RFR: 8263549: 8263412 can cause jtreg testlibrary split

[Ioi Lam]

On Sat, 13 Mar 2021 04:31:31 GMT, Igor Ignatyev <iignatyev at openjdk.org> wrote:

> Hi all,
> 
> could you please review this dull patch that replaces `ClassFileInstaller` w/ `jdk.test.lib.helpers.ClassFileInstaller` in all jtreg test descriptions to ensure we won't get split testlibrary, and removes `jdk/test/lib/ClassFileInstaller.java` (so it won't be accidentally used).
> 
> from JBS:
>> after JDK-8263412, we might (again) encounter NCDFE b/c parts of testlibraries aren't on the classpath. this happens when jtreg builds `jdk.test.lib.helpers.ClassFileInstaller` as a part of test-specific code, but `ClassFileInstaller` as part of shared testibrary directory in one test, when in the following test, jtreg sees `ClassFileInstaller` in the shared directory, hence javac won't recompile it/its dependencies, but in runtime `jdk.test.lib.helpers.ClassFileInstaller` is nowhere to be found, hence we get NCDFE. 
> 
> testing:
> - [x]  `grep ' ClassFileInstaller[^.]`
> - [ ] tier1-3
> 
> Thanks,
> -- Igor

I did this and scanned the differences (with the diff file from the webrev) and it looks reasonable to me.

grep '^[+-]' diff.txt | grep -v Copyright | grep -v '^.[+-]' | less

It looks like most of the changes are mechanical. There were only a few cases where manual changes were made. I trusted that you have tested those cases individually.

But I don't understand why this error can happen. It seems like jtreg would allow two test cases to interfere with each other.

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Marked as reviewed by iklam (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/2985