be able to skip automatic closing of a hash resource

src/main/java/net/openhft/chronicle/hash/ChronicleHashBuilder.java

@@ -762,6 +762,17 @@ public interface ChronicleHashBuilder<K, H extends ChronicleHash<K, ?, ?, ?>,
      */
     B setPreShutdownAction(Runnable preShutdownAction);
 
+    /**
+     * Skips the default automatic close configuration on the {@link ChronicleHash} created by
+     * this builder. By setting this to true, the caller agrees to closing the built {@link ChronicleHash}
+     * explicitly. Any pre-shutdown action configured via {@link this#setPreShutdownAction(Runnable)}
+     * won't be executed if skipCloseOnExitHook is set to true.
+     *
+     * @param skipCloseOnExitHook if {@code true}, default automatic close configuration is not enabled.
+     * @return this builder back
+     */
+    B skipCloseOnExitHook(boolean skipCloseOnExitHook);
+
     /**
      * @deprecated don't use private API in the client code
      */

src/main/java/net/openhft/chronicle/hash/ChronicleHashBuilderPrivateAPI.java

@@ -97,4 +97,9 @@ public interface ChronicleHashBuilderPrivateAPI<K, RO> {
      * @return registered pre-shutdown action.
      */
     Runnable getPreShutdownAction();
+
+    /**
+     * Whether to skip closing a {@link ChronicleHash} using the default shutdown hook.
+     */
+    boolean skipCloseOnExitHook();
 }

src/main/java/net/openhft/chronicle/hash/impl/VanillaChronicleHash.java

@@ -126,6 +126,7 @@ public abstract class VanillaChronicleHash<K,
     public transient Identity identity;
     protected int log2TiersInBulk;
     private Runnable preShutdownAction;
+    private boolean skipCloseOnExitHook;
     /////////////////////////////////////////////////
     // Bytes Store (essentially, the base address) and serialization-dependent offsets
     protected transient BytesStore bs;
@@ -211,6 +212,7 @@ public abstract class VanillaChronicleHash<K,
         checksumEntries = privateAPI.checksumEntries();
 
         preShutdownAction = privateAPI.getPreShutdownAction();
+        skipCloseOnExitHook = privateAPI.skipCloseOnExitHook();
     }
 
     public static IOException throwRecoveryOrReturnIOException(
@@ -476,7 +478,9 @@ public abstract class VanillaChronicleHash<K,
     }
 
     public void addToOnExitHook() {
-        ChronicleHashCloseOnExitHook.add(this);
+        if (!skipCloseOnExitHook) {
+            ChronicleHashCloseOnExitHook.add(this);
+        }
     }
 
     public final void createMappedStoreAndSegments(ChronicleHashResources resources)
@@ -664,7 +668,9 @@ public abstract class VanillaChronicleHash<K,
         // Releases nothing after resources.releaseManually(), only removes the cleaner
         // from the internal linked list of all cleaners.
         cleaner.clean();
-        ChronicleHashCloseOnExitHook.remove(this);
+        if (!skipCloseOnExitHook) {
+            ChronicleHashCloseOnExitHook.remove(this);
+        }
         // Make GC life easier
         keyReader = null;
         keyDataAccess = null;

src/main/java/net/openhft/chronicle/map/ChronicleMapBuilder.java

@@ -181,6 +181,7 @@ public final class ChronicleMapBuilder<K, V> implements
     MapEntryOperations<K, V, ?> entryOperations = mapEntryOperations();
     MapRemoteOperations<K, V, ?> remoteOperations = mapRemoteOperations();
     Runnable preShutdownAction;
+    boolean skipCloseOnExitHook = false;
     private String name;
     // not final because of cloning
     private ChronicleMapBuilderPrivateAPI<K, V> privateAPI =
@@ -1607,6 +1608,12 @@ public final class ChronicleMapBuilder<K, V> implements
         return this;
     }
 
+    @Override
+    public ChronicleMapBuilder<K, V> skipCloseOnExitHook(boolean skipCloseOnExitHook) {
+        this.skipCloseOnExitHook = skipCloseOnExitHook;
+        return this;
+    }
+
     @Override
     public ChronicleMap<K, V> create() {
         // clone() to make this builder instance thread-safe, because createWithoutFile() method

src/main/java/net/openhft/chronicle/map/ChronicleMapBuilderPrivateAPI.java

@@ -120,4 +120,9 @@ class ChronicleMapBuilderPrivateAPI<K, V>
     public Runnable getPreShutdownAction() {
         return b.preShutdownAction;
     }
+
+    @Override
+    public boolean skipCloseOnExitHook() {
+        return b.skipCloseOnExitHook;
+    }
 }

src/main/java/net/openhft/chronicle/set/ChronicleSetBuilder.java

@@ -358,6 +358,12 @@ public final class ChronicleSetBuilder<K>
         return this;
     }
 
+    @Override
+    public ChronicleSetBuilder<K> skipCloseOnExitHook(boolean skipCloseOnExitHook) {
+        chronicleMapBuilder.skipCloseOnExitHook(skipCloseOnExitHook);
+        return this;
+    }
+
     /**
      * @deprecated don't use private API in the client code
      */

src/main/java/net/openhft/chronicle/set/ChronicleSetBuilderPrivateAPI.java

@@ -138,4 +138,9 @@ class ChronicleSetBuilderPrivateAPI<K>
     public Runnable getPreShutdownAction() {
         return mapB.getPreShutdownAction();
     }
+
+    @Override
+    public boolean skipCloseOnExitHook() {
+        return mapB.skipCloseOnExitHook();
+    }
 }