Fiber refactorings

core/http/client/src/main/java/org/eclipse/rdf4j/http/client/SharedHttpClientSessionManager.java

@@ -164,18 +164,9 @@ public long getRetryInterval() {
 	 *--------------*/
 
 	public SharedHttpClientSessionManager() {
-		final ThreadFactory backingThreadFactory = Executors.defaultThreadFactory();
-
-		ExecutorService threadPoolExecutor = Executors.newCachedThreadPool((Runnable runnable) -> {
-			Thread thread = backingThreadFactory.newThread(runnable);
-			thread.setName(
-					String.format("rdf4j-SharedHttpClientSessionManager-%d", threadCount.getAndIncrement()));
-			thread.setDaemon(true);
-			return thread;
-		});
-
-		Integer corePoolSize = Integer.getInteger(CORE_POOL_SIZE_PROPERTY, 1);
-		((ThreadPoolExecutor) threadPoolExecutor).setCorePoolSize(corePoolSize);
+		ExecutorService threadPoolExecutor = Executors.newThreadPerTaskExecutor(Thread.ofVirtual()
+				.name("rdf4j-SharedHttpClientSessionManager-", threadCount.getAndIncrement())
+				.factory());
 		this.executor = threadPoolExecutor;
 	}
 

core/repository/sparql/src/main/java/org/eclipse/rdf4j/repository/sparql/query/SPARQLOperation.java

@@ -35,7 +35,7 @@
 @Deprecated
 public abstract class SPARQLOperation implements Operation {
 
-	private static final Executor executor = Executors.newCachedThreadPool();
+	private static final Executor executor = Executors.newVirtualThreadPerTaskExecutor();
 
 	protected HttpClient client;
 

core/sail/api/src/test/java/org/eclipse/rdf4j/common/concurrent/locks/benchmarks/BaseLockManagerBenchmark.java

@@ -33,7 +33,7 @@ public class BaseLockManagerBenchmark {
 	public void setUp() {
 		Logger root = (Logger) LoggerFactory.getLogger(ReadPrefReadWriteLockManager.class.getName());
 		root.setLevel(ch.qos.logback.classic.Level.ERROR);
-		executorService = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors() * 2);
+		executorService = Executors.newVirtualThreadPerTaskExecutor();
 	}
 
 	@TearDown(Level.Trial)

core/sail/lmdb/src/main/java/org/eclipse/rdf4j/sail/lmdb/LmdbSailStore.java

@@ -64,7 +64,7 @@ class LmdbSailStore implements SailStore {
 
 	private final ValueStore valueStore;
 
-	private final ExecutorService tripleStoreExecutor = Executors.newCachedThreadPool();
+	private final ExecutorService tripleStoreExecutor = Executors.newVirtualThreadPerTaskExecutor();
 	private final CircularBuffer<Operation> opQueue = new CircularBuffer<>(1024);
 	private volatile Throwable tripleStoreException;
 	private final AtomicBoolean running = new AtomicBoolean(false);

core/sail/lmdb/src/test/java/org/eclipse/rdf4j/sail/lmdb/benchmark/OverflowBenchmarkConcurrent.java

@@ -109,7 +109,7 @@ public void manyConcurrentTransactions() throws IOException {
 		SailRepository sailRepository = new SailRepository(new NotifySailWrapper(new NotifySailWrapper(
 				new NotifySailWrapper(
 						new NotifySailWrapper(new NotifySailWrapper(new LmdbStore(temporaryFolder)))))));
-		ExecutorService executorService = Executors.newFixedThreadPool(10);
+		ExecutorService executorService = Executors.newVirtualThreadPerTaskExecutor();
 
 		try {
 

core/sail/memory/src/test/java/org/eclipse/rdf4j/sail/memory/benchmark/BaseConcurrentBenchmark.java

@@ -42,7 +42,7 @@ public void setup() throws Exception {
 		if (executorService != null) {
 			executorService.shutdownNow();
 		}
-		executorService = Executors.newFixedThreadPool(8);
+		executorService = Executors.newVirtualThreadPerTaskExecutor();
 	}
 
 	@TearDown(Level.Trial)

core/sail/nativerdf/src/test/java/org/eclipse/rdf4j/sail/nativerdf/benchmark/OverflowBenchmarkConcurrent.java

@@ -101,7 +101,7 @@ public void manyConcurrentTransactions() throws IOException {
 		SailRepository sailRepository = new SailRepository(new NotifySailWrapper(new NotifySailWrapper(
 				new NotifySailWrapper(
 						new NotifySailWrapper(new NotifySailWrapper(new NativeStore(temporaryFolder)))))));
-		ExecutorService executorService = Executors.newFixedThreadPool(10);
+		ExecutorService executorService = Executors.newVirtualThreadPerTaskExecutor();
 
 		try {
 

core/sail/shacl/src/main/java/org/eclipse/rdf4j/sail/shacl/ShaclSail.java

@@ -252,13 +252,12 @@ public void setBaseSail(Sail baseSail) {
 	@Experimental
 	protected RevivableExecutorService getExecutorService() {
 		return new RevivableExecutorService(
-				() -> Executors.newFixedThreadPool(AVAILABLE_PROCESSORS,
+				() -> Executors.newThreadPerTaskExecutor(
 						r -> {
-							Thread t = Executors.defaultThreadFactory().newThread(r);
+							Thread t = Thread.ofVirtual().factory().newThread(r);
 							// this thread pool does not need to stick around if the all other threads are done, because
 							// it is only used for SHACL validation and if all other threads have ended then there would
 							// be no thread to receive the validation results.
-							t.setDaemon(true);
 							t.setName("ShaclSail validation thread " + t.getId());
 							return t;
 						}));

tools/federation/src/main/java/org/eclipse/rdf4j/federated/FederationManager.java

@@ -92,6 +92,8 @@ public FederationManager() {
 	public void init(FedX federation, FederationContext federationContext) {
 		this.federation = federation;
 		this.federationContext = federationContext;
+		// Refactoring this causes ServicesTest to hang forever
+		// (https://github.com/ponder-lab/rdf4j/actions/runs/10239404923/job/28324948852?pr=2)
 		this.executor = Executors.newCachedThreadPool(new NamingThreadFactory("FedX Executor"));
 
 		updateFederationType();

tools/federation/src/main/java/org/eclipse/rdf4j/federated/evaluation/concurrent/ControlledWorkerScheduler.java

@@ -117,7 +117,8 @@ public int getNumberOfTasks() {
 	}
 
 	private ExecutorService createExecutorService() {
-
+		// Refactoring this causes ServicesTest to hang forever
+		// (https://github.com/ponder-lab/rdf4j/actions/runs/10239404923/job/28324948852?pr=2)
 		ThreadPoolExecutor executor = new ThreadPoolExecutor(nWorkers, nWorkers, 60L, TimeUnit.SECONDS, _taskQueue,
 				new NamingThreadFactory(name));
 		executor.allowCoreThreadTimeOut(true);

tools/federation/src/main/java/org/eclipse/rdf4j/federated/evaluation/concurrent/NamingThreadFactory.java

@@ -29,6 +29,8 @@ public NamingThreadFactory(String baseName) {
 
 	@Override
 	public Thread newThread(Runnable r) {
+		// Refactoring this causes ServicesTest to hang forever
+		// (https://github.com/ponder-lab/rdf4j/actions/runs/10239404923/job/28324948852?pr=2)
 		Thread t = Executors.defaultThreadFactory().newThread(r);
 		t.setName(baseName + "-" + nextThreadId.incrementAndGet());
 		return t;

tools/federation/src/test/java/org/eclipse/rdf4j/federated/performance/RemoteRepositoryTest.java

@@ -40,7 +40,7 @@ public class RemoteRepositoryTest {
 	 */
 	public static void main(String[] args) throws Exception {
 
-		ExecutorService executor = Executors.newFixedThreadPool(30);
+		ExecutorService executor = Executors.newVirtualThreadPerTaskExecutor();
 
 		Repository repo = new HTTPRepository("http://10.212.10.29:8081/openrdf-sesame", "drugbank");
 

tools/federation/src/test/java/org/eclipse/rdf4j/federated/performance/RepositoryPerformance.java

@@ -55,7 +55,7 @@ private static abstract class PerformanceBase {
 
 		private static final int MAX_INSTANCES = Integer.MAX_VALUE;
 		private static final int N_QUERIES = 100;
-		private final ExecutorService executor = Executors.newFixedThreadPool(30);
+		private final ExecutorService executor = Executors.newVirtualThreadPerTaskExecutor();
 
 		private final IRI type;
 

tools/federation/src/test/java/org/eclipse/rdf4j/federated/performance/SparqlRepositoryTest.java

@@ -29,7 +29,7 @@ public class SparqlRepositoryTest {
 
 	public static void main(String[] args) throws Exception {
 
-		ExecutorService executor = Executors.newFixedThreadPool(20);
+		ExecutorService executor = Executors.newVirtualThreadPerTaskExecutor();
 
 		SPARQLRepository repo = new SPARQLRepository("http://dbpedia.org/sparql");
 		repo.init();

tools/server/src/test/java/org/eclipse/rdf4j/http/server/ProtocolIT.java

@@ -45,6 +45,7 @@
 import org.apache.http.impl.client.HttpClients;
 import org.apache.http.message.BasicNameValuePair;
 import org.eclipse.rdf4j.common.io.IOUtil;
+import org.eclipse.rdf4j.federated.evaluation.concurrent.NamingThreadFactory;
 import org.eclipse.rdf4j.http.protocol.Protocol;
 import org.eclipse.rdf4j.model.Namespace;
 import org.eclipse.rdf4j.model.ValueFactory;
@@ -61,7 +62,6 @@
 import org.junit.jupiter.api.Test;
 
 import com.google.common.collect.Sets;
-import com.google.common.util.concurrent.ThreadFactoryBuilder;
 import com.opencsv.CSVReader;
 
 public class ProtocolIT {
@@ -442,8 +442,7 @@ public void testConcurrentNamespaceUpdates() throws Exception {
 		// "Test-NativeStore");
 		String repositoryLocation = TestServer.REPOSITORY_URL;
 
-		ExecutorService threadPool = Executors.newFixedThreadPool(20,
-				new ThreadFactoryBuilder().setNameFormat("rdf4j-protocoltest-%d").build());
+		ExecutorService threadPool = Executors.newThreadPerTaskExecutor(new NamingThreadFactory("rdf4j-protocoltest-"));
 
 		for (int count = 0; count < limitCount; count++) {
 			final int number = count;

tools/workbench/src/main/java/org/eclipse/rdf4j/workbench/commands/SummaryServlet.java

@@ -34,7 +34,7 @@
 
 public class SummaryServlet extends TransformationServlet {
 
-	private final ExecutorService executorService = Executors.newCachedThreadPool();
+	private final ExecutorService executorService = Executors.newVirtualThreadPerTaskExecutor();
 
 	private static final Logger LOGGER = LoggerFactory.getLogger(SummaryServlet.class);