> This is fork off the SizeOf JEP, JDK-8249196. There is already the entry > point in JDK that can use the intrinsic like > this: `Instrumentation.getInstanceSize`. Therefore, we can implement the > C1/C2 intrinsic now, hook it up to > `Instrumentation`, and let the tools use that fast path today. With this > patch, JOL is able to be close to > `deepSizeOf` implementation from SizeOf JEP. > Example performance improvements for sizing up a custom linked list: > > Benchmark (size) Mode Cnt Score Error Units > > # Default > LinkedChainBench.linkedChain 1 avgt 5 705.835 ± 8.051 ns/op > LinkedChainBench.linkedChain 10 avgt 5 3148.874 ± 37.856 ns/op > LinkedChainBench.linkedChain 100 avgt 5 28693.256 ± 142.254 ns/op > LinkedChainBench.linkedChain 1000 avgt 5 290161.590 ± 4594.631 ns/op > > # Instrumentation attached, no intrinsics > LinkedChainBench.linkedChain 1 avgt 5 159.659 ± 19.238 ns/op > LinkedChainBench.linkedChain 10 avgt 5 717.659 ± 22.540 ns/op > LinkedChainBench.linkedChain 100 avgt 5 7739.394 ± 111.683 ns/op > LinkedChainBench.linkedChain 1000 avgt 5 80724.238 ± 2887.794 ns/op > > # Instrumentation attached, new intrinsics > LinkedChainBench.linkedChain 1 avgt 5 95.254 ± 0.808 ns/op > LinkedChainBench.linkedChain 10 avgt 5 261.564 ± 8.524 ns/op > LinkedChainBench.linkedChain 100 avgt 5 3367.192 ± 21.128 ns/op > LinkedChainBench.linkedChain 1000 avgt 5 34148.851 ± 373.080 ns/op
Aleksey Shipilev has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains one commit: 8253525: Implement getInstanceSize/sizeOf intrinsics ------------- Changes: https://git.openjdk.java.net/jdk/pull/650/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=650&range=01 Stats: 612 lines in 10 files changed: 563 ins; 0 del; 49 mod Patch: https://git.openjdk.java.net/jdk/pull/650.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/650/head:pull/650 PR: https://git.openjdk.java.net/jdk/pull/650
