Integrated: 8275185: Remove dead code and clean up jvmstat LocalVmManager

[Ioi Lam]

On Wed, 13 Oct 2021 04:17:25 GMT, Ioi Lam <iklam at openjdk.org> wrote:

> LocalVmManager and PerfDataFile have APIs that are supposed to look for VMs owned by a specific user. No one uses these APIs, and they don't work anyway.
> 
> The current code is very confusing to look at. Since we're likely to change code in this area for further container support, it's better to clean up the code now.
> 
> - Remove all APIs that take a user name
> - Also removed PerfDataFile.getFile() methods that are unused
> - Cleaned up the code that looks up the hsperfdata_xxx files
>   - Fix comments to explain what's happening
>   - Avoid using Matcher.reset which is not thread-safe
>   - Renamed confusing variables such as `userFilter` to make the code more readable
>   - LocalVmManager.activeVms() probably doesn't need to be synchronized, but I kept it anyway to avoid unnecessary risks.
> 
> Testing with Oracle CI: tiers1-4, plus hs-tier5-rt (which tests containers and have extensive use of the management tools).

This pull request has now been integrated.

Changeset: 8e17ce00
Author:    Ioi Lam <iklam at openjdk.org>
URL:       https://git.openjdk.java.net/jdk/commit/8e17ce00316a765bbedefc34dc5898ba4f3f2144
Stats:     296 lines in 2 files changed: 9 ins; 255 del; 32 mod

8275185: Remove dead code and clean up jvmstat LocalVmManager

Reviewed-by: cjplummer, redestad, kevinw

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PR: https://git.openjdk.java.net/jdk/pull/5923