SOLR-10104: BlockDirectoryCache release hooks do not work with multiple directories.

# Conflicts:
#	solr/CHANGES.txt

solr/CHANGES.txt

@@ -157,6 +157,8 @@ Bug Fixes
 
 * SOLR-10063: CoreContainer shutdown has race condition that can cause a hang on shutdown. (Mark Miller)
 
+* SOLR-10104: BlockDirectoryCache release hooks do not work with multiple directories. (Mike Drob, Mark Miller)
+
 Optimizations
 ----------------------
 

solr/core/src/java/org/apache/solr/store/blockcache/BlockCache.java

@@ -17,6 +17,8 @@
 package org.apache.solr.store.blockcache;
 
 import java.nio.ByteBuffer;
+import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.atomic.AtomicInteger;
 
 import com.github.benmanes.caffeine.cache.Cache;
@@ -38,8 +40,8 @@ public class BlockCache {
   private final int numberOfBlocksPerBank;
   private final int maxEntries;
   private final Metrics metrics;
-  private volatile OnRelease onRelease;
-  
+  private final List<OnRelease> onReleases = new CopyOnWriteArrayList<>();
+
   public static interface OnRelease {
     public void release(BlockCacheKey blockCacheKey);
   }
@@ -95,7 +97,7 @@ public class BlockCache {
     location.setRemoved(true);
     locks[bankId].clear(block);
     lockCounters[bankId].decrementAndGet();
-    if (onRelease != null) {
+    for (OnRelease onRelease : onReleases) {
       onRelease.release(blockCacheKey);
     }
     metrics.blockCacheEviction.incrementAndGet();
@@ -239,6 +241,6 @@ public class BlockCache {
   }
 
   void setOnRelease(OnRelease onRelease) {
-    this.onRelease = onRelease;
+    this.onReleases.add(onRelease);
   }
 }

solr/test-framework/src/java/org/apache/solr/cloud/MiniSolrCloudCluster.java

@@ -457,7 +457,7 @@ public class MiniSolrCloudCluster {
       }
     } finally {
       executor.shutdown();
-      executor.awaitTermination(2, TimeUnit.SECONDS);
+      executor.awaitTermination(15, TimeUnit.SECONDS);
       try {
         if (!externalZkServer) {
           zkServer.shutdown();