@@ -560,7 +560,7 @@ Building on separation logic with concurrent abstract predicates (CAP), we intro
doi={10.1007/978-3-662-54434-1_36},
Abstract={Despite recent advances in reasoning about concurrent data structure libraries, the largest implementations in java.util.concurrent have yet to be verified. The key issue lies in the development of modular specifications, which provide clear logical boundaries between clients and implementations. A solution is to use recent advances in fine-grained concurrency reasoning, in particular the introduction of abstract atomicity to concurrent separation logic reasoning. We present two specifications of concurrent maps, both providing the clear boundaries we seek. We show that these specifications are equivalent, in that they can be built from each other. We show how we can verify client programs, such as a concurrent set and a producer-consumer client. We also give a substantial first proof that the main operations of ConcurrentSkipListMap in java.util.concurrent satisfy the map specification. This work demonstrates that we now have the technology to verify the largest implementations in java.util.concurrent.},
project={concurrency, tada},
project={concurrency, tada},
}
@Article{Fragoso2016Mashic,
Title={{Mashic Compiler: Mashup Sandboxing based on Inter-frame Communication}},
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@@ -575,7 +575,7 @@ Building on separation logic with concurrent abstract predicates (CAP), we intro
Abstract={ Mashups are a prevailing kind of web applications integrating external gadget APIs often written in the JavaScript programming language. Writing secure mashups is a challenging task due to the heterogeneity of existing gadget APIs, the privileges granted to gadgets during mashup executions, and JavaScript’s highly dynamic environment. We propose a new compiler, called Mashic, for the automatic generation of secure JavaScript-based mashups from existing mashup code. The Mashic compiler can effortlessly be applied to existing mashups based on a wide-range of gadget APIs. It offers security and correctness guarantees. Security is achieved via the Same Origin Policy. Correctness is ensured in the presence of benign gadgets, that satisfy confidentiality and integrity constraints with regard to the integrator code. The compiler has been successfully applied to real world mashups based on Google maps, Bing maps, YouTube, and Zwibbler APIs.},
Project={ web }
Project={ web },
}
@phdthesis{Ntzik2016Reasoning,
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@@ -583,9 +583,19 @@ Building on separation logic with concurrent abstract predicates (CAP), we intro
school={Imperial College London},
author={Gian Ntzik},
year={2016},
Project={ concurrency },
Abstract={POSIX is a standard for operating systems, with a substantial part devoted to specifying file-system operations. File-system operations exhibit complex concurrent behaviour, comprising multiple actions affecting different parts of the state: typically, multiple atomic reads followed by an atomic update. However, the standard's description of concurrent behaviour is unsatisfactory: it is fragmented; contains ambiguities; and is generally under-specified. We provide a formal concurrent specification of POSIX le systems and demonstrate scalable reasoning for clients. Our speciation is based on a concurrent specification language, which uses a modern concurrent separation logic for reasoning about abstract atomic operations, and an associated refinement calculus. Our reasoning about clients highlights an important difference between reasoning about modules built over a heap, where the interference on the shared state is restricted to the operations of the module, and modules built over a file system, where the interference cannot be restricted as the file system is a public namespace. We introduce specifications conditional on context invariants used to restrict the interference, and apply our reasoning to lock les and named pipes. Program reasoning based on separation logic has been successful at verifying that programs do not crash due to illegal use of resources, such invalid memory accesses. The underlying assumption of separation logics, however, is that machines do not fail. In practice, machines can fail unpredictably for various reasons, such as power loss, corrupting resources or resulting in permanent data loss. Critical software, such as le systems and databases, employ recovery methods to mitigate these effects. We introduce an extension of the Views framework to reason about programs in the presence of such events and their associated recovery methods. We use concurrent separation logic as an instance of the framework to illustrate our reasoning, and explore programs using write-ahead logging, such a stylised ARIES recovery algorithm.}
Project={concurrency},
}
Abstract={POSIX is a standard for operating systems, with a substantial part devoted to specifying file-system operations. File-system operations exhibit complex concurrent behaviour, comprising multiple actions affecting different parts of the state: typically, multiple atomic reads followed by an atomic update. However, the standard's description of concurrent behaviour is unsatisfactory: it is fragmented; contains ambiguities; and is generally under-specified. We provide a formal concurrent specification of POSIX le systems and demonstrate scalable reasoning for clients. Our speciation is based on a concurrent specification language, which uses a modern concurrent separation logic for reasoning about abstract atomic operations, and an associated refinement calculus. Our reasoning about clients highlights an important difference between reasoning about modules built over a heap, where the interference on the shared state is restricted to the operations of the module, and modules built over a file system, where the interference cannot be restricted as the file system is a public namespace. We introduce specifications conditional on context invariants used to restrict the interference, and apply our reasoning to lock les and named pipes. Program reasoning based on separation logic has been successful at verifying that programs do not crash due to illegal use of resources, such invalid memory accesses. The underlying assumption of separation logics, however, is that machines do not fail. In practice, machines can fail unpredictably for various reasons, such as power loss, corrupting resources or resulting in permanent data loss. Critical software, such as le systems and databases, employ recovery methods to mitigate these effects. We introduce an extension of the Views framework to reason about programs in the presence of such events and their associated recovery methods. We use concurrent separation logic as an instance of the framework to illustrate our reasoning, and explore programs using write-ahead logging, such a stylised ARIES recovery algorithm.}
@phdthesis{daRochaPinto2016Reasoning,
title={Reasoning with Time and Data Abstractions},
school={Imperial College London},
author={{Pedro {da Rocha Pinto}},
year = {2016},
Abstract = {In this thesis, we address the problem of verifying the functional correctness of concurrent programs, with emphasis on fine-grained concurrent data structures. Reasoning about such programs is challenging since data can be concurrently accessed by multiple threads: the reasoning must account for the interference between threads, which is often subtle. To reason about interference, concurrent operations should either be at distinct times or on distinct data. We present TaDA, a sound program logic for verifying clients and implementations that use abstract specifications that incorporate both abstract atomicity—the abstraction that operations take effect at a single, discrete instant in time—and abstract disjointness—the abstraction that operations act on distinct data resources. Our key contribution is the introduction of atomic triples, which offer an expressive approach for specifying program modules. We also present Total-TaDA, a sound extension of TaDA with which we can verify total correctness of concurrent programs, i.e. that such programs both produce the correct result and terminate. With Total-TaDA, we can specify constraints on a thread’s concurrent environment that are necessary to guarantee termination. This allows us to verify total correctness for nonblocking algorithms and express lock- and wait-freedom. More generally, the abstract specifications can express that one operation cannot impede the progress of another, a new non-blocking property that we call non-impedance. Finally, we describe how to extend TaDA for proving abstract atomicity for data structures that make use of helping—where one thread is performing an abstract operation on behalf of another—and speculation—where an abstract operation is determined by future behaviour.}
