8298612: Refactor archiving of java String objects

[iklam]

This is the last prerequisite PR for JDK-8296344 (Remove dependency on G1 for writing the CDS archive heap).

The old StringTable::write_to_archive() violates requirements [1] and [2] as stated in JDK-8298600.

In the new implementation, copying of strings into the archive has been moved inside of heapShared.cpp. Now we no longer expose the HeapShared::archive_object() API. This addresses requirement [1].

Also, we no longer hand-assemble the String object and its internal value array. Instead, we use HeapShared::archive_reachable_objects_from to recursively copy the value. This addresses requirement [2].

Test: tiers 1-4.

---

Progress

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Issue

• JDK-8298612: Refactor archiving of java String objects

Reviewers

• Calvin Cheung (@calvinccheung - Reviewer) ⚠️ Review applies to 2c939684

Reviewing

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[mlbridge]

Webrevs

• 02: Full (b4490d29)
• 01: Full - Incremental (2c939684)
• 00: Full (757e0467)

[calvinccheung]

LGTM

[openjdk]

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

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8298612: Refactor archiving of java String objects

Reviewed-by: ccheung

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[iklam]

Thanks @calvinccheung for the review.
Passed tiers 1-4
/integrate

[openjdk]

Going to push as commit 1ff4646.
Since your change was applied there have been 2 commits pushed to the master branch:

• d4e9f5e: 8238170: BeanContextSupport remove and propertyChange can deadlock
• 6475501: 8300208: Optimize Adler32 stub for AVX-512 targets.

Your commit was automatically rebased without conflicts.

[openjdk]

@iklam Pushed as commit 1ff4646.

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