On Thursday, 18 October 2018 at 16:31:33 UTC, Vijay Nayar wrote:
Imagine a simple algorithm that does logic on very long numbers, split into bytes. One multi-threaded implementation may use 4 threads. The first operating on bytes 0, 4, 8, etc. The second operating on bytes 1, 5, 9, etc.In this case, a mutex or lock isn't actually needed, because the algorithm itself assures that threads don't collide.
Yes, they do collide. You just turned your cache into a giant clusterf**k. Keyword: MESIF.
