JDK-8276983: Small fixes to DumpAllocStat::print_stats

[tstuefe]

When looking at CDS code in the context of Lilliput, I had to spend some time in DumpAllocStat::print(). I noticed two small things which can be fixed independently:

• the divide-by-zero check at lines 45ff is not needed, since percent_of does this already. It also can cause the asserts at the end of the function to fire wrongly.

• About those asserts: it makes sense to flush the debug message before scope end, otherwise, we won't see the debug message if the asserts fire. If they fire, the debug message would be helpful.

I also improved the assert message somewhat. I noticed that all sizes in this method are int, but left it that way because changing it would have too many ripple effects. I guess we won't get CDS archives beyond int_max any time soon.

Thanks, Thomas

---

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Issue

• JDK-8276983: Small fixes to DumpAllocStat::print_stats

Reviewers

• David Holmes (@dholmes-ora - Reviewer)
• Ioi Lam (@iklam - Reviewer)

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[mlbridge]

Webrevs

• 00: Full (45a2c3c4)

[dholmes-ora]

Hi Thomas,

Seems okay. Relying on percent_of rather than passing in 1 does seem to change what will be output, but AFAICS we should never be able to pass zero in the first place.

Thanks,
David

[openjdk]

@tstuefe This change now passes all automated pre-integration checks.

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After integration, the commit message for the final commit will be:

8276983: Small fixes to DumpAllocStat::print_stats

Reviewed-by: dholmes, iklam

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At the time when this comment was updated there had been 28 new commits pushed to the master branch:

• 8c5f030: 8276453: Undefined behavior in C1 LIR_OprDesc causes SEGV in fastdebug build
• 176d21d: 8276824: refactor Thread::is_JavaThread_protected
• 74f3e69: 8277071: [BACKOUT] JDK-8276743 Make openjdk build Zip Archive generation "reproducible"
• b85500e: 8276123: ZipFile::getEntry will not return a file entry when there is a directory entry of the same name within a Zip File
• 0d2980c: 8258192: Obsolete the CriticalJNINatives flag
• 5a2452c: 8274835: Remove unnecessary castings in java.base
• 3b2585c: 8276658: Clean up JNI local handles code
• aeba653: 8276743: Make openjdk build Zip Archive generation "reproducible"
• 51a5731: 8277016: Use blessed modifier order in jdk.httpserver
• c4b4432: 8277012: Use blessed modifier order in src/utils
• ... and 18 more: https://git.openjdk.java.net/jdk/compare/ad3be04d2ac84836e393d696ff03ddfe72779094...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

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[iklam]

LGTM. Good clean up.

[tstuefe]

Thanks @dholmes-ora and @iklam !

/integrate

[openjdk]

Going to push as commit 296780c.
Since your change was applied there have been 28 commits pushed to the master branch:

• 8c5f030: 8276453: Undefined behavior in C1 LIR_OprDesc causes SEGV in fastdebug build
• 176d21d: 8276824: refactor Thread::is_JavaThread_protected
• 74f3e69: 8277071: [BACKOUT] JDK-8276743 Make openjdk build Zip Archive generation "reproducible"
• b85500e: 8276123: ZipFile::getEntry will not return a file entry when there is a directory entry of the same name within a Zip File
• 0d2980c: 8258192: Obsolete the CriticalJNINatives flag
• 5a2452c: 8274835: Remove unnecessary castings in java.base
• 3b2585c: 8276658: Clean up JNI local handles code
• aeba653: 8276743: Make openjdk build Zip Archive generation "reproducible"
• 51a5731: 8277016: Use blessed modifier order in jdk.httpserver
• c4b4432: 8277012: Use blessed modifier order in src/utils
• ... and 18 more: https://git.openjdk.java.net/jdk/compare/ad3be04d2ac84836e393d696ff03ddfe72779094...master

Your commit was automatically rebased without conflicts.

[openjdk]

@tstuefe Pushed as commit 296780c.

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