8267666: Add option to jcmd GC.heap_dump to use existing file

[RealCLanger]

Backport of the heap dump enhancement. CSR includes update releases.

Patch did not apply cleanly, I had to resolve/modify
src/hotspot/share/services/diagnosticCommand.cpp
src/hotspot/share/services/diagnosticCommand.hpp
src/hotspot/share/services/heapDumper.cpp
src/hotspot/share/services/heapDumper.hpp

Following files do not exist in 11u:
src/hotspot/share/services/heapDumperCompression.cpp
src/hotspot/share/services/heapDumperCompression.hpp
Changes had been made in heapDumper.cpp/heapDumper.hpp

I have built it on linuxx86_64 and verified that the modified test succeeds. Will also run it through SAP's test suite before merging.

---

Progress

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

Issue

• JDK-8267666: Add option to jcmd GC.heap_dump to use existing file

Reviewers

• Ralf Schmelter (@schmelter-sap - no project role)
• Goetz Lindenmaier (@GoeLin - Reviewer)
• Thomas Stuefe (@tstuefe - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.java.net/jdk11u-dev pull/131/head:pull/131
$ git checkout pull/131

Update a local copy of the PR:
$ git checkout pull/131
$ git pull https://git.openjdk.java.net/jdk11u-dev pull/131/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 131

View PR using the GUI difftool:
$ git pr show -t 131

Using diff file

Download this PR as a diff file:
https://git.openjdk.java.net/jdk11u-dev/pull/131.diff

[bridgekeeper]

👋 Welcome back clanger! 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]

This backport pull request has now been updated with issue from the original commit.

[mlbridge]

Webrevs

• 00: Full (65fe35d1)

[schmelter-sap]

Looks good to me.

[GoeLin]

LGTM

[openjdk]

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

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

8267666: Add option to jcmd GC.heap_dump to use existing file

Reviewed-by: rschmelter, goetz, stuefe

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

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[tstuefe]

+1

[AntonKozlov]

Don't we need https://bugs.openjdk.java.net/browse/JDK-8234510 to be backported as well? Just want to be sure, since I see DumpWriter::seek_to_offset in the source code, and it is used.

[schmelter-sap]

To be able to use the -overwrite flag for domain sockets or pipes this would be needed, but overwriting an existing file would work.

I had not backported my change to 11, because the diff between 15 and 11 was large and it wasn't a bugfix, so not strictly needed. But if there is interest, it should be possible.

[RealCLanger]

To be able to use the -overwrite flag for domain sockets or pipes this would be needed, but overwriting an existing file would work.

I had not backported my change to 11, because the diff between 15 and 11 was large and it wasn't a bugfix, so not strictly needed. But if there is interest, it should be possible.

Hm, together with this change actually https://bugs.openjdk.java.net/browse/JDK-8234510 seems more worthwhile to do. Maybe you want to look into bringing it to JDK11 now, @schmelter-sap? In any case, this backport seems to be good as is and does not need JDK-8234510 as a prerequisite, though its use is limited for the moment.

[schmelter-sap]

Hm, together with this change actually https://bugs.openjdk.java.net/browse/JDK-8234510 seems more worthwhile to do. Maybe you want to look into bringing it to JDK11 now, @schmelter-sap? In any case, this backport seems to be good as is and does not need JDK-8234510 as a prerequisite, though its use is limited for the moment.

Yes, it would make sense to downport it now, since we now have an actual use for it.

[buddyliao]

Hm, together with this change actually https://bugs.openjdk.java.net/browse/JDK-8234510 seems more worthwhile to do. Maybe you want to look into bringing it to JDK11 now, @schmelter-sap? In any case, this backport seems to be good as is and does not need JDK-8234510 as a prerequisite, though its use is limited for the moment.

Yes, it would make sense to downport it now, since we now have an actual use for it.

I had backport your patch(JDK-8234510 ) here #134
Would you help me to review it? Thank you.

[RealCLanger]

/integrate

[openjdk]

Going to push as commit 6762216.
Since your change was applied there have been 38 commits pushed to the master branch:

• 63c4ec2: 8259535: ECDSA SignatureValue do not always have the specified length
• 133eca0: 8235211: serviceability/attach/RemovingUnixDomainSocketTest.java fails with AttachNotSupportedException: Unable to open socket file
• 7501084: 8268965: TCP Connection Reset when connecting simple socket to SSL server
• d78e2be: 8227738: jvmti/DataDumpRequest/datadumpreq001 failed due to "exit code is 134"
• 8637f65: 8227815: Minimal VM: set_state is not a member of AttachListener
• f3098c4: 8225690: Multiple AttachListener threads can be created
• 2b3a641: 8245134: test/lib/jdk/test/lib/security/KeyStoreUtils.java should allow to specify aliases
• 8f49220: 8206350: java/util/Locale/bcp47u/SystemPropertyTests.java failed on Mac 10.13 with zh_CN and zh_TW locales.
• deba308: 8206083: Make tools/javac/api/T6265137.java robust to JDK version changes
• cbce000: Merge
• ... and 28 more: https://git.openjdk.java.net/jdk11u-dev/compare/23918db4b7e65797318ec5f5c5a452ec9d3ea0c5...master

Your commit was automatically rebased without conflicts.

[openjdk]

@RealCLanger Pushed as commit 6762216.

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