GH-5347 make the ShaclSail more robust during shutdown()

[hmottestad]

GitHub issue resolved: #5347

Briefly describe the changes proposed in this PR:

---

PR Author Checklist (see the contributor guidelines for more details):

• my pull request is self-contained
• I've added tests for the changes I made
• I've applied code formatting (you can use mvn process-resources to format from the command line)
• I've squashed my commits where necessary
• every commit message starts with the issue number (GH-xxxx) followed by a meaningful description of the change

[hmottestad]

TODO

• Test for serial validation
• Test that actually fails SHACL validation
• Test for bulk validation

[Copilot]

Pull Request Overview

Enhance SHACL Sail shutdown robustness by adding interruption checks, tracking and cancelling in-progress validation tasks, and improving resource cleanup.

• Added thread-interruption guards across plan nodes and iterators to abort validation on shutdown
• Tracked and cancelled in-flight validation futures and shape validation containers in ShaclSailConnection
• Improved shutdown logic in ShaclSail, AbstractSailConnection, and AbstractSail to avoid resource leaks and hanging threads

Reviewed Changes

Copilot reviewed 27 out of 27 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
ShutdownDuringValidationTest.java	New parameterized tests for concurrent shutdown during validation
PrepareCommitTest.java	New tests for shutdown timing around prepare and commit
ConnectionsGroup.java	Catch UncheckedExecutionException when loading cache entries
ValidationResultIterator.java	Interrupt check in tuple iteration loop
ValidationTuple.java	Interrupt check in comparison methods
UnionNode.java	Early exit on interrupt and closed state
Sort.java	Added interrupt/closed checks and iterator cleanup
Select.java	Added interrupt close handling, cleaned up bindingSet
SparqlQueryParserCache.java	Unified exception catch, added logging for parse errors
ShapeValidationContainer.java	Track and force-close active ValidationResultIterator
ShaclValidator.java	Interruption check before building lazy report
ShaclSailConnection.java	Track and cancel validation futures; shutdown guards
ShaclSail.java	Executor shutdown improvements and isShutdown check
DelegatingSailSource.java	Null delegate guard
AbstractSailConnection.java	Adjusted close sequence and active-iteration tracking
AbstractSail.java	Interrupt and close active connections on shutdown
LookAheadIteration.java	Log and swallow stray NoSuchElementException in hasNext
FilterIteration.java	Interrupt guard in findNextElement

Comments suppressed due to low confidence (3)

core/sail/shacl/src/test/java/org/eclipse/rdf4j/sail/shacl/ShutdownDuringValidationTest.java:59

• The error message references benchmarkFiles/datagovbe-valid.ttl but the resource path is complexBenchmark/datagovbe-valid.ttl; please correct the path in the message.

			throw new RuntimeException("Could not load file: benchmarkFiles/datagovbe-valid.ttl", e);

core/sail/shacl/src/main/java/org/eclipse/rdf4j/sail/shacl/ast/SparqlQueryParserCache.java:58

• The logger identifier is not defined in this class, leading to a compile error. You should add a private static final Logger logger = LoggerFactory.getLogger(SparqlQueryParserCache.class); declaration or use an existing logger.

				logger.error("Error parsing query: \n{}", query, cause);

[Copilot]

[nitpick] The exception constructor is modifying the thread's interrupt flag as a side effect, which is unexpected. It's better to let callers decide when to interrupt the thread.

Suggested change

	Thread.currentThread().interrupt();
	}
	public InterruptedSailException() {
	super();
	Thread.currentThread().interrupt();
	}
	public InterruptedSailException() {
	super();

[Copilot]

[nitpick] Commented-out code remains in localHasNext. Please remove dead code or restore proper exception handling.

Suggested change

	// try {
	return bindingSet.hasNext();
	// } catch (NoSuchElementException e) {
	// // This can happen if the connection is closed while we are iterating.
	// // In that case, we just return false.
	// return false;
	// }
	try {
	return bindingSet.hasNext();
	} catch (NoSuchElementException e) {
	// This can happen if the connection is closed while we are iterating.
	// In that case, we just return false.
	return false;
	}