/// <summary>test</summary>
 private void PrintStorages(FSImage image)
 {
     FSImageTestUtil.LogStorageContents(Log, image.GetStorage());
 }
        /// <exception cref="System.Exception"/>
        public virtual void TestCancelSaveNamespace()
        {
            Configuration conf = GetConf();

            NameNode.InitMetrics(conf, HdfsServerConstants.NamenodeRole.Namenode);
            DFSTestUtil.FormatNameNode(conf);
            FSNamesystem fsn = FSNamesystem.LoadFromDisk(conf);
            // Replace the FSImage with a spy
            FSImage   image   = fsn.GetFSImage();
            NNStorage storage = image.GetStorage();

            storage.Close();
            // unlock any directories that FSNamesystem's initialization may have locked
            storage.SetStorageDirectories(FSNamesystem.GetNamespaceDirs(conf), FSNamesystem.GetNamespaceEditsDirs
                                              (conf));
            FSNamesystem spyFsn   = Org.Mockito.Mockito.Spy(fsn);
            FSNamesystem finalFsn = spyFsn;

            GenericTestUtils.DelayAnswer delayer = new GenericTestUtils.DelayAnswer(Log);
            BlockIdManager bid = Org.Mockito.Mockito.Spy(spyFsn.GetBlockIdManager());

            Whitebox.SetInternalState(finalFsn, "blockIdManager", bid);
            Org.Mockito.Mockito.DoAnswer(delayer).When(bid).GetGenerationStampV2();
            ExecutorService pool = Executors.NewFixedThreadPool(2);

            try
            {
                DoAnEdit(fsn, 1);
                Canceler canceler = new Canceler();
                // Save namespace
                fsn.SetSafeMode(HdfsConstants.SafeModeAction.SafemodeEnter);
                try
                {
                    Future <Void> saverFuture = pool.Submit(new _Callable_561(image, finalFsn, canceler
                                                                              ));
                    // Wait until saveNamespace calls getGenerationStamp
                    delayer.WaitForCall();
                    // then cancel the saveNamespace
                    Future <Void> cancelFuture = pool.Submit(new _Callable_572(canceler));
                    // give the cancel call time to run
                    Sharpen.Thread.Sleep(500);
                    // allow saveNamespace to proceed - it should check the cancel flag after
                    // this point and throw an exception
                    delayer.Proceed();
                    cancelFuture.Get();
                    saverFuture.Get();
                    NUnit.Framework.Assert.Fail("saveNamespace did not fail even though cancelled!");
                }
                catch (Exception t)
                {
                    GenericTestUtils.AssertExceptionContains("SaveNamespaceCancelledException", t);
                }
                Log.Info("Successfully cancelled a saveNamespace");
                // Check that we have only the original image and not any
                // cruft left over from half-finished images
                FSImageTestUtil.LogStorageContents(Log, storage);
                foreach (Storage.StorageDirectory sd in storage.DirIterable(null))
                {
                    FilePath curDir = sd.GetCurrentDir();
                    GenericTestUtils.AssertGlobEquals(curDir, "fsimage_.*", NNStorage.GetImageFileName
                                                          (0), NNStorage.GetImageFileName(0) + MD5FileUtils.Md5Suffix);
                }
            }
            finally
            {
                fsn.Close();
            }
        }