1. Effective Interprocedural Resource Leak Detection ICSE 10 Emina Torlak Satish Chandra IBM T.J. Watson Research Center, USA

2. Author Emina Torlak Publications 2010 MemSAT: checking axiomatic specifications of memory modelsMemSAT: checking axiomatic specifications of memory models Proceedings of the 2010 ACM SIGPLAN Correct Refactoring of Concurrent Java Code Correct Refactoring of Concurrent Java Code 24th European Conference on Object- Oriented Programming (ECOOP) 2008 Controlled physical random functions and applicationsControlled physical random functions and applications ACM Transactions on Information and System Security (TISSEC)

3. Author Satish Chandra Publications 2010 Making defect-finding tools work for youMaking defect-finding tools work for you ICSE Programming with Angelic Non-determinism Programming with Angelic Non-determinism POPL 2009 Snugglebug: a powerful approach to weakest preconditionsSnugglebug: a powerful approach to weakest preconditions PLDI 2008 Verifying dereference safety via expanding- scope analysisVerifying dereference safety via expanding- scope analysis ISSTA Generating precise and concise procedure summariesGenerating precise and concise procedure summaries POPL

4. Related Publications in ICSE ’10 LEAKPOINT: Pinpointing the Causes of Memory Leaks, James A. Clause and Alessandro Orso (Georgia Institute of Technology, Atlanta, USA) Efficient and precise Typestate Analysis by determining Continuation-equivalent States, Eric Bodden (Technische Universitaet Darmstadt, Germany) Precise Calling Context Encoding, William N. Sumner, Yunhui Zheng, Dasarath Weeratunge and Xiangyu Zhang (Purdue University, Lafayette, USA) Khasiana: Making Defect-Finding Tools Work for You, Mangala Gowri Nanda, Monika Gupta, Saurabh Sinha (IBM Research, India, India), Satish Chandra (IBM T.J. Watson Research Center, USA), David Schmidt (IBM Tivoli, USA), and Pradeep Balachandran (IBM Rational, India)

5. Example Exception might occur here Exception expected here Exception cause FileOutputStream instance never released!

6. Contributions of “Tracker” Useful –the reports produced by the tool is actionable by a user Scalable –the tool is able to handle real-world Java applications consisting of tens of thousands of classes

7. Call edge

8. p = new FileOutputStream(file) P.close()

9. Interprocedural Optimization A method is RELEVANT to a fact if it (or any of its transitive callees) contains a statement that may alter the fact's State. (much like slicing in some sense) This optimization is fruitful, because in practice a lot of methods are auxiliary in nature

10. COMPUTING ACTIONABLE REPORTS Prioritization Exception Flow –processes exceptional edges selectively –Customizable relevant exception types Nested Resources –Cluster reports around nested resources like: FileOutputStream fos = new FileOutputStream(file); OutputStreamWriter osw = new OutputStreamWriter(fos, enc);... fos.close();

11. Evaluation of Efficiency Time used

12. Results are the number of true positives and false positives generated by full exception edge flow. Base TP and FP are the results obtained by selective exception flow. Evaluation of Exception Flow Filtering The lower the better The higher the better

13. Comparison with Related Techniques The higher the better The lower the better

14. CONCLUSION Their contribution is in overcoming engineering challenges, using a blend of existing and new techniques. An empirical evaluation of the tool showed its overall effectiveness.

15. FUTURE WORK Discovering specifications automatically, especially with regards to identifying which pairs of types are related by a wrapper- wrappee relationship. Another promising direction is to extend the leak detection algorithm to automatically suggest code refactorings.

16. REFERENCES M. Arnold, M. Vechev, and E. Yahav. QVM: an efficient runtime for detecting defects in deployed systems OOPSLA `07 N. Ayewah, D. Hovemeyer, J. D. Morgenthaler, J. Penix, and W. Pugh. Using static analysis to find bugs IEEE Software `08 R. Cytron, J. Ferrante, B. K. Rosen, M. N. Wegman, and F. K. Zadeck. Efficiently computing static single assignment form and the control dependence graph ACM TRANS PROG LANG M. Das, S. Lerner, and M. Seigle. Esp: Path-sensitive program verification in polynomial time PLDI `02 N. Dor, S. Adams, M. Das, and Z. Yang. Software validation via scalable path-sensitive value flow analysis ISSTA `04 T. Reps, S. Horwitz, and M. Sagiv. Precise interprocedural data flow analysis via graph reachability POPL `95

17. THANK YOU