[FLINK-37159][runtime] Fix the test timeout by yielding Modifier thread

[showuon]

What is the purpose of the change

Fixing the MemoryManagerConcurrentModReleaseTest.testConcurrentModificationWhileReleasing timeout in AZP.
This test is testing concurrent segment modification while releasing. It creates 10k segments at the beginning and creates an additional thread to keep doing the segment modification, while the main thread is releasing the segments. During the releasing, if the segment is concurrently modified, the ConcurrentModificationException will be thrown and retry. So, this is a non-deterministic test that the concurrent change might happen forever and cause timeout exception.

To fix this issue, we can set a timeout, and after the timeout, we start to lower the priority of the modifier thread to let the release completes soon.

Brief change log

Fix the MemoryManagerConcurrentModReleaseTest.testConcurrentModificationWhileReleasing timeout in AZP.

Verifying this change

This change is already covered by existing tests, such as (please describe tests).

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): no
• The public API, i.e., is any changed class annotated with @Public(Evolving): no
• The serializers: no
• The runtime per-record code paths (performance sensitive): no
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Kubernetes/Yarn, ZooKeeper: no
• The S3 file system connector: no

Documentation

• Does this pull request introduce a new feature? no
• If yes, how is the feature documented? not applicable

[showuon]

@reswqa , please take a look. Thanks.

[davidradl]

nit: this code does not lower the thread priority, yield is just a hint to the scheduler that the current thread is willing to yield its current use of a processor.

[showuon]

@davidradl , thanks for the comment. I agree yield depends on the OS implementation. I changed to sleep(1) to force yield the CPU resource.

[flinkbot]

CI report:

• 6249c0a Azure: SUCCESS

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