A Compression-Based Design for Higher Throughput in a Lock-Free Hash Map


Lock-free implementation techniques are known to improve the overall throughput of concurrent data structures. A hash map is an important data structure used to organize information that must be accessed frequently. A key role of a hash map is the ability to balance workloads by dynamically adjusting its internal data structures in order to provide the fastest possible access to the information. This work extends a previous lock-free hash map design to also support lock-free compression. The main goal is to significantly reduce the depth of the internal hash levels within the hash map, in order to minimize cache misses and increase the overall throughput. To materialize our design, we redesigned the existent search, insert, remove and expand operations in order to maintain the lock-freedom property of the whole design. Experimental results show that lock-free compression effectively improves the search operation and, in doing so, it outperforms the previous design, which was already quite competitive when compared against the concurrent hash map design supported by Intel.


  author =    {P. Moreno and M. Areias and R. Rocha},
  title =     {{A Compression-Based Design for Higher Throughput in a
Lock-Free Hash Map}},
  booktitle = {Proceedings of the 26th International European
  Conference on Parallel and Distributed Computing (Euro-Par 2020)}, 
  pages =     {458--473},
  series =    {LNCS},
  publisher = {Springer International Publishing},
  editor =    {M. Malawski and K. Rzadca},
  month =     {August},
  year =      {2020},
  address =   {Warsaw, Poland},

Download Paper

PDF file
Springer (Paper)
Springer (Artifact)