Ali Sezgin. IST Austria, Am Campus 1, Klosterneuburg 3400, AUSTRIA. Phone: (43)

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1 IST Austria, Am Campus 1, Klosterneuburg 3400, AUSTRIA Phone: (43) Education Ph.D., Computer Science, University of Utah, Salt Lake City, UT, USA Dissertation Title: Formalization and Verification of Shared Memory Advisor: Dr. Ganesh Gopalakrishnan M.Sc., Electrical-Electronics Engineering, Middle East Technical University, Ankara, TURKEY Thesis Title: A Comparison of Process Specifications Using the Languages SDL and ERPAL Advisor: Dr. Kemal Inan B.Sc., Electrical-Electronics Engineering, Middle East Technical University, Ankara, TURKEY Research and Experience Post-Doctoral Researcher Henzinger Group IST Austria Klosterneuburg, AUSTRIA September 2010 Present - Did research on fundamental aspects of concurrent implementations. - Investigated the impact of strict conformance to sequential data structure semantics on the performance of their linearizable implementations. - Developed a formal framework within which relaxation of sequential specifications can be defined quantitatively. - Designed novel concurrent queue implementations achieving high throughput. - Worked on new verification techniques that simplify linearizability proofs of non-blocking concurrent queue implementations. - Collaborated with biologists on the modeling aspects of genetic regulatory circuits. - Extended continuous time markov chain models with time delays. - Investigated the accuracy of existing models for the mrna transcription process.

2 Post-Doctoral Researcher Department of Computer Engineering Koc University Istanbul, TURKEY August 2008 August Implemented a simplified model of the Bartok Software Transactional Memory in C#. - Worked on statically verifying optimistic concurrency, e.g. transactional memory implementations and non-blocking data structures. - Developed the formal foundations and tool support for proving assertions, atomicity and linearizability of optimistically concurrent programs in the QED proof system. - Developed a novel atomicity reduction technique. - Worked on a novel partial specification and runtime verification method for optimistically concurrent programs. Assistant Professor Department of Computer Engineering Yeditepe University Istanbul, TURKEY 2006 July 2008 Taught undergraduate classes at various levels: an introductory course for freshman, data structures course for sophomore and automata theory course for junior students. Assistant Professor Department of Computer Engineering Atilim University Ankara, TURKEY Taught undergraduate and graduate level classes, e.g., theory of computation, formal verification theory and practice. Research Assistant Department of Computer Science University of Utah Salt Lake City, UT, USA As a member of the Utah Verification (UV) group, developed a theoretical framework whereby memory consistency models and implementations are uniformly represented as regular language transducers, and verification of an implementation is reduced to language inclusion. Visiting Researcher MOSEL Group LORIA (Laboratoires Lorrain de Recherche en Informatique et ses Applications) Nancy, France Summer 2003 Together with Stephan Merz, developed an algorithm for the checking of the emptiness of linear weak alternating automata and coded the algorithm using a functional programming language (OCAML).

3 Summer Intern Intel Corporation Austin, TX, USA Summer 2000 Worked on the formal specification of the design of a new multiprocessor on a single chip. Researcher Centre for Defense Studies, Istanbul Technical University Foundation, Ankara-Istanbul, Turkey Worked as a computer engineer on several projects. Teaching/Research Assistant Department of Electrical and Electronics Engineering Middle East Technical University Ankara, Turkey Did research on various aspects of formal specification. Teaching assistant for operating systems, and numerical analysis. Researcher ASELSAN (Military Electronics Industry) Ankara, Turkey Worked on the design, implementation and debugging of an embedded system. Awards - Graduate Research Fellowship awarded by the University of Utah for the academic year (a highly competitive university-wide award on the anticipated impact of the PhD research topic) - Full scholarship by the School of Computing, University of Utah (from Fall 99 to Fall 02 and from Summer 03 to Spring 04) - Awarded NATO ASI travel and accommodation fellowship, paid for attending NATO ASI International Summer School on Verification of Digital and Hybrid Systems, Antalya (26/05 06/06, 1997)

4 Published Work - Thomas A. Henzinger, Christoph Kirsch, Hannes Payer, Ali Sezgin and Ana Sokolova, Quantitative Relaxation of Concurrent Data Structures, To appear in ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages, POPL Calin Guet, Ashutosh Gupta, Thomas A. Henzinger, Maria Mateescu and Ali Sezgin, Delayed Continuous Time Markov Chains for Genetic Regulatory Circuits, Computer-Aided Verification, CAV Ali Sezgin, Serdar Tasiran, Kivanc Muslu and Shaz Qadeer, Run-Time Verification of Optimistic Concurrency, International Conference of Runtime Verification, RV Ali Sezgin, Serdar Tasiran and Shaz Qadeer, Tressa: Claiming the Future, Verified Software: Theories, Tools and Experiments, VSTTE Tayfun Elmas, Shaz Qadeer, Ali Sezgin, Omer Subasi and Serdar Tasiran, Simplifying Linearizability Proofs with Reduction and Abstraction, Tools and Algorithms for the Construction and Analysis of Systems, 16th International Conference, TACAS 2010, pp , Paphos, Cyprus. - Shaz Qadeer, Ali Sezgin and Serdar Tasiran, Back and Forth: Prophecy Variables for Static Verification of Concurrent Programs, Microsoft Research Technical Report, MSR-TR , Also published in the Dagstuhl Seminar Proceedings: Design and Validation of Concurrent Systems, Tayfun Elmas, Ali Sezgin, Serdar Tasiran and Shaz Qadeer, An Annotation Assistant for Interactive Debugging of Programs with Common Synchronization Idioms, PADTAD Ali Sezgin and Ganesh Gopalakrishnan, On the Definition of Sequential Consistency, Information Processing Letters, Vol. 96, Issue 6, 31 December 2005, pp Ali Sezgin and Ganesh Gopalakrishnan, On the Decidability of Shared Memory Consistency Verification, Proceedings of the Third ACM & IEEE International Conference on Formal Methods and Models for Co-Design, MEMO- CODE 2005, pp , Verona, Italy. - Stephan Merz and Ali Sezgin, Emptiness of Linear Weak Alternating Automata, Technical Report, LORIA, December A. Sezgin, H. Yenigün, and K. İnan, ERPAL: A New Algebraic Language with Novel Features, in Proceedings of the Tenth International Symposium on Computer and Information Sciences, ISCIS X, October 1995, , Kuşadası, Aydın.

5 Working Papers - Replacing Competition with Cooperation to Achieve Scalable Lock-Free FIFO Queues. Synopsis: A new concurrent queue implementation, called Speculative Pairing (SP), is presented. SP uses the Fetch-And-Increment (FAI) primitive instead of the more common Compare-And-Swap (CAS) primitive. It is shown that the use of FAI leads to an implementation outperforming state-of-the-art queue implementations. It is argued that better performance is due to the removal of competitive synchronization via CAS statements and the use of cooperative synchronization via FAI statements. - How Free is Your Linearizable Concurrent Data Structure? Synopsis: Commit-order-dependence is the restriction on the implementation that whenever all threads observe the same logical state, the updates to the logical state and the temporal order of commit coincide. It is shown that the existing concurrent queue implementations are commit-order-dependent. A commit-orderindependent queue implementation is given and shown to have better performance. - Verifying Non-Blocking Queue Implementations. Synopsis: It is shown that a queue implementation is linearizable iff it satisfies a small number of properties, which are simplified considerable if the implementation is non-blocking. Unlike existing methods, a proof based on checking these properties leads to existential proofs where precise updates to the logical state at commit points do not need to be specified. The new technique is illustrated on proving implementations challenging from a verification perspective.

6 References Dr. Ganesh Gopalakrishnan Professor, Computer Science School of Computing, University of Utah 50 S. Central Campus Dr., Rm. 3190, Salt Lake City, UT , USA Dr. Thomas A. Henzinger Professor, Computer Science IST Austria, Klosterneuburg 3400, Austria Dr. Serdar Tasiran Assistant Professor, Computer Engineering KoU niversity, Istanbul 34450, Turkey