8264413: Data is written to file header even if its CRC32 was calculated

[y1yang0]

Many tests under runtime/cds/appcds/dynamicArchive are crashed when turning on VerifySharedSpaces, VM reports inconsistent crc32 between dumptime and runtime(See detailed content on JBS attachments):

$ diff dump.log run.log
17c17
< - base_archive_is_default:        0
---
> - base_archive_is_default:        1
19c19
< - base_archive_name_size:         0
---
> - base_archive_name_size:         113

The root cause is that even if the CRC32 is calculated(Line 1902), ArchiveBuilder is still writing data to FileMapInfo(Line 1903):

jdk/src/hotspot/share/memory/archiveBuilder.cpp

Lines 1091 to 1094 in 4ea6abf

	mapinfo->set_requested_base((char*)MetaspaceShared::requested_base_address());
	mapinfo->set_header_crc(mapinfo->compute_header_crc());
	mapinfo->write_header();
	mapinfo->close();

jdk/src/hotspot/share/memory/filemap.cpp

Lines 1236 to 1251 in 4ea6abf

	void FileMapInfo::write_header() {
	_file_offset = 0;
	seek_to_position(_file_offset);
	char* base_archive_name = NULL;
	if (header()->magic() == CDS_DYNAMIC_ARCHIVE_MAGIC) {
	base_archive_name = (char*)Arguments::GetSharedArchivePath();
	header()->set_base_archive_name_size(strlen(base_archive_name) + 1);
	header()->set_base_archive_is_default(FLAG_IS_DEFAULT(SharedArchiveFile));
	}
	assert(is_file_position_aligned(), "must be");
	write_bytes(header(), header()->header_size());
	if (base_archive_name != NULL) {
	write_bytes(base_archive_name, header()->base_archive_name_size());
	}
	}

Now the expected CRC32(serialized in CDS archive) is different from the calculated ones at runtime. This patch addresses this problem, it writes base_archive_name and size into header before calculating CRC32(if needed).

Thanks~
Yang

---

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Issue

• JDK-8264413: Data is written to file header even if its CRC32 was calculated

Reviewers

• Calvin Cheung (@calvinccheung - Reviewer)
• Yumin Qi (@yminqi - Reviewer)

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[bridgekeeper]

👋 Welcome back yyang! 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]

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Webrevs

• 03: Full - Incremental (c4b27fdc)
• 02: Full - Incremental (4502220d)
• 01: Full - Incremental (40b70a2a)
• 00: Full (c5a051a)

[y1yang0]

We can freeze(just like Metaspace::freeze) the FileMapInfo after CRC32 was calculated, any subsequent writing actions would be reported as illegal. Do you think this is worth doing? Looking forward to your comments.

[calvinccheung]

Looks good.
I've tried your patch on linux-x64. It passed all cds tests and also in dynamic archive mode by specifying -vmoptions:'-Dtest.dynamic.cds.archive=true -XX:+VerifySharedSpaces' and test group <open repo>/test/hotspot/jtreg:hotspot_appcds_dynamic to the jtreg command line. It also passed the first 4 tiers of testing on Oracle supported platforms.
I've filed the following RFE for adding a test group for running CDS tests with -XX:+VerifySharedSpaces:
https://bugs.openjdk.java.net/browse/JDK-8264472

[openjdk]

@kelthuzadx 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:

8264413: Data is written to file header even if its CRC32 was calculated

Reviewed-by: ccheung, minqi

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At the time when this comment was updated there had been 35 new commits pushed to the master branch:

• 52d8a22: 8264054: Bad XMM performance on java.lang.MathBench.sqrtDouble
• 16acfaf: 8012229: [lcms] Improve performance of color conversion for images with alpha channel
• cb70ab0: 8263235: sanity/client/SwingSet/src/ColorChooserDemoTest.java failed throwing java.lang.NoClassDefFoundError
• e2ec997: 8263551: Provide shared lock-free FIFO queue implementation
• dec3447: 8264346: nullptr_t undefined in global namespace for clang+libstdc++
• 0fa3572: 8264489: Add more logging to LargeCopyWithMark.java
• f43d14a: 8264396: Use the blessed modifier order in jdk.internal.jvmstat
• 6225ae6: 8264466: Cut-paste error in InterfaceCalls JMH
• 40c3249: 8264149: BreakpointInfo::set allocates metaspace object in VM thread
• 999c134: 8264417: ParallelCompactData::region_offset should not accept pointers outside the current region
• ... and 25 more: https://git.openjdk.java.net/jdk/compare/bcdf4694e07178de7d218f0dc21bda1c92e8f456...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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➡️ To flag this PR as ready for integration with the above commit message, type /integrate in a new comment. (Afterwards, your sponsor types /sponsor in a new comment to perform the integration).

[y1yang0]

I've tried your patch on linux-x64. It passed all cds tests and also in dynamic archive mode by specifying -vmoptions:'-Dtest.dynamic.cds.archive=true -XX:+VerifySharedSpaces' and test group /test/hotspot/jtreg:hotspot_appcds_dynamic to the jtreg command line. It also passed the first 4 tiers of testing on Oracle supported platforms.

Besides, I've added a new dynamic cds test with -XX:+VerifySharedSpaces.

I've filed the following RFE for adding a test group for running CDS tests with -XX:+VerifySharedSpaces:
https://bugs.openjdk.java.net/browse/JDK-8264472

Looks good!

[yminqi]

LGTM.

[y1yang0]

Thanks @calvinccheung @yminqi for reviews.

/integrate

[openjdk]

@kelthuzadx
Your change (at version c4b27fd) is now ready to be sponsored by a Committer.

[calvinccheung]

/sponsor

[openjdk]

@calvinccheung @kelthuzadx Since your change was applied there have been 35 commits pushed to the master branch:

• 52d8a22: 8264054: Bad XMM performance on java.lang.MathBench.sqrtDouble
• 16acfaf: 8012229: [lcms] Improve performance of color conversion for images with alpha channel
• cb70ab0: 8263235: sanity/client/SwingSet/src/ColorChooserDemoTest.java failed throwing java.lang.NoClassDefFoundError
• e2ec997: 8263551: Provide shared lock-free FIFO queue implementation
• dec3447: 8264346: nullptr_t undefined in global namespace for clang+libstdc++
• 0fa3572: 8264489: Add more logging to LargeCopyWithMark.java
• f43d14a: 8264396: Use the blessed modifier order in jdk.internal.jvmstat
• 6225ae6: 8264466: Cut-paste error in InterfaceCalls JMH
• 40c3249: 8264149: BreakpointInfo::set allocates metaspace object in VM thread
• 999c134: 8264417: ParallelCompactData::region_offset should not accept pointers outside the current region
• ... and 25 more: https://git.openjdk.java.net/jdk/compare/bcdf4694e07178de7d218f0dc21bda1c92e8f456...master

Your commit was automatically rebased without conflicts.

Pushed as commit de495df.

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