Using await in CreateChild causes "Cannot wait on monitors on this runtime"

[clodewyks]

Describe the bug
Our application makes use of a lot of Lookup objects, simply key value pairs that are read from the database and maintained on the server and client for selection components. We would like each object to be in charge of loading its own lookups, and caching them in a generic store once done. The below code works fine in a unit test, and is fine if child objects are not setup, but as soon as the Blazor WASM client attempts to setup a child object which loads it's own lookups asynchronously we are met with "Cannot wait on monitors on this runtime".

Version and Platform
CSLA version: 6.2.2
OS: Windows
Platform: Blazor WASM

Code that Fails
The below code fails when attempting to add an item to the NumberContactList

Although CreateClient makes an async call of its own:

When the CreateChild method is hit for NumberContactList and tries to fetch its lookups:

We get the error described. I found this issue which describes improving the message, which makes me believe the exception I am receiving is not expected.

Apologies for screenshots, Github refused to format code when opening the issue.

Stack Trace or Exception Detail

Message: 'DataPortal.Create failed (Cannot wait on monitors on this runtime.)'
Trace:
at System.Threading.Monitor.ObjWait(Int32 millisecondsTimeout, Object obj)
   at System.Threading.Monitor.Wait(Object obj, Int32 millisecondsTimeout)
   at System.Threading.ManualResetEventSlim.Wait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
   at System.Threading.Tasks.Task.SpinThenBlockingWait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
   at System.Threading.Tasks.Task.InternalWaitCore(Int32 millisecondsTimeout, CancellationToken cancellationToken)
   at System.Threading.Tasks.Task.InternalWait(Int32 millisecondsTimeout, CancellationToken cancellationToken)
   at System.Threading.Tasks.Task`1[[System.Object, System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].GetResultCore(Boolean waitCompletionNotification)
   at System.Threading.Tasks.Task`1[[System.Object, System.Private.CoreLib, Version=6.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].get_Result()
   at Csla.Server.ChildDataPortal.Create(Type objectType)
   at Csla.DataPortal`1[[Kronos.Business.Client.ContactDetails.NumberContactDetail, Kronos.Business.Client, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].CreateChild()
   at Csla.BusinessBindingListBase`2[[Kronos.Business.Client.ContactDetails.NumberContactDetailList, Kronos.Business.Client, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[Kronos.Business.Client.ContactDetails.NumberContactDetail, Kronos.Business.Client, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].AddNewCore()
   at System.ComponentModel.BindingList`1[[Kronos.Business.Client.ContactDetails.NumberContactDetail, Kronos.Business.Client, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].System.ComponentModel.IBindingList.AddNew()
   at System.ComponentModel.BindingList`1[[Kronos.Business.Client.ContactDetails.NumberContactDetail, Kronos.Business.Client, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].AddNew()
   at Kronos.Business.Client.Client.CreateClient(ClientInitializer initializer, ClientFactory factory) in E:\Repos\Kronos Framework\Kronos.Business.Client\Client.cs:line 879
   at Csla.Reflection.ServiceProviderMethodCaller.CallMethodTryAsync(Object obj, ServiceProviderMethodInfo method, Object[] parameters)
   at Csla.Reflection.ServiceProviderMethodCaller.CallMethodTryAsync(Object obj, ServiceProviderMethodInfo method, Object[] parameters)
   at Csla.Reflection.LateBoundObject.<CallMethodTryAsyncDI>d__22`1[[Csla.CreateAttribute, Csla, Version=6.2.2.0, Culture=neutral, PublicKeyToken=93be5fdc093e4c30]].MoveNext()
   at Csla.Server.DataPortalTarget.<InvokeOperationAsync>d__14`1[[Csla.CreateAttribute, Csla, Version=6.2.2.0, Culture=neutral, PublicKeyToken=93be5fdc093e4c30]].MoveNext()
   at Csla.Server.DataPortalTarget.CreateAsync(Object criteria, Boolean isSync)
   at Csla.Server.SimpleDataPortal.Create(Type objectType, Object criteria, DataPortalContext context, Boolean isSync)
   at Csla.DataPortal`1[[Kronos.Business.Client.Client, Kronos.Business.Client, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].HandleDataPortalException(String operation, DataPortalException ex, Boolean isSync, IDataPortalProxy proxy)
   at Csla.DataPortal`1[[Kronos.Business.Client.Client, Kronos.Business.Client, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].HandleCreateDataPortalException(DataPortalException ex, Boolean isSync, IDataPortalProxy proxy)
   at Csla.DataPortal`1.<DoCreateAsync>d__14[[Kronos.Business.Client.Client, Kronos.Business.Client, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].MoveNext()
   at Csla.DataPortal`1.<CreateAsync>d__18[[Kronos.Business.Client.Client, Kronos.Business.Client, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].MoveNext()
   at Kronos.Business.Client.Factories.ClientFactory.NewClient(ClientInitializer initializer) in E:\Repos\Kronos Framework\Kronos.Business.Client\Factories\ClientFactory.cs:line 79
   at Kronos.EOSOnline.Components.ClientCaptureCtl.MainMemberNext() in E:\Repos\Kronos Framework\Kronos.EOSOnline\Components\ClientCaptureCtl.razor:line 214

[clodewyks]

This appears to happen in any [ CreateChild ], regardless of whether it is being called from within another [ Create ] or directly from the client.

[clodewyks]

In its simplest form:

Are we incorrect in expected that we should be able to call a Command from within a CreateChild?

[StefanOssendorf]

Hi. Can you share the code of the Lookups.Load*() methods?

Regarding the command. I've only used csla 7+ but I think that should be possible.

[clodewyks]

Hi @StefanOssendorf,

I reduced the Lookups.Load*() to it's simplest form and the section of code that is causing the error.

Removing all of the caching etc, essentially Lookups just calls a CommandBase which returns a Dictionary.

I get the error on the CreateAsync within a CreateChild

        IDataPortal<TextListCommand> textListCommandPortal = ApplicationContext.GetRequiredService<IDataPortalFactory>().GetPortal<TextListCommand>();
        var command = await textListCommandPortal.CreateAsync(TextListCriteria.DependantTypesCriteria());
        var lookup = await textListCommandPortal.ExecuteAsync(command);

[StefanOssendorf]

Ah now I see - I think.
In your first screenshot. You can't use AddNew() from the list. It's internally sync over async. Please try instead an explicit create child call and .Add() on the list with the new item.

[clodewyks]

Thanks @StefanOssendorf , is the below what you meant?

var number = await numberPortal.CreateChildAsync();

number.Number = initializer.CellNumber;

number.NumberType = "Cell";

NumberContactList.Add(number);

[StefanOssendorf]

Yes. Did that fix the exception?

[rockfordlhotka]

@clodewyks you actually want the create to occur on the app server or the client?

Your latest code will do the create on the client, and allow the child's create operation method to invoke root data portal operations that do call the server.

fwiw, this should all improve with changes coming in CSLA 9, where there'll be async add methods on collections.

[clodewyks]

@StefanOssendorf yes it did, thank you!

@rockfordlhotka I am comfortable with it executing on the client as the DataPortal call is brokered to the Command, the creates currently run locally as they only set default values and have no reason to run on the app server.

While this change works it would require a fortune of work to convert all uses of .AddNew() to this method.

[clodewyks]

Great to see we are on the same page, then I can do this while we wait for v9.

For interest sake, why is this being added to v9 and not existing v6 and v8? I'd be happy to contribute.

[rockfordlhotka]

We'd love to have you as a contributor!

As a general rule I entertain PRs for the current version (8) and the next version (9). In rare cases where there's a major blocking issue, bug, or security issue, I'll do a PR for the previous version (7).

I am always happy to have people backport new features that aren't breaking changes from main (v9) to the current version in v8.x.

Here's info on how to become a contributor.

[clodewyks]

Thanks @rockfordlhotka , considering this is something I experienced but did not find any other members struggling with, do you believe it is worth backporting to v8? Could we open it for votes and I'd be happy to implement for v8 if there is interest.

For my own case I will be doing my solution on top of v6.2.2 until our team has capacity to upgrade from v6.2.2 to likely v9 (since we won't have capacity soon)

[rockfordlhotka]

@clodewyks I hope you are pure wasm in your app? CSLA 6 has known issues with Blazor Server that were fixed in 7 and 8, but wasm should work fine in 6.

I don't know that it is worth backporting. As you note, you are the first/only project to encounter the issue.

It is likely that CSLA 9 will now come out in November of this year, so that's not very long really.

[clodewyks]

@rockfordlhotka the app in question here is wasm, but we do have two other apps running Blazor Server and CSLA 6. Do you have a list of known issues so that I can gauge the priority of the upgrade?

Agreed that it may not be worth it right now, if someone reads this before v9 or cannot upgrade to v9 I'd happily jump in and get my hands dirty ;)