Make OldDeletedCleanupThread daemon and don't wait for this thread to cease in ReplicatedChronicleMap.close(), because if the thread is already dead by the time cleanupThread.join() is called, this call hangs

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

@@ -1811,19 +1811,6 @@ public final class ChronicleMapBuilder<K, V> implements
         OldDeletedEntriesCleanupThread cleanupThread = new OldDeletedEntriesCleanupThread(map);
         map.addCloseable(cleanupThread);
         cleanupThread.start();
-        // WARNING this relies on the fact that ReplicatedChronicleMap closes closeables in the same
-        // order as they are added, i. e. OldDeletedEntriesCleanupThread instance close()d before
-        // the following closeable
-        String mapIdentityString = map.toIdentityString();
-        map.addCloseable(() -> {
-            try {
-                cleanupThread.join();
-            } catch (InterruptedException e) {
-                LOG.warn(mapIdentityString +
-                        ": Interrupted while waiting for the cleanup thread to cease");
-                Thread.currentThread().interrupt();
-            }
-        });
     }
 
     /**

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

@@ -76,6 +76,7 @@ class OldDeletedEntriesCleanupThread extends Thread
 
     OldDeletedEntriesCleanupThread(ReplicatedChronicleMap<?, ?, ?> map) {
         super("Cleanup Thread for " + map.toIdentityString());
+        setDaemon(true);
         this.mapRef = new WeakReference<>(map);
         cleanupTimeout = map.cleanupTimeout;
         cleanupTimeoutUnit = map.cleanupTimeoutUnit;