retry intermittent truncate failures on windows

close file/release lock on failures

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

@@ -168,12 +168,14 @@ public class FileStore {
                         "The file is locked: {0}", fileName, e);
             }
             if (fileLock == null) {
+                try { close(); } catch (Exception ignore) {}
                 throw DataUtils.newIllegalStateException(
                         DataUtils.ERROR_FILE_LOCKED,
                         "The file is locked: {0}", fileName);
             }
             fileSize = file.size();
         } catch (IOException e) {
+            try { close(); } catch (Exception ignore) {}
             throw DataUtils.newIllegalStateException(
                     DataUtils.ERROR_READING_FAILED,
                     "Could not open file {0}", fileName, e);
@@ -184,6 +186,7 @@ public class FileStore {
      * Close this store.
      */
     public void close() {
+        if(file != null) {
             try {
                 if (fileLock != null) {
                     fileLock.release();
@@ -199,11 +202,13 @@ public class FileStore {
                 file = null;
             }
         }
+    }
 
     /**
      * Flush all changes.
      */
     public void sync() {
+        if (file != null) {
             try {
                 file.force(true);
             } catch (IOException e) {
@@ -212,6 +217,7 @@ public class FileStore {
                         "Could not sync file {0}", fileName, e);
             }
         }
+    }
 
     /**
      * Get the file size.
@@ -228,16 +234,24 @@ public class FileStore {
      * @param size the new file size
      */
     public void truncate(long size) {
+        int attemptCount = 0;
+        while (true) {
             try {
                 writeCount.incrementAndGet();
                 file.truncate(size);
                 fileSize = Math.min(fileSize, size);
+                return;
             } catch (IOException e) {
+                if (++attemptCount == 10) {
                     throw DataUtils.newIllegalStateException(
                             DataUtils.ERROR_WRITING_FAILED,
                             "Could not truncate file {0} to size {1}",
                             fileName, size, e);
                 }
+                System.gc();
+                Thread.yield();
+            }
+        }
     }
 
     /**