Merge pull request #112 from aspnetzero/uow-enhancements

Uow enhancements

Volo.Abp.sln

@@ -138,6 +138,7 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Volo.Abp.Identity.Domain",
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Volo.Abp.Identity.Domain.Shared", "src\Volo.Abp.Identity.Domain.Shared\Volo.Abp.Identity.Domain.Shared.csproj", "{DF676F73-3FC9-46CE-909A-2D75E19982AD}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Volo.Abp.EntityFrameworkCore.Tests", "test\Volo.Abp.EntityFrameworkCore.Tests\Volo.Abp.EntityFrameworkCore.Tests.csproj", "{3AF7C7F5-6513-47D4-8DD0-6E1AF14568D8}"
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SimpleConsoleDemo", "test\SimpleConsoleDemo\SimpleConsoleDemo.csproj", "{2B48CF90-DBDB-469F-941C-5B5AECEEACE0}"
 EndProject
 Global
@@ -350,6 +351,10 @@ Global
 		{DF676F73-3FC9-46CE-909A-2D75E19982AD}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{DF676F73-3FC9-46CE-909A-2D75E19982AD}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{DF676F73-3FC9-46CE-909A-2D75E19982AD}.Release|Any CPU.Build.0 = Release|Any CPU
+		{3AF7C7F5-6513-47D4-8DD0-6E1AF14568D8}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{3AF7C7F5-6513-47D4-8DD0-6E1AF14568D8}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{3AF7C7F5-6513-47D4-8DD0-6E1AF14568D8}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{3AF7C7F5-6513-47D4-8DD0-6E1AF14568D8}.Release|Any CPU.Build.0 = Release|Any CPU
 		{2B48CF90-DBDB-469F-941C-5B5AECEEACE0}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{2B48CF90-DBDB-469F-941C-5B5AECEEACE0}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{2B48CF90-DBDB-469F-941C-5B5AECEEACE0}.Release|Any CPU.ActiveCfg = Release|Any CPU
@@ -419,6 +424,7 @@ Global
 		{40E21A35-1C66-4E89-A16E-0475011F7EFD} = {146F561E-C7B8-4166-9383-47E1BC1A2E62}
 		{43D4005C-4F04-4128-937B-52BEAC5A113B} = {1895A5C9-50D4-4568-9A3A-14657E615A5E}
 		{DF676F73-3FC9-46CE-909A-2D75E19982AD} = {1895A5C9-50D4-4568-9A3A-14657E615A5E}
+		{3AF7C7F5-6513-47D4-8DD0-6E1AF14568D8} = {37087D1B-3693-4E96-983D-A69F210BDE53}
 		{2B48CF90-DBDB-469F-941C-5B5AECEEACE0} = {37087D1B-3693-4E96-983D-A69F210BDE53}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution

src/Volo.Abp.AspNetCore.Mvc/Microsoft/AspNetCore/Builder/AbpAspNetCoreMvcApplicationBuilderExtensions.cs

@@ -0,0 +1,12 @@
+using Volo.Abp.AspNetCore.Mvc.Uow;
+
+namespace Microsoft.AspNetCore.Builder
+{
+    public static class AbpAspNetCoreMvcApplicationBuilderExtensions
+    {
+        public static IApplicationBuilder UseUnitOfWork(this IApplicationBuilder app)
+        {
+            return app.UseMiddleware<AbpUnitOfWorkMiddleware>();
+        }
+    }
+}

src/Volo.Abp.AspNetCore.Mvc/Volo/Abp/AspNetCore/Mvc/AbpController.cs

@@ -1,10 +1,27 @@
-using Microsoft.AspNetCore.Mvc;
+using System;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Logging.Abstractions;
 using Volo.Abp.DependencyInjection;
+using Volo.Abp.Guids;
+using Volo.Abp.ObjectMapping;
+using Volo.Abp.Uow;
 
 namespace Volo.Abp.AspNetCore.Mvc
 {
     public abstract class AbpController : Controller, ITransientDependency
     {
+        public IUnitOfWorkManager UnitOfWorkManager { get; set; }
 
+        public IObjectMapper ObjectMapper { get; set; }
+
+        public IGuidGenerator GuidGenerator { get; set; }
+
+        public ILoggerFactory LoggerFactory { get; set; }
+
+        protected IUnitOfWork CurrentUnitOfWork => UnitOfWorkManager?.Current;
+
+        protected ILogger Logger => _lazyLogger.Value;
+        private Lazy<ILogger> _lazyLogger => new Lazy<ILogger>(() => LoggerFactory?.CreateLogger(GetType().FullName) ?? NullLogger.Instance, true);
     }
 }

src/Volo.Abp.AspNetCore.Mvc/Volo/Abp/AspNetCore/Mvc/AbpMvcOptionsExtensions.cs

@@ -1,6 +1,7 @@
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.DependencyInjection;
 using Volo.Abp.AspNetCore.Mvc.ExceptionHandling;
+using Volo.Abp.AspNetCore.Mvc.Uow;
 using Volo.Abp.AspNetCore.Mvc.Validation;
 
 namespace Volo.Abp.AspNetCore.Mvc
@@ -24,7 +25,7 @@ namespace Volo.Abp.AspNetCore.Mvc
             //options.Filters.AddService(typeof(AbpAuthorizationFilter));
             //options.Filters.AddService(typeof(AbpAuditActionFilter));
             options.Filters.AddService(typeof(AbpValidationActionFilter));
-            //options.Filters.AddService(typeof(AbpUowActionFilter));
+            options.Filters.AddService(typeof(AbpUowActionFilter));
             options.Filters.AddService(typeof(AbpExceptionFilter));
             //options.Filters.AddService(typeof(AbpResultFilter));
         }

src/Volo.Abp.AspNetCore.Mvc/Volo/Abp/AspNetCore/Mvc/Uow/AbpUnitOfWorkMiddleware.cs

@@ -0,0 +1,25 @@
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Http;
+using Volo.Abp.Uow;
+
+namespace Volo.Abp.AspNetCore.Mvc.Uow
+{
+    public class AbpUnitOfWorkMiddleware
+    {
+        private readonly RequestDelegate _next;
+
+        public AbpUnitOfWorkMiddleware(RequestDelegate next)
+        {
+            _next = next;
+        }
+
+        public async Task Invoke(HttpContext httpContext, IUnitOfWorkManager unitOfWorkManager)
+        {
+            using (var uow = unitOfWorkManager.Reserve(AbpUowActionFilter.UnitOfWorkReservationName))
+            {
+                await _next(httpContext);
+                await uow.CompleteAsync(httpContext.RequestAborted);
+            }
+        }
+    }
+}

src/Volo.Abp.AspNetCore.Mvc/Volo/Abp/AspNetCore/Mvc/Uow/AbpUowActionFilter.cs

@@ -0,0 +1,72 @@
+using System;
+using System.Net.Http;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Mvc.Filters;
+using Microsoft.Extensions.Options;
+using Volo.Abp.DependencyInjection;
+using Volo.Abp.Uow;
+
+namespace Volo.Abp.AspNetCore.Mvc.Uow
+{
+    public class AbpUowActionFilter : IAsyncActionFilter, ITransientDependency
+    {
+        public const string UnitOfWorkReservationName = "_AbpActionUnitOfWork";
+
+        private readonly IUnitOfWorkManager _unitOfWorkManager;
+        private readonly UnitOfWorkDefaultOptions _defaultOptions;
+
+        public AbpUowActionFilter(IUnitOfWorkManager unitOfWorkManager, IOptions<UnitOfWorkDefaultOptions> options)
+        {
+            _unitOfWorkManager = unitOfWorkManager;
+            _defaultOptions = options.Value;
+        }
+
+        public async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)
+        {
+            if (!context.ActionDescriptor.IsControllerAction())
+            {
+                await next();
+                return;
+            }
+
+            var methodInfo = context.ActionDescriptor.GetMethodInfo();
+            var unitOfWorkAttr = UnitOfWorkHelper.GetUnitOfWorkAttributeOrNull(methodInfo);
+
+            if (unitOfWorkAttr?.IsDisabled == true)
+            {
+                await next();
+                return;
+            }
+
+            var options = CreateOptions(context, unitOfWorkAttr);
+
+            if (_unitOfWorkManager.TryBeginReserved(UnitOfWorkReservationName, options))
+            {
+                await next();
+                return;
+            }
+
+            using (var uow = _unitOfWorkManager.Begin(options))
+            {
+                var result = await next();
+                if (result.Exception == null || result.ExceptionHandled)
+                {
+                    await uow.CompleteAsync(context.HttpContext.RequestAborted);
+                }
+            }
+        }
+
+        private UnitOfWorkOptions CreateOptions(ActionExecutingContext context, UnitOfWorkAttribute unitOfWorkAttr)
+        {
+            var options = new UnitOfWorkOptions();
+
+            unitOfWorkAttr?.SetOptions(options);
+
+            options.IsTransactional = _defaultOptions.CalculateIsTransactional(
+                autoValue: !string.Equals(context.HttpContext.Request.Method, HttpMethod.Get.Method, StringComparison.OrdinalIgnoreCase)
+            );
+
+            return options;
+        }
+    }
+}

src/Volo.Abp.EntityFrameworkCore/Volo.Abp.EntityFrameworkCore.csproj

@@ -17,6 +17,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.EntityFrameworkCore" Version="2.0.0" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Relational" Version="2.0.0" />
   </ItemGroup>
 
 </Project>

src/Volo.Abp.EntityFrameworkCore/Volo/Abp/EntityFrameworkCore/DatabaseFacadeExtensions.cs

@@ -0,0 +1,14 @@
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Storage;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace Volo.Abp.EntityFrameworkCore
+{
+    public static class DatabaseFacadeExtensions
+    {
+        public static bool IsRelational(this DatabaseFacade database)
+        {
+            return database.GetInfrastructure().GetService<IRelationalConnection>() != null;
+        }
+    }
+}

src/Volo.Abp.EntityFrameworkCore/Volo/Abp/EntityFrameworkCore/DbContextExtensions.cs

@@ -0,0 +1,14 @@
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Storage;
+
+namespace Volo.Abp.EntityFrameworkCore
+{
+    internal static class DbContextExtensions
+    {
+        public static bool HasRelationalTransactionManager(this DbContext dbContext)
+        {
+            return dbContext.Database.GetService<IDbContextTransactionManager>() is IRelationalTransactionManager;
+        }
+    }
+}

src/Volo.Abp.EntityFrameworkCore/Volo/Abp/EntityFrameworkCore/DependencyInjection/DbContextCreationContext.cs

@@ -0,0 +1,31 @@
+using System;
+using System.Data.Common;
+using System.Threading;
+
+namespace Volo.Abp.EntityFrameworkCore.DependencyInjection
+{
+    public class DbContextCreationContext
+    {
+        public static DbContextCreationContext Current => _current.Value;
+        private static readonly AsyncLocal<DbContextCreationContext> _current = new AsyncLocal<DbContextCreationContext>();
+
+        public string ConnectionStringName { get; }
+
+        public string ConnectionString { get; }
+
+        public DbConnection ExistingConnection { get; set; }
+
+        public DbContextCreationContext(string connectionStringName, string connectionString)
+        {
+            ConnectionStringName = connectionStringName;
+            ConnectionString = connectionString;
+        }
+
+        public static IDisposable Use(DbContextCreationContext context)
+        {
+            var previousValue = Current;
+            _current.Value = context;
+            return new DisposeAction(() => _current.Value = previousValue);
+        }
+    }
+}

src/Volo.Abp.EntityFrameworkCore/Volo/Abp/EntityFrameworkCore/DependencyInjection/DbContextOptionsFactory.cs

@@ -12,44 +12,55 @@ namespace Volo.Abp.EntityFrameworkCore.DependencyInjection
         public static DbContextOptions<TDbContext> Create<TDbContext>(IServiceProvider serviceProvider)
             where TDbContext : AbpDbContext<TDbContext>
         {
-            var connectionStringName = ConnectionStringNameAttribute.GetConnStringName<TDbContext>();
+            var creationContext = GetCreationContext<TDbContext>(serviceProvider);
+
+            var context = new AbpDbContextConfigurationContext<TDbContext>(
+                creationContext.ConnectionString,
+                creationContext.ConnectionStringName,
+                serviceProvider
+            );
 
-            using (var scope = serviceProvider.CreateScope())
+            var dbContextOptions = GetDbContextOptions<TDbContext>(serviceProvider);
+
+            var configureAction = dbContextOptions.ConfigureActions.GetOrDefault(typeof(TDbContext));
+            if (configureAction != null)
+            {
+                ((Action<AbpDbContextConfigurationContext<TDbContext>>)configureAction).Invoke(context);
+            }
+            else if (dbContextOptions.DefaultConfigureAction != null)
+            {
+                dbContextOptions.DefaultConfigureAction.Invoke(context);
+            }
+            else
             {
-                var context = new AbpDbContextConfigurationContext<TDbContext>(
-                    GetConnectionString(scope, connectionStringName),
-                    connectionStringName,
-                    scope.ServiceProvider
-                );
-
-                var dbContextOptions = GetDbContextOptions<TDbContext>(scope);
-
-                var configureAction = dbContextOptions.ConfigureActions.GetOrDefault(typeof(TDbContext));
-                if (configureAction != null)
-                {
-                    ((Action<AbpDbContextConfigurationContext<TDbContext>>)configureAction).Invoke(context);
-                }
-                else if (dbContextOptions.DefaultConfigureAction != null)
-                {
-                    dbContextOptions.DefaultConfigureAction.Invoke(context);
-                }
-                else
-                {
-                    throw new AbpException($"No configuration found for {typeof(DbContext).AssemblyQualifiedName}! Use services.Configure<AbpDbContextOptions>(...) to configure it.");
-                }
-
-                return context.DbContextOptions.Options;
+                throw new AbpException($"No configuration found for {typeof(DbContext).AssemblyQualifiedName}! Use services.Configure<AbpDbContextOptions>(...) to configure it.");
             }
+
+            return context.DbContextOptions.Options;
         }
 
-        private static AbpDbContextOptions GetDbContextOptions<TDbContext>(IServiceScope scope) where TDbContext : AbpDbContext<TDbContext>
+        private static AbpDbContextOptions GetDbContextOptions<TDbContext>(IServiceProvider serviceProvider)
+            where TDbContext : AbpDbContext<TDbContext>
         {
-            return scope.ServiceProvider.GetRequiredService<IOptions<AbpDbContextOptions>>().Value;
+            return serviceProvider.GetRequiredService<IOptions<AbpDbContextOptions>>().Value;
         }
 
-        private static string GetConnectionString(IServiceScope scope, string connectionStringName)
+        private static DbContextCreationContext GetCreationContext<TDbContext>(IServiceProvider serviceProvider)
+            where TDbContext : AbpDbContext<TDbContext>
         {
-            return scope.ServiceProvider.GetRequiredService<IConnectionStringResolver>().Resolve(connectionStringName);
+            var context = DbContextCreationContext.Current;
+            if (context != null)
+            {
+                return context;
+            }
+
+            var connectionStringName = ConnectionStringNameAttribute.GetConnStringName<TDbContext>();
+            var connectionString = serviceProvider.GetRequiredService<IConnectionStringResolver>().Resolve(connectionStringName);
+
+            return new DbContextCreationContext(
+                connectionStringName,
+                connectionString
+            );
         }
     }
 }

src/Volo.Abp.EntityFrameworkCore/Volo/Abp/Uow/EntityFrameworkCore/EfCoreDatabaseApi.cs

@@ -4,12 +4,12 @@ using Volo.Abp.EntityFrameworkCore;
 
 namespace Volo.Abp.Uow.EntityFrameworkCore
 {
-    public class DbContextDatabaseApi<TDbContext> : IDatabaseApi, ISupportsSavingChanges
+    public class EfCoreDatabaseApi<TDbContext> : IDatabaseApi, ISupportsSavingChanges
         where TDbContext : AbpDbContext<TDbContext>
     {
         public TDbContext DbContext { get; }
 
-        public DbContextDatabaseApi(TDbContext dbContext)
+        public EfCoreDatabaseApi(TDbContext dbContext)
         {
             DbContext = dbContext;
         }

src/Volo.Abp.EntityFrameworkCore/Volo/Abp/Uow/EntityFrameworkCore/EfCoreTransactionApi.cs

@@ -0,0 +1,60 @@
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Storage;
+using Volo.Abp.EntityFrameworkCore;
+
+namespace Volo.Abp.Uow.EntityFrameworkCore
+{
+    public class EfCoreTransactionApi : ITransactionApi, ISupportsRollback
+    {
+        public IDbContextTransaction DbContextTransaction { get; }
+        public DbContext StarterDbContext { get; }
+        public List<DbContext> AttendedDbContexts { get; }
+
+        public EfCoreTransactionApi(IDbContextTransaction dbContextTransaction, DbContext starterDbContext)
+        {
+            DbContextTransaction = dbContextTransaction;
+            StarterDbContext = starterDbContext;
+            AttendedDbContexts = new List<DbContext>();
+        }
+
+        public void Commit()
+        {
+            DbContextTransaction.Commit();
+
+            foreach (var dbContext in AttendedDbContexts)
+            {
+                if (dbContext.HasRelationalTransactionManager())
+                {
+                    continue; //Relational databases use the shared transaction
+                }
+
+                dbContext.Database.CommitTransaction();
+            }
+        }
+
+        public Task CommitAsync()
+        {
+            Commit();
+            return Task.CompletedTask;
+        }
+
+        public void Dispose()
+        {
+            DbContextTransaction.Dispose();
+        }
+
+        public void Rollback()
+        {
+            DbContextTransaction.Rollback();
+        }
+
+        public Task RollbackAsync(CancellationToken cancellationToken)
+        {
+            DbContextTransaction.Rollback();
+            return Task.CompletedTask;
+        }
+    }
+}

src/Volo.Abp.EntityFrameworkCore/Volo/Abp/Uow/EntityFrameworkCore/UnitOfWorkDbContextProvider.cs

@@ -1,9 +1,15 @@
+using System;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Storage;
 using Microsoft.Extensions.DependencyInjection;
 using Volo.Abp.Data;
 using Volo.Abp.EntityFrameworkCore;
+using Volo.Abp.EntityFrameworkCore.DependencyInjection;
 
 namespace Volo.Abp.Uow.EntityFrameworkCore
 {
+    //TODO: Implement logic in DefaultDbContextResolver.Resolve in old ABP.
+
     public class UnitOfWorkDbContextProvider<TDbContext> : IDbContextProvider<TDbContext>
         where TDbContext : AbpDbContext<TDbContext>
     {
@@ -26,16 +32,87 @@ namespace Volo.Abp.Uow.EntityFrameworkCore
                 throw new AbpException("A DbContext can only be created inside a unit of work!");
             }
 
-            var connectionString = _connectionStringResolver.Resolve<TDbContext>();
+            var connectionStringName = ConnectionStringNameAttribute.GetConnStringName<TDbContext>();
+            var connectionString = _connectionStringResolver.Resolve(connectionStringName);
+
             var dbContextKey = $"{typeof(TDbContext).FullName}_{connectionString}";
 
             var databaseApi = unitOfWork.GetOrAddDatabaseApi(
                 dbContextKey,
-                () => new DbContextDatabaseApi<TDbContext>(
-                    unitOfWork.ServiceProvider.GetRequiredService<TDbContext>()
+                () => new EfCoreDatabaseApi<TDbContext>(
+                    CreateDbContext(unitOfWork, connectionStringName, connectionString)
                 ));
-            
-            return ((DbContextDatabaseApi<TDbContext>)databaseApi).DbContext;
+
+            return ((EfCoreDatabaseApi<TDbContext>)databaseApi).DbContext;
+        }
+
+        private TDbContext CreateDbContext(IUnitOfWork unitOfWork, string connectionStringName, string connectionString)
+        {
+            var creationContext = new DbContextCreationContext(connectionStringName, connectionString);
+            using (DbContextCreationContext.Use(creationContext))
+            {
+                var dbContext = CreateDbContext(unitOfWork);
+
+                if (unitOfWork.Options.Timeout.HasValue &&
+                    dbContext.Database.IsRelational() &&
+                    !dbContext.Database.GetCommandTimeout().HasValue)
+                {
+                    dbContext.Database.SetCommandTimeout(unitOfWork.Options.Timeout.Value.TotalSeconds.To<int>());
+                }
+
+                return dbContext;
+            }
+        }
+
+        private TDbContext CreateDbContext(IUnitOfWork unitOfWork)
+        {
+            return unitOfWork.Options.IsTransactional
+                ? CreateDbContextWithTransaction(unitOfWork)
+                : unitOfWork.ServiceProvider.GetRequiredService<TDbContext>();
+        }
+
+        public TDbContext CreateDbContextWithTransaction(IUnitOfWork unitOfWork) 
+        {
+            var transactionApiKey = $"EntityFrameworkCore_{DbContextCreationContext.Current.ConnectionString}";
+            var activeTransaction = unitOfWork.FindTransactionApi(transactionApiKey) as EfCoreTransactionApi;
+
+            if (activeTransaction == null)
+            {
+                var dbContext = unitOfWork.ServiceProvider.GetRequiredService<TDbContext>();
+
+                var dbtransaction = unitOfWork.Options.IsolationLevel.HasValue
+                    ? dbContext.Database.BeginTransaction(unitOfWork.Options.IsolationLevel.Value)
+                    : dbContext.Database.BeginTransaction();
+
+                unitOfWork.AddTransactionApi(
+                    transactionApiKey,
+                    new EfCoreTransactionApi(
+                        dbtransaction,
+                        dbContext
+                    )
+                );
+
+                return dbContext;
+            }
+            else
+            {
+                DbContextCreationContext.Current.ExistingConnection = activeTransaction.DbContextTransaction.GetDbTransaction().Connection;
+
+                var dbContext = unitOfWork.ServiceProvider.GetRequiredService<TDbContext>();
+
+                if (dbContext.HasRelationalTransactionManager())
+                {
+                    dbContext.Database.UseTransaction(activeTransaction.DbContextTransaction.GetDbTransaction());
+                }
+                else
+                {
+                    dbContext.Database.BeginTransaction(); //TODO: Why not using the new created transaction?
+                }
+
+                activeTransaction.AttendedDbContexts.Add(dbContext);
+
+                return dbContext;
+            }
         }
     }
 }

src/Volo.Abp/Volo/Abp/AbpApplicationBase.cs

@@ -39,6 +39,18 @@ namespace Volo.Abp
             Modules = LoadModules(services, options);
         }
 
+        public virtual void Shutdown()
+        {
+            ServiceProvider
+                .GetRequiredService<IModuleManager>()
+                .ShutdownModules(new ApplicationShutdownContext());
+        }
+
+        public virtual void Dispose()
+        {
+
+        }
+
         private IReadOnlyList<IAbpModuleDescriptor> LoadModules(IServiceCollection services, AbpApplicationCreationOptions options)
         {
             return services
@@ -50,16 +62,14 @@ namespace Volo.Abp
                 );
         }
 
-        public virtual void Shutdown()
-        {
-            ServiceProvider
-                .GetRequiredService<IModuleManager>()
-                .ShutdownModules(new ApplicationShutdownContext());
-        }
-
-        public virtual void Dispose()
+        protected virtual void InitializeModules()
         {
-
+            using (var scope = ServiceProvider.CreateScope())
+            {
+                ServiceProvider
+                    .GetRequiredService<IModuleManager>()
+                    .InitializeModules(new ApplicationInitializationContext(scope.ServiceProvider));
+            }
         }
     }
 }

src/Volo.Abp/Volo/Abp/AbpApplicationWithExternalServiceProvider.cs

@@ -1,7 +1,6 @@
 using System;
 using JetBrains.Annotations;
 using Microsoft.Extensions.DependencyInjection;
-using Volo.Abp.Modularity;
 
 namespace Volo.Abp
 {
@@ -25,12 +24,7 @@ namespace Volo.Abp
 
             ServiceProvider = serviceProvider;
 
-            using (var scope = ServiceProvider.CreateScope())
-            {
-                ServiceProvider
-                    .GetRequiredService<IModuleManager>()
-                    .InitializeModules(new ApplicationInitializationContext(scope.ServiceProvider));
-            }
+            InitializeModules();
         }
     }
 }

src/Volo.Abp/Volo/Abp/AbpApplicationWithInternalServiceProvider.cs

@@ -1,7 +1,6 @@
 using System;
 using JetBrains.Annotations;
 using Microsoft.Extensions.DependencyInjection;
-using Volo.Abp.Modularity;
 
 namespace Volo.Abp
 {
@@ -37,12 +36,7 @@ namespace Volo.Abp
             ServiceScope = Services.BuildServiceProviderFromFactory().CreateScope();
             ServiceProvider = ServiceScope.ServiceProvider;
 
-            using (var scope = ServiceProvider.CreateScope())
-            {
-                ServiceProvider
-                    .GetRequiredService<IModuleManager>()
-                    .InitializeModules(new ApplicationInitializationContext(scope.ServiceProvider));
-            }
+            InitializeModules();
         }
 
         public override void Dispose()

src/Volo.Abp/Volo/Abp/AbpKernelModule.cs

@@ -37,6 +37,14 @@ namespace Volo.Abp
             services.AddAssemblyOf<AbpKernelModule>();
 
             services.TryAddObjectAccessor<IServiceProvider>();
+
+            services.Configure<ModuleLifecycleOptions>(options =>
+            {
+                options.Contributers.Add<OnPreApplicationInitializationModuleLifecycleContributer>();
+                options.Contributers.Add<OnApplicationInitializationModuleLifecycleContributer>();
+                options.Contributers.Add<OnPostApplicationInitializationModuleLifecycleContributer>();
+                options.Contributers.Add<OnApplicationShutdownModuleLifecycleContributer>();
+            });
         }
 
         public override void OnApplicationInitialization(ApplicationInitializationContext context)

src/Volo.Abp/Volo/Abp/AbpServiceBase.cs

@@ -15,10 +15,10 @@ namespace Volo.Abp
 
         public IGuidGenerator GuidGenerator { get; set; }
 
-        protected IUnitOfWork CurrentUnitOfWork => UnitOfWorkManager?.Current;
-
         public ILoggerFactory LoggerFactory { get; set; }
 
+        protected IUnitOfWork CurrentUnitOfWork => UnitOfWorkManager?.Current;
+
         protected ILogger Logger => _lazyLogger.Value;
         private Lazy<ILogger> _lazyLogger => new Lazy<ILogger>(() => LoggerFactory?.CreateLogger(GetType().FullName) ?? NullLogger.Instance, true);
         

src/Volo.Abp/Volo/Abp/Modularity/AbpModule.cs

@@ -4,7 +4,14 @@ using Microsoft.Extensions.DependencyInjection;
 
 namespace Volo.Abp.Modularity
 {
-    public abstract class AbpModule : IAbpModule, IOnApplicationInitialization, IOnApplicationShutdown, IPreConfigureServices, IPostConfigureServices
+    public abstract class AbpModule : 
+        IAbpModule,
+        IOnPreApplicationInitialization,
+        IOnApplicationInitialization,
+        IOnPostApplicationInitialization,
+        IOnApplicationShutdown, 
+        IPreConfigureServices, 
+        IPostConfigureServices
     {
         public virtual void PreConfigureServices(IServiceCollection services)
         {
@@ -21,11 +28,21 @@ namespace Volo.Abp.Modularity
             
         }
 
+        public virtual void OnPreApplicationInitialization(ApplicationInitializationContext context)
+        {
+            
+        }
+
         public virtual void OnApplicationInitialization(ApplicationInitializationContext context)
         {
             
         }
 
+        public virtual void OnPostApplicationInitialization(ApplicationInitializationContext context)
+        {
+
+        }
+
         public virtual void OnApplicationShutdown(ApplicationShutdownContext context)
         {
 

src/Volo.Abp/Volo/Abp/Modularity/DefaultModuleLifecycleContributer.cs

@@ -1,15 +1,34 @@
 namespace Volo.Abp.Modularity
 {
-    public class DefaultModuleLifecycleContributer : ModuleLifecycleContributerBase
+    public class OnApplicationInitializationModuleLifecycleContributer : ModuleLifecycleContributerBase
     {
         public override void Initialize(ApplicationInitializationContext context, IAbpModule module)
         {
             (module as IOnApplicationInitialization)?.OnApplicationInitialization(context);
         }
+    }
 
+    public class OnApplicationShutdownModuleLifecycleContributer : ModuleLifecycleContributerBase
+    {
         public override void Shutdown(ApplicationShutdownContext context, IAbpModule module)
         {
             (module as IOnApplicationShutdown)?.OnApplicationShutdown(context);
         }
     }
+
+    public class OnPreApplicationInitializationModuleLifecycleContributer : ModuleLifecycleContributerBase
+    {
+        public override void Initialize(ApplicationInitializationContext context, IAbpModule module)
+        {
+            (module as IOnPreApplicationInitialization)?.OnPreApplicationInitialization(context);
+        }
+    }
+
+    public class OnPostApplicationInitializationModuleLifecycleContributer : ModuleLifecycleContributerBase
+    {
+        public override void Initialize(ApplicationInitializationContext context, IAbpModule module)
+        {
+            (module as IOnPostApplicationInitialization)?.OnPostApplicationInitialization(context);
+        }
+    }
 }

src/Volo.Abp/Volo/Abp/Modularity/IOnPostApplicationInitialization.cs

@@ -0,0 +1,9 @@
+using JetBrains.Annotations;
+
+namespace Volo.Abp.Modularity
+{
+    public interface IOnPostApplicationInitialization
+    {
+        void OnPostApplicationInitialization([NotNull] ApplicationInitializationContext context);
+    }
+}

src/Volo.Abp/Volo/Abp/Modularity/IOnPreApplicationInitialization.cs

@@ -0,0 +1,9 @@
+using JetBrains.Annotations;
+
+namespace Volo.Abp.Modularity
+{
+    public interface IOnPreApplicationInitialization
+    {
+        void OnPreApplicationInitialization([NotNull] ApplicationInitializationContext context);
+    }
+}

src/Volo.Abp/Volo/Abp/Modularity/ModuleLifecycleOptions.cs

@@ -0,0 +1,14 @@
+using Volo.Abp.Collections;
+
+namespace Volo.Abp.Modularity
+{
+    public class ModuleLifecycleOptions
+    {
+        public ITypeList<IModuleLifecycleContributer> Contributers { get; }
+
+        public ModuleLifecycleOptions()
+        {
+            Contributers = new TypeList<IModuleLifecycleContributer>();
+        }
+    }
+}

src/Volo.Abp/Volo/Abp/Modularity/ModuleManager.cs

@@ -1,5 +1,9 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
 using Volo.Abp.DependencyInjection;
 
 namespace Volo.Abp.Modularity
@@ -12,12 +16,18 @@ namespace Volo.Abp.Modularity
 
         public ModuleManager(
             IModuleContainer moduleContainer,
-            IEnumerable<IModuleLifecycleContributer> lifecycleContributers,
-            ILogger<ModuleManager> logger)
+            ILogger<ModuleManager> logger,
+            IOptions<ModuleLifecycleOptions> options,
+            IServiceProvider serviceProvider)
         {
             _moduleContainer = moduleContainer;
-            _lifecycleContributers = lifecycleContributers;
             _logger = logger;
+
+            _lifecycleContributers = options.Value
+                .Contributers
+                .Select(serviceProvider.GetRequiredService)
+                .Cast<IModuleLifecycleContributer>()
+                .ToArray();
         }
 
         public void InitializeModules(ApplicationInitializationContext context)

src/Volo.Abp/Volo/Abp/Uow/AmbientUnitOfWork.cs

@@ -6,18 +6,18 @@ namespace Volo.Abp.Uow
     [ExposeServices(typeof(IAmbientUnitOfWork), typeof(IUnitOfWorkAccessor))]
     public class AmbientUnitOfWork : IAmbientUnitOfWork, ISingletonDependency
     {
-        public IUnitOfWork UnitOfWork => _currentUowInfo.Value;
+        public IUnitOfWork UnitOfWork => _currentUow.Value;
 
-        private readonly AsyncLocal<IUnitOfWork> _currentUowInfo;
+        private readonly AsyncLocal<IUnitOfWork> _currentUow;
 
         public AmbientUnitOfWork()
         {
-            _currentUowInfo = new AsyncLocal<IUnitOfWork>();
+            _currentUow = new AsyncLocal<IUnitOfWork>();
         }
 
         public void SetUnitOfWork(IUnitOfWork unitOfWork)
         {
-            _currentUowInfo.Value = unitOfWork;
+            _currentUow.Value = unitOfWork;
         }
     }
 }

src/Volo.Abp/Volo/Abp/Uow/ChildUnitOfWork.cs

@@ -7,9 +7,19 @@ namespace Volo.Abp.Uow
 {
     internal class ChildUnitOfWork : IUnitOfWork
     {
-        public event EventHandler Completed;
+        public Guid Id => _parent.Id;
+
+        public IUnitOfWorkOptions Options => _parent.Options;
+
+        public IUnitOfWork Outer => _parent.Outer;
+
+        public bool IsReserved => _parent.IsReserved;
+
+        public string ReservationName => _parent.ReservationName;
+
+        public event EventHandler<UnitOfWorkEventArgs> Completed;
         public event EventHandler<UnitOfWorkFailedEventArgs> Failed;
-        public event EventHandler Disposed;
+        public event EventHandler<UnitOfWorkEventArgs> Disposed;
 
         public IServiceProvider ServiceProvider => _parent.ServiceProvider;
 
@@ -26,6 +36,21 @@ namespace Volo.Abp.Uow
             _parent.Disposed += (sender, args) => { Disposed.InvokeSafely(sender, args); };
         }
 
+        public void SetOuter(IUnitOfWork outer)
+        {
+            _parent.SetOuter(outer);
+        }
+
+        public void Initialize(UnitOfWorkOptions options)
+        {
+            _parent.Initialize(options);
+        }
+
+        public void Reserve(string reservationName)
+        {
+            _parent.Reserve(reservationName);
+        }
+
         public void SaveChanges()
         {
             _parent.SaveChanges();
@@ -35,30 +60,65 @@ namespace Volo.Abp.Uow
         {
             return _parent.SaveChangesAsync(cancellationToken);
         }
-        
+
         public void Complete()
         {
-            
+
         }
 
         public Task CompleteAsync(CancellationToken cancellationToken = default(CancellationToken))
         {
             return Task.CompletedTask;
         }
-        
-        public IDatabaseApi FindDatabaseApi(string id)
+
+        public void Rollback()
+        {
+            _parent.Rollback();
+        }
+
+        public Task RollbackAsync(CancellationToken cancellationToken = default(CancellationToken))
         {
-            return _parent.FindDatabaseApi(id);
+            return _parent.RollbackAsync(cancellationToken);
         }
 
-        public IDatabaseApi GetOrAddDatabaseApi(string id, Func<IDatabaseApi> factory)
+        public IDatabaseApi FindDatabaseApi(string key)
         {
-            return _parent.GetOrAddDatabaseApi(id, factory);
+            return _parent.FindDatabaseApi(key);
         }
-        
+
+        public void AddDatabaseApi(string key, IDatabaseApi api)
+        {
+            _parent.AddDatabaseApi(key, api);
+        }
+
+        public IDatabaseApi GetOrAddDatabaseApi(string key, Func<IDatabaseApi> factory)
+        {
+            return _parent.GetOrAddDatabaseApi(key, factory);
+        }
+
+        public ITransactionApi FindTransactionApi(string key)
+        {
+            return _parent.FindTransactionApi(key);
+        }
+
+        public void AddTransactionApi(string key, ITransactionApi api)
+        {
+            _parent.AddTransactionApi(key, api);
+        }
+
+        public ITransactionApi GetOrAddTransactionApi(string key, Func<ITransactionApi> factory)
+        {
+            return _parent.GetOrAddTransactionApi(key, factory);
+        }
+
         public void Dispose()
         {
 
         }
+
+        public override string ToString()
+        {
+            return $"[UnitOfWork {Id}]";
+        }
     }
 }

src/Volo.Abp/Volo/Abp/Uow/IBasicUnitOfWork.cs

@@ -1,24 +0,0 @@
-using System;
-using System.Threading;
-using System.Threading.Tasks;
-
-namespace Volo.Abp.Uow
-{
-    //TODO: Find a better naming :(
-    public interface IBasicUnitOfWork : IDisposable
-    {
-        event EventHandler Completed;
-
-        event EventHandler<UnitOfWorkFailedEventArgs> Failed;
-
-        event EventHandler Disposed;
-
-        void SaveChanges();
-
-        Task SaveChangesAsync(CancellationToken cancellationToken = default(CancellationToken));
-
-        void Complete();
-
-        Task CompleteAsync(CancellationToken cancellationToken = default(CancellationToken));
-    }
-}

src/Volo.Abp/Volo/Abp/Uow/IDatabaseApiContainer.cs

@@ -7,9 +7,11 @@ namespace Volo.Abp.Uow
     public interface IDatabaseApiContainer : IServiceProviderAccessor
     {
         [CanBeNull]
-        IDatabaseApi FindDatabaseApi([NotNull] string id);
+        IDatabaseApi FindDatabaseApi([NotNull] string key);
+
+        void AddDatabaseApi([NotNull] string key, [NotNull] IDatabaseApi api);
 
         [NotNull]
-        IDatabaseApi GetOrAddDatabaseApi(string id, Func<IDatabaseApi> factory);
+        IDatabaseApi GetOrAddDatabaseApi([NotNull] string key, [NotNull] Func<IDatabaseApi> factory);
     }
 }

src/Volo.Abp/Volo/Abp/Uow/ISupportsRollback.cs

@@ -0,0 +1,12 @@
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Volo.Abp.Uow
+{
+    public interface ISupportsRollback
+    {
+        void Rollback();
+
+        Task RollbackAsync(CancellationToken cancellationToken);
+    }
+}

src/Volo.Abp/Volo/Abp/Uow/ITransactionApi.cs

@@ -0,0 +1,13 @@
+using System.Threading.Tasks;
+
+namespace Volo.Abp.Uow
+{
+    public interface ITransactionApi
+    {
+        void Commit();
+
+        Task CommitAsync();
+
+        void Dispose();
+    }
+}

src/Volo.Abp/Volo/Abp/Uow/ITransactionApiContainer.cs

@@ -0,0 +1,16 @@
+using System;
+using JetBrains.Annotations;
+
+namespace Volo.Abp.Uow
+{
+    public interface ITransactionApiContainer
+    {
+        [CanBeNull]
+        ITransactionApi FindTransactionApi([NotNull] string key);
+
+        void AddTransactionApi([NotNull] string key, [NotNull] ITransactionApi api);
+
+        [NotNull]
+        ITransactionApi GetOrAddTransactionApi([NotNull] string key, [NotNull] Func<ITransactionApi> factory);
+    }
+}

src/Volo.Abp/Volo/Abp/Uow/IUnitOfWork.cs

@@ -1,7 +1,44 @@
-namespace Volo.Abp.Uow
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using JetBrains.Annotations;
+
+namespace Volo.Abp.Uow
 {
-    public interface IUnitOfWork : IBasicUnitOfWork, IDatabaseApiContainer
+    public interface IUnitOfWork : IDatabaseApiContainer, ITransactionApiContainer, IDisposable
     {
-        
+        Guid Id { get; }
+
+        event EventHandler<UnitOfWorkEventArgs> Completed;
+
+        event EventHandler<UnitOfWorkFailedEventArgs> Failed;
+
+        event EventHandler<UnitOfWorkEventArgs> Disposed;
+
+        IUnitOfWorkOptions Options { get; }
+
+        IUnitOfWork Outer { get; }
+
+        bool IsReserved { get; }
+
+        string ReservationName { get; }
+
+        void SetOuter([CanBeNull] IUnitOfWork outer);
+
+        void Initialize([NotNull] UnitOfWorkOptions options);
+
+        void Reserve([NotNull] string reservationName);
+
+        void SaveChanges();
+
+        Task SaveChangesAsync(CancellationToken cancellationToken = default(CancellationToken));
+
+        void Complete();
+
+        Task CompleteAsync(CancellationToken cancellationToken = default(CancellationToken));
+
+        void Rollback();
+
+        Task RollbackAsync(CancellationToken cancellationToken = default(CancellationToken));
     }
 }

src/Volo.Abp/Volo/Abp/Uow/IUnitOfWorkManager.cs

@@ -8,6 +8,13 @@ namespace Volo.Abp.Uow
         IUnitOfWork Current { get; }
 
         [NotNull]
-        IBasicUnitOfWork Begin();
+        IUnitOfWork Begin([NotNull] UnitOfWorkOptions options, bool requiresNew = false);
+
+        [NotNull]
+        IUnitOfWork Reserve([NotNull] string reservationName, bool requiresNew = false);
+
+        void BeginReserved([NotNull] string reservationName, [NotNull] UnitOfWorkOptions options);
+
+        bool TryBeginReserved([NotNull] string reservationName, [NotNull] UnitOfWorkOptions options);
     }
 }

src/Volo.Abp/Volo/Abp/Uow/IUnitOfWorkOptions.cs

@@ -0,0 +1,14 @@
+using System;
+using System.Data;
+
+namespace Volo.Abp.Uow
+{
+    public interface IUnitOfWorkOptions
+    {
+        bool IsTransactional { get; }
+
+        IsolationLevel? IsolationLevel { get; }
+
+        TimeSpan? Timeout { get; }
+    }
+}

src/Volo.Abp/Volo/Abp/Uow/UnitOfWork.cs

@@ -2,46 +2,71 @@
 using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
+using Microsoft.Extensions.Options;
 using Volo.Abp.DependencyInjection;
 
 namespace Volo.Abp.Uow
 {
     public class UnitOfWork : IUnitOfWork, ITransientDependency
     {
-        public event EventHandler Completed;
+        public Guid Id { get; } = Guid.NewGuid();
+
+        public IUnitOfWorkOptions Options { get; private set; }
+
+        public IUnitOfWork Outer { get; private set; }
+
+        public bool IsReserved { get; set; }
+
+        public string ReservationName { get; set; }
+
+        public event EventHandler<UnitOfWorkEventArgs> Completed;
         public event EventHandler<UnitOfWorkFailedEventArgs> Failed;
-        public event EventHandler Disposed;
+        public event EventHandler<UnitOfWorkEventArgs> Disposed;
 
         public IServiceProvider ServiceProvider { get; }
 
         private readonly Dictionary<string, IDatabaseApi> _databaseApis;
+        private readonly Dictionary<string, ITransactionApi> _transactionApis;
+        private readonly UnitOfWorkDefaultOptions _defaultOptions;
 
         private Exception _exception;
         private bool _isCompleted;
         private bool _isDisposed;
+        private bool _isRolledback;
 
-        public UnitOfWork(IServiceProvider serviceProvider)
+        public UnitOfWork(IServiceProvider serviceProvider, IOptions<UnitOfWorkDefaultOptions> options)
         {
             ServiceProvider = serviceProvider;
+            _defaultOptions = options.Value;
 
             _databaseApis = new Dictionary<string, IDatabaseApi>();
+            _transactionApis = new Dictionary<string, ITransactionApi>();
         }
 
-        public void Dispose()
+        public void Initialize(UnitOfWorkOptions options)
         {
-            if (_isDisposed)
+            Check.NotNull(options, nameof(options));
+
+            if (Options != null)
             {
-                return;
+                throw new AbpException("This unit of work is already initialized before!");
             }
 
-            _isDisposed = true;
+            Options = _defaultOptions.Normalize(options.Clone());
+            IsReserved = false;
+        }
 
-            if (!_isCompleted || _exception != null)
-            {
-                OnFailed(_exception);
-            }
+        public void Reserve(string reservationName)
+        {
+            Check.NotNull(reservationName, nameof(reservationName));
 
-            OnDisposed();
+            ReservationName = reservationName;
+            IsReserved = true;
+        }
+
+        public void SetOuter(IUnitOfWork outer)
+        {
+            Outer = outer;
         }
 
         public void SaveChanges()
@@ -65,10 +90,17 @@ namespace Volo.Abp.Uow
 
         public void Complete()
         {
+            if (_isRolledback)
+            {
+                return;
+            }
+
             PreventMultipleComplete();
+
             try
             {
                 SaveChanges();
+                CommitTransactions();
                 OnCompleted();
             }
             catch (Exception ex)
@@ -80,11 +112,17 @@ namespace Volo.Abp.Uow
 
         public async Task CompleteAsync(CancellationToken cancellationToken = default(CancellationToken))
         {
+            if (_isRolledback)
+            {
+                return;
+            }
+
             PreventMultipleComplete();
 
             try
             {
                 await SaveChangesAsync(cancellationToken);
+                await CommitTransactionsAsync();
                 OnCompleted();
             }
             catch (Exception ex)
@@ -94,32 +132,136 @@ namespace Volo.Abp.Uow
             }
         }
 
-        public IDatabaseApi FindDatabaseApi(string id)
+        public void Rollback()
+        {
+            if (_isRolledback)
+            {
+                return;
+            }
+
+            _isRolledback = true;
+
+            foreach (var databaseApi in _databaseApis.Values)
+            {
+                (databaseApi as ISupportsRollback)?.Rollback();
+            }
+
+            foreach (var transactionApi in _transactionApis.Values)
+            {
+                (transactionApi as ISupportsRollback)?.Rollback();
+            }
+        }
+
+        public async Task RollbackAsync(CancellationToken cancellationToken = default(CancellationToken))
+        {
+            if (_isRolledback)
+            {
+                return;
+            }
+
+            _isRolledback = true;
+
+            foreach (var databaseApi in _databaseApis.Values)
+            {
+                if (databaseApi is ISupportsRollback)
+                {
+                    await (databaseApi as ISupportsRollback).RollbackAsync(cancellationToken);
+                }
+            }
+
+            foreach (var transactionApi in _transactionApis.Values)
+            {
+                if (transactionApi is ISupportsRollback)
+                {
+                    await (transactionApi as ISupportsRollback).RollbackAsync(cancellationToken);
+                }
+            }
+        }
+
+        public IDatabaseApi FindDatabaseApi(string key)
+        {
+            return _databaseApis.GetOrDefault(key);
+        }
+
+        public void AddDatabaseApi(string key, IDatabaseApi api)
+        {
+            Check.NotNull(key, nameof(key));
+            Check.NotNull(api, nameof(api));
+
+            if (_databaseApis.ContainsKey(key))
+            {
+                throw new AbpException("There is already a database API in this unit of work with given key: " + key);
+            }
+
+            _databaseApis.Add(key, api);
+        }
+
+        public IDatabaseApi GetOrAddDatabaseApi(string key, Func<IDatabaseApi> factory)
         {
-            return _databaseApis.GetOrDefault(id);
+            Check.NotNull(key, nameof(key));
+            Check.NotNull(factory, nameof(factory));
+
+            return _databaseApis.GetOrAdd(key, factory);
+        }
+
+        public ITransactionApi FindTransactionApi(string key)
+        {
+            Check.NotNull(key, nameof(key));
+
+            return _transactionApis.GetOrDefault(key);
+        }
+
+        public void AddTransactionApi(string key, ITransactionApi api)
+        {
+            Check.NotNull(key, nameof(key));
+            Check.NotNull(api, nameof(api));
+
+            if (_transactionApis.ContainsKey(key))
+            {
+                throw new AbpException("There is already a transaction API in this unit of work with given key: " + key);
+            }
+
+            _transactionApis.Add(key, api);
         }
 
-        public IDatabaseApi GetOrAddDatabaseApi(string id, Func<IDatabaseApi> factory)
+        public ITransactionApi GetOrAddTransactionApi(string key, Func<ITransactionApi> factory)
         {
-            Check.NotNull(id, nameof(id));
+            Check.NotNull(key, nameof(key));
             Check.NotNull(factory, nameof(factory));
 
-            return _databaseApis.GetOrAdd(id, factory);
+            return _transactionApis.GetOrAdd(key, factory);
         }
 
         protected virtual void OnCompleted()
         {
-            Completed.InvokeSafely(this);
+            Completed.InvokeSafely(this, new UnitOfWorkEventArgs(this));
         }
 
-        protected virtual void OnFailed(Exception exception)
+        protected virtual void OnFailed()
         {
-            Failed.InvokeSafely(this, new UnitOfWorkFailedEventArgs(exception));
+            Failed.InvokeSafely(this, new UnitOfWorkFailedEventArgs(this, _exception, _isRolledback));
         }
 
         protected virtual void OnDisposed()
         {
-            Disposed.InvokeSafely(this);
+            Disposed.InvokeSafely(this, new UnitOfWorkEventArgs(this));
+        }
+
+        public void Dispose()
+        {
+            if (_isDisposed)
+            {
+                return;
+            }
+
+            _isDisposed = true;
+
+            if (!_isCompleted || _exception != null)
+            {
+                OnFailed();
+            }
+
+            OnDisposed();
         }
 
         private void PreventMultipleComplete()
@@ -131,5 +273,26 @@ namespace Volo.Abp.Uow
 
             _isCompleted = true;
         }
+
+        public override string ToString()
+        {
+            return $"[UnitOfWork {Id}]";
+        }
+
+        protected virtual void CommitTransactions()
+        {
+            foreach (var transaction in _transactionApis.Values)
+            {
+                transaction.Commit();
+            }
+        }
+
+        protected virtual async Task CommitTransactionsAsync()
+        {
+            foreach (var transaction in _transactionApis.Values)
+            {
+                await transaction.CommitAsync();
+            }
+        }
     }
 }

src/Volo.Abp/Volo/Abp/Uow/UnitOfWorkAttribute.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Data;
 
 namespace Volo.Abp.Uow
 {
@@ -11,5 +12,47 @@ namespace Volo.Abp.Uow
     [AttributeUsage(AttributeTargets.Method | AttributeTargets.Class | AttributeTargets.Interface)]
     public class UnitOfWorkAttribute : Attribute
     {
+        /// <summary>
+        /// Is this UOW transactional?
+        /// Uses default value if not supplied.
+        /// </summary>
+        public bool? IsTransactional { get; set; }
+
+        /// <summary>
+        /// Timeout of UOW As milliseconds.
+        /// Uses default value if not supplied.
+        /// </summary>
+        public TimeSpan? Timeout { get; set; }
+
+        /// <summary>
+        /// If this UOW is transactional, this option indicated the isolation level of the transaction.
+        /// Uses default value if not supplied.
+        /// </summary>
+        public IsolationLevel? IsolationLevel { get; set; }
+
+        /// <summary>
+        /// Used to prevent starting a unit of work for the method.
+        /// If there is already a started unit of work, this property is ignored.
+        /// Default: false.
+        /// </summary>
+        public bool IsDisabled { get; set; }
+
+        public virtual void SetOptions(UnitOfWorkOptions options)
+        {
+            if (IsTransactional.HasValue)
+            {
+                options.IsTransactional = IsTransactional.Value;
+            }
+
+            if (Timeout.HasValue)
+            {
+                options.Timeout = Timeout;
+            }
+
+            if (IsolationLevel.HasValue)
+            {
+                options.IsolationLevel = IsolationLevel;
+            }
+        }
     }
 }

src/Volo.Abp/Volo/Abp/Uow/UnitOfWorkDefaultOptions.cs

@@ -0,0 +1,50 @@
+using System;
+using System.Data;
+using System.Reflection;
+
+namespace Volo.Abp.Uow
+{
+    //TODO: Implement default options!
+    
+    /// <summary>
+    /// Global (default) unit of work options
+    /// </summary>
+    public class UnitOfWorkDefaultOptions
+    {
+        public UnitOfWorkTransactionBehavior TransactionBehavior { get; set; }
+
+        public IsolationLevel? IsolationLevel { get; set; }
+
+        public TimeSpan? Timeout { get; set; }
+
+        internal UnitOfWorkOptions Normalize(UnitOfWorkOptions options)
+        {
+            if (options.IsolationLevel == null)
+            {
+                options.IsolationLevel = IsolationLevel;
+            }
+
+            if (options.Timeout == null)
+            {
+                options.Timeout = Timeout;
+            }
+
+            return options;
+        }
+
+        internal bool CalculateIsTransactional(bool autoValue)
+        {
+            switch (TransactionBehavior)
+            {
+                case UnitOfWorkTransactionBehavior.Enabled:
+                    return true;
+                case UnitOfWorkTransactionBehavior.Disabled:
+                    return false;
+                case UnitOfWorkTransactionBehavior.Auto:
+                    return autoValue;
+                default:
+                    throw new AbpException("Not implemented TransactionBehavior value: " + TransactionBehavior);
+            }
+        }
+    }
+}

src/Volo.Abp/Volo/Abp/Uow/UnitOfWorkEventArgs.cs

@@ -0,0 +1,20 @@
+using System;
+using JetBrains.Annotations;
+
+namespace Volo.Abp.Uow
+{
+    public class UnitOfWorkEventArgs : EventArgs
+    {
+        /// <summary>
+        /// Reference to the unit of work related to this event.
+        /// </summary>
+        public IUnitOfWork UnitOfWork { get; }
+
+        public UnitOfWorkEventArgs([NotNull] IUnitOfWork unitOfWork)
+        {
+            Check.NotNull(unitOfWork, nameof(unitOfWork));
+
+            UnitOfWork = unitOfWork;
+        }
+    }
+}

src/Volo.Abp/Volo/Abp/Uow/UnitOfWorkExtensions.cs

@@ -0,0 +1,14 @@
+using JetBrains.Annotations;
+
+namespace Volo.Abp.Uow
+{
+    public static class UnitOfWorkExtensions
+    {
+        public static bool IsReservedFor([NotNull] this IUnitOfWork unitOfWork, string reservationName)
+        {
+            Check.NotNull(unitOfWork, nameof(unitOfWork));
+
+            return unitOfWork.IsReserved && unitOfWork.ReservationName == reservationName;
+        }
+    }
+}

src/Volo.Abp/Volo/Abp/Uow/UnitOfWorkFailedEventArgs.cs

@@ -6,23 +6,29 @@ namespace Volo.Abp.Uow
     /// <summary>
     /// Used as event arguments on <see cref="IUnitOfWork.Failed"/> event.
     /// </summary>
-    public class UnitOfWorkFailedEventArgs : EventArgs
+    public class UnitOfWorkFailedEventArgs : UnitOfWorkEventArgs
     {
         /// <summary>
-        /// Exception that caused failure. This is set only if an error occured during <see cref="IBasicUnitOfWork.Complete"/>.
-        /// Can be null if there is no exception, but <see cref="IBasicUnitOfWork.Complete"/> is not called. 
+        /// Exception that caused failure. This is set only if an error occured during <see cref="IUnitOfWork.Complete"/>.
+        /// Can be null if there is no exception, but <see cref="IUnitOfWork.Complete"/> is not called. 
         /// Can be null if another exception occurred during the UOW.
         /// </summary>
         [CanBeNull]
-        public Exception Exception { get; private set; }
+        public Exception Exception { get; }
+
+        /// <summary>
+        /// True, if the unit of work is manually rolled back.
+        /// </summary>
+        public bool IsRolledback { get; }
 
         /// <summary>
         /// Creates a new <see cref="UnitOfWorkFailedEventArgs"/> object.
         /// </summary>
-        /// <param name="exception">Exception that caused failure</param>
-        public UnitOfWorkFailedEventArgs([CanBeNull] Exception exception)
+        public UnitOfWorkFailedEventArgs([NotNull] IUnitOfWork unitOfWork, [CanBeNull] Exception exception, bool isRolledback)
+            : base(unitOfWork)
         {
             Exception = exception;
+            IsRolledback = isRolledback;
         }
     }
 }

src/Volo.Abp/Volo/Abp/Uow/UnitOfWorkHelper.cs

@@ -1,5 +1,6 @@
 using System.Linq;
 using System.Reflection;
+using JetBrains.Annotations;
 using Volo.Abp.Application.Services;
 using Volo.Abp.Domain.Repositories;
 
@@ -25,13 +26,16 @@ namespace Volo.Abp.Uow
             return false;
         }
 
-        public static bool IsUnitOfWorkMethod(MethodInfo methodInfo)
+        public static bool IsUnitOfWorkMethod([NotNull] MethodInfo methodInfo, [CanBeNull] out UnitOfWorkAttribute unitOfWorkAttribute)
         {
+            Check.NotNull(methodInfo, nameof(methodInfo));
+
             //Method declaration
             var attrs = methodInfo.GetCustomAttributes(true).OfType<UnitOfWorkAttribute>().ToArray();
             if (attrs.Any())
             {
-                return true;
+                unitOfWorkAttribute = attrs.First();
+                return !unitOfWorkAttribute.IsDisabled;
             }
 
             if (methodInfo.DeclaringType != null)
@@ -40,20 +44,41 @@ namespace Volo.Abp.Uow
                 attrs = methodInfo.DeclaringType.GetTypeInfo().GetCustomAttributes(true).OfType<UnitOfWorkAttribute>().ToArray();
                 if (attrs.Any())
                 {
-                    return true;
+                    unitOfWorkAttribute = attrs.First();
+                    return !unitOfWorkAttribute.IsDisabled;
                 }
 
-                //Conventional classes
+                //Conventional classes //TODO: Make this extendible to add new conventions!
                 if (typeof(IApplicationService).GetTypeInfo().IsAssignableFrom(methodInfo.DeclaringType) ||
                     typeof(IRepository).GetTypeInfo().IsAssignableFrom(methodInfo.DeclaringType))
                 {
+                    unitOfWorkAttribute = null;
                     return true;
                 }
             }
 
+            unitOfWorkAttribute = null;
             return false;
         }
 
+        public static UnitOfWorkAttribute GetUnitOfWorkAttributeOrNull(MethodInfo methodInfo)
+        {
+            var attrs = methodInfo.GetCustomAttributes(true).OfType<UnitOfWorkAttribute>().ToArray();
+            if (attrs.Length > 0)
+            {
+                return attrs[0];
+            }
+
+            attrs = methodInfo.DeclaringType.GetTypeInfo().GetCustomAttributes(true).OfType<UnitOfWorkAttribute>().ToArray();
+            if (attrs.Length > 0)
+            {
+                return attrs[0];
+            }
+            
+            return null;
+        }
+
+
         private static bool AnyMethodHasUnitOfWorkAttribute(TypeInfo implementationType)
         {
             return implementationType

src/Volo.Abp/Volo/Abp/Uow/UnitOfWorkInterceptor.cs

@@ -1,4 +1,8 @@
-using System.Threading.Tasks;
+using System;
+using System.Net.Http;
+using System.Threading.Tasks;
+using JetBrains.Annotations;
+using Microsoft.Extensions.Options;
 using Volo.Abp.DependencyInjection;
 using Volo.Abp.DynamicProxy;
 
@@ -7,40 +11,55 @@ namespace Volo.Abp.Uow
     public class UnitOfWorkInterceptor : AbpInterceptor, ITransientDependency
     {
         private readonly IUnitOfWorkManager _unitOfWorkManager;
+        private readonly UnitOfWorkDefaultOptions _defaultOptions;
 
-        public UnitOfWorkInterceptor(IUnitOfWorkManager unitOfWorkManager)
+        public UnitOfWorkInterceptor(IUnitOfWorkManager unitOfWorkManager, IOptions<UnitOfWorkDefaultOptions> options)
         {
             _unitOfWorkManager = unitOfWorkManager;
+            _defaultOptions = options.Value;
         }
 
 	    public override void Intercept(IAbpMethodInvocation invocation)
 	    {
-	        if (!UnitOfWorkHelper.IsUnitOfWorkMethod(invocation.Method))
+	        if (!UnitOfWorkHelper.IsUnitOfWorkMethod(invocation.Method, out var unitOfWorkAttribute))
 	        {
 				invocation.Proceed();
 	            return;
             }
 
-			using (var uow = _unitOfWorkManager.Begin())
+	        using (var uow = _unitOfWorkManager.Begin(CreateOptions(invocation, unitOfWorkAttribute)))
 			{
 				invocation.Proceed();
 				uow.Complete();
 			}
 		}
 
-	    public override async Task InterceptAsync(IAbpMethodInvocation invocation)
+        public override async Task InterceptAsync(IAbpMethodInvocation invocation)
         {
-            if (!UnitOfWorkHelper.IsUnitOfWorkMethod(invocation.Method))
+            if (!UnitOfWorkHelper.IsUnitOfWorkMethod(invocation.Method, out var unitOfWorkAttribute))
             {
                 await invocation.ProceedAsync();
                 return;
             }
 
-            using (var uow = _unitOfWorkManager.Begin())
+            using (var uow = _unitOfWorkManager.Begin(CreateOptions(invocation, unitOfWorkAttribute)))
             {
                 await invocation.ProceedAsync();
                 await uow.CompleteAsync();
             }
         }
+
+        private UnitOfWorkOptions CreateOptions(IAbpMethodInvocation invocation, [CanBeNull] UnitOfWorkAttribute unitOfWorkAttribute)
+        {
+            var options = new UnitOfWorkOptions();
+
+            unitOfWorkAttribute?.SetOptions(options);
+
+            options.IsTransactional = _defaultOptions.CalculateIsTransactional(
+                autoValue: !invocation.Method.Name.StartsWith("Get", StringComparison.InvariantCultureIgnoreCase)
+            );
+
+            return options;
+        }
     }
 }

src/Volo.Abp/Volo/Abp/Uow/UnitOfWorkManager.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Diagnostics;
 using Microsoft.Extensions.DependencyInjection;
 using Volo.Abp.DependencyInjection;
 
@@ -7,61 +6,120 @@ namespace Volo.Abp.Uow
 {
     public class UnitOfWorkManager : IUnitOfWorkManager, ISingletonDependency
     {
-        public IUnitOfWork Current => _ambientUnitOfWork.UnitOfWork;
+        public IUnitOfWork Current => GetCurrentUnitOfWork();
 
         private readonly IServiceProvider _serviceProvider;
         private readonly IAmbientUnitOfWork _ambientUnitOfWork;
 
-        public UnitOfWorkManager(IServiceProvider serviceProvider, IAmbientUnitOfWork ambientUnitOfWork)
+        public UnitOfWorkManager(
+            IServiceProvider serviceProvider, 
+            IAmbientUnitOfWork ambientUnitOfWork)
         {
             _serviceProvider = serviceProvider;
             _ambientUnitOfWork = ambientUnitOfWork;
         }
 
-        public IBasicUnitOfWork Begin()
+        public IUnitOfWork Begin(UnitOfWorkOptions options, bool requiresNew = false)
         {
-            if (_ambientUnitOfWork.UnitOfWork != null)
+            Check.NotNull(options, nameof(options));
+
+            if (!requiresNew && _ambientUnitOfWork.UnitOfWork != null && !_ambientUnitOfWork.UnitOfWork.IsReserved)
             {
                 return new ChildUnitOfWork(_ambientUnitOfWork.UnitOfWork);
             }
 
-            var parentUow = _ambientUnitOfWork.UnitOfWork;
+            var unitOfWork = CreateNewUnitOfWork();
+            unitOfWork.Initialize(options);
 
-            var scope = _serviceProvider.CreateScope();
-            IUnitOfWork unitOfWork;
-            try
+            return unitOfWork;
+        }
+
+        public IUnitOfWork Reserve(string reservationName, bool requiresNew = false)
+        {
+            Check.NotNull(reservationName, nameof(reservationName));
+
+            if (!requiresNew && 
+                _ambientUnitOfWork.UnitOfWork != null &&
+                _ambientUnitOfWork.UnitOfWork.IsReservedFor(reservationName))
             {
-                unitOfWork = scope.ServiceProvider.GetRequiredService<IUnitOfWork>();
+                return new ChildUnitOfWork(_ambientUnitOfWork.UnitOfWork);
             }
-            catch
+
+            var unitOfWork = CreateNewUnitOfWork();
+            unitOfWork.Reserve(reservationName);
+
+            return unitOfWork;
+        }
+
+        public void BeginReserved(string reservationName, UnitOfWorkOptions options)
+        {
+            if (!TryBeginReserved(reservationName, options))
             {
-                scope.Dispose();
-                throw;
+                throw new AbpException($"Could not find a reserved unit of work with reservation name: {reservationName}");
+            }
+        }
+
+        public bool TryBeginReserved(string reservationName, UnitOfWorkOptions options)
+        {
+            Check.NotNull(reservationName, nameof(reservationName));
+
+            var uow = _ambientUnitOfWork.UnitOfWork;
+
+            //Find reserved unit of work starting from current and going to outers
+            while (uow != null && !uow.IsReservedFor(reservationName))
+            {
+                uow = uow.Outer;
+            }
+
+            if (uow == null)
+            {
+                return false;
             }
 
-            _ambientUnitOfWork.SetUnitOfWork(unitOfWork);
+            uow.Initialize(options);
 
-            Debug.Assert(
-                _ambientUnitOfWork.UnitOfWork != null,
-                "_ambientUnitOfWork.UnitOfWork can not be null since it's set by _ambientUnitOfWork.SetUnitOfWork method!"
-            );
+            return true;
+        }
 
-            unitOfWork.Completed += (sender, args) =>
+        private IUnitOfWork GetCurrentUnitOfWork()
+        {
+            var uow = _ambientUnitOfWork.UnitOfWork;
+
+            //Skip reserved unit of work
+            while (uow != null && uow.IsReserved)
             {
-                _ambientUnitOfWork.SetUnitOfWork(parentUow);
-            };
+                uow = uow.Outer;
+            }
 
-            unitOfWork.Failed += (sender, args) =>
+            return uow;
+        }
+
+        private IUnitOfWork CreateNewUnitOfWork()
+        {
+            var scope = _serviceProvider.CreateScope();
+            try
             {
-                _ambientUnitOfWork.SetUnitOfWork(parentUow);
-            };
+                var outerUow = _ambientUnitOfWork.UnitOfWork;
+
+                var unitOfWork = scope.ServiceProvider.GetRequiredService<IUnitOfWork>();
+
+                unitOfWork.SetOuter(outerUow);
+
+                _ambientUnitOfWork.SetUnitOfWork(unitOfWork);
+
+                unitOfWork.Disposed += (sender, args) =>
+                {
+                    _ambientUnitOfWork.SetUnitOfWork(outerUow);
+                    scope.Dispose();
+                };
 
-            unitOfWork.Disposed += (sender, args) =>
+                return unitOfWork;
+            }
+            catch
             {
                 scope.Dispose();
-            };
-
-            return _ambientUnitOfWork.UnitOfWork;
+                throw;
+            }
         }
     }
 }

src/Volo.Abp/Volo/Abp/Uow/UnitOfWorkManagerExtensions.cs

@@ -0,0 +1,31 @@
+using JetBrains.Annotations;
+
+namespace Volo.Abp.Uow
+{
+    public static class UnitOfWorkManagerExtensions
+    {
+        [NotNull]
+        public static IUnitOfWork Begin([NotNull] this IUnitOfWorkManager unitOfWorkManager, bool requiresNew = false)
+        {
+            Check.NotNull(unitOfWorkManager, nameof(unitOfWorkManager));
+
+            return unitOfWorkManager.Begin(new UnitOfWorkOptions(), requiresNew);
+        }
+
+        public static void BeginReserved([NotNull] this IUnitOfWorkManager unitOfWorkManager, [NotNull] string reservationName)
+        {
+            Check.NotNull(unitOfWorkManager, nameof(unitOfWorkManager));
+            Check.NotNull(reservationName, nameof(reservationName));
+
+            unitOfWorkManager.BeginReserved(reservationName, new UnitOfWorkOptions());
+        }
+
+        public static void TryBeginReserved([NotNull] this IUnitOfWorkManager unitOfWorkManager, [NotNull] string reservationName)
+        {
+            Check.NotNull(unitOfWorkManager, nameof(unitOfWorkManager));
+            Check.NotNull(reservationName, nameof(reservationName));
+
+            unitOfWorkManager.TryBeginReserved(reservationName, new UnitOfWorkOptions());
+        }
+    }
+}

src/Volo.Abp/Volo/Abp/Uow/UnitOfWorkOptions.cs

@@ -0,0 +1,27 @@
+using System;
+using System.Data;
+
+namespace Volo.Abp.Uow
+{
+    public class UnitOfWorkOptions : IUnitOfWorkOptions
+    {
+        /// <summary>
+        /// Default: false.
+        /// </summary>
+        public bool IsTransactional { get; set; }
+
+        public IsolationLevel? IsolationLevel { get; set; }
+
+        public TimeSpan? Timeout { get; set; }
+
+        public UnitOfWorkOptions Clone()
+        {
+            return new UnitOfWorkOptions
+            {
+                IsTransactional = IsTransactional,
+                IsolationLevel = IsolationLevel,
+                Timeout = Timeout
+            };
+        }
+    }
+}

src/Volo.Abp/Volo/Abp/Uow/UnitOfWorkTransactionBehavior.cs

@@ -0,0 +1,11 @@
+namespace Volo.Abp.Uow
+{
+    public enum UnitOfWorkTransactionBehavior
+    {
+        Auto,
+
+        Enabled,
+
+        Disabled
+    }
+}

test/Volo.Abp.AspNetCore.Mvc.Tests/Volo/Abp/AspNetCore/App/AbpAspNetCoreMvcTestModule.cs

@@ -34,6 +34,8 @@ namespace Volo.Abp.AspNetCore.App
         public override void OnApplicationInitialization(ApplicationInitializationContext context)
         {
             var app = context.GetApplicationBuilder();
+
+            app.UseUnitOfWork();
             app.UseMvcWithDefaultRoute();
         }
     }

test/Volo.Abp.AspNetCore.Mvc.Tests/Volo/Abp/AspNetCore/App/UnitOfWorkTestController.cs

@@ -0,0 +1,30 @@
+using Microsoft.AspNetCore.Mvc;
+using Shouldly;
+using Volo.Abp.AspNetCore.Mvc;
+
+namespace Volo.Abp.AspNetCore.App
+{
+    [Route("api/unitofwork-test")]
+    public class UnitOfWorkTestController : AbpController
+    {
+        [HttpGet]
+        [Route("ActionRequiresUow")]
+        public ActionResult ActionRequiresUow()
+        {
+            CurrentUnitOfWork.ShouldNotBeNull();
+            CurrentUnitOfWork.Options.IsTransactional.ShouldBeFalse();
+
+            return Content("OK");
+        }
+
+        [HttpPost]
+        [Route("ActionRequiresUowPost")]
+        public ActionResult ActionRequiresUowPost()
+        {
+            CurrentUnitOfWork.ShouldNotBeNull();
+            CurrentUnitOfWork.Options.IsTransactional.ShouldBeTrue();
+
+            return Content("OK");
+        }
+    }
+}

test/Volo.Abp.AspNetCore.Mvc.Tests/Volo/Abp/AspNetCore/Mvc/Uow/UnitOfWorkMiddleware_Tests.cs

@@ -0,0 +1,22 @@
+using System.Threading.Tasks;
+using Shouldly;
+using Xunit;
+
+namespace Volo.Abp.AspNetCore.Mvc.Uow
+{
+    public class UnitOfWorkMiddleware_Tests : AspNetCoreMvcTestBase
+    {
+        [Fact]
+        public async Task Get_Actions_Should_Not_Be_Transactional()
+        {
+            await GetResponseAsStringAsync("/api/unitofwork-test/ActionRequiresUow");
+        }
+
+        [Fact]
+        public async Task Non_Get_Actions_Should_Be_Transactional()
+        {
+            var result = await Client.PostAsync("/api/unitofwork-test/ActionRequiresUowPost", null);
+            result.IsSuccessStatusCode.ShouldBeTrue();
+        }
+    }
+}

test/Volo.Abp.EntityFrameworkCore.Tests/Volo.Abp.EntityFrameworkCore.Tests.csproj

@@ -0,0 +1,30 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netcoreapp2.0</TargetFramework>
+    <AssemblyName>Volo.Abp.EntityFrameworkCore.Tests</AssemblyName>
+    <PackageId>Volo.Abp.EntityFrameworkCore.Tests</PackageId>
+    <GenerateRuntimeConfigurationFiles>true</GenerateRuntimeConfigurationFiles>
+    <GenerateAssemblyConfigurationAttribute>false</GenerateAssemblyConfigurationAttribute>
+    <GenerateAssemblyCompanyAttribute>false</GenerateAssemblyCompanyAttribute>
+    <GenerateAssemblyProductAttribute>false</GenerateAssemblyProductAttribute>
+    <RootNamespace />
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\Volo.Abp.Autofac\Volo.Abp.Autofac.csproj" />
+    <ProjectReference Include="..\..\src\Volo.Abp.EntityFrameworkCore\Volo.Abp.EntityFrameworkCore.csproj" />
+    <ProjectReference Include="..\AbpTestBase\AbpTestBase.csproj" />
+    <ProjectReference Include="..\Volo.Abp.TestApp\Volo.Abp.TestApp.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.3.0" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="2.0.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Folder Include="Volo\Abp\TestApp\EntityFrameworkCore\" />
+  </ItemGroup>
+
+</Project>

test/Volo.Abp.EntityFrameworkCore.Tests/Volo/Abp/EntityFrameworkCore/AbpEntityFrameworkCoreTestModule.cs

@@ -0,0 +1,42 @@
+using Microsoft.Data.Sqlite;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.DependencyInjection;
+using Volo.Abp.Autofac;
+using Volo.Abp.Modularity;
+using Volo.Abp.TestApp;
+using Volo.Abp.TestApp.EntityFrameworkCore;
+
+namespace Volo.Abp.EntityFrameworkCore
+{
+    [DependsOn(typeof(AbpEntityFrameworkCoreModule))]
+    [DependsOn(typeof(TestAppModule))]
+    [DependsOn(typeof(AbpAutofacModule))]
+    public class AbpEntityFrameworkCoreTestModule : AbpModule
+    {
+        public override void ConfigureServices(IServiceCollection services)
+        {
+            services.AddAssemblyOf<AbpEntityFrameworkCoreTestModule>();
+
+            services.AddAbpDbContext<TestAppDbContext>(options =>
+            {
+                options.WithDefaultRepositories();
+            });
+
+            var inMemorySqlite = new SqliteConnection("Data Source=:memory:");
+            inMemorySqlite.Open();
+
+            services.Configure<AbpDbContextOptions>(options =>
+            {
+                options.Configure(context =>
+                {
+                    context.DbContextOptions.UseSqlite(inMemorySqlite);
+                });
+            });
+        }
+
+        public override void OnPreApplicationInitialization(ApplicationInitializationContext context)
+        {
+            context.ServiceProvider.GetRequiredService<TestAppDbContext>().Database.EnsureCreated();
+        }
+    }
+}

test/Volo.Abp.EntityFrameworkCore.Tests/Volo/Abp/EntityFrameworkCore/EntityFrameworkCoreTestBase.cs

@@ -0,0 +1,12 @@
+using Volo.Abp.TestBase;
+
+namespace Volo.Abp.EntityFrameworkCore
+{
+    public abstract class EntityFrameworkCoreTestBase : AbpIntegratedTest<AbpEntityFrameworkCoreTestModule>
+    {
+        protected override void SetAbpApplicationCreationOptions(AbpApplicationCreationOptions options)
+        {
+            options.UseAutofac();
+        }
+    }
+}

test/Volo.Abp.EntityFrameworkCore.Tests/Volo/Abp/EntityFrameworkCore/Repositories/Basic_Repository_Tests.cs

@@ -0,0 +1,38 @@
+using System;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.Extensions.DependencyInjection;
+using Shouldly;
+using Volo.Abp.Domain.Repositories;
+using Volo.Abp.TestApp.Domain;
+using Xunit;
+
+namespace Volo.Abp.EntityFrameworkCore.Repositories
+{
+    public class Basic_Repository_Tests : EntityFrameworkCoreTestBase
+    {
+        private readonly IRepository<Person> _personRepository;
+
+        public Basic_Repository_Tests()
+        {
+            _personRepository = ServiceProvider.GetRequiredService<IRepository<Person>>();
+        }
+
+        [Fact]
+        public void GetList()
+        {
+            _personRepository.GetList().Any().ShouldBeTrue();
+        }
+
+        [Fact]
+        public async Task InsertAsync()
+        {
+            var personId = Guid.NewGuid();
+
+            await _personRepository.InsertAsync(new Person(personId, "Adam", 42));
+
+            var person = await _personRepository.FindAsync(personId);
+            person.ShouldNotBeNull();
+        }
+    }
+}

test/Volo.Abp.EntityFrameworkCore.Tests/Volo/Abp/EntityFrameworkCore/Transaction_Tests.cs

@@ -0,0 +1,62 @@
+using System;
+using System.Threading.Tasks;
+using Microsoft.Extensions.DependencyInjection;
+using Shouldly;
+using Volo.Abp.Domain.Repositories;
+using Volo.Abp.TestApp.Domain;
+using Volo.Abp.Uow;
+using Xunit;
+
+namespace Volo.Abp.EntityFrameworkCore
+{
+    public class Transaction_Tests : EntityFrameworkCoreTestBase
+    {
+        private readonly IRepository<Person> _personRepository;
+        private readonly IUnitOfWorkManager _unitOfWorkManager;
+
+        public Transaction_Tests()
+        {
+            _personRepository = ServiceProvider.GetRequiredService<IRepository<Person>>();
+            _unitOfWorkManager = ServiceProvider.GetRequiredService<IUnitOfWorkManager>();
+        }
+
+        [Fact]
+        public async Task Should_Rollback_Transaction_When_An_Exception_Is_Thrown()
+        {
+            var personId = Guid.NewGuid();
+            const string exceptionMessage = "thrown to rollback the transaction!";
+
+            try
+            {
+                await WithUnitOfWorkAsync(async () =>
+                {
+                    await _personRepository.InsertAsync(new Person(personId, "Adam", 42));
+                    throw new Exception(exceptionMessage);
+                });
+            }
+            catch (Exception e) when (e.Message == exceptionMessage)
+            {
+
+            }
+
+            var person = await _personRepository.FindAsync(personId);
+            person.ShouldBeNull();
+        }
+
+        [Fact]
+        public async Task Should_Rollback_Transaction_Manually()
+        {
+            var personId = Guid.NewGuid();
+
+            await WithUnitOfWorkAsync(async () =>
+            {
+                _unitOfWorkManager.Current.ShouldNotBeNull();
+                await _personRepository.InsertAsync(new Person(personId, "Adam", 42));
+                await _unitOfWorkManager.Current.RollbackAsync();
+            });
+
+            var person = await _personRepository.FindAsync(personId);
+            person.ShouldBeNull();
+        }
+    }
+}

test/Volo.Abp.EntityFrameworkCore.Tests/Volo/Abp/TestApp/EntityFrameworkCore/TestAppDbContext.cs

@@ -0,0 +1,17 @@
+using Microsoft.EntityFrameworkCore;
+using Volo.Abp.EntityFrameworkCore;
+using Volo.Abp.TestApp.Domain;
+
+namespace Volo.Abp.TestApp.EntityFrameworkCore
+{
+    public class TestAppDbContext : AbpDbContext<TestAppDbContext>
+    {
+        public DbSet<Person> People { get; set; }
+        
+        public TestAppDbContext(DbContextOptions<TestAppDbContext> options) 
+            : base(options)
+        {
+
+        }
+    }
+}

test/Volo.Abp.Identity.Application.Tests/Volo/Abp/Identity/AbpIdentityApplicationTestModule.cs

@@ -5,6 +5,7 @@ using Volo.Abp.Autofac;
 using Volo.Abp.EntityFrameworkCore;
 using Volo.Abp.Identity.EntityFrameworkCore;
 using Volo.Abp.Modularity;
+using Volo.Abp.Uow;
 
 namespace Volo.Abp.Identity
 {
@@ -26,6 +27,11 @@ namespace Volo.Abp.Identity
                     context.DbContextOptions.UseInMemoryDatabase(databaseName);
                 });
             });
+
+            services.Configure<UnitOfWorkDefaultOptions>(options =>
+            {
+                options.TransactionBehavior = UnitOfWorkTransactionBehavior.Disabled; //EF in-memory database does not support transactions
+            });
         }
 
         public override void OnApplicationInitialization(ApplicationInitializationContext context)

test/Volo.Abp.Tests/Volo/Abp/Uow/UnitOfWork_Ambient_Scope_Tests.cs

@@ -0,0 +1,76 @@
+using System.Threading.Tasks;
+using Microsoft.Extensions.DependencyInjection;
+using Shouldly;
+using Volo.Abp.Modularity;
+using Volo.Abp.TestBase;
+using Xunit;
+
+namespace Volo.Abp.Uow
+{
+    public class UnitOfWork_Ambient_Scope_Tests : AbpIntegratedTest<IndependentEmptyModule>
+    {
+        private readonly IUnitOfWorkManager _unitOfWorkManager;
+
+        public UnitOfWork_Ambient_Scope_Tests()
+        {
+            _unitOfWorkManager = ServiceProvider.GetRequiredService<IUnitOfWorkManager>();
+        }
+
+        [Fact]
+        public async Task UnitOfWorkManager_Current_Should_Set_Correctly()
+        {
+            _unitOfWorkManager.Current.ShouldBeNull();
+
+            using (var uow1 = _unitOfWorkManager.Begin())
+            {
+                _unitOfWorkManager.Current.ShouldNotBeNull();
+                _unitOfWorkManager.Current.ShouldBe(uow1);
+
+                using (var uow2 = _unitOfWorkManager.Begin())
+                {
+                    _unitOfWorkManager.Current.ShouldNotBeNull();
+                    _unitOfWorkManager.Current.Id.ShouldBe(uow1.Id);
+
+                    await uow2.CompleteAsync();
+                }
+
+                _unitOfWorkManager.Current.ShouldNotBeNull();
+                _unitOfWorkManager.Current.ShouldBe(uow1);
+
+                await uow1.CompleteAsync();
+            }
+
+            _unitOfWorkManager.Current.ShouldBeNull();
+        }
+
+        [Fact]
+        public async Task UnitOfWorkManager_Reservation_Test()
+        {
+            _unitOfWorkManager.Current.ShouldBeNull();
+
+            using (var uow1 = _unitOfWorkManager.Reserve("Reservation1"))
+            {
+                _unitOfWorkManager.Current.ShouldBeNull();
+
+                using (var uow2 = _unitOfWorkManager.Begin())
+                {
+                    _unitOfWorkManager.Current.ShouldNotBeNull();
+                    _unitOfWorkManager.Current.Id.ShouldNotBe(uow1.Id);
+
+                    await uow2.CompleteAsync();
+                }
+
+                _unitOfWorkManager.Current.ShouldBeNull();
+
+                _unitOfWorkManager.BeginReserved("Reservation1");
+
+                _unitOfWorkManager.Current.ShouldNotBeNull();
+                _unitOfWorkManager.Current.Id.ShouldBe(uow1.Id);
+
+                await uow1.CompleteAsync();
+            }
+
+            _unitOfWorkManager.Current.ShouldBeNull();
+        }
+    }
+}

test/Volo.Abp.Tests/Volo/Abp/Uow/UnitOfWork_Events_Tests.cs

@@ -108,5 +108,36 @@ namespace Volo.Abp.Uow
             failed.ShouldBeTrue();
             disposed.ShouldBeTrue();
         }
+
+        [InlineData(true)]
+        [InlineData(false)]
+        [Theory]
+        public void Should_Trigger_Failed_If_Rolled_Back(bool callComplete)
+        {
+            var completed = false;
+            var failed = false;
+            var disposed = false;
+
+            Assert.Throws<Exception>(() =>
+            {
+                using (var uow = _unitOfWorkManager.Begin())
+                {
+                    uow.Completed += (sender, args) => completed = true;
+                    uow.Failed += (sender, args) => { failed = true; args.IsRolledback.ShouldBeTrue(); };
+                    uow.Disposed += (sender, args) => disposed = true;
+
+                    uow.Rollback();
+
+                    if (callComplete)
+                    {
+                        uow.Complete();
+                    }
+                }
+            }).Message.ShouldBe("test exception");
+
+            completed.ShouldBeFalse();
+            failed.ShouldBeTrue();
+            disposed.ShouldBeTrue();
+        }
     }
 }

test/Volo.Abp.Tests/Volo/Abp/Uow/UnitOfWork_Nested_Tests.cs

@@ -0,0 +1,46 @@
+using System.Threading.Tasks;
+using Microsoft.Extensions.DependencyInjection;
+using Shouldly;
+using Volo.Abp.Modularity;
+using Volo.Abp.TestBase;
+using Xunit;
+
+namespace Volo.Abp.Uow
+{
+    public class UnitOfWork_Nested_Tests : AbpIntegratedTest<IndependentEmptyModule>
+    {
+        private readonly IUnitOfWorkManager _unitOfWorkManager;
+
+        public UnitOfWork_Nested_Tests()
+        {
+            _unitOfWorkManager = ServiceProvider.GetRequiredService<IUnitOfWorkManager>();
+        }
+
+        [Fact]
+        public async Task Should_Create_Nested_UnitOfWorks()
+        {
+            _unitOfWorkManager.Current.ShouldBeNull();
+
+            using (var uow1 = _unitOfWorkManager.Begin())
+            {
+                _unitOfWorkManager.Current.ShouldNotBeNull();
+                _unitOfWorkManager.Current.ShouldBe(uow1);
+
+                using (var uow2 = _unitOfWorkManager.Begin(requiresNew: true))
+                {
+                    _unitOfWorkManager.Current.ShouldNotBeNull();
+                    _unitOfWorkManager.Current.Id.ShouldNotBe(uow1.Id);
+
+                    await uow2.CompleteAsync();
+                }
+
+                _unitOfWorkManager.Current.ShouldNotBeNull();
+                _unitOfWorkManager.Current.ShouldBe(uow1);
+
+                await uow1.CompleteAsync();
+            }
+
+            _unitOfWorkManager.Current.ShouldBeNull();
+        }
+    }
+}