Merge pull request #1657 from h2database/panic-bkg

Failure to stop background thread

h2/src/main/org/h2/mvstore/FileStore.java

@@ -186,21 +186,20 @@ public class FileStore {
      * Close this store.
      */
     public void close() {
-        if(file != null) {
-            try {
+        try {
+            if(file != null && file.isOpen()) {
                 if (fileLock != null) {
                     fileLock.release();
-                    fileLock = null;
                 }
                 file.close();
-                freeSpace.clear();
-            } catch (Exception e) {
-                throw DataUtils.newIllegalStateException(
-                        DataUtils.ERROR_WRITING_FAILED,
-                        "Closing failed for file {0}", fileName, e);
-            } finally {
-                file = null;
             }
+        } catch (Exception e) {
+            throw DataUtils.newIllegalStateException(
+                    DataUtils.ERROR_WRITING_FAILED,
+                    "Closing failed for file {0}", fileName, e);
+        } finally {
+            fileLock = null;
+            file = null;
         }
     }
 

h2/src/main/org/h2/mvstore/MVStore.java

@@ -2845,19 +2845,20 @@ public class MVStore implements AutoCloseable {
         // which should not happen with non-weak flavour of CAS operation,
         // but I've seen it, so just to be safe...
         BackgroundWriterThread t;
-        while ((t = backgroundWriterThread.get()) != null &&
-                // if called from within the thread itself - can not join
-                t != Thread.currentThread()) {
+        while ((t = backgroundWriterThread.get()) != null) {
             if (backgroundWriterThread.compareAndSet(t, null)) {
-                synchronized (t.sync) {
-                    t.sync.notifyAll();
-                }
+                // if called from within the thread itself - can not join
+                if (t != Thread.currentThread()) {
+                    synchronized (t.sync) {
+                        t.sync.notifyAll();
+                    }
 
-                if (waitForIt) {
-                    try {
-                        t.join();
-                    } catch (Exception e) {
-                        // ignore
+                    if (waitForIt) {
+                        try {
+                            t.join();
+                        } catch (Exception e) {
+                            // ignore
+                        }
                     }
                 }
                 break;