Integrated: 8285447: StackWalker minimal batch size should be optimized for getCallerClass

[Mandy Chung]

On Fri, 8 Sep 2023 16:57:14 GMT, Mandy Chung <mchung at openjdk.org> wrote:

> Typically it will find the caller class at the second stack frame from the frame of executing `StackWalker::getCallerClass`.   The initial size of the buffer can be changed from 8 to 4 (the top 2 elements are reserved for implementation use).   If it fetches another batch, `getCallerClass` may be invoked via core reflection, so subsequent batches can be increased to a larger size.   This PR also moves the benchmark for `getCallerClass` in its own file because it does not need to test with different depth and can be separated from StackWalkBench.

This pull request has now been integrated.

Changeset: d75d9774
Author:    Mandy Chung <mchung at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/d75d9774c806e4bf73caa69cd78c31a132e4c812
Stats:     83 lines in 3 files changed: 65 ins; 12 del; 6 mod

8285447: StackWalker minimal batch size should be optimized for getCallerClass

Reviewed-by: simonis

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PR: https://git.openjdk.org/jdk/pull/15642