8295402: G1: Tighten assertion in G1ScanHRForRegionClosure::scan_heap_roots

[albertnetymk]

Simple change of asserting the to-be-scanned card is strictly dirty.

Test: tier1-6

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• Commit message must refer to an issue

Issue

• JDK-8295402: G1: Tighten assertion in G1ScanHRForRegionClosure::scan_heap_roots

Reviewers

• Thomas Schatzl (@tschatzl - Reviewer)
• Ivan Walulya (@walulyai - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk pull/10725/head:pull/10725
$ git checkout pull/10725

Update a local copy of the PR:
$ git checkout pull/10725
$ git pull https://git.openjdk.org/jdk pull/10725/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 10725

View PR using the GUI difftool:
$ git pr show -t 10725

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/10725.diff

[bridgekeeper]

👋 Welcome back ayang! 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]

@albertnetymk The following label will be automatically applied to this pull request:

• hotspot-gc

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing list. If you would like to change these labels, use the /label pull request command.

[mlbridge]

Webrevs

• 00: Full (907b6483)

[tschatzl]

Lgtm.

[tschatzl]

Suggested change

	#ifdef ASSERT
	{
	CardTable::CardValue value = *_ct->byte_for_index(region_card_base_idx + first_scan_idx);
	assert(value == CardTable::dirty_card_val(), "is %d at region %u idx " SIZE_FORMAT, value, region_idx, first_scan_idx);
	}
	#endif
	DEBUG_ONLY(CardTable::CardValue value = *_ct->byte_for_index(region_card_base_idx + first_scan_idx);)
	assert(value == CardTable::dirty_card_val(), "is %d at region %u idx " SIZE_FORMAT, value, region_idx, first_scan_idx);

Just fyi, an alternative that does not create that many lines with almost no content.

[openjdk]

@albertnetymk 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:

8295402: G1: Tighten assertion in G1ScanHRForRegionClosure::scan_heap_roots

Reviewed-by: tschatzl, iwalulya

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 225 new commits pushed to the master branch:

• af2de97: 8287754: Update jib GNU make dependency on Windows to latest cygwin build
• 9051dde: 8294993: LingeredApp test update
• f37a605: 8295212: G1: Add wrapper for TruncatedSeqs that need separation by gc phase
• 6673cd8: 8295554: Move the "sizecalc.h" to the correct location
• 706d1b7: 8295798: (ch) Test java/nio/channels/Channels/ReadXBytes.java is very slow on Windows
• 89dafc0: 8292699: Improve printing of classes in native debugger
• 7520d0a: 8295855: ProblemList jdk/jshell/CommandCompletionTest.java on linux-all
• 1d15e5c: 8295716: Minimize disabled warnings in security libs
• 8c86e92: 8295847: slow debug build error after JDK-8294466
• e122321: 8295844: jdk/test/whitebox/CPUInfoTest.java failed with "not all features are known: expected true, was false"
• ... and 215 more: https://git.openjdk.org/jdk/compare/6ed74ef654f0b3e5c748895654d6925e2b832732...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.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[albertnetymk]

I think #ifdef is more visible than debug_only, enabling people to skip debug-only code quickly.

Thanks for the review.

/integrate

[openjdk]

Going to push as commit 33ff80d.
Since your change was applied there have been 244 commits pushed to the master branch:

• 303548b: 8294752: G1: Remove redundant checks in check_obj_during_refinement
• cf121df: 8295889: NMT preinit code does not handle allocation errors
• 772be2e: 8295868: 32-bit Windows build failures after JDK-8294466
• e173fd7: 8295885: GHA: Bump gcc versions
• b2878c9: 8295710: remove os::dll_file_extension
• e3a5a34: 8295767: Remove unused fields in sun.awt.geom.Edge
• 324bec1: 8295863: JFR: Use expected size for Maps and Sets
• 3bd3caf: 8294486: Remove vmTestbase/nsk/jvmti/ tests ported to serviceability/jvmti.
• fec6174: 8295816: jdwp jck tests failing with "FATAL ERROR in native method: JDWP SetTag, jvmtiError=JVMTI_ERROR_WRONG_PHASE(112)"
• e0c2930: 8295282: Use Zicboz/cbo.zero to zero-out memory on RISC-V
• ... and 234 more: https://git.openjdk.org/jdk/compare/6ed74ef654f0b3e5c748895654d6925e2b832732...master

Your commit was automatically rebased without conflicts.

[openjdk]

@albertnetymk Pushed as commit 33ff80d.

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