Use resource

pom.xml

@@ -90,7 +90,7 @@
 			<dependency>
 				<groupId>io.projectreactor</groupId>
 				<artifactId>reactor-bom</artifactId>
-				<version>2020.0.19</version>
+				<version>2020.0.20</version>
 				<type>pom</type>
 				<scope>import</scope>
 			</dependency>
@@ -102,7 +102,7 @@
       <artifactId>reactor-tools</artifactId>
       <classifier>original</classifier>
       <scope>runtime</scope>
-      <version>3.4.18</version>
+      <version>3.4.19</version>
     </dependency>
 		<dependency>
 			<groupId>com.google.guava</groupId>
@@ -157,12 +157,28 @@
 			<artifactId>junit-jupiter-params</artifactId>
 			<version>${junit.jupiter.version}</version>
 			<scope>test</scope>
+      <exclusions>
+        <exclusion>
+          <groupId>org.mockito</groupId>
+          <artifactId>mockito-core</artifactId>
+        </exclusion>
+      </exclusions>
 		</dependency>
 		<dependency>
 			<groupId>org.assertj</groupId>
 			<artifactId>assertj-core</artifactId>
 			<version>3.23.1</version>
 			<scope>test</scope>
+      <exclusions>
+        <exclusion>
+          <groupId>org.mockito</groupId>
+          <artifactId>mockito-core</artifactId>
+        </exclusion>
+        <exclusion>
+          <groupId>net.bytebuddy</groupId>
+          <artifactId>byte-buddy</artifactId>
+        </exclusion>
+      </exclusions>
 		</dependency>
 		<!-- This will get hamcrest-core automatically -->
 		<dependency>
@@ -579,6 +595,25 @@
 					</execution>
 				</executions>
 			</plugin>
+      <plugin>
+        <groupId>net.bytebuddy</groupId>
+        <artifactId>byte-buddy-maven-plugin</artifactId>
+        <version>1.12.13-20220629</version>
+        <executions>
+          <execution>
+            <goals>
+              <goal>transform</goal>
+            </goals>
+          </execution>
+        </executions>
+        <configuration>
+          <transformations>
+            <transformation>
+              <plugin>reactor.tools.agent.ReactorDebugByteBuddyPlugin</plugin>
+            </transformation>
+          </transformations>
+        </configuration>
+      </plugin>
 		</plugins>
 		<pluginManagement>
 			<plugins>
@@ -613,18 +648,6 @@
 						</lifecycleMappingMetadata>
 					</configuration>
 				</plugin>
-        <plugin>
-          <groupId>net.bytebuddy</groupId>
-          <artifactId>byte-buddy-maven-plugin</artifactId>
-          <version>1.12.10</version>
-          <configuration>
-            <transformations>
-              <transformation>
-                <plugin>reactor.tools.agent.ReactorDebugByteBuddyPlugin</plugin>
-              </transformation>
-            </transformations>
-          </configuration>
-        </plugin>
 			</plugins>
 		</pluginManagement>
 	</build>

src/main/java/it/cavallium/dbengine/client/LuceneIndex.java

@@ -66,7 +66,7 @@ public interface LuceneIndex<T, U> extends LLSnapshottable {
 
 	boolean isLowMemoryMode();
 
-	Mono<Void> close();
+	void close();
 
 	Mono<Void> flush();
 

src/main/java/it/cavallium/dbengine/client/LuceneIndexImpl.java

@@ -109,9 +109,10 @@ public class LuceneIndexImpl<T, U> implements LuceneIndex<T, U> {
 						mltDocumentFields
 				)
 				.collectList()
-				.flatMap(shards -> mergeResults(queryParams, shards))
+				.mapNotNull(shards -> mergeResults(queryParams, shards))
 				.map(this::mapResults)
-				.single();
+				.defaultIfEmpty(Hits.empty())
+				.doOnDiscard(SimpleResource.class, SimpleResource::close);
 	}
 
 	@Override
@@ -122,11 +123,10 @@ public class LuceneIndexImpl<T, U> implements LuceneIndex<T, U> {
 						indicizer.getKeyFieldName()
 				)
 				.collectList()
-				.flatMap(shards -> mergeResults(queryParams, shards))
+				.mapNotNull(shards -> mergeResults(queryParams, shards))
 				.map(this::mapResults)
 				.defaultIfEmpty(Hits.empty())
-				.doOnDiscard(LLSearchResultShard.class, SimpleResource::close)
+				.doOnDiscard(SimpleResource.class, SimpleResource::close);
-				.doOnDiscard(Hits.class, SimpleResource::close);
 	}
 
 	@Override
@@ -162,8 +162,8 @@ public class LuceneIndexImpl<T, U> implements LuceneIndex<T, U> {
 	}
 
 	@Override
-	public Mono<Void> close() {
+	public void close() {
-		return luceneIndex.close();
+		luceneIndex.close();
 	}
 
 	/**
@@ -202,41 +202,40 @@ public class LuceneIndexImpl<T, U> implements LuceneIndex<T, U> {
 		return luceneIndex.releaseSnapshot(snapshot);
 	}
 
-	private static Mono<LLSearchResultShard> mergeResults(ClientQueryParams queryParams,
+	@Nullable
+	private static LLSearchResultShard mergeResults(ClientQueryParams queryParams,
 			List<LLSearchResultShard> shards) {
 		if (shards.size() == 0) {
-			return Mono.empty();
+			return null;
 		} else if (shards.size() == 1) {
-			return Mono.just(shards.get(0));
+			return shards.get(0);
 		}
-		return Mono.fromCallable(() -> {
+		TotalHitsCount count = null;
-			TotalHitsCount count = null;
+		ObjectArrayList<Flux<LLKeyScore>> results = new ObjectArrayList<>(shards.size());
-			ObjectArrayList<Flux<LLKeyScore>> results = new ObjectArrayList<>(shards.size());
+		ObjectArrayList<SimpleResource> resources = new ObjectArrayList<>(shards.size());
-			ObjectArrayList<SimpleResource> resources = new ObjectArrayList<>(shards.size());
+		for (LLSearchResultShard shard : shards) {
-			for (LLSearchResultShard shard : shards) {
+			if (count == null) {
-				if (count == null) {
+				count = shard.totalHitsCount();
-					count = shard.totalHitsCount();
-				} else {
-					count = LuceneUtils.sum(count, shard.totalHitsCount());
-				}
-				var maxLimit = queryParams.offset() + queryParams.limit();
-				results.add(shard.results().take(maxLimit, true));
-				resources.add(shard);
-			}
-			Objects.requireNonNull(count);
-			Flux<LLKeyScore> resultsFlux;
-			if (results.size() == 0) {
-				resultsFlux = Flux.empty();
-			} else if (results.size() == 1) {
-				resultsFlux = results.get(0);
 			} else {
-				resultsFlux = Flux.merge(results);
+				count = LuceneUtils.sum(count, shard.totalHitsCount());
+			}
+			var maxLimit = queryParams.offset() + queryParams.limit();
+			results.add(shard.results().take(maxLimit, true));
+			resources.add(shard);
+		}
+		Objects.requireNonNull(count);
+		Flux<LLKeyScore> resultsFlux;
+		if (results.size() == 0) {
+			resultsFlux = Flux.empty();
+		} else if (results.size() == 1) {
+			resultsFlux = results.get(0);
+		} else {
+			resultsFlux = Flux.merge(results);
+		}
+		return new LLSearchResultShard(resultsFlux, count, () -> {
+			for (var resource : resources) {
+				resource.close();
 			}
-			return new LLSearchResultShard(resultsFlux, count, () -> {
-				for (var resource : resources) {
-					resource.close();
-				}
-			});
 		});
 	}
 }

src/main/java/it/cavallium/dbengine/database/LLEntry.java

@@ -6,6 +6,7 @@ import io.netty5.buffer.api.Owned;
 import io.netty5.buffer.api.Resource;
 import io.netty5.buffer.api.Send;
 import io.netty5.buffer.api.internal.ResourceSupport;
+import it.cavallium.dbengine.utils.SimpleResource;
 import java.util.Objects;
 import java.util.StringJoiner;
 import org.apache.logging.log4j.LogManager;
@@ -13,7 +14,7 @@ import org.apache.logging.log4j.Logger;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
-public class LLEntry implements SafeCloseable {
+public class LLEntry extends SimpleResource implements SafeCloseable {
 
 	private static final Logger logger = LogManager.getLogger(LLEntry.class);
 	private Buffer key;
@@ -91,7 +92,7 @@ public class LLEntry implements SafeCloseable {
 	}
 
 	@Override
-	public void close() {
+	protected void onClose() {
 		try {
 			if (key != null && key.isAccessible()) {
 				key.close();

src/main/java/it/cavallium/dbengine/database/LLLuceneIndex.java

@@ -15,7 +15,7 @@ import org.jetbrains.annotations.Nullable;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
-public interface LLLuceneIndex extends LLSnapshottable {
+public interface LLLuceneIndex extends LLSnapshottable, SafeCloseable {
 
 	String getLuceneIndexName();
 
@@ -74,8 +74,6 @@ public interface LLLuceneIndex extends LLSnapshottable {
 
 	boolean isLowMemoryMode();
 
-	Mono<Void> close();
-
 	/**
 	 * Flush writes to disk.
 	 * This does not commit, it syncs the data to the disk

src/main/java/it/cavallium/dbengine/database/LLMultiLuceneIndex.java

@@ -193,9 +193,9 @@ public class LLMultiLuceneIndex implements LLLuceneIndex {
 	}
 
 	@Override
-	public Mono<Void> close() {
+	public void close() {
-		Iterable<Mono<Void>> it = () -> luceneIndicesSet.stream().map(LLLuceneIndex::close).iterator();
+		Iterable<Mono<Void>> it = () -> luceneIndicesSet.stream().map(e -> Mono.<Void>fromRunnable(e::close)).iterator();
-		return Mono.whenDelayError(it);
+		Mono.whenDelayError(it).block();
 	}
 
 	@Override

src/main/java/it/cavallium/dbengine/database/LLUtils.java

@@ -25,6 +25,7 @@ import it.cavallium.dbengine.lucene.RandomSortField;
 import it.cavallium.dbengine.utils.SimpleResource;
 import java.io.Closeable;
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.nio.ByteBuffer;
 import java.nio.charset.Charset;
 import java.util.ArrayList;
@@ -947,13 +948,13 @@ public class LLUtils {
 		} else if (next instanceof LLIndexSearcher searcher) {
 			try {
 				searcher.close();
-			} catch (IOException e) {
+			} catch (UncheckedIOException e) {
 				logger.error("Failed to close searcher {}", searcher, e);
 			}
 		} else if (next instanceof LLIndexSearchers searchers) {
 			try {
 				searchers.close();
-			} catch (IOException e) {
+			} catch (UncheckedIOException e) {
 				logger.error("Failed to close searchers {}", searchers, e);
 			}
 		} else if (next instanceof Optional<?> optional) {

src/main/java/it/cavallium/dbengine/database/disk/CachedIndexSearcherManager.java

@@ -9,6 +9,7 @@ import it.cavallium.dbengine.database.LLSnapshot;
 import it.cavallium.dbengine.database.LLUtils;
 import it.cavallium.dbengine.utils.SimpleResource;
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.lang.ref.Cleaner;
 import java.time.Duration;
 import java.util.concurrent.ExecutorService;
@@ -28,6 +29,7 @@ import org.apache.lucene.store.AlreadyClosedException;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import it.cavallium.dbengine.utils.ShortNamedThreadFactory;
+import reactor.core.Disposable;
 import reactor.core.publisher.Mono;
 import reactor.core.publisher.Sinks;
 import reactor.core.publisher.Sinks.Empty;
@@ -35,7 +37,7 @@ import reactor.core.scheduler.Scheduler;
 import reactor.core.scheduler.Schedulers;
 
 // todo: deduplicate code between Cached and Simple searcher managers
-public class CachedIndexSearcherManager implements IndexSearcherManager {
+public class CachedIndexSearcherManager extends SimpleResource implements IndexSearcherManager {
 
 	private static final Logger LOG = LogManager.getLogger(SimpleIndexSearcherManager.class);
 	private static final ExecutorService SEARCH_EXECUTOR = Executors.newFixedThreadPool(
@@ -57,10 +59,7 @@ public class CachedIndexSearcherManager implements IndexSearcherManager {
 
 	private final LoadingCache<LLSnapshot, Mono<LLIndexSearcher>> cachedSnapshotSearchers;
 	private final Mono<LLIndexSearcher> cachedMainSearcher;
-
+	private final Disposable refreshSubscription;
-	private final AtomicBoolean closeRequested = new AtomicBoolean();
-	private final Empty<Void> closeRequestedMono = Sinks.empty();
-	private final Mono<Void> closeMono;
 
 	public CachedIndexSearcherManager(IndexWriter indexWriter,
 			@Nullable SnapshotsManager snapshotsManager,
@@ -76,8 +75,7 @@ public class CachedIndexSearcherManager implements IndexSearcherManager {
 
 		this.searcherManager = new SearcherManager(indexWriter, applyAllDeletes, writeAllDeletes, SEARCHER_FACTORY);
 
-		Empty<Void> refresherClosed = Sinks.empty();
+		this.refreshSubscription = Mono
-		var refreshSubscription = Mono
 				.fromRunnable(() -> {
 					try {
 						maybeRefresh();
@@ -85,11 +83,9 @@ public class CachedIndexSearcherManager implements IndexSearcherManager {
 						LOG.error("Failed to refresh the searcher manager", ex);
 					}
 				})
-				.subscribeOn(luceneHeavyTasksScheduler)
+				.subscribeOn(uninterruptibleScheduler(luceneHeavyTasksScheduler))
 				.publishOn(Schedulers.parallel())
 				.repeatWhen(s -> s.delayElements(queryRefreshDebounceTime))
-				.takeUntilOther(closeRequestedMono.asMono())
-				.doAfterTerminate(refresherClosed::tryEmitEmpty)
 				.transform(LLUtils::handleDiscard)
 				.subscribe();
 
@@ -104,91 +100,52 @@ public class CachedIndexSearcherManager implements IndexSearcherManager {
 					}
 				});
 		this.cachedMainSearcher = this.generateCachedSearcher(null);
-
-		this.closeMono = Mono
-				.fromRunnable(() -> {
-					LOG.debug("Closing IndexSearcherManager...");
-					this.closeRequested.set(true);
-					this.closeRequestedMono.tryEmitEmpty();
-					refreshSubscription.dispose();
-				})
-				.then(refresherClosed.asMono())
-				.then(Mono.<Void>fromRunnable(() -> {
-					LOG.debug("Closed IndexSearcherManager");
-					LOG.debug("Closing refreshes...");
-					long initTime = System.nanoTime();
-					while (activeRefreshes.get() > 0 && (System.nanoTime() - initTime) <= 15000000000L) {
-						LockSupport.parkNanos(50000000);
-					}
-					LOG.debug("Closed refreshes...");
-					LOG.debug("Closing active searchers...");
-					initTime = System.nanoTime();
-					while (activeSearchers.get() > 0 && (System.nanoTime() - initTime) <= 15000000000L) {
-						LockSupport.parkNanos(50000000);
-					}
-					LOG.debug("Closed active searchers");
-					LOG.debug("Stopping searcher executor...");
-					cachedSnapshotSearchers.invalidateAll();
-					cachedSnapshotSearchers.cleanUp();
-					SEARCH_EXECUTOR.shutdown();
-					try {
-						//noinspection BlockingMethodInNonBlockingContext
-						if (!SEARCH_EXECUTOR.awaitTermination(15, TimeUnit.SECONDS)) {
-							SEARCH_EXECUTOR.shutdownNow();
-						}
-					} catch (InterruptedException e) {
-						LOG.error("Failed to stop executor", e);
-					}
-					LOG.debug("Stopped searcher executor");
-				}).subscribeOn(uninterruptibleScheduler(Schedulers.boundedElastic())))
-				.publishOn(Schedulers.parallel())
-				.cache();
 	}
 
 	private Mono<LLIndexSearcher> generateCachedSearcher(@Nullable LLSnapshot snapshot) {
 		return Mono.fromCallable(() -> {
-			if (closeRequested.get()) {
+					if (isClosed()) {
-				return null;
+						return null;
-			}
-			activeSearchers.incrementAndGet();
-			try {
-				IndexSearcher indexSearcher;
-				boolean fromSnapshot;
-				if (snapshotsManager == null || snapshot == null) {
-					indexSearcher = searcherManager.acquire();
-					fromSnapshot = false;
-				} else {
-					//noinspection resource
-					indexSearcher = snapshotsManager.resolveSnapshot(snapshot).getIndexSearcher(SEARCH_EXECUTOR);
-					fromSnapshot = true;
-				}
-				indexSearcher.setSimilarity(similarity);
-				assert indexSearcher.getIndexReader().getRefCount() > 0;
-				var closed = new AtomicBoolean();
-				LLIndexSearcher llIndexSearcher;
-				if (fromSnapshot) {
-					llIndexSearcher = new SnapshotIndexSearcher(indexSearcher, closed);
-				} else {
-					llIndexSearcher = new MainIndexSearcher(indexSearcher, closed);
-				}
-				SimpleResource.CLEANER.register(llIndexSearcher, () -> {
-					if (closed.compareAndSet(false, true)) {
-						LOG.warn("An index searcher was not closed!");
-						if (!fromSnapshot) {
-							try {
-								searcherManager.release(indexSearcher);
-							} catch (IOException e) {
-								LOG.error("Failed to release the index searcher", e);
-							}
-						}
 					}
-				});
+					activeSearchers.incrementAndGet();
-				return llIndexSearcher;
+					try {
-			} catch (Throwable ex) {
+						IndexSearcher indexSearcher;
-				activeSearchers.decrementAndGet();
+						boolean fromSnapshot;
-				throw ex;
+						if (snapshotsManager == null || snapshot == null) {
-			}
+							indexSearcher = searcherManager.acquire();
-		})
+							fromSnapshot = false;
+						} else {
+							//noinspection resource
+							indexSearcher = snapshotsManager.resolveSnapshot(snapshot).getIndexSearcher(SEARCH_EXECUTOR);
+							fromSnapshot = true;
+						}
+						indexSearcher.setSimilarity(similarity);
+						assert indexSearcher.getIndexReader().getRefCount() > 0;
+						var closed = new AtomicBoolean();
+						LLIndexSearcher llIndexSearcher;
+						if (fromSnapshot) {
+							llIndexSearcher = new SnapshotIndexSearcher(indexSearcher, closed);
+						} else {
+							llIndexSearcher = new MainIndexSearcher(indexSearcher, closed);
+						}
+						SimpleResource.CLEANER.register(llIndexSearcher, () -> {
+							if (closed.compareAndSet(false, true)) {
+								LOG.warn("An index searcher was not closed!");
+								if (!fromSnapshot) {
+									try {
+										searcherManager.release(indexSearcher);
+									} catch (IOException e) {
+										LOG.error("Failed to release the index searcher", e);
+									}
+								}
+							}
+						});
+						return llIndexSearcher;
+					} catch (Throwable ex) {
+						activeSearchers.decrementAndGet();
+						throw ex;
+					}
+				})
 				.subscribeOn(uninterruptibleScheduler(Schedulers.boundedElastic()))
 				.publishOn(Schedulers.parallel());
 	}
@@ -232,8 +189,34 @@ public class CachedIndexSearcherManager implements IndexSearcherManager {
 	}
 
 	@Override
-	public Mono<Void> close() {
+	protected void onClose() {
-		return closeMono;
+		LOG.debug("Closing IndexSearcherManager...");
+		refreshSubscription.dispose();
+		LOG.debug("Closed IndexSearcherManager");
+		LOG.debug("Closing refreshes...");
+		long initTime = System.nanoTime();
+		while (activeRefreshes.get() > 0 && (System.nanoTime() - initTime) <= 15000000000L) {
+			LockSupport.parkNanos(50000000);
+		}
+		LOG.debug("Closed refreshes...");
+		LOG.debug("Closing active searchers...");
+		initTime = System.nanoTime();
+		while (activeSearchers.get() > 0 && (System.nanoTime() - initTime) <= 15000000000L) {
+			LockSupport.parkNanos(50000000);
+		}
+		LOG.debug("Closed active searchers");
+		LOG.debug("Stopping searcher executor...");
+		cachedSnapshotSearchers.invalidateAll();
+		cachedSnapshotSearchers.cleanUp();
+		SEARCH_EXECUTOR.shutdown();
+		try {
+			if (!SEARCH_EXECUTOR.awaitTermination(15, TimeUnit.SECONDS)) {
+				SEARCH_EXECUTOR.shutdownNow();
+			}
+		} catch (InterruptedException e) {
+			LOG.error("Failed to stop executor", e);
+		}
+		LOG.debug("Stopped searcher executor");
 	}
 
 	public long getActiveSearchers() {
@@ -251,10 +234,12 @@ public class CachedIndexSearcherManager implements IndexSearcherManager {
 		}
 
 		@Override
-		public void onClose() throws IOException {
+		public void onClose() {
 			dropCachedIndexSearcher();
-			if (getClosed().compareAndSet(false, true)) {
+			try {
 				searcherManager.release(indexSearcher);
+			} catch (IOException ex) {
+				throw new UncheckedIOException(ex);
 			}
 		}
 	}
@@ -267,7 +252,7 @@ public class CachedIndexSearcherManager implements IndexSearcherManager {
 		}
 
 		@Override
-		public void onClose() throws IOException {
+		public void onClose() {
 			dropCachedIndexSearcher();
 		}
 	}

src/main/java/it/cavallium/dbengine/database/disk/HugePqEnv.java

@@ -5,10 +5,12 @@ import static it.cavallium.dbengine.database.disk.LLTempHugePqEnv.getColumnOptio
 import com.google.common.primitives.Ints;
 import io.micrometer.core.instrument.composite.CompositeMeterRegistry;
 import io.netty5.buffer.api.BufferAllocator;
+import it.cavallium.dbengine.utils.SimpleResource;
 import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
 import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
 import java.io.Closeable;
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.util.ArrayList;
 import java.util.Objects;
 import java.util.concurrent.locks.ReentrantLock;
@@ -20,7 +22,7 @@ import org.rocksdb.ColumnFamilyHandle;
 import org.rocksdb.RocksDB;
 import org.rocksdb.RocksDBException;
 
-public class HugePqEnv implements Closeable {
+public class HugePqEnv extends SimpleResource {
 
 	private final RocksDB db;
 	private final ArrayList<ColumnFamilyHandle> defaultCfh;
@@ -32,14 +34,14 @@ public class HugePqEnv implements Closeable {
 	}
 
 	@Override
-	public void close() throws IOException {
+	protected void onClose() {
 		for (var cfh : defaultCfh) {
 			db.destroyColumnFamilyHandle(cfh);
 		}
 		try {
 			db.closeE();
 		} catch (RocksDBException e) {
-			throw new IOException(e);
+			throw new IllegalStateException(e);
 		}
 	}
 

src/main/java/it/cavallium/dbengine/database/disk/IndexSearcherManager.java

@@ -2,6 +2,7 @@ package it.cavallium.dbengine.database.disk;
 
 import io.netty5.buffer.api.Send;
 import it.cavallium.dbengine.database.LLSnapshot;
+import it.cavallium.dbengine.database.SafeCloseable;
 import java.io.IOException;
 import java.util.function.Function;
 import org.apache.lucene.search.IndexSearcher;
@@ -9,13 +10,11 @@ import org.jetbrains.annotations.Nullable;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
-public interface IndexSearcherManager {
+public interface IndexSearcherManager extends SafeCloseable {
 
 	void maybeRefreshBlocking() throws IOException;
 
 	void maybeRefresh() throws IOException;
 
 	Mono<LLIndexSearcher> retrieveSearcher(@Nullable LLSnapshot snapshot);
-
-	Mono<Void> close();
 }

src/main/java/it/cavallium/dbengine/database/disk/LLIndexSearcher.java

@@ -4,6 +4,7 @@ import io.netty5.buffer.api.Drop;
 import io.netty5.buffer.api.Owned;
 import io.netty5.buffer.api.internal.ResourceSupport;
 import it.cavallium.dbengine.database.SafeCloseable;
+import it.cavallium.dbengine.utils.SimpleResource;
 import java.io.Closeable;
 import java.io.IOException;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -12,43 +13,33 @@ import org.apache.logging.log4j.Logger;
 import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.search.IndexSearcher;
 
-public abstract class LLIndexSearcher implements Closeable {
+public abstract class LLIndexSearcher extends SimpleResource {
 
 	protected static final Logger LOG = LogManager.getLogger(LLIndexSearcher.class);
 
 	protected final IndexSearcher indexSearcher;
-	private final AtomicBoolean closed;
 
 	public LLIndexSearcher(IndexSearcher indexSearcher) {
+		super();
 		this.indexSearcher = indexSearcher;
-		this.closed = new AtomicBoolean();
 	}
 
 	public LLIndexSearcher(IndexSearcher indexSearcher, AtomicBoolean closed) {
+		super(closed);
 		this.indexSearcher = indexSearcher;
-		this.closed = closed;
 	}
 
 	public IndexReader getIndexReader() {
-		if (closed.get()) throw new IllegalStateException("Closed");
+		ensureOpen();
 		return indexSearcher.getIndexReader();
 	}
 
 	public IndexSearcher getIndexSearcher() {
-		if (closed.get()) throw new IllegalStateException("Closed");
+		ensureOpen();
 		return indexSearcher;
 	}
 
 	public AtomicBoolean getClosed() {
-		return closed;
+		return super.getClosed();
 	}
-
-	@Override
-	public final void close() throws IOException {
-		if (closed.compareAndSet(false, true)) {
-			onClose();
-		}
-	}
-
-	protected abstract void onClose() throws IOException;
 }

src/main/java/it/cavallium/dbengine/database/disk/LLIndexSearchers.java

@@ -5,7 +5,9 @@ import io.netty5.buffer.api.Owned;
 import io.netty5.buffer.api.Resource;
 import io.netty5.buffer.api.Send;
 import io.netty5.buffer.api.internal.ResourceSupport;
+import it.cavallium.dbengine.database.SafeCloseable;
 import it.cavallium.dbengine.lucene.searcher.ShardIndexSearcher;
+import it.cavallium.dbengine.utils.SimpleResource;
 import it.unimi.dsi.fastutil.objects.Object2IntOpenHashMap;
 import java.io.Closeable;
 import java.io.IOException;
@@ -21,7 +23,7 @@ import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.MultiReader;
 import org.apache.lucene.search.IndexSearcher;
 
-public interface LLIndexSearchers extends Closeable {
+public interface LLIndexSearchers extends SafeCloseable {
 
 	static LLIndexSearchers of(List<LLIndexSearcher> indexSearchers) {
 		return new ShardedIndexSearchers(indexSearchers);
@@ -41,7 +43,7 @@ public interface LLIndexSearchers extends Closeable {
 
 	IndexReader allShards();
 
-	class UnshardedIndexSearchers implements LLIndexSearchers {
+	class UnshardedIndexSearchers extends SimpleResource implements LLIndexSearchers {
 
 		private final LLIndexSearcher indexSearcher;
 
@@ -89,12 +91,12 @@ public interface LLIndexSearchers extends Closeable {
 		}
 
 		@Override
-		public void close() throws IOException {
+		protected void onClose() {
 			indexSearcher.close();
 		}
 	}
 
-	class ShardedIndexSearchers implements LLIndexSearchers {
+	class ShardedIndexSearchers extends SimpleResource implements LLIndexSearchers {
 
 		private final List<LLIndexSearcher> indexSearchers;
 		private final List<IndexSearcher> indexSearchersVals;
@@ -160,7 +162,7 @@ public interface LLIndexSearchers extends Closeable {
 		}
 
 		@Override
-		public void close() throws IOException {
+		protected void onClose() {
 			for (LLIndexSearcher indexSearcher : indexSearchers) {
 				indexSearcher.close();
 			}
@@ -186,8 +188,8 @@ public interface LLIndexSearchers extends Closeable {
 			}
 
 			@Override
-			protected void onClose() throws IOException {
+			protected void onClose() {
-				parent.onClose();
+				parent.close();
 			}
 		}
 	}

src/main/java/it/cavallium/dbengine/database/disk/LLLocalLuceneIndex.java

@@ -40,7 +40,9 @@ import it.cavallium.dbengine.lucene.searcher.LocalSearcher;
 import it.cavallium.dbengine.rpc.current.data.IndicizerAnalyzers;
 import it.cavallium.dbengine.rpc.current.data.IndicizerSimilarities;
 import it.cavallium.dbengine.rpc.current.data.LuceneOptions;
+import it.cavallium.dbengine.utils.SimpleResource;
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.time.Duration;
 import java.util.ArrayList;
 import java.util.List;
@@ -76,7 +78,7 @@ import reactor.core.publisher.SignalType;
 import reactor.core.scheduler.Scheduler;
 import reactor.core.scheduler.Schedulers;
 
-public class LLLocalLuceneIndex implements LLLuceneIndex {
+public class LLLocalLuceneIndex extends SimpleResource implements LLLuceneIndex {
 
 	protected static final Logger logger = LogManager.getLogger(LLLocalLuceneIndex.class);
 
@@ -135,7 +137,6 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 	private final boolean lowMemory;
 
 	private final Phaser activeTasks = new Phaser(1);
-	private final AtomicBoolean closeRequested = new AtomicBoolean();
 
 	public LLLocalLuceneIndex(LLTempHugePqEnv env,
 			MeterRegistry meterRegistry,
@@ -304,7 +305,7 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 
 	private <V> Mono<V> ensureOpen(Mono<V> mono) {
 		return Mono.<Void>fromCallable(() -> {
-			if (closeRequested.get()) {
+			if (isClosed()) {
 				throw new IllegalStateException("Lucene index is closed");
 			} else {
 				return null;
@@ -538,39 +539,24 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 	}
 
 	@Override
-	public Mono<Void> close() {
+	protected void onClose() {
-		return Mono
+		logger.debug("Waiting IndexWriter tasks...");
-				.<Void>fromCallable(() -> {
+		activeTasks.arriveAndAwaitAdvance();
-					logger.debug("Waiting IndexWriter tasks...");
+		logger.debug("IndexWriter tasks ended");
-					activeTasks.arriveAndAwaitAdvance();
+		shutdownLock.lock();
-					logger.debug("IndexWriter tasks ended");
+		try {
-					return null;
+			logger.debug("Closing searcher manager...");
-				})
+			searcherManager.close();
-				.subscribeOn(luceneHeavyTasksScheduler)
+			logger.debug("Searcher manager closed");
-				.then(searcherManager.close())
+			logger.debug("Closing IndexWriter...");
-				.then(Mono.<Void>fromCallable(() -> {
+			indexWriter.close();
-					shutdownLock.lock();
+			directory.close();
-					try {
+			logger.debug("IndexWriter closed");
-						logger.debug("Closing IndexWriter...");
+		} catch (IOException ex) {
-						indexWriter.close();
+			throw new UncheckedIOException(ex);
-						directory.close();
+		} finally {
-						logger.debug("IndexWriter closed");
+			shutdownLock.unlock();
-					} finally {
+		}
-						shutdownLock.unlock();
-					}
-					return null;
-				}).subscribeOn(luceneHeavyTasksScheduler))
-
-				// Avoid closing multiple times
-				.transformDeferred(mono -> {
-					if (this.closeRequested.compareAndSet(false, true)) {
-						logger.trace("Set closeRequested to true. Further update/write calls will result in an error");
-						return mono;
-					} else {
-						logger.debug("Tried to close more than once");
-						return Mono.empty();
-					}
-				});
 	}
 
 	@Override
@@ -580,7 +566,7 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 					if (activeTasks.isTerminated()) return null;
 					shutdownLock.lock();
 					try {
-						if (closeRequested.get()) {
+						if (isClosed()) {
 							return null;
 						}
 						flushTime.recordCallable(() -> {
@@ -603,7 +589,7 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 					if (activeTasks.isTerminated()) return null;
 					shutdownLock.lock();
 					try {
-						if (closeRequested.get()) {
+						if (isClosed()) {
 							return null;
 						}
 						var mergeScheduler = indexWriter.getConfig().getMergeScheduler();
@@ -626,7 +612,7 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 					if (activeTasks.isTerminated()) return null;
 					shutdownLock.lock();
 					try {
-						if (closeRequested.get()) {
+						if (isClosed()) {
 							return null;
 						}
 						indexWriter.getConfig().setMergePolicy(NoMergePolicy.INSTANCE);
@@ -653,7 +639,7 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 						if (activeTasks.isTerminated()) return null;
 						shutdownLock.lock();
 						try {
-							if (closeRequested.get()) {
+							if (isClosed()) {
 								return null;
 							}
 							refreshTime.recordCallable(() -> {
@@ -681,7 +667,7 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 	public void scheduledCommit() {
 		shutdownLock.lock();
 		try {
-			if (closeRequested.get()) {
+			if (isClosed()) {
 				return;
 			}
 			commitTime.recordCallable(() -> {
@@ -702,7 +688,7 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 	public void scheduledMerge() { // Do not use. Merges are done automatically by merge policies
 		shutdownLock.lock();
 		try {
-			if (closeRequested.get()) {
+			if (isClosed()) {
 				return;
 			}
 			mergeTime.recordCallable(() -> {
@@ -724,7 +710,7 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 	private double getSnapshotsCount() {
 		shutdownLock.lock();
 		try {
-			if (closeRequested.get()) {
+			if (isClosed()) {
 				return 0d;
 			}
 			if (snapshotsManager == null) return 0d;
@@ -737,7 +723,7 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 	private double getIndexWriterFlushingBytes() {
 		shutdownLock.lock();
 		try {
-			if (closeRequested.get()) {
+			if (isClosed()) {
 				return 0d;
 			}
 			return indexWriter.getFlushingBytes();
@@ -749,7 +735,7 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 	private double getIndexWriterMaxCompletedSequenceNumber() {
 		shutdownLock.lock();
 		try {
-			if (closeRequested.get()) {
+			if (isClosed()) {
 				return 0d;
 			}
 			return indexWriter.getMaxCompletedSequenceNumber();
@@ -761,7 +747,7 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 	private double getIndexWriterPendingNumDocs() {
 		shutdownLock.lock();
 		try {
-			if (closeRequested.get()) {
+			if (isClosed()) {
 				return 0d;
 			}
 			return indexWriter.getPendingNumDocs();
@@ -773,7 +759,7 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 	private double getIndexWriterMergingSegmentsSize() {
 		shutdownLock.lock();
 		try {
-			if (closeRequested.get()) {
+			if (isClosed()) {
 				return 0d;
 			}
 			return indexWriter.getMergingSegments().size();
@@ -785,7 +771,7 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 	private double getDirectoryPendingDeletionsCount() {
 		shutdownLock.lock();
 		try {
-			if (closeRequested.get()) {
+			if (isClosed()) {
 				return 0d;
 			}
 			return indexWriter.getDirectory().getPendingDeletions().size();
@@ -799,7 +785,7 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 	private double getDocCount() {
 		shutdownLock.lock();
 		try {
-			if (closeRequested.get()) {
+			if (isClosed()) {
 				return 0d;
 			}
 			var docStats = indexWriter.getDocStats();
@@ -816,7 +802,7 @@ public class LLLocalLuceneIndex implements LLLuceneIndex {
 	private double getMaxDoc() {
 		shutdownLock.lock();
 		try {
-			if (closeRequested.get()) {
+			if (isClosed()) {
 				return 0d;
 			}
 			var docStats = indexWriter.getDocStats();

src/main/java/it/cavallium/dbengine/database/disk/LLLocalMultiLuceneIndex.java

@@ -29,9 +29,11 @@ import it.cavallium.dbengine.lucene.searcher.MultiSearcher;
 import it.cavallium.dbengine.rpc.current.data.IndicizerAnalyzers;
 import it.cavallium.dbengine.rpc.current.data.IndicizerSimilarities;
 import it.cavallium.dbengine.rpc.current.data.LuceneOptions;
+import it.cavallium.dbengine.utils.SimpleResource;
 import it.unimi.dsi.fastutil.ints.IntList;
 import java.io.Closeable;
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
@@ -54,7 +56,7 @@ import reactor.core.publisher.Mono;
 import reactor.core.publisher.SignalType;
 import reactor.core.scheduler.Schedulers;
 
-public class LLLocalMultiLuceneIndex implements LLLuceneIndex {
+public class LLLocalMultiLuceneIndex extends SimpleResource implements LLLuceneIndex {
 
 	private static final Logger LOG = LogManager.getLogger(LLLuceneIndex.class);
 	private static final boolean BYPASS_GROUPBY_BUG = Boolean.parseBoolean(System.getProperty(
@@ -157,7 +159,7 @@ public class LLLocalMultiLuceneIndex implements LLLuceneIndex {
 				.doOnDiscard(LLIndexSearcher.class, indexSearcher -> {
 					try {
 						indexSearcher.close();
-					} catch (IOException ex) {
+					} catch (UncheckedIOException ex) {
 						LOG.error("Failed to close an index searcher", ex);
 					}
 				})
@@ -314,10 +316,17 @@ public class LLLocalMultiLuceneIndex implements LLLuceneIndex {
 	}
 
 	@Override
-	public Mono<Void> close() {
+	protected void onClose() {
-		Iterable<Mono<Void>> it = () -> luceneIndicesSet.stream().map(LLLocalLuceneIndex::close).iterator();
+		Iterable<Mono<Void>> it = () -> luceneIndicesSet
+				.stream()
+				.map(part -> Mono
+						.<Void>fromRunnable(part::close)
+						.subscribeOn(uninterruptibleScheduler(Schedulers.boundedElastic()))
+						.publishOn(Schedulers.parallel())
+				)
+				.iterator();
 		var indicesCloseMono = Mono.whenDelayError(it);
-		return indicesCloseMono
+		indicesCloseMono
 				.then(Mono.fromCallable(() -> {
 					if (multiSearcher instanceof Closeable closeable) {
 						//noinspection BlockingMethodInNonBlockingContext
@@ -326,7 +335,8 @@ public class LLLocalMultiLuceneIndex implements LLLuceneIndex {
 					return null;
 				}).subscribeOn(uninterruptibleScheduler(Schedulers.boundedElastic())))
 				.publishOn(Schedulers.parallel())
-				.then();
+				.then()
+				.block();
 	}
 
 	@Override

src/main/java/it/cavallium/dbengine/database/disk/LuceneIndexSnapshot.java

@@ -1,7 +1,9 @@
 package it.cavallium.dbengine.database.disk;
 
+import it.cavallium.dbengine.utils.SimpleResource;
 import java.io.Closeable;
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.util.concurrent.Executor;
 import java.util.concurrent.ForkJoinPool;
 import org.apache.lucene.index.DirectoryReader;
@@ -9,7 +11,7 @@ import org.apache.lucene.index.IndexCommit;
 import org.apache.lucene.search.IndexSearcher;
 import org.jetbrains.annotations.Nullable;
 
-public class LuceneIndexSnapshot implements Closeable {
+public class LuceneIndexSnapshot extends SimpleResource {
 	private final IndexCommit snapshot;
 
 	private boolean initialized;
@@ -57,11 +59,16 @@ public class LuceneIndexSnapshot implements Closeable {
 		}
 	}
 
-	public synchronized void close() throws IOException {
+	@Override
+	protected synchronized void onClose() {
 		closed = true;
 
 		if (initialized && !failed) {
-			indexReader.close();
+			try {
+				indexReader.close();
+			} catch (IOException e) {
+				throw new UncheckedIOException(e);
+			}
 			indexSearcher = null;
 		}
 	}

src/main/java/it/cavallium/dbengine/database/disk/SimpleIndexSearcherManager.java

@@ -9,6 +9,7 @@ import it.cavallium.dbengine.database.LLSnapshot;
 import it.cavallium.dbengine.database.LLUtils;
 import it.cavallium.dbengine.utils.SimpleResource;
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.lang.ref.Cleaner;
 import java.time.Duration;
 import java.util.concurrent.ExecutorService;
@@ -28,6 +29,7 @@ import org.apache.lucene.store.AlreadyClosedException;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import it.cavallium.dbengine.utils.ShortNamedThreadFactory;
+import reactor.core.Disposable;
 import reactor.core.publisher.Mono;
 import reactor.core.publisher.Sinks;
 import reactor.core.publisher.Sinks.Empty;
@@ -35,7 +37,7 @@ import reactor.core.scheduler.Scheduler;
 import reactor.core.scheduler.Schedulers;
 
 // todo: deduplicate code between Cached and Simple searcher managers
-public class SimpleIndexSearcherManager implements IndexSearcherManager {
+public class SimpleIndexSearcherManager extends SimpleResource implements IndexSearcherManager {
 
 	private static final Logger LOG = LogManager.getLogger(SimpleIndexSearcherManager.class);
 	private static final ExecutorService SEARCH_EXECUTOR = Executors.newFixedThreadPool(
@@ -56,10 +58,7 @@ public class SimpleIndexSearcherManager implements IndexSearcherManager {
 
 	private final AtomicLong activeSearchers = new AtomicLong(0);
 	private final AtomicLong activeRefreshes = new AtomicLong(0);
-
+	private final Disposable refreshSubscription;
-	private final AtomicBoolean closeRequested = new AtomicBoolean();
-	private final Empty<Void> closeRequestedMono = Sinks.empty();
-	private final Mono<Void> closeMono;
 
 	public SimpleIndexSearcherManager(IndexWriter indexWriter,
 			@Nullable SnapshotsManager snapshotsManager,
@@ -75,8 +74,7 @@ public class SimpleIndexSearcherManager implements IndexSearcherManager {
 
 		this.searcherManager = new SearcherManager(indexWriter, applyAllDeletes, writeAllDeletes, SEARCHER_FACTORY);
 
-		Empty<Void> refresherClosed = Sinks.empty();
+		refreshSubscription = Mono
-		var refreshSubscription = Mono
 				.fromRunnable(() -> {
 					try {
 						maybeRefresh();
@@ -87,47 +85,9 @@ public class SimpleIndexSearcherManager implements IndexSearcherManager {
 				.subscribeOn(luceneHeavyTasksScheduler)
 				.publishOn(Schedulers.parallel())
 				.repeatWhen(s -> s.delayElements(queryRefreshDebounceTime))
-				.takeUntilOther(closeRequestedMono.asMono())
-				.doAfterTerminate(refresherClosed::tryEmitEmpty)
 				.transform(LLUtils::handleDiscard)
 				.subscribe();
 
-		this.closeMono = Mono
-				.fromRunnable(() -> {
-					LOG.debug("Closing IndexSearcherManager...");
-					this.closeRequested.set(true);
-					this.closeRequestedMono.tryEmitEmpty();
-					refreshSubscription.dispose();
-				})
-				.then(refresherClosed.asMono())
-				.then(Mono.<Void>fromRunnable(() -> {
-					LOG.debug("Closed IndexSearcherManager");
-					LOG.debug("Closing refreshes...");
-					long initTime = System.nanoTime();
-					while (activeRefreshes.get() > 0 && (System.nanoTime() - initTime) <= 15000000000L) {
-						LockSupport.parkNanos(50000000);
-					}
-					LOG.debug("Closed refreshes...");
-					LOG.debug("Closing active searchers...");
-					initTime = System.nanoTime();
-					while (activeSearchers.get() > 0 && (System.nanoTime() - initTime) <= 15000000000L) {
-						LockSupport.parkNanos(50000000);
-					}
-					LOG.debug("Closed active searchers");
-					LOG.debug("Stopping searcher executor...");
-					SEARCH_EXECUTOR.shutdown();
-					try {
-						//noinspection BlockingMethodInNonBlockingContext
-						if (!SEARCH_EXECUTOR.awaitTermination(15, TimeUnit.SECONDS)) {
-							SEARCH_EXECUTOR.shutdownNow();
-						}
-					} catch (InterruptedException e) {
-						LOG.error("Failed to stop executor", e);
-					}
-					LOG.debug("Stopped searcher executor");
-				}).subscribeOn(uninterruptibleScheduler(Schedulers.boundedElastic())))
-				.publishOn(Schedulers.parallel())
-				.cache();
 		this.noSnapshotSearcherMono = retrieveSearcherInternal(null);
 	}
 
@@ -171,7 +131,7 @@ public class SimpleIndexSearcherManager implements IndexSearcherManager {
 
 	private Mono<LLIndexSearcher> retrieveSearcherInternal(@Nullable LLSnapshot snapshot) {
 		return Mono.fromCallable(() -> {
-					if (closeRequested.get()) {
+					if (isClosed()) {
 						return null;
 					}
 					activeSearchers.incrementAndGet();
@@ -218,8 +178,32 @@ public class SimpleIndexSearcherManager implements IndexSearcherManager {
 	}
 
 	@Override
-	public Mono<Void> close() {
+	protected void onClose() {
-		return closeMono;
+		LOG.debug("Closing IndexSearcherManager...");
+		refreshSubscription.dispose();
+		LOG.debug("Closed IndexSearcherManager");
+		LOG.debug("Closing refreshes...");
+		long initTime = System.nanoTime();
+		while (activeRefreshes.get() > 0 && (System.nanoTime() - initTime) <= 15000000000L) {
+			LockSupport.parkNanos(50000000);
+		}
+		LOG.debug("Closed refreshes...");
+		LOG.debug("Closing active searchers...");
+		initTime = System.nanoTime();
+		while (activeSearchers.get() > 0 && (System.nanoTime() - initTime) <= 15000000000L) {
+			LockSupport.parkNanos(50000000);
+		}
+		LOG.debug("Closed active searchers");
+		LOG.debug("Stopping searcher executor...");
+		SEARCH_EXECUTOR.shutdown();
+		try {
+			if (!SEARCH_EXECUTOR.awaitTermination(15, TimeUnit.SECONDS)) {
+				SEARCH_EXECUTOR.shutdownNow();
+			}
+		} catch (InterruptedException e) {
+			LOG.error("Failed to stop executor", e);
+		}
+		LOG.debug("Stopped searcher executor");
 	}
 
 	public long getActiveSearchers() {
@@ -237,10 +221,12 @@ public class SimpleIndexSearcherManager implements IndexSearcherManager {
 		}
 
 		@Override
-		public void onClose() throws IOException {
+		public void onClose() {
 			dropCachedIndexSearcher();
-			if (getClosed().compareAndSet(false, true)) {
+			try {
 				searcherManager.release(indexSearcher);
+			} catch (IOException ex) {
+				throw new UncheckedIOException(ex);
 			}
 		}
 	}
@@ -253,7 +239,7 @@ public class SimpleIndexSearcherManager implements IndexSearcherManager {
 		}
 
 		@Override
-		public void onClose() throws IOException {
+		public void onClose() {
 			dropCachedIndexSearcher();
 		}
 	}

src/main/java/it/cavallium/dbengine/database/disk/SnapshotsManager.java

@@ -3,7 +3,9 @@ package it.cavallium.dbengine.database.disk;
 import static it.cavallium.dbengine.client.UninterruptibleScheduler.uninterruptibleScheduler;
 
 import it.cavallium.dbengine.database.LLSnapshot;
+import it.cavallium.dbengine.utils.SimpleResource;
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.util.Objects;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.Executor;
@@ -16,7 +18,7 @@ import org.jetbrains.annotations.Nullable;
 import reactor.core.publisher.Mono;
 import reactor.core.scheduler.Schedulers;
 
-public class SnapshotsManager {
+public class SnapshotsManager extends SimpleResource {
 
 	private final IndexWriter indexWriter;
 	private final SnapshotDeletionPolicy snapshotter;
@@ -70,7 +72,7 @@ public class SnapshotsManager {
 			if (prevSnapshot != null) {
 				try {
 					prevSnapshot.close();
-				} catch (IOException e) {
+				} catch (UncheckedIOException e) {
 					throw new IllegalStateException("Can't close snapshot", e);
 				}
 			}
@@ -105,7 +107,8 @@ public class SnapshotsManager {
 		return Math.max(snapshots.size(), snapshotter.getSnapshotCount());
 	}
 
-	public void close() {
+	@Override
+	protected void onClose() {
 		if (!activeTasks.isTerminated()) {
 			activeTasks.arriveAndAwaitAdvance();
 		}

src/main/java/it/cavallium/dbengine/database/remote/LLQuicConnection.java

@@ -509,8 +509,8 @@ public class LLQuicConnection implements LLDatabaseConnection {
 					}
 
 					@Override
-					public Mono<Void> close() {
+					public void close() {
-						return sendRequest(new CloseLuceneIndex(id)).then();
+						sendRequest(new CloseLuceneIndex(id)).then().block();
 					}
 
 					@Override

src/main/java/it/cavallium/dbengine/lucene/FullDocs.java

@@ -4,6 +4,7 @@ import static it.cavallium.dbengine.lucene.LLDocElementScoreComparator.SCORE_DOC
 import static org.apache.lucene.search.TotalHits.Relation.*;
 
 import it.cavallium.dbengine.lucene.collector.FullFieldDocs;
+import it.cavallium.dbengine.utils.SimpleResource;
 import java.io.IOException;
 import java.util.Comparator;
 import org.apache.lucene.search.FieldComparator;
@@ -31,27 +32,7 @@ public interface FullDocs<T extends LLDoc> extends ResourceIterable<T> {
 	static <T extends LLDoc> FullDocs<T> merge(@Nullable Sort sort, FullDocs<T>[] fullDocs) {
 		ResourceIterable<T> mergedIterable = mergeResourceIterable(sort, fullDocs);
 		TotalHits mergedTotalHits = mergeTotalHits(fullDocs);
-		FullDocs<T> docs = new FullDocs<>() {
+		FullDocs<T> docs = new MergedFullDocs<>(mergedIterable, mergedTotalHits);
-			@Override
-			public void close() {
-				mergedIterable.close();
-			}
-
-			@Override
-			public Flux<T> iterate() {
-				return mergedIterable.iterate();
-			}
-
-			@Override
-			public Flux<T> iterate(long skips) {
-				return mergedIterable.iterate(skips);
-			}
-
-			@Override
-			public TotalHits totalHits() {
-				return mergedTotalHits;
-			}
-		};
 		if (sort != null) {
 			return new FullFieldDocs<>(docs, sort.getSort());
 		} else {
@@ -76,88 +57,7 @@ public interface FullDocs<T extends LLDoc> extends ResourceIterable<T> {
 	static <T extends LLDoc> ResourceIterable<T> mergeResourceIterable(
 			@Nullable Sort sort,
 			FullDocs<T>[] fullDocs) {
-		return new ResourceIterable<>() {
+		return new MergedResourceIterable<>(fullDocs, sort);
-			@Override
-			public void close() {
-				for (FullDocs<T> fullDoc : fullDocs) {
-					fullDoc.close();
-				}
-			}
-
-			@Override
-			public Flux<T> iterate() {
-				@SuppressWarnings("unchecked") Flux<T>[] iterables = new Flux[fullDocs.length];
-
-				for (int i = 0; i < fullDocs.length; i++) {
-					var singleFullDocs = fullDocs[i].iterate();
-					iterables[i] = singleFullDocs;
-				}
-
-				Comparator<LLDoc> comp;
-				if (sort == null) {
-					// Merge maintaining sorting order (Algorithm taken from TopDocs.ScoreMergeSortQueue)
-
-					comp = SCORE_DOC_SCORE_ELEM_COMPARATOR.thenComparing(DEFAULT_TIE_BREAKER);
-				} else {
-					// Merge maintaining sorting order (Algorithm taken from TopDocs.MergeSortQueue)
-
-					SortField[] sortFields = sort.getSort();
-					var comparators = new FieldComparator[sortFields.length];
-					var reverseMul = new int[sortFields.length];
-
-					for (int compIDX = 0; compIDX < sortFields.length; ++compIDX) {
-						SortField sortField = sortFields[compIDX];
-						comparators[compIDX] = sortField.getComparator(1, compIDX == 0);
-						reverseMul[compIDX] = sortField.getReverse() ? -1 : 1;
-					}
-
-					comp = (first, second) -> {
-						assert first != second;
-
-						LLFieldDoc firstFD = (LLFieldDoc) first;
-						LLFieldDoc secondFD = (LLFieldDoc) second;
-
-						for (int compIDX = 0; compIDX < comparators.length; ++compIDX) {
-							//noinspection rawtypes
-							FieldComparator fieldComp = comparators[compIDX];
-							//noinspection unchecked
-							int cmp = reverseMul[compIDX] * fieldComp.compareValues(firstFD.fields().get(compIDX),
-									secondFD.fields().get(compIDX)
-							);
-							if (cmp != 0) {
-								return cmp;
-							}
-						}
-
-						return tieBreakCompare(first, second, DEFAULT_TIE_BREAKER);
-					};
-				}
-
-				@SuppressWarnings("unchecked") Flux<T>[] fluxes = new Flux[fullDocs.length];
-				for (int i = 0; i < iterables.length; i++) {
-					var shardIndex = i;
-					fluxes[i] = iterables[i].map(shard -> {
-						if (shard instanceof LLScoreDoc scoreDoc) {
-							//noinspection unchecked
-							return (T) new LLScoreDoc(scoreDoc.doc(), scoreDoc.score(), shardIndex);
-						} else if (shard instanceof LLFieldDoc fieldDoc) {
-							//noinspection unchecked
-							return (T) new LLFieldDoc(fieldDoc.doc(), fieldDoc.score(), shardIndex, fieldDoc.fields());
-						} else if (shard instanceof LLSlotDoc slotDoc) {
-							//noinspection unchecked
-							return (T) new LLSlotDoc(slotDoc.doc(), slotDoc.score(), shardIndex, slotDoc.slot());
-						} else {
-							throw new UnsupportedOperationException("Unsupported type " + (shard == null ? null : shard.getClass()));
-						}
-					});
-					if (fullDocs[i].totalHits().relation == EQUAL_TO) {
-						fluxes[i] = fluxes[i].take(fullDocs[i].totalHits().value, true);
-					}
-				}
-
-				return Flux.mergeComparing(comp, fluxes);
-			}
-		};
 	}
 
 	static <T extends LLDoc> TotalHits mergeTotalHits(FullDocs<T>[] fullDocs) {
@@ -173,4 +73,127 @@ public interface FullDocs<T extends LLDoc> extends ResourceIterable<T> {
 		}
 		return new TotalHits(totalCount, totalRelation);
 	}
+
+	class MergedResourceIterable<T extends LLDoc> extends SimpleResource implements ResourceIterable<T> {
+
+		private final FullDocs<T>[] fullDocs;
+		private final @Nullable Sort sort;
+
+		public MergedResourceIterable(FullDocs<T>[] fullDocs, @Nullable Sort sort) {
+			this.fullDocs = fullDocs;
+			this.sort = sort;
+		}
+
+		@Override
+		protected void onClose() {
+			for (FullDocs<T> fullDoc : fullDocs) {
+				fullDoc.close();
+			}
+		}
+
+		@Override
+		public Flux<T> iterate() {
+			@SuppressWarnings("unchecked") Flux<T>[] iterables = new Flux[fullDocs.length];
+
+			for (int i = 0; i < fullDocs.length; i++) {
+				var singleFullDocs = fullDocs[i].iterate();
+				iterables[i] = singleFullDocs;
+			}
+
+			Comparator<LLDoc> comp;
+			if (sort == null) {
+				// Merge maintaining sorting order (Algorithm taken from TopDocs.ScoreMergeSortQueue)
+
+				comp = SCORE_DOC_SCORE_ELEM_COMPARATOR.thenComparing(DEFAULT_TIE_BREAKER);
+			} else {
+				// Merge maintaining sorting order (Algorithm taken from TopDocs.MergeSortQueue)
+
+				SortField[] sortFields = sort.getSort();
+				var comparators = new FieldComparator[sortFields.length];
+				var reverseMul = new int[sortFields.length];
+
+				for (int compIDX = 0; compIDX < sortFields.length; ++compIDX) {
+					SortField sortField = sortFields[compIDX];
+					comparators[compIDX] = sortField.getComparator(1, compIDX == 0);
+					reverseMul[compIDX] = sortField.getReverse() ? -1 : 1;
+				}
+
+				comp = (first, second) -> {
+					assert first != second;
+
+					LLFieldDoc firstFD = (LLFieldDoc) first;
+					LLFieldDoc secondFD = (LLFieldDoc) second;
+
+					for (int compIDX = 0; compIDX < comparators.length; ++compIDX) {
+						//noinspection rawtypes
+						FieldComparator fieldComp = comparators[compIDX];
+						//noinspection unchecked
+						int cmp = reverseMul[compIDX] * fieldComp.compareValues(firstFD.fields().get(compIDX),
+								secondFD.fields().get(compIDX)
+						);
+						if (cmp != 0) {
+							return cmp;
+						}
+					}
+
+					return tieBreakCompare(first, second, DEFAULT_TIE_BREAKER);
+				};
+			}
+
+			@SuppressWarnings("unchecked") Flux<T>[] fluxes = new Flux[fullDocs.length];
+			for (int i = 0; i < iterables.length; i++) {
+				var shardIndex = i;
+				fluxes[i] = iterables[i].map(shard -> {
+					if (shard instanceof LLScoreDoc scoreDoc) {
+						//noinspection unchecked
+						return (T) new LLScoreDoc(scoreDoc.doc(), scoreDoc.score(), shardIndex);
+					} else if (shard instanceof LLFieldDoc fieldDoc) {
+						//noinspection unchecked
+						return (T) new LLFieldDoc(fieldDoc.doc(), fieldDoc.score(), shardIndex, fieldDoc.fields());
+					} else if (shard instanceof LLSlotDoc slotDoc) {
+						//noinspection unchecked
+						return (T) new LLSlotDoc(slotDoc.doc(), slotDoc.score(), shardIndex, slotDoc.slot());
+					} else {
+						throw new UnsupportedOperationException("Unsupported type " + (shard == null ? null : shard.getClass()));
+					}
+				});
+				if (fullDocs[i].totalHits().relation == EQUAL_TO) {
+					fluxes[i] = fluxes[i].take(fullDocs[i].totalHits().value, true);
+				}
+			}
+
+			return Flux.mergeComparing(comp, fluxes);
+		}
+	}
+
+	class MergedFullDocs<T extends LLDoc> extends SimpleResource implements FullDocs<T> {
+
+		private final ResourceIterable<T> mergedIterable;
+		private final TotalHits mergedTotalHits;
+
+		public MergedFullDocs(ResourceIterable<T> mergedIterable, TotalHits mergedTotalHits) {
+			this.mergedIterable = mergedIterable;
+			this.mergedTotalHits = mergedTotalHits;
+		}
+
+		@Override
+		public void onClose() {
+			mergedIterable.close();
+		}
+
+		@Override
+		public Flux<T> iterate() {
+			return mergedIterable.iterate();
+		}
+
+		@Override
+		public Flux<T> iterate(long skips) {
+			return mergedIterable.iterate(skips);
+		}
+
+		@Override
+		public TotalHits totalHits() {
+			return mergedTotalHits;
+		}
+	}
 }

src/main/java/it/cavallium/dbengine/lucene/HugePqArray.java

@@ -6,6 +6,7 @@ import it.cavallium.dbengine.database.SafeCloseable;
 import it.cavallium.dbengine.database.disk.LLTempHugePqEnv;
 import it.cavallium.dbengine.database.disk.HugePqEnv;
 import it.cavallium.dbengine.database.disk.StandardRocksDBColumn;
+import it.cavallium.dbengine.utils.SimpleResource;
 import java.util.concurrent.atomic.AtomicBoolean;
 import org.jetbrains.annotations.Nullable;
 import org.rocksdb.ReadOptions;
@@ -13,13 +14,12 @@ import org.rocksdb.RocksDB;
 import org.rocksdb.RocksDBException;
 import org.rocksdb.WriteOptions;
 
-public class HugePqArray<V> implements IArray<V>, SafeCloseable {
+public class HugePqArray<V> extends SimpleResource implements IArray<V>, SafeCloseable {
 
 	static {
 		RocksDB.loadLibrary();
 	}
 
-	private final AtomicBoolean closed = new AtomicBoolean();
 	private final HugePqCodec<V> valueCodec;
 	private final LLTempHugePqEnv tempEnv;
 	private final HugePqEnv env;
@@ -118,11 +118,9 @@ public class HugePqArray<V> implements IArray<V>, SafeCloseable {
 	}
 
 	@Override
-	public void close() {
+	public void onClose() {
-		if (closed.compareAndSet(false, true)) {
+		ensureThread();
-			ensureThread();
+		this.tempEnv.freeDb(hugePqId);
-			this.tempEnv.freeDb(hugePqId);
-		}
 	}
 
 	@Override

src/main/java/it/cavallium/dbengine/lucene/HugePqPriorityQueue.java

@@ -10,6 +10,7 @@ import it.cavallium.dbengine.database.disk.RocksIterWithReadOpts;
 import it.cavallium.dbengine.database.disk.StandardRocksDBColumn;
 import it.cavallium.dbengine.database.disk.UpdateAtomicResultMode;
 import it.cavallium.dbengine.database.disk.UpdateAtomicResultPrevious;
+import it.cavallium.dbengine.utils.SimpleResource;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -26,13 +27,13 @@ import org.rocksdb.WriteBatch;
 import org.rocksdb.WriteOptions;
 import reactor.core.publisher.Flux;
 
-public class HugePqPriorityQueue<T> implements PriorityQueue<T>, Reversable<ReversableResourceIterable<T>>, ReversableResourceIterable<T> {
+public class HugePqPriorityQueue<T> extends SimpleResource
+		implements PriorityQueue<T>, Reversable<ReversableResourceIterable<T>>, ReversableResourceIterable<T> {
 
 	static {
 		RocksDB.loadLibrary();
 	}
 
-	private final AtomicBoolean closed = new AtomicBoolean();
 	private final LLTempHugePqEnv tempEnv;
 	private final HugePqEnv env;
 	private final int hugePqId;
@@ -351,12 +352,10 @@ public class HugePqPriorityQueue<T> implements PriorityQueue<T>, Reversable<Reve
 	}
 
 	@Override
-	public void close() {
+	protected void onClose() {
-		if (closed.compareAndSet(false, true)) {
+		this.tempEnv.freeDb(hugePqId);
-			this.tempEnv.freeDb(hugePqId);
+		if (this.codec instanceof SafeCloseable closeable) {
-			if (this.codec instanceof SafeCloseable closeable) {
+			closeable.close();
-				closeable.close();
-			}
 		}
 	}
 
@@ -369,26 +368,29 @@ public class HugePqPriorityQueue<T> implements PriorityQueue<T>, Reversable<Reve
 
 	@Override
 	public ReversableResourceIterable<T> reverse() {
-		return new ReversableResourceIterable<>() {
+		return new ReversedResourceIterable();
-			@Override
+	}
-			public void close() {
-				HugePqPriorityQueue.this.close();
-			}
 
-			@Override
+	private class ReversedResourceIterable extends SimpleResource implements ReversableResourceIterable<T> {
-			public Flux<T> iterate() {
-				return reverseIterate();
-			}
 
-			@Override
+		@Override
-			public Flux<T> iterate(long skips) {
+		public void onClose() {
-				return reverseIterate(skips);
+			HugePqPriorityQueue.this.close();
-			}
+		}
 
-			@Override
+		@Override
-			public ReversableResourceIterable<T> reverse() {
+		public Flux<T> iterate() {
-				return HugePqPriorityQueue.this;
+			return reverseIterate();
-			}
+		}
-		};
+
+		@Override
+		public Flux<T> iterate(long skips) {
+			return reverseIterate(skips);
+		}
+
+		@Override
+		public ReversableResourceIterable<T> reverse() {
+			return HugePqPriorityQueue.this;
+		}
 	}
 }

src/main/java/it/cavallium/dbengine/lucene/LLSlotDocCodec.java

@@ -3,6 +3,7 @@ package it.cavallium.dbengine.lucene;
 import io.netty5.buffer.api.Buffer;
 import it.cavallium.dbengine.database.SafeCloseable;
 import it.cavallium.dbengine.database.disk.LLTempHugePqEnv;
+import it.cavallium.dbengine.utils.SimpleResource;
 import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
@@ -18,7 +19,8 @@ import org.apache.lucene.search.SortField;
 import org.rocksdb.AbstractComparator;
 import org.rocksdb.ComparatorOptions;
 
-public class LLSlotDocCodec implements HugePqCodec<LLSlotDoc>, FieldValueHitQueue, SafeCloseable {
+public class LLSlotDocCodec extends SimpleResource
+		implements HugePqCodec<LLSlotDoc>, FieldValueHitQueue, SafeCloseable {
 
 	private final SortField[] fields;
 
@@ -189,7 +191,7 @@ public class LLSlotDocCodec implements HugePqCodec<LLSlotDoc>, FieldValueHitQueu
 	}
 
 	@Override
-	public void close() {
+	protected void onClose() {
 		for (FieldComparator<?> comparator : this.comparators) {
 			if (comparator instanceof SafeCloseable closeable) {
 				closeable.close();

src/main/java/it/cavallium/dbengine/lucene/LazyFullDocs.java

@@ -1,11 +1,12 @@
 package it.cavallium.dbengine.lucene;
 
+import it.cavallium.dbengine.utils.SimpleResource;
 import java.io.Closeable;
 import java.io.IOException;
 import org.apache.lucene.search.TotalHits;
 import reactor.core.publisher.Flux;
 
-public class LazyFullDocs<T extends LLDoc> implements FullDocs<T> {
+public class LazyFullDocs<T extends LLDoc> extends SimpleResource implements FullDocs<T> {
 
 	private final ResourceIterable<T> pq;
 	private final TotalHits totalHits;
@@ -31,7 +32,7 @@ public class LazyFullDocs<T extends LLDoc> implements FullDocs<T> {
 	}
 
 	@Override
-	public void close() {
+	protected void onClose() {
 		pq.close();
 	}
 }

src/main/java/it/cavallium/dbengine/lucene/collector/FullDocsCollector.java

@@ -24,6 +24,7 @@ import it.cavallium.dbengine.lucene.PriorityQueue;
 import it.cavallium.dbengine.lucene.ResourceIterable;
 import it.cavallium.dbengine.lucene.Reversable;
 import it.cavallium.dbengine.lucene.ReversableResourceIterable;
+import it.cavallium.dbengine.utils.SimpleResource;
 import java.io.Closeable;
 import org.apache.lucene.search.Collector;
 import org.apache.lucene.search.TopDocs;
@@ -39,7 +40,7 @@ import org.apache.lucene.search.TotalHits;
  * all methods, in order to avoid a NullPointerException.
  */
 public abstract class FullDocsCollector<PQ extends PriorityQueue<INTERNAL> & Reversable<ReversableResourceIterable<INTERNAL>>, INTERNAL extends LLDoc,
-		EXTERNAL extends LLDoc> implements Collector, SafeCloseable {
+		EXTERNAL extends LLDoc> extends SimpleResource implements Collector, SafeCloseable {
 
 	/**
 	 * The priority queue which holds the top documents. Note that different implementations of
@@ -72,7 +73,7 @@ public abstract class FullDocsCollector<PQ extends PriorityQueue<INTERNAL> & Rev
 	public abstract ResourceIterable<EXTERNAL> mapResults(ResourceIterable<INTERNAL> it);
 
 	@Override
-	public void close() {
+	public void onClose() {
 		pq.close();
 	}
 }

src/main/java/it/cavallium/dbengine/lucene/collector/FullFieldDocs.java

@@ -4,13 +4,14 @@ import it.cavallium.dbengine.database.SafeCloseable;
 import it.cavallium.dbengine.lucene.FullDocs;
 import it.cavallium.dbengine.lucene.LLDoc;
 import it.cavallium.dbengine.lucene.LLFieldDoc;
+import it.cavallium.dbengine.utils.SimpleResource;
 import java.io.Closeable;
 import java.io.IOException;
 import org.apache.lucene.search.SortField;
 import org.apache.lucene.search.TotalHits;
 import reactor.core.publisher.Flux;
 
-public class FullFieldDocs<T extends LLDoc> implements FullDocs<T>, SafeCloseable {
+public class FullFieldDocs<T extends LLDoc> extends SimpleResource implements FullDocs<T>, SafeCloseable {
 
 	private final FullDocs<T> fullDocs;
 	private final SortField[] fields;
@@ -40,7 +41,7 @@ public class FullFieldDocs<T extends LLDoc> implements FullDocs<T>, SafeCloseabl
 	}
 
 	@Override
-	public void close() {
+	protected void onClose() {
 		fullDocs.close();
 	}
 }

src/main/java/it/cavallium/dbengine/lucene/hugepq/search/HugePqFullFieldDocCollector.java

@@ -485,11 +485,11 @@ public abstract class HugePqFullFieldDocCollector extends
 	}
 
 	@Override
-	public void close() {
+	public void onClose() {
 		this.pq.close();
 		if (this.firstComparator instanceof SafeCloseable closeable) {
 			closeable.close();
 		}
-		super.close();
+		super.onClose();
 	}
 }

src/main/java/it/cavallium/dbengine/lucene/searcher/CountMultiSearcher.java

@@ -11,6 +11,7 @@ import it.cavallium.dbengine.database.disk.LLIndexSearcher;
 import it.cavallium.dbengine.database.disk.LLIndexSearchers;
 import it.cavallium.dbengine.utils.SimpleResource;
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.util.ArrayList;
 import java.util.List;
 import org.apache.logging.log4j.LogManager;
@@ -77,7 +78,7 @@ public class CountMultiSearcher implements MultiSearcher {
 								resultsToDrop.forEach(LLUtils::finalizeResourceNow);
 								try {
 									indexSearchers.close();
-								} catch (IOException e) {
+								} catch (UncheckedIOException e) {
 									LOG.error("Can't close index searchers", e);
 								}
 							});
@@ -122,7 +123,7 @@ public class CountMultiSearcher implements MultiSearcher {
 					.map(count -> new LuceneSearchResult(TotalHitsCount.of(count, true), Flux.empty(), () -> {
 						try {
 							indexSearcher.close();
-						} catch (IOException e) {
+						} catch (UncheckedIOException e) {
 							LOG.error("Can't close index searchers", e);
 						}
 					}));

src/main/java/it/cavallium/dbengine/lucene/searcher/DecimalBucketMultiSearcher.java

@@ -53,10 +53,16 @@ public class DecimalBucketMultiSearcher {
 					bucketParams.collectionRate(),
 					bucketParams.sampleSize()
 			);
-			return Flux.fromIterable(indexSearchers).flatMap(shard -> Mono.fromCallable(() -> {
+			return Flux
-				LLUtils.ensureBlocking();
+					.fromIterable(indexSearchers)
-				return cmm.search(shard);
+					.flatMap(shard -> Mono.fromCallable(() -> {
-			})).collectList().flatMap(results -> Mono.fromSupplier(() -> cmm.reduce(results)));
+						LLUtils.ensureBlocking();
+						return cmm.search(shard);
+					}))
+					.collectList()
+					.flatMap(results -> Mono.fromSupplier(() -> cmm.reduce(results)))
+					.subscribeOn(uninterruptibleScheduler(Schedulers.boundedElastic()))
+					.publishOn(Schedulers.parallel());
 		});
 	}
 }

src/main/java/it/cavallium/dbengine/lucene/searcher/PagedLocalSearcher.java

@@ -14,6 +14,7 @@ import it.cavallium.dbengine.database.disk.LLIndexSearchers;
 import it.cavallium.dbengine.lucene.LuceneUtils;
 import it.cavallium.dbengine.lucene.collector.TopDocsCollectorMultiManager;
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.util.Arrays;
 import java.util.List;
 import org.apache.logging.log4j.LogManager;
@@ -69,7 +70,7 @@ public class PagedLocalSearcher implements LocalSearcher {
 							() -> {
 								try {
 									indexSearcher.close();
-								} catch (IOException e) {
+								} catch (UncheckedIOException e) {
 									LOG.error(e);
 								}
 							}

src/main/java/it/cavallium/dbengine/lucene/searcher/ScoredPagedMultiSearcher.java

@@ -13,6 +13,7 @@ import it.cavallium.dbengine.lucene.LuceneUtils;
 import it.cavallium.dbengine.lucene.PageLimits;
 import it.cavallium.dbengine.lucene.collector.ScoringShardsCollectorMultiManager;
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.util.Arrays;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicReference;
@@ -68,7 +69,7 @@ public class ScoredPagedMultiSearcher implements MultiSearcher {
 								() -> {
 									try {
 										indexSearchers.close();
-									} catch (IOException e) {
+									} catch (UncheckedIOException e) {
 										LOG.error("Can't close index searchers", e);
 									}
 								}

src/main/java/it/cavallium/dbengine/lucene/searcher/SortedByScoreFullMultiSearcher.java

@@ -13,6 +13,7 @@ import it.cavallium.dbengine.lucene.FullDocs;
 import it.cavallium.dbengine.lucene.LLScoreDoc;
 import it.cavallium.dbengine.lucene.hugepq.search.HugePqFullScoreDocCollector;
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.apache.lucene.search.IndexSearcher;
@@ -124,7 +125,7 @@ public class SortedByScoreFullMultiSearcher implements MultiSearcher {
 			return new LuceneSearchResult(totalHitsCount, hitsFlux, () -> {
 				try {
 					indexSearchers.close();
-				} catch (IOException e) {
+				} catch (UncheckedIOException e) {
 					LOG.error("Can't close index searchers", e);
 				}
 				try {

src/main/java/it/cavallium/dbengine/lucene/searcher/SortedScoredFullMultiSearcher.java

@@ -13,6 +13,7 @@ import it.cavallium.dbengine.lucene.LLFieldDoc;
 import it.cavallium.dbengine.lucene.LuceneUtils;
 import it.cavallium.dbengine.lucene.hugepq.search.HugePqFullFieldDocCollector;
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.apache.lucene.search.IndexSearcher;
@@ -118,7 +119,7 @@ public class SortedScoredFullMultiSearcher implements MultiSearcher {
 			return new LuceneSearchResult(totalHitsCount, hitsFlux, () -> {
 				try {
 					indexSearchers.close();
-				} catch (IOException e) {
+				} catch (UncheckedIOException e) {
 					LOG.error("Can't close index searchers", e);
 				}
 				data.close();

src/main/java/it/cavallium/dbengine/lucene/searcher/StandardSearcher.java

@@ -9,6 +9,7 @@ import it.cavallium.dbengine.database.LLUtils;
 import it.cavallium.dbengine.database.disk.LLIndexSearchers;
 import it.cavallium.dbengine.lucene.LuceneUtils;
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.util.List;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
@@ -143,7 +144,7 @@ public class StandardSearcher implements MultiSearcher {
 			return new LuceneSearchResult(totalHitsCount, hitsFlux, () -> {
 				try {
 					indexSearchers.close();
-				} catch (IOException e) {
+				} catch (UncheckedIOException e) {
 					LOG.error("Can't close index searchers", e);
 				}
 			});

src/main/java/it/cavallium/dbengine/lucene/searcher/UnsortedStreamingMultiSearcher.java

@@ -11,6 +11,7 @@ import it.cavallium.dbengine.database.disk.LLIndexSearchers;
 import it.cavallium.dbengine.lucene.LuceneUtils;
 import it.cavallium.dbengine.lucene.MaxScoreAccumulator;
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.util.List;
 import it.cavallium.dbengine.lucene.hugepq.search.CustomHitsThresholdChecker;
 import org.apache.logging.log4j.LogManager;
@@ -62,7 +63,7 @@ public class UnsortedStreamingMultiSearcher implements MultiSearcher {
 				return new LuceneSearchResult(totalHitsCount, mergedFluxes, () -> {
 					try {
 						indexSearchers.close();
-					} catch (IOException e) {
+					} catch (UncheckedIOException e) {
 						LOG.error("Can't close index searchers", e);
 					}
 				});

src/main/java/it/cavallium/dbengine/utils/SimpleResource.java

@@ -24,8 +24,15 @@ public abstract class SimpleResource implements SafeCloseable {
 	}
 
 	protected SimpleResource(boolean canClose) {
+		this(canClose, new AtomicBoolean());
+	}
+
+	protected SimpleResource(AtomicBoolean closed) {
+		this(true, closed);
+	}
+
+	private SimpleResource(boolean canClose, AtomicBoolean closed) {
 		this.canClose = canClose;
-		var closed = new AtomicBoolean();
 		this.closed = closed;
 
 		if (ENABLE_LEAK_DETECTION && canClose) {
@@ -53,10 +60,14 @@ public abstract class SimpleResource implements SafeCloseable {
 		}
 	}
 
-	private boolean isClosed() {
+	protected boolean isClosed() {
 		return canClose && closed.get();
 	}
 
+	protected AtomicBoolean getClosed() {
+		return closed;
+	}
+
 	protected void ensureOpen() {
 		if (canClose && closed.get()) {
 			throw new IllegalStateException("Resource is closed");

src/test/java/it/cavallium/dbengine/PriorityQueueAdaptor.java

@@ -1,6 +1,7 @@
 package it.cavallium.dbengine;
 
 import it.cavallium.dbengine.lucene.PriorityQueue;
+import it.cavallium.dbengine.utils.SimpleResource;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
@@ -8,7 +9,7 @@ import java.util.Objects;
 import org.apache.lucene.search.HitQueue;
 import reactor.core.publisher.Flux;
 
-public class PriorityQueueAdaptor<T> implements PriorityQueue<T> {
+public class PriorityQueueAdaptor<T> extends SimpleResource implements PriorityQueue<T> {
 	
 	private final org.apache.lucene.util.PriorityQueue<T> hitQueue;
 
@@ -72,7 +73,7 @@ public class PriorityQueueAdaptor<T> implements PriorityQueue<T> {
 	}
 
 	@Override
-	public void close() {
+	protected void onClose() {
 		hitQueue.clear();
 		hitQueue.updateTop();
 	}

src/test/java/it/cavallium/dbengine/UnsortedUnscoredSimpleMultiSearcher.java

@@ -18,6 +18,7 @@ import it.cavallium.dbengine.lucene.searcher.MultiSearcher;
 import it.cavallium.dbengine.lucene.searcher.ShardIndexSearcher;
 import it.cavallium.dbengine.utils.SimpleResource;
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.util.ArrayList;
 import java.util.List;
 import org.apache.logging.log4j.LogManager;
@@ -81,7 +82,7 @@ public class UnsortedUnscoredSimpleMultiSearcher implements MultiSearcher {
 										resultsToDrop.forEach(SimpleResource::close);
 										try {
 											indexSearchers.close();
-										} catch (IOException e) {
+										} catch (UncheckedIOException e) {
 											LOG.error("Can't close index searchers", e);
 										}
 									});