On Fri, 28 Oct 2022 01:47:23 GMT, David Holmes <dhol...@openjdk.org> wrote:
> So the data structure for lock records (per thread) could consist of a series > of distinct values [ A B C ] and each of the values could be repeated, but > only adjacently: [ A A A B C C ] for example. > @rose00 why only adjacently? Nested locking can be interleaved on different > monitors. Yes it can; you can have nesting A, B, A. But the thread-based fast-locking list might not cover that case. If it were restricted to only adjacent records in the way I sketched, it would need to use a different, slower technique for the A, B, A case. The trade-off is that if you only allow adjacent recursive locks on the list, you don't need to search the list beyond the first element, to detect re-locking. Dunno if that pencils out to a real advantage, though, since the fallback is slow. ------------- PR: https://git.openjdk.org/jdk/pull/10590
