8258742: Move PtrQueue reset to PtrQueueSet subclasses

[kimbarrett]

Please review this change to the PtrQueue hierarchy, changing queue reset
from an intrinsic operation of the queue to an operation the qset performs
on a queue. This is another piece of the refactoring being done under
JDK-8258251, separated out for easier review.

After the refactoring of queue reset, PtrQueue::is_empty and PtrQueue::size
are no longer used, so are removed. Further, PtrQueue::{set_}index_in_bytes
are removed, directly using _index instead.

A less obvious part of the change is in the G1 remark task and Shenandoah
final marking task. The threads walk performed by these no longer directly
processes the partial per-thread SATB buffers. Instead they just flush the
queues for later completed buffer processing.

Testing:
mach5 tier1
local (linux-x64) hotspot:tier1 with -XX:+UseShenandoahGC

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• Change must be properly reviewed

Issue

• JDK-8258742: Move PtrQueue reset to PtrQueueSet subclasses

Reviewers

• Thomas Schatzl (@tschatzl - Reviewer) ⚠️ Review applies to 593b40b
• Ivan Walulya (@walulyai - Committer) ⚠️ Review applies to 593b40b

Download

$ git fetch https://git.openjdk.java.net/jdk pull/2115/head:pull/2115
$ git checkout pull/2115

[bridgekeeper]

👋 Welcome back kbarrett! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

@kimbarrett The following labels will be automatically applied to this pull request:

• hotspot-gc
• shenandoah

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[mlbridge]

Webrevs

• 01: Full (8c3407a)
• 00: Full (593b40b)

[tschatzl]

Lgtm.

[openjdk]

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

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

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

8258742: Move PtrQueue reset to PtrQueueSet subclasses

Reviewed-by: tschatzl, iwalulya

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[walulyai]

Looks good!

[openjdk]

@kimbarrett this pull request can not be integrated into master due to one or more merge conflicts. To resolve these merge conflicts and update this pull request you can run the following commands in the local repository for your personal fork:

git checkout move_reset
git fetch https://git.openjdk.java.net/jdk master
git merge FETCH_HEAD
# resolve conflicts and follow the instructions given by git merge
git commit -m "Merge master"
git push

[kimbarrett]

Thanks @tschatzl and @walulyai for reviews.

[kimbarrett]

/integrate

[openjdk]

@kimbarrett Pushed as commit 6c4c96f.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.