I am facing this issue with my asp.net MVC5 web application, using Identity v2.0.0.0, EF 6, Castle Windsor IOC Container, Microsoft SQL Server 2005
I am trying to get the current logged in User by using UserManagerExtensions,FindById() method but it is throwing an error "System.NotSupportedException : A second operation started on this context before a previous asynchronous operation completed. Use 'await' to ensure that any asynchronous operations have completed before calling another method on this context. Any instance members are not guaranteed to be thread safe"
What I understood from the stack trace is that "AsyncHelper.RunSync()" causing the issues, I am not using any asynch functions in my code but the "FindById()" using AsyncHelper Reference -: http://www.symbolsource.org/MyGet/Metadata/aspnetwebstacknightly/Project/Microsoft.AspNet.Identity.Core/2.0.0-beta1-140129/Release/Default/Microsoft.AspNet.Identity.Core/Microsoft.AspNet.Identity.Core/Extensions/UserManagerExtensions.cs?ImageName=Microsoft.AspNet.Identity.Core
There seems to be very little information on this Identity error, I am using the current logged in user's details in different parts of my application and this error seems to occur randomly when calls get to GetCurrentLoggedInUser() function in my service layer. Please help....
My code and stack trace below ---- Note: I found another incident of the similar type reported here: https://aspnetidentity.codeplex.com/workitem/2408
Global.asax:
.Register(Component
.For<UserManager<ApplicationUser>>()
.UsingFactoryMethod((kernel, creationContext) =>
new TempoUserManager<ApplicationUser>(new UserStore<ApplicationUser>(new ApplicationDbContext(ASPUserDatabaseConnectionString))))
.LifestylePerWebRequest()
)
.Register(Component
.For<RoleManager<IdentityRole>>()
.UsingFactoryMethod((kernel, creationContext) =>
new RoleManager<IdentityRole>(new RoleStore<IdentityRole>(new ApplicationDbContext(ASPUserDatabaseConnectionString))))
.LifestylePerWebRequest()
)
Service layer Code:
public class GenericService
{
protected IRepository _repository;
protected UserManager<ApplicationUser> _userManager;
public GenericService(IRepository repository, UserManager<ApplicationUser> userManager)
{
_repository = repository;
_userManager = userManager;
}
public ApplicationUser GetCurrentLoggedInUser()
{
//Error is thrown when calling this
return _userManager.FindById(HttpContext.Current.User.Identity.GetUserId());
}
}
Below is the stack trace,
System.NotSupportedException: A second operation started on this context before a previous asynchronous operation completed. Use 'await' to ensure that any asynchronous operations have completed before calling another method on this context. Any instance members are not guaranteed to be thread safe.
at System.Data.Entity.Internal.ThrowingMonitor.Enter()
at System.Data.Entity.Core.Objects.ObjectQuery`1.<GetResultsAsync>d__e.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Data.Entity.Internal.LazyAsyncEnumerator`1.<FirstMoveNextAsync>d__0.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Data.Entity.Infrastructure.IDbAsyncEnumerableExtensions.<FirstOrDefaultAsync>d__25`1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
**at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.AspNet.Identity.AsyncHelper.RunSync[TResult](Func`1 func)
at Microsoft.AspNet.Identity.UserManagerExtensions.FindById[TUser,TKey](UserManager`2 manager, TKey userId)
at Tempo.BusinessLogics.Services.GenericService.GetCurrentLoggedInUser()
at Tempo.BusinessLogics.Services.GenericService.GetCurrentLoggedInUserID()
at Tempo.BusinessLogics.Services.TimeService.UpdateSignOfChildDetails(EntryLog toUpdate, Boolean targetSignState)
at Tempo.BusinessLogics.Services.TimeService.SignEntries(SignOffs sgnOffs, Byte flag)
at Tempo.Controllers.TimeEntryController.SignOffAll(String cbxStatus)**
at lambda_method(Closure , ControllerBase , Object[] )
at System.Web.Mvc.ActionMethodDispatcher.<>c__DisplayClass1.<WrapVoidAction>b__0(ControllerBase controller, Object[] parameters)
at System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters)
at System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters)
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<BeginInvokeSynchronousActionMethod>b__39(IAsyncResult asyncResult, ActionInvocation innerInvokeState)
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`2.CallEndDelegate(IAsyncResult asyncResult)
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResultBase`1.End()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult)
at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3f()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass48.<InvokeActionMethodFilterAsynchronouslyRecursive>b__41()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass33.<BeginInvokeActionMethodWithFilters>b__32(IAsyncResult asyncResult)
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`1.CallEndDelegate(IAsyncResult asyncResult)
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResultBase`1.End()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters(IAsyncResult asyncResult)
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass21.<>c__DisplayClass2b.<BeginInvokeAction>b__1c()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass21.<BeginInvokeAction>b__1e(IAsyncResult asyncResult)
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`1.CallEndDelegate(IAsyncResult asyncResult)
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResultBase`1.End()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult)
at System.Web.Mvc.Controller.<BeginExecuteCore>b__1d(IAsyncResult asyncResult, ExecuteCoreState innerState)
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult)
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResultBase`1.End()
at System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult)
at System.Web.Mvc.Controller.<BeginExecute>b__15(IAsyncResult asyncResult, Controller controller)
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult)
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResultBase`1.End()
at System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult)
at System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult)
at System.Web.Mvc.MvcHandler.<BeginProcessRequest>b__5(IAsyncResult asyncResult, ProcessRequestState innerState)
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult)
at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResultBase`1.End()
at System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult)
at System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result)
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
Maybe You forgot to await async function, and then next statement is trying to execute two queries on single connection?
It sounds like you are creating two contexts, both of which are of the same type of ApplicationDbContext. When EF detects two calls happening at the same time to the same context you get your error.
You will either have to create only one instance of your context per web request or split your context into it's component parts so both can be injected without a conflict.
来源：https://stackoverflow.com/questions/26351917/usermanager-error-a-second-operation-started-on-this-context-before-a-previous