| 1. |
- Chatterjee, Bapi, 1982, et al.
(författare)
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Help-optimal and Language-portable Lock-free Concurrent Data Structures
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Helping is the most common mechanism to guarantee lock-freedom in many concurrent data structures. An optimized helping strategy improves the overall performance of a lock-free algorithm. In this paper, we propose help-optimality, which essentially implies that no operationstep is accounted for exclusive helping in the lock-free synchronization of concurrent operations. To describe the concept, we revisit the designs of a lock-free linked-list and a lock-free binary search tree and present improved algorithms. Our algorithms employ atomic single-word compare-and-swap (CAS) primitives and are linearizable.Additionally, we do not use a language/platform speci?c mechanism to modulate helping, speci?cally, we use neither bit-stealing from a pointer nor runtime type introspection of objects, making the algorithms language-portable. Further, to optimize the amortized numberof steps per operation, if a CAS execution to modify a shared pointer fails, we obtain a fresh set of thread-local variables without restarting an operation from scratch.We use several micro-benchmarks in both C/C++ and Java to validate the e?ciency of our algorithms against existing state-of-the-art. The experiments show that the algorithms are scalable. Our implementations perform on a par with highly optimized ones and in manycases yield 10%-50% higher throughput.
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| 2. |
- Chatterjee, Bapi, 1982, et al.
(författare)
-
Help-Optimal and Language-Portable Lock-Free Concurrent Data Structures
- 2016
-
Ingår i: 45th International Conference on Parallel Processing (ICPP), 2016. - 0190-3918. - 9781509028238 ; 2016 september, s. 360-369
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Konferensbidrag (refereegranskat)abstract
- Helping is a widely used technique to guarantee lock-freedom in many concurrent data structures. An optimized helping strategy improves the overall performance of a lock-free algorithm. In this paper, we propose help-optimality, which essentially implies that no operation step is accounted for exclusive helping in the lock-free synchronization of concurrent operations. To describe the concept, we revisit the designs of a lock-free linked-list and a lock-free binary search tree and present improved algorithms. Our algorithms employ atomic single-word compare-and-swap (CAS) primitives and are linearizable. We design the algorithms without using any language/platformspecific mechanism. Specifically, we use neither bit-stealing froma pointer nor runtime type introspection of objects. Thus, our algorithms are language-portable. Further, to optimize the amortized number of steps per operation, if a CAS execution tomodify a shared pointer fails, we obtain a fresh set of thread-local variables without restarting an operation from scratch. We use several micro-benchmarks in both C/C++ and Java to validate the efficiency of our algorithms against existing state-of-the-art. The experiments show that the algorithms are scalable. Our implementations perform on a par with highly optimizedones and in many cases yield 10%-50% higher throughput.
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