RFR: 8316967: Correct the scope of vmtimer in UnregisteredClasses::load_class [v2]

Fri Oct 6 23:26:05 UTC 2023

On Fri, 6 Oct 2023 05:09:13 GMT, David Holmes <dholmes at openjdk.org> wrote:

> I have to wonder why the original code only timed the `open_stream` call? Is it because that is what `perf_sys_class_lookup_time` does versus `perf_sys_classload_time`? If so then removal may be better after all. Perhaps @iklam or @jianglizhou can recall this early AppCDS v2 code?

I paged in some of my memory on this. @iklam added the `ClassLoaderExt::load_class` specifically related change, so he probably can add additional background. I think the `perf_sys_class_lookup_time` part was simply based on how it was used in [ClassLoader::load_classfile](https://github.com/openjdk/jdk8u-dev/blob/27608e1e36154fcbedc627bc2afa965b1a06ebfb/hotspot/src/share/vm/classfile/classLoader.cpp#L1157C21-L1157C21).

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PR Comment: https://git.openjdk.org/jdk/pull/16046#issuecomment-1751480587