8328592: hprof tests fail with -XX:-CompactStrings

[shipilev]

See the bug for symptoms. The tests are failing because hprof test library is confused about non-compact strings.

Additional testing:

• serviceability/HeapDump lib-test:all with -XX:-CompactStrings now pass
• serviceability/HeapDump lib-test:all with -XX:+CompactStrings still pass

---

Progress

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Issue

• JDK-8328592: hprof tests fail with -XX:-CompactStrings (Bug - P4)

Reviewers

• Paul Hohensee (@phohensee - Reviewer) ⚠️ Review applies to f783418d
• Leonid Mesnik (@lmesnik - Reviewer) ⚠️ Review applies to 5ba1f4b8
• Alex Menkov (@alexmenkov - Reviewer) ⚠️ Review applies to f783418d

Reviewing

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[bridgekeeper]

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[openjdk]

@shipilev 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:

8328592: hprof tests fail with -XX:-CompactStrings

Reviewed-by: phh, lmesnik, amenkov

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At the time when this comment was updated there had been 10 new commits pushed to the master branch:

• 93d1700: 8328589: unify os::breakpoint among posix platforms
• a5a2eca: 8327683: Crash with primitive type pattern and generic expression in instanceof
• 65d9f11: 8328328: Convert javax/swing/JTabbedPane/4666224/bug4666224.java applet test to main
• 481473e: 8328035: Convert javax/swing/text/html/TableView/7030332/bug7030332.java applet test to main
• dea94f4: 8328300: Convert PrintDialogsTest.java from Applet to main program
• d32746e: 8296244: Alternate implementation of user-based authorization Subject APIs that doesn’t depend on Security Manager APIs
• 000f4d8: 8319251: [REDO] Change LockingMode default from LM_LEGACY to LM_LIGHTWEIGHT
• fbeac98: 8328379: Convert URLDragTest.html applet test to main
• 96530bc: 8326521: JFR: CompilerPhase event test fails on windows 32 bit
• a112fc8: 8328225: Convert ImageDecoratedDnD.html applet test to main

Please see this link for an up-to-date comparison between the source branch of this pull request and the master branch.
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.

[openjdk]

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

• hotspot-runtime
• serviceability

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[mlbridge]

Webrevs

• 02: Full - Incremental (6c677007)
• 01: Full - Incremental (f783418d)
• 00: Full (5ba1f4b8)

[phohensee]

Are we guaranteed that non-compact string char component bytes are stored in little-endian order?

[shipilev]

Are we guaranteed that non-compact string char component bytes are stored in little-endian order?

No, I don't think we are guaranteed any particular endianness, argh. The new patch follows what StringUTF16 does:

jdk/src/java.base/share/classes/java/lang/StringUTF16.java

Lines 1663 to 1673 in 4e83f4c

	private static final int HI_BYTE_SHIFT;
	private static final int LO_BYTE_SHIFT;
	static {
	if (Unsafe.getUnsafe().isBigEndian()) {
	HI_BYTE_SHIFT = 8;
	LO_BYTE_SHIFT = 0;
	} else {
	HI_BYTE_SHIFT = 0;
	LO_BYTE_SHIFT = 8;
	}
	}

[alexmenkov]

Looks good. Please update copyright years before push

[shipilev]

GHA failures look environmental. I am integrating this.

/integrate

[openjdk]

Going to push as commit bb3e84b.
Since your change was applied there have been 16 commits pushed to the master branch:

• ac2f8e5: 8327994: Update code gen in CallGeneratorHelper
• c434b79: 8327169: serviceability/dcmd/vm/SystemMapTest.java and SystemDumpMapTest.java may fail after JDK-8326586
• 7006790: 8328628: JDK-8328157 incorrectly sets -MT on all compilers in jdk.jpackage
• 68170ae: 8328238: Convert few closed manual applet tests to main
• 9f5ad43: 8320675: PrinterJob/SecurityDialogTest.java hangs
• 684678f: 8328633: s390x: Improve vectorization of Match.sqrt() on floats
• 93d1700: 8328589: unify os::breakpoint among posix platforms
• a5a2eca: 8327683: Crash with primitive type pattern and generic expression in instanceof
• 65d9f11: 8328328: Convert javax/swing/JTabbedPane/4666224/bug4666224.java applet test to main
• 481473e: 8328035: Convert javax/swing/text/html/TableView/7030332/bug7030332.java applet test to main
• ... and 6 more: https://git.openjdk.org/jdk/compare/4e83f4cfc779e39cca0070b5729a508aeaa74654...master

Your commit was automatically rebased without conflicts.

[openjdk]

@shipilev Pushed as commit bb3e84b.

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