Fast concurrent queues for x86 processors

Conventional wisdom in designing concurrent data structures is to use the most powerful synchronization primitive, namely compare-and-swap (CAS), and to avoid contended hot spots. In building concurrent FIFO queues, this reasoning has led re-searchers to propose combining-based concurrent queues. This paper takes a different approach, showing how to rely on fetch-and-add (F&A), a less powerful primitive that is available on x86 processors, to construct a nonblocking (lock-free) lineariz-able concurrent FIFO queue which, despite the F&A being a con-tended hot spot, outperforms combining-based implementations by 1.5 × to 2.5 × in all concurrency levels on an x86 server with four multicore processors, in both single-processor and multi-processor executions. Categories and Subject Descriptors D.1.3 [Programming Tech