diff --git a/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/BackgroundJobWorker.cs b/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/BackgroundJobWorker.cs
index f23ecbf239..b2a66f6fc4 100644
--- a/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/BackgroundJobWorker.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/BackgroundJobWorker.cs
@@ -4,13 +4,12 @@ using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 using Volo.Abp.BackgroundWorkers;
-using Volo.Abp.DependencyInjection;
 using Volo.Abp.Threading;
 using Volo.Abp.Timing;
 
 namespace Volo.Abp.BackgroundJobs
 {
-    public class BackgroundJobWorker : PeriodicBackgroundWorkerBase, IBackgroundJobWorker, ISingletonDependency
+    public class BackgroundJobWorker : PeriodicBackgroundWorkerBase, IBackgroundJobWorker
     {
         protected BackgroundJobOptions JobOptions { get; }
 
diff --git a/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/DefaultBackgroundJobManager.cs b/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/DefaultBackgroundJobManager.cs
index 0c8aff450c..0994029f70 100644
--- a/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/DefaultBackgroundJobManager.cs
+++ b/framework/src/Volo.Abp.BackgroundJobs/Volo/Abp/BackgroundJobs/DefaultBackgroundJobManager.cs
@@ -10,7 +10,7 @@ namespace Volo.Abp.BackgroundJobs
     /// Default implementation of <see cref="IBackgroundJobManager"/>.
     /// </summary>
     [Dependency(ReplaceServices = true)]
-    public class DefaultBackgroundJobManager : IBackgroundJobManager, ISingletonDependency
+    public class DefaultBackgroundJobManager : IBackgroundJobManager, ITransientDependency
     {
         protected IClock Clock { get; }
         protected IBackgroundJobSerializer Serializer { get; }
diff --git a/framework/src/Volo.Abp.BackgroundWorkers/Volo/Abp/BackgroundWorkers/BackgroundWorkerManager.cs b/framework/src/Volo.Abp.BackgroundWorkers/Volo/Abp/BackgroundWorkers/BackgroundWorkerManager.cs
index 16c9f08d10..6f8d57ed5c 100644
--- a/framework/src/Volo.Abp.BackgroundWorkers/Volo/Abp/BackgroundWorkers/BackgroundWorkerManager.cs
+++ b/framework/src/Volo.Abp.BackgroundWorkers/Volo/Abp/BackgroundWorkers/BackgroundWorkerManager.cs
@@ -26,7 +26,7 @@ namespace Volo.Abp.BackgroundWorkers
             _backgroundWorkers = new List<IBackgroundWorker>();
         }
 
-        public void Add(IBackgroundWorker worker)
+        public virtual void Add(IBackgroundWorker worker)
         {
             _backgroundWorkers.Add(worker);
 
@@ -36,7 +36,7 @@ namespace Volo.Abp.BackgroundWorkers
             }
         }
 
-        public void Dispose()
+        public virtual void Dispose()
         {
             if (_isDisposed)
             {
@@ -48,7 +48,7 @@ namespace Volo.Abp.BackgroundWorkers
             //TODO: ???
         }
 
-        public async Task StartAsync(CancellationToken cancellationToken = default)
+        public virtual async Task StartAsync(CancellationToken cancellationToken = default)
         {
             IsRunning = true;
 
@@ -58,7 +58,7 @@ namespace Volo.Abp.BackgroundWorkers
             }
         }
 
-        public async Task StopAsync(CancellationToken cancellationToken = default)
+        public virtual async Task StopAsync(CancellationToken cancellationToken = default)
         {
             IsRunning = false;
 
diff --git a/framework/src/Volo.Abp.BackgroundWorkers/Volo/Abp/BackgroundWorkers/IBackgroundWorker.cs b/framework/src/Volo.Abp.BackgroundWorkers/Volo/Abp/BackgroundWorkers/IBackgroundWorker.cs
index 1aec158155..6f514172e7 100644
--- a/framework/src/Volo.Abp.BackgroundWorkers/Volo/Abp/BackgroundWorkers/IBackgroundWorker.cs
+++ b/framework/src/Volo.Abp.BackgroundWorkers/Volo/Abp/BackgroundWorkers/IBackgroundWorker.cs
@@ -1,11 +1,12 @@
-using Volo.Abp.Threading;
+using Volo.Abp.DependencyInjection;
+using Volo.Abp.Threading;
 
 namespace Volo.Abp.BackgroundWorkers
 {
     /// <summary>
     /// Interface for a worker (thread) that runs on background to perform some tasks.
     /// </summary>
-    public interface IBackgroundWorker : IRunnable
+    public interface IBackgroundWorker : IRunnable, ISingletonDependency
     {
 
     }
diff --git a/framework/src/Volo.Abp.ObjectMapping/Volo/Abp/ObjectMapping/DefaultObjectMapper.cs b/framework/src/Volo.Abp.ObjectMapping/Volo/Abp/ObjectMapping/DefaultObjectMapper.cs
index f76ddad634..b746ab3973 100644
--- a/framework/src/Volo.Abp.ObjectMapping/Volo/Abp/ObjectMapping/DefaultObjectMapper.cs
+++ b/framework/src/Volo.Abp.ObjectMapping/Volo/Abp/ObjectMapping/DefaultObjectMapper.cs
@@ -6,7 +6,7 @@ namespace Volo.Abp.ObjectMapping
 {
     //TODO: It can be slow to always check if service is available. Test it and optimize if necessary.
 
-    public class DefaultObjectMapper : IObjectMapper, ISingletonDependency
+    public class DefaultObjectMapper : IObjectMapper, ITransientDependency
     {
         private readonly IServiceProvider _serviceProvider;
 
diff --git a/framework/src/Volo.Abp.Threading/Volo/Abp/Linq/DefaultAsyncQueryableExecuter.cs b/framework/src/Volo.Abp.Threading/Volo/Abp/Linq/DefaultAsyncQueryableExecuter.cs
index 8018bf7e87..2a5da24a58 100644
--- a/framework/src/Volo.Abp.Threading/Volo/Abp/Linq/DefaultAsyncQueryableExecuter.cs
+++ b/framework/src/Volo.Abp.Threading/Volo/Abp/Linq/DefaultAsyncQueryableExecuter.cs
@@ -2,14 +2,18 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
-using Volo.Abp.DependencyInjection;
 
 namespace Volo.Abp.Linq
 {
-    public class DefaultAsyncQueryableExecuter : IAsyncQueryableExecuter, ISingletonDependency
+    public class DefaultAsyncQueryableExecuter : IAsyncQueryableExecuter
     {
         public static DefaultAsyncQueryableExecuter Instance { get; } = new DefaultAsyncQueryableExecuter();
 
+        private DefaultAsyncQueryableExecuter()
+        {
+            
+        }
+
         public Task<int> CountAsync<T>(IQueryable<T> queryable)
         {
             return Task.FromResult(queryable.Count());
diff --git a/framework/src/Volo.Abp.Threading/Volo/Abp/Threading/AbpThreadingModule.cs b/framework/src/Volo.Abp.Threading/Volo/Abp/Threading/AbpThreadingModule.cs
index bf72d3ce44..14bb90834e 100644
--- a/framework/src/Volo.Abp.Threading/Volo/Abp/Threading/AbpThreadingModule.cs
+++ b/framework/src/Volo.Abp.Threading/Volo/Abp/Threading/AbpThreadingModule.cs
@@ -1,4 +1,5 @@
 using Microsoft.Extensions.DependencyInjection;
+using Volo.Abp.Linq;
 using Volo.Abp.Modularity;
 
 namespace Volo.Abp.Threading
@@ -7,6 +8,7 @@ namespace Volo.Abp.Threading
     {
         public override void ConfigureServices(ServiceConfigurationContext context)
         {
+            context.Services.AddSingleton<IAsyncQueryableExecuter>(DefaultAsyncQueryableExecuter.Instance);
             context.Services.AddSingleton<ICancellationTokenProvider>(NullCancellationTokenProvider.Instance);
             context.Services.AddSingleton(typeof(IAmbientScopeProvider<>), typeof(AmbientDataContextAmbientScopeProvider<>));
         }
diff --git a/framework/src/Volo.Abp.VirtualFileSystem/Volo/Abp/VirtualFileSystem/DynamicFileProvider.cs b/framework/src/Volo.Abp.VirtualFileSystem/Volo/Abp/VirtualFileSystem/DynamicFileProvider.cs
index dcf95222ce..a270616e3a 100644
--- a/framework/src/Volo.Abp.VirtualFileSystem/Volo/Abp/VirtualFileSystem/DynamicFileProvider.cs
+++ b/framework/src/Volo.Abp.VirtualFileSystem/Volo/Abp/VirtualFileSystem/DynamicFileProvider.cs
@@ -21,11 +21,11 @@ namespace Volo.Abp.VirtualFileSystem
 
         protected ConcurrentDictionary<string, IFileInfo> DynamicFiles { get; }
 
-        private readonly ConcurrentDictionary<string, ChangeTokenInfo> _filePathTokenLookup =
-            new ConcurrentDictionary<string, ChangeTokenInfo>(StringComparer.OrdinalIgnoreCase);
+        protected ConcurrentDictionary<string, ChangeTokenInfo> FilePathTokenLookup { get; }
 
         public DynamicFileProvider()
         {
+            FilePathTokenLookup = new ConcurrentDictionary<string, ChangeTokenInfo>(StringComparer.OrdinalIgnoreCase);;
             DynamicFiles = new ConcurrentDictionary<string, IFileInfo>();
         }
 
@@ -53,12 +53,12 @@ namespace Volo.Abp.VirtualFileSystem
 
         private IChangeToken GetOrAddChangeToken(string filePath)
         {
-            if (!_filePathTokenLookup.TryGetValue(filePath, out var tokenInfo))
+            if (!FilePathTokenLookup.TryGetValue(filePath, out var tokenInfo))
             {
                 var cancellationTokenSource = new CancellationTokenSource();
                 var cancellationChangeToken = new CancellationChangeToken(cancellationTokenSource.Token);
                 tokenInfo = new ChangeTokenInfo(cancellationTokenSource, cancellationChangeToken);
-                tokenInfo = _filePathTokenLookup.GetOrAdd(filePath, tokenInfo);
+                tokenInfo = FilePathTokenLookup.GetOrAdd(filePath, tokenInfo);
             }
 
             return tokenInfo.ChangeToken;
@@ -66,13 +66,13 @@ namespace Volo.Abp.VirtualFileSystem
 
         private void ReportChange(string filePath)
         {
-            if (_filePathTokenLookup.TryRemove(filePath, out var tokenInfo))
+            if (FilePathTokenLookup.TryRemove(filePath, out var tokenInfo))
             {
                 tokenInfo.TokenSource.Cancel();
             }
         }
 
-        private struct ChangeTokenInfo
+        protected struct ChangeTokenInfo
         {
             public ChangeTokenInfo(
                 CancellationTokenSource tokenSource,