Paralell executing tasks in an app service method crashes

Example:

        public async Task GetAllParallel()
        {
            const int threadCount = 32;

            var tasks = new List<Task<int>>();

            for (int i = 0; i < threadCount; i++)
            {
                tasks.Add(GetAllParallelMethod());
            }

            await Task.WhenAll(tasks.Cast<Task>().ToArray());

            foreach (var task in tasks)
            {
                Debug.Assert(task.Result > 0);
            }
        }

        [UnitOfWork(TransactionScopeOption.RequiresNew)]
        protected virtual async Task<int> GetAllParallelMethod()
        {
            return await _productRepository.CountAsync();
        }

When we call GetAllParallel() from client, we get the following exception:

ERROR 2017-05-04 14:05:30,823 [13   ] Mvc.ExceptionHandling.AbpExceptionFilter - Cannot access a disposed object. A common cause of this error is disposing a context that was resolved from dependency injection and then later trying to use the same context instance elsewhere in your application. This may occur if you are calling Dispose() on the context, or wrapping the context in a using statement. If you are using dependency injection, you should let the dependency injection container take care of disposing context instances.
Object name: 'MyDbContext'.
System.ObjectDisposedException: Cannot access a disposed object. A common cause of this error is disposing a context that was resolved from dependency injection and then later trying to use the same context instance elsewhere in your application. This may occur if you are calling Dispose() on the context, or wrapping the context in a using statement. If you are using dependency injection, you should let the dependency injection container take care of disposing context instances.
Object name: 'MyDbContext'.
   at Microsoft.EntityFrameworkCore.DbContext.get_InternalServiceProvider()
   at Microsoft.EntityFrameworkCore.Infrastructure.AccessorExtensions.GetService[TService](IInfrastructure`1 accessor)
   at Microsoft.EntityFrameworkCore.DbContext.get_QueryProvider()
   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.<.ctor>b__3_0()
   at Microsoft.EntityFrameworkCore.Internal.LazyRef`1.get_Value()
   at Microsoft.EntityFrameworkCore.Internal.InternalDbSet`1.System.Linq.IQueryable.get_Provider()
   at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.ExecuteAsync[TSource,TResult](MethodInfo operatorMethodInfo, IQueryable`1 source, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.CountAsync[TSource](IQueryable`1 source, CancellationToken cancellationToken)
   at Abp.EntityFrameworkCore.Repositories.EfCoreRepositoryBase`3.<CountAsync>d__23.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.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at Abp.Threading.InternalAsyncHelper.<AwaitTaskWithPostActionAndFinallyAndGetResult>d__5`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 System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at AbpAspNetCoreDemo.Core.Application.ProductAppService.<GetAllParallelMethod>d__6.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.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at Abp.Threading.InternalAsyncHelper.<AwaitTaskWithPostActionAndFinallyAndGetResult>d__5`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 System.Runtime.CompilerServices.TaskAwaiter.GetResult()
   at AbpAspNetCoreDemo.Core.Application.ProductAppService.<GetAllParallel>d__5.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.AspNetCore.Mvc.Internal.ControllerActionInvoker.<InvokeActionMethodAsync>d__27.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.AspNetCore.Mvc.Internal.ControllerActionInvoker.<InvokeNextActionFilterAsync>d__25.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Rethrow(ActionExecutedContext context)
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.<InvokeNextExceptionFilterAsync>d__24.MoveNext()

Test code: https://github.com/aspnetboilerplate/aspnetboilerplate/blob/dev/test/aspnet-core-demo/AbpAspNetCoreDemo.Core/Application/ProductAppService.cs#L44

[ogix]

I am facing the same issue with .NET Core 3.1 and ABP 5.4. Is it possible to fix this somehow?

[ismcagdas]

@ogix could you share your code which causes this problem ?