8299813: java/nio/channels/DatagramChannel/Disconnect.java fails with jtreg test timeout due to lost datagram

[dfuch]

Please find here a simple fix to solve an intermittent failure in java/nio/channels/DatagramChannel/Disconnect.java

On some platform, the underlying system may allow two datagram sockets to bind to the same port, if one of them uses the wildcard address and the other doesn't.

What happens here is that during DC:connect, if the socket is unbound, it will get bound to the wildcard.
From time to time, this results into binding to the same port that the server is using in the test.
When that happens, datagram sent to the connected server may get misrouted and may not get delivered, and the call server::receive may block forever.

This change does two things:

1. explicitly bind the server to the loopback address instead of InetAddress.getLocalHost()
2. skip the receive part of the test if the client local address obtained after connecting uses the same port than the server.

This is rare, and skipping the receive part in that case does not invalidate the test.

---

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Issue

• JDK-8299813: java/nio/channels/DatagramChannel/Disconnect.java fails with jtreg test timeout due to lost datagram (Bug - P4)

Reviewers

• Aleksei Efimov (@AlekseiEfimov - Reviewer)

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[bridgekeeper]

👋 Welcome back dfuchs! 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]

@dfuch 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:

8299813: java/nio/channels/DatagramChannel/Disconnect.java fails with jtreg test timeout due to lost datagram

Reviewed-by: aefimov

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 69 new commits pushed to the master branch:

• c798316: 8269657: Test java/nio/channels/DatagramChannel/Loopback.java failed: Unexpected message
• 99d2bbf: 8334433: jshell.exe runs an executable test.exe on startup
• 6f4ddc2: 8335142: compiler/c1/TestTraceLinearScanLevel.java occasionally times out with -Xcomp
• 3b3a19e: 8335314: Problem list compiler/uncommontrap/DeoptReallocFailure.java
• d457609: 8319947: Recursive lightweight locking: s390x implementation
• c47a0e0: 8334147: Shenandoah: Avoid taking lock for disabled free set logging
• 308a812: 8334645: Un-problemlist vmTestbase/nsk/sysdict/vm/stress/chain/chain007/chain007.java
• b4df380: 8334763: --enable-asan: assert(_thread->is_in_live_stack((address)this)) failed: not on stack?
• cd46c87: 8334843: RISC-V: Fix wraparound checking for r_array_index in lookup_secondary_supers_table_slow_path
• 4e8cbf8: 8335134: Test com/sun/jdi/BreakpointOnClassPrepare.java timeout
• ... and 59 more: https://git.openjdk.org/jdk/compare/55c796946158aab1d019a57b77a33441d7b13065...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.

[openjdk]

@dfuch The following label will be automatically applied to this pull request:

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[mlbridge]

Webrevs

• 00: Full (6422faa4)

[AlekseiEfimov]

The changes look good to me.

[dfuch]

Thanks @AlekseiEfimov ! If I don't receive further feedback I will integrate shortly

[dfuch]

/integrate

[openjdk]

Going to push as commit 49eb00d.
Since your change was applied there have been 70 commits pushed to the master branch:

• 8ec378a: 8277949: (dc) java/nio/channels/DatagramChannel/AdaptorBasic.java failed in timeout
• c798316: 8269657: Test java/nio/channels/DatagramChannel/Loopback.java failed: Unexpected message
• 99d2bbf: 8334433: jshell.exe runs an executable test.exe on startup
• 6f4ddc2: 8335142: compiler/c1/TestTraceLinearScanLevel.java occasionally times out with -Xcomp
• 3b3a19e: 8335314: Problem list compiler/uncommontrap/DeoptReallocFailure.java
• d457609: 8319947: Recursive lightweight locking: s390x implementation
• c47a0e0: 8334147: Shenandoah: Avoid taking lock for disabled free set logging
• 308a812: 8334645: Un-problemlist vmTestbase/nsk/sysdict/vm/stress/chain/chain007/chain007.java
• b4df380: 8334763: --enable-asan: assert(_thread->is_in_live_stack((address)this)) failed: not on stack?
• cd46c87: 8334843: RISC-V: Fix wraparound checking for r_array_index in lookup_secondary_supers_table_slow_path
• ... and 60 more: https://git.openjdk.org/jdk/compare/55c796946158aab1d019a57b77a33441d7b13065...master

Your commit was automatically rebased without conflicts.

[openjdk]

@dfuch Pushed as commit 49eb00d.

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