8283930: IGV: add toggle button to show/hide empty blocks in CFG view

[robcasloz]

This change introduces a toggle button to show or hide empty blocks in the control-flow graph view. Showing empty blocks can be useful to provide context, for example when extracting a small set of nodes. On the other hand, for large graphs it can be preferable to hide empty blocks so that the extracted nodes can be localized more easily. Since both modes have advantages or disadvantages, this change gives the user the option to quickly switch between them. The toggle button is only active in the control-flow graph view: empty blocks in the clustered sea-of-nodes view are never shown because they would be disconnected and hence would not provide any additional context.

Testing

• Tested manually on a small selection of graphs.

• Tested automatically viewing thousands of graphs with random node subsets extracted, in all four combinations of showing/hiding empty blocks and showing/hiding neighbors of extracted nodes. The automatic test is performed by instrumenting IGV to view graphs and extract nodes randomly as the graphs are loaded, and running java -Xcomp -XX:-TieredCompilation -XX:PrintIdealGraphLevel=4.

Screenshots

• New toggle button:

• Example control-flow graph with extracted node (85) and shown empty blocks:

Example control-flow graph with the same extracted node and hidden empty blocks:

---

Progress

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

Issue

• JDK-8283930: IGV: add toggle button to show/hide empty blocks in CFG view

Reviewers

• Vladimir Kozlov (@vnkozlov - Reviewer) ⚠️ Review applies to 13f5b4a
• Christian Hagedorn (@chhagedorn - Reviewer)

Reviewing

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Update a local copy of the PR:
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$ git pull https://git.openjdk.java.net/jdk pull/8128/head

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https://git.openjdk.java.net/jdk/pull/8128.diff

[bridgekeeper]

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[openjdk]

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[mlbridge]

Webrevs

• 01: Full - Incremental (14b0ff34)
• 00: Full (13f5b4a7)

[vnkozlov]

Good feature

[openjdk]

@robcasloz 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:

8283930: IGV: add toggle button to show/hide empty blocks in CFG view

Reviewed-by: kvn, chagedorn

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 56 new commits pushed to the master branch:

• a445ecd: 8284297: Move FILE_AND_LINE to a platform independent header
• 003aa2e: 8282043: IGV: speed up schedule approximation
• 8c18705: 8284433: Cleanup Disassembler::find_prev_instr() on all platforms
• e572a52: 8280511: AArch64: Combine shift and negate to a single instruction
• de9596c: 8284495: [testbug] Adapt nsk tests to the RISC-V platform
• d4a4884: 8284458: CodeHeapState::aggregate() leaks blob_name
• e98c32d: 8284043: com/sun/jdi/MethodInvokeWithTraceOnTest.java failing with com.sun.jdi.ObjectCollectedException
• 343e5f0: 8282040: Remove unnecessary check made obsolete by JDK-8261941
• d6f01e9: 8234128: jarsigner will not show not-signed-by-alias warning if an intermediate cert is in this keystore
• 5bafcfd: 8284444: Sting typo
• ... and 46 more: https://git.openjdk.java.net/jdk/compare/9d200d6e7a3399d2b5448c27e40eb3b4d14a02df...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.

[robcasloz]

Good feature

Thanks for reviewing, Vladimir!

[chhagedorn]

That looks nice! Thanks for following up with this RFE which I think is especially valuable for large graphs.

[robcasloz]

Thanks for reviewing, Christian! I just applied your suggested refactorings.

[chhagedorn]

Thanks, looks good!

[robcasloz]

/integrate

[openjdk]

Going to push as commit 6028181.
Since your change was applied there have been 56 commits pushed to the master branch:

• a445ecd: 8284297: Move FILE_AND_LINE to a platform independent header
• 003aa2e: 8282043: IGV: speed up schedule approximation
• 8c18705: 8284433: Cleanup Disassembler::find_prev_instr() on all platforms
• e572a52: 8280511: AArch64: Combine shift and negate to a single instruction
• de9596c: 8284495: [testbug] Adapt nsk tests to the RISC-V platform
• d4a4884: 8284458: CodeHeapState::aggregate() leaks blob_name
• e98c32d: 8284043: com/sun/jdi/MethodInvokeWithTraceOnTest.java failing with com.sun.jdi.ObjectCollectedException
• 343e5f0: 8282040: Remove unnecessary check made obsolete by JDK-8261941
• d6f01e9: 8234128: jarsigner will not show not-signed-by-alias warning if an intermediate cert is in this keystore
• 5bafcfd: 8284444: Sting typo
• ... and 46 more: https://git.openjdk.java.net/jdk/compare/9d200d6e7a3399d2b5448c27e40eb3b4d14a02df...master

Your commit was automatically rebased without conflicts.

[openjdk]

@robcasloz Pushed as commit 6028181.

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