
Quantitative abstraction refinement
POPL '13 Proceedings of the 40th annual ACM SIGPLAN-SIGACT symposium on Principles of programming languages
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The Worst-Case Execution Time (WCET) computed by a WCET analyzer is usually not tight, leaving a gap between the actual and the computed WCET of a program. In this article we present a novel on-demand WCET feasibility refinement technique, called WCET Squeezing, for minimizing this gap. WCET Squeezing provides conceptually new means for addressing the classical problem of WCET computation, by deriving a WCET bound that comes as close as possible to the actual one. WCET Squeezing is an anytime algorithm, that is, it can be stopped at any time without violating the soundness of its results. This anytime property allows to apply WCET Squeezing not only for deriving precise WCET bounds but to also prove additional timing constraints over the program. Namely, WCET Squeezing can be used to guarantee that a program is fast enough by ensuring that the WCET of the program is below some required limit. If the initially computed WCET of the program is above this limit, WCET Squeezing can be stopped as soon as the squeezed WCET of the program is below the limit (proving the program meets the required timing constraint), or if the squeezed WCET is tight but above the given limit (proving the program cannot meet the timing constraint). WCET Squeezing can also be used until a given time budget is exhausted to compute a tight(er) WCET bound for a program. These new applications of WCET Squeezing are out of the scope of traditional WCET analyzers. WCET Squeezing combines symbolic program execution with the Implicit Path Enumeration Technique (IPET) for computing a precise WCET bound. WCET Squeezing is applicable as a post-process to any WCET analyzer which encodes the IPET problem as an Integer Linear Program (ILP). We implemented our method in the r-TuBound toolchain and evaluated our implementation on a set examples taken from the Mälardalen WCET benchmark suite. Our experiments demonstrate that WCET Squeezing can significantly tighten the WCET bounds of programs. Moreover, the derived WCET bounds are proven to be precise at a moderate computational cost.