SOLR-4463: Fix SolrCoreState reference counting.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1446716 13f79535-47bb-0310-9956-ffa450edef68

solr/CHANGES.txt

@@ -123,6 +123,8 @@ Bug Fixes
 * SOLR-4426: NRTCachingDirectoryFactory does not initialize maxCachedMB and maxMergeSizeMB
   if <directoryFactory> is not present in solrconfig.xml (Jack Krupansky via shalin)
 
+* SOLR-4463: Fix SolrCoreState reference counting. (Mark Miller)
+
 Optimizations
 ----------------------
 

solr/core/src/java/org/apache/solr/core/SolrCore.java

@@ -44,7 +44,6 @@ import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.Future;
-import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.concurrent.locks.ReentrantLock;
@@ -150,7 +149,6 @@ public final class SolrCore implements SolrInfoMBean {
   private final String dataDir;
   private final UpdateHandler updateHandler;
   private final SolrCoreState solrCoreState;
-  private int solrCoreStateRefCnt = 1;
   
   private final long startTime;
   private final RequestHandlers reqHandlers;
@@ -396,7 +394,7 @@ public final class SolrCore implements SolrInfoMBean {
     IndexSchema schema = new IndexSchema(config,
         getSchema().getResourceName(), null);
     
-    increfSolrCoreState();
+    solrCoreState.increfSolrCoreState();
     
     SolrCore core = new SolrCore(getName(), getDataDir(), config,
         schema, coreDescriptor, updateHandler, prev);
@@ -867,32 +865,6 @@ public final class SolrCore implements SolrInfoMBean {
   public SolrCoreState getSolrCoreState() {
     return solrCoreState;
   }  
-  
-  private void increfSolrCoreState() {
-    synchronized (solrCoreState) {
-      if (solrCoreStateRefCnt == 0) {
-        throw new IllegalStateException("IndexWriter has been closed");
-      }
-      solrCoreStateRefCnt++;
-    }
-  }
-  
-  private void decrefSolrCoreState(IndexWriterCloser closer) {
-    synchronized (solrCoreState) {
-      
-      solrCoreStateRefCnt--;
-      if (solrCoreStateRefCnt == 0) {
-
-        try {
-          log.info("Closing SolrCoreState");
-          solrCoreState.close(closer);
-        } catch (Throwable t) {
-          log.error("Error closing SolrCoreState", t);
-        }
-        
-      }
-    }
-  }
 
   /**
    * @return an update processor registered to the given name.  Throw an exception if this chain is undefined
@@ -976,10 +948,12 @@ public final class SolrCore implements SolrInfoMBean {
     }
     
     try {
-      if (updateHandler instanceof IndexWriterCloser) {
-        decrefSolrCoreState((IndexWriterCloser) updateHandler);
-      } else {
-        decrefSolrCoreState(null);
+      if (solrCoreState != null) {
+        if (updateHandler instanceof IndexWriterCloser) {
+          solrCoreState.decrefSolrCoreState((IndexWriterCloser) updateHandler);
+        } else {
+          solrCoreState.decrefSolrCoreState(null);
+        }
       }
     } catch (Throwable e) {
       SolrException.log(log, e);
@@ -1005,15 +979,14 @@ public final class SolrCore implements SolrInfoMBean {
     }
     
     if (solrCoreState != null) { // bad startup case
-      synchronized (solrCoreState) {
-        if (solrCoreStateRefCnt == 0) {
-          try {
-            directoryFactory.close();
-          } catch (Throwable t) {
-            SolrException.log(log, t);
-          }
+      if (solrCoreState.getSolrCoreStateRefCnt() == 0) {
+        try {
+          directoryFactory.close();
+        } catch (Throwable t) {
+          SolrException.log(log, t);
         }
       }
+      
     }
 
     

solr/core/src/java/org/apache/solr/update/SolrCoreState.java

@@ -25,6 +25,8 @@ import org.apache.solr.core.CoreContainer;
 import org.apache.solr.core.DirectoryFactory;
 import org.apache.solr.core.SolrCore;
 import org.apache.solr.util.RefCounted;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * The state in this class can be easily shared between SolrCores across
@@ -32,12 +34,46 @@ import org.apache.solr.util.RefCounted;
  * 
  */
 public abstract class SolrCoreState {
+  public static Logger log = LoggerFactory.getLogger(SolrCoreState.class);
+  
   private final Object deleteLock = new Object();
   
   public Object getUpdateLock() {
     return deleteLock;
   }
   
+  private int solrCoreStateRefCnt = 1;
+  
+  public synchronized int getSolrCoreStateRefCnt() {
+    return solrCoreStateRefCnt;
+  }
+
+  public void increfSolrCoreState() {
+    synchronized (this) {
+      if (solrCoreStateRefCnt == 0) {
+        throw new IllegalStateException("IndexWriter has been closed");
+      }
+      solrCoreStateRefCnt++;
+    }
+  }
+  
+  public void decrefSolrCoreState(IndexWriterCloser closer) {
+    synchronized (this) {
+      
+      solrCoreStateRefCnt--;
+      if (solrCoreStateRefCnt == 0) {
+
+        try {
+          log.info("Closing SolrCoreState");
+          close(closer);
+        } catch (Throwable t) {
+          log.error("Error closing SolrCoreState", t);
+        }
+        
+      }
+    }
+  }
+  
   public abstract Lock getCommitLock();
   
   /**

solr/core/src/test/org/apache/solr/core/TestCoreContainer.java

@@ -22,6 +22,8 @@ import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.OutputStreamWriter;
+import java.util.ArrayList;
+import java.util.List;
 
 import javax.xml.parsers.ParserConfigurationException;
 import javax.xml.xpath.XPathExpressionException;
@@ -77,6 +79,33 @@ public class TestCoreContainer extends SolrTestCaseJ4 {
       System.clearProperty("shareSchema");
     }
   }
+  
+  @Test
+  public void testReload() throws Exception {
+    final CoreContainer cc = h.getCoreContainer();
+    
+    class TestThread extends Thread {
+      @Override
+      public void run() {
+        cc.reload("collection1");
+      }
+    }
+    
+    List<Thread> threads = new ArrayList<Thread>();
+    int numThreads = 4;
+    for (int i = 0; i < numThreads; i++) {
+      threads.add(new TestThread());
+    }
+    
+    for (Thread thread : threads) {
+      thread.start();
+    }
+    
+    for (Thread thread : threads) {
+      thread.join();
+    }
+
+  }
 
   @Test
   public void testPersist() throws Exception {