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| 2. |
- Abdulla, Parosh Aziz, et al.
(författare)
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An Integrated Specification and Verification Technique for Highly Concurrent Data Structures
- 2013
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Ingår i: Tools and Algorithms for the Construction and Analysis of Systems. - Berlin, Heidelberg : Springer Berlin Heidelberg.
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Konferensbidrag (refereegranskat)abstract
- We present a technique for automatically verifying safety properties of concurrent programs, in particular programs which rely on subtle dependen- cies of local states of different threads, such as lock-free implementations of stacks and queues in an environment without garbage collection. Our technique addresses the joint challenges of infinite-state specifications, an unbounded num- ber of threads, and an unbounded heap managed by explicit memory allocation. Our technique builds on the automata-theoretic approach to model checking, in which a specification is given by an automaton that observes the execution of a program and accepts executions that violate the intended specification. We extend this approach by allowing specifications to be given by a class of infinite-state au- tomata. We show how such automata can be used to specify queues, stacks, and other data structures, by extending a data-independence argument. For verifica- tion, we develop a shape analysis, which tracks correlations between pairs of threads, and a novel abstraction to make the analysis practical. We have imple- mented our method and used it to verify programs, some of which have not been verified by any other automatic method before.
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| 3. |
- Abdulla, Parosh Aziz, et al.
(författare)
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Block me if you can! : Context-sensitive parameterized verification
- 2014
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Ingår i: Static Analysis. - Cham : Springer. - 9783319109350 ; , s. 1-17
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Konferensbidrag (refereegranskat)abstract
- We present a method for automatic verification of systems with a parameterized number of communicating processes, such as mutual exclusion protocols or agreement protocols. To that end, we present a powerful abstraction framework that uses an efficient and precise symbolic encoding of (infinite) sets of configurations. In particular, it generalizes downward-closed sets that have successfully been used in earlier approaches to parameterized verification. We show experimentally the efficiency of the method, on various examples, including a fine-grained model of Szymanski’s mutual exclusion protocol, whose correctness, to the best of our knowledge, has not been proven automatically by any other existing methods.
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| 4. |
- Abdulla, Parosh Aziz, et al.
(författare)
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Constrained monotonic abstraction : A CEGAR for parameterized verification
- 2010
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Ingår i: CONCUR 2010 – Concurrency Theory. - Berlin : Springer-Verlag. - 9783642153747 ; , s. 86-101
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Konferensbidrag (refereegranskat)abstract
- In this paper, we develop a counterexample-guided abstraction refinement (CEGAR) framework for monotonic abstraction, an approach that is particularly useful in automatic verification of safety properties for parameterized systems The main drawback of verification using monotonic abstraction is that it sometimes generates spurious counterexamples Our CEGAR algorithm automatically extracts from each spurious counterexample a set of configurations called a "Safety Zone" and uses it to refine the abstract transition system of the next iteration We have developed a prototype based on this idea, and our experimentation shows that the approach allows to verify many of the examples that cannot be handled by the original monotonic abstraction approach.
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| 5. |
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| 6. |
- Abdulla, Parosh Aziz, et al.
(författare)
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Model Checking Race-Freeness
- 2008
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Ingår i: Proc. 1st Swedish Workshop on Multi-Core Computing. ; , s. 89-96
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 7. |
- Abdulla, Parosh Aziz, et al.
(författare)
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Monotonic abstraction for programs with dynamic memory heaps
- 2008
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Ingår i: Computer Aided Verification. - Berlin : Springer-Verlag. ; , s. 341-354
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Konferensbidrag (refereegranskat)abstract
- We propose a new approach for automatic verification of programs with dynamic heap manipulation. The method is based on symbolic (backward) reachability analysis using upward-closed sets of heaps w.r.t. an appropriate preorder on graphs. These sets are represented by a finite set of minimal graph patterns corresponding to a set of bad configurations. We define an abstract semantics for the programs which is monotonic w.r.t. the preorder. Moreover, we prove that our analysis always terminates by showing that the preorder is a well-quasi ordering. Our results are presented for the case of programs with 1-next selector. We provide experimental results showing the effectiveness of our approach.
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| 8. |
- Abdulla, Parosh Aziz, et al.
(författare)
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Parameterized tree systems
- 2008
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Ingår i: Formal Techniques for Networked and Distributed Systems. - Berlin : Springer-Verlag. - 9783540688549 ; , s. 69-83
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Konferensbidrag (refereegranskat)abstract
- Several recent works have considered parameterized verification, i.e. automatic verification of systems consisting of an arbitrary number of finite-state processes organized in a linear array. The aim of this paper is to extend these works by giving a simple and efficient method to prove safety properties for systems with tree-like architectures. A process in the system is a finite-state automaton and a transition is performed jointly by a process and its parent and children processes. The method derives an over-approximation of the induced transition system, which allows the use of finite trees as symbolic representations of infinite sets of configurations. Compared to traditional methods for parameterized verification of systems with tree topologies, our method does not require the manipulation of tree transducers, hence its simplicity and efficiency. We have implemented a prototype which works well on several nontrivial tree-based protocols.
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| 9. |
- Abdulla, Parosh Aziz, et al.
(författare)
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Parameterized verification through view abstraction
- 2016
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Ingår i: International Journal on Software Tools for Technology Transfer. - : Springer Science and Business Media LLC. - 1433-2779 .- 1433-2787. ; 18:5, s. 495-516
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Tidskriftsartikel (refereegranskat)abstract
- We present a simple and efficient framework for automatic verification of systems with a parametric number of communicating processes. The processes may be organized in various topologies such as words, multisets, rings, or trees. Our method needs to inspect only a small number of processes in order to show correctness of the whole system. It relies on an abstraction function that views the system from the perspective of a fixed number of processes. The abstraction is used during the verification procedure in order to dynamically detect cut-off points beyond which the search of the state space need not continue. We show that the method is complete for a large class of well quasi-ordered systems including Petri nets. Our experimentation on a variety of benchmarks demonstrate that the method is highly efficient and that it works well even for classes of systems with undecidable verification problems. In particular, the method handles the fine-grained and full version of Szymanski's mutual exclusion protocol, whose correctness, to the best of our knowledge, has not been proven automatically by any other existing methods.
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| 10. |
- Abdulla, Parosh, 1961-, et al.
(författare)
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An integrated specification and verification technique for highly concurrent data structures for highly concurrent data structures
- 2017
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Ingår i: International Journal on Software Tools for Technology Transfer. - : SPRINGER HEIDELBERG. - 1433-2779 .- 1433-2787. ; 19:5, s. 549-563
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Tidskriftsartikel (refereegranskat)abstract
- We present a technique for automatically verifying safety properties of concurrent programs, in particular programs that rely on subtle dependencies of local states of different threads, such as lock-free implementations of stacks and queues in an environment without garbage collection. Our technique addresses the joint challenges of infinite-state specifications, an unbounded number of threads, and an unbounded heap managed by explicit memory allocation. Our technique builds on the automata-theoretic approach to model checking, in which a specification is given by an automaton that observes the execution of a program and accepts executions that violate the intended specification. We extend this approach by allowing specifications to be given by a class of infinite-state automata. We show how such automata can be used to specify queues, stacks, and other data structures, by extending a data-independence argument. For verification, we develop a shape analysis, which tracks correlations between pairs of threads, and a novel abstraction to make the analysis practical. We have implemented our method and used it to verify programs, some of which have not been verified by any other automatic method before.
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| 11. |
- Aziz Abdulla, Parosh, et al.
(författare)
-
An integrated specification and verification technique for highly concurrent data structures
- 2017
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Ingår i: International Journal on Software Tools for Technology Transfer. - : SPRINGER HEIDELBERG. - 1433-2779 .- 1433-2787. ; 19:5, s. 549-563
-
Tidskriftsartikel (refereegranskat)abstract
- We present a technique for automatically verifying safety properties of concurrent programs, in particular programs that rely on subtle dependencies of local states of different threads, such as lock-free implementations of stacks and queues in an environment without garbage collection. Our technique addresses the joint challenges of infinite-state specifications, an unbounded number of threads, and an unbounded heap managed by explicit memory allocation. Our technique builds on the automata-theoretic approach to model checking, in which a specification is given by an automaton that observes the execution of a program and accepts executions that violate the intended specification. We extend this approach by allowing specifications to be given by a class of infinite-state automata. We show how such automata can be used to specify queues, stacks, and other data structures, by extending a data-independence argument. For verification, we develop a shape analysis, which tracks correlations between pairs of threads, and a novel abstraction to make the analysis practical. We have implemented our method and used it to verify programs, some of which have not been verified by any other automatic method before.
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| 12. |
- Dahlö, Martin, et al.
(författare)
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BioImg.org : A catalog of virtual machine images for the life sciences
- 2015
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Ingår i: Bioinformatics and Biology Insights. - 1177-9322. ; 9, s. 125-128
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Tidskriftsartikel (refereegranskat)abstract
- Virtualization is becoming increasingly important in bioscience, enabling assembly and provisioning of complete computer setups, including operating system, data, software, and services packaged as virtual machine images (VMIs). We present an open catalog of VMIs for the life sciences, where scientists can share information about images and optionally upload them to a server equipped with a large file system and fast Internet connection. Other scientists can then search for and download images that can be run on the local computer or in a cloud computing environment, providing easy access to bioinformatics environments. We also describe applications where VMIs aid life science research, including distributing tools and data, supporting reproducible analysis, and facilitating education.
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| 13. |
- Haziza, Frédéric, 1978-
(författare)
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Few is Just Enough! : Small Model Theorem for Parameterized Verification and Shape Analysis
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This doctoral thesis considers the automatic verification of parameterized systems, i.e. systems with an arbitrary number of communicating components, such as mutual exclusion protocols, cache coherence protocols or heap manipulating programs. The components may be organized in various topologies such as words, multisets, rings, or trees.The task is to show correctness regardless of the size of the system and we consider two methods to prove safety:(i) a backward reachability analysis, using the well-quasi ordered framework and monotonic abstraction, and (ii) a forward analysis which only needs to inspect a small number of components in order to show correctness of the whole system. The latter relies on an abstraction function that views the system from the perspective of a fixed number of components. The abstraction is used during the verification procedure in order to dynamically detect cut-off points beyond which the search of the state-space need not continue.Our experimentation on a variety of benchmarks demonstrate that the method is highly efficient and that it works well even for classes of systems with undecidable property. It has been, for example, successfully applied to verify a fine-grained model of Szymanski's mutual exclusion protocol. Finally, we applied the methods to solve the complex problem of verifying highly concurrent data-structures, in a challenging setting: We do not a priori bound the number of threads, the size of the data-structure, the domain of the data to store nor do we require the presence of a garbage collector. We successfully verified the concurrent Treiber's stack and Michael & Scott's queue, in the aforementioned setting.To the best of our knowledge, these verification problems have been considered challenging in the parameterized verification community and could not be carried out automatically by other existing methods.
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| 14. |
- Haziza, Frédéric, et al.
(författare)
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Pointer Race Freedom
- 2016
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Ingår i: Verification, Model Checking, And Abstract Interpretation, VMCAI 2016. - Berlin, Heidelberg : Springer. - 9783662491225 - 9783662491218 ; , s. 393-412
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Konferensbidrag (refereegranskat)abstract
- We propose a novel notion of pointer race for concurrent programs manipulating a shared heap. A pointer race is an access to a memory address which was freed, and it is out of the accessor's control whether or not the cell has been re-allocated. We establish two results. (1) Under the assumption of pointer race freedom, it is sound to verify a program running under explicit memory management as if it was running with garbage collection. (2) Even the requirement of pointer race freedom itself can be verified under the garbage-collected semantics. We then prove analogues of the theorems for a stronger notion of pointer race needed to cope with performance-critical code purposely using racy comparisons and even racy dereferences of pointers. As a practical contribution, we apply our results to optimize a thread-modular analysis under explicit memory management. Our experiments confirm a speedup of up to two orders of magnitude.
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