AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.

[jhm-ciberman]

Hi! First, thanks for writting this amazing library. I love it. 💖

Secondly, I am using this library in my game developed using a custom game engine.
The bindings work fine but I found this special case when it crashes with a fatal AccessViolationException.

The code in question is something like this:

public class BuildModeFurniturePreviewNode : ObservableObject, IBuildModeTab, IDisposable
{
    private readonly BuildModeActivityViewModel _parent;
    private readonly EBinding _bindings;
    public BuildModeFurniturePreviewNode(BuildModeActivityViewModel parent)
    {
        this._parent = vm;

        // More stuff here...

        this._bindings = new EBinding
        {
            () => this.CursorWorldPosition == this._parent.CursorWorldPosition,
        };
    }

    public void Dispose()
    {
        this._bindings.Dispose();
    }

    // More stuff here...
}


public class BuildModeActivityViewModel : ObservableObject
{
    private readonly List<IBuildModeTab> _tabs = new();

    public IReadOnlyList<IBuildModeTab> Tabs => this._tabs;

    public BuildModeActivityViewModel()
    {
        this.ChangeTabCommand = new RelayCommand<IBuildModeTab>(tab => this.CurrentTab = tab!, (tab) => this.CurrentTab != tab);

        this._tabs.AddRange(new IBuildModeTab[]
        {
            new FurnitureTabViewModel(this),

            // More tabs here...
            //new FloorsTabViewModel(this),
            //new WallsTabViewModel(this),
            //new RoofsTabViewModel(this),
        });

        this._currentTab = this._tabs[0];
    }

    private IBuildModeTab _currentTab;
    public IBuildModeTab CurrentTab
    {
        get => this._currentTab;
        set => this.SetProperty(ref this._currentTab, value);
    }

    // More stuff here...
}

I this the problem is when I try to bind to properties of a parent object that hasn't finished to run it's constructor code.

Here is the stack trace:

Fatal error. System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
   at System.Runtime.CompilerServices.CastHelpers.ChkCastInterface(Void*, System.Object)
   at EBind.TriggerDelegate+<>c.<.ctor>b__1_1(System.Object, System.Object)
   at EBind.ExpressionBinding.Subscribe(System.Collections.Generic.IEnumerable`1<EBind.Trigger>, System.Action)
   at EBind.EqualityBindings.EqualityBinding`1[[System.Nullable`1[[System.Numerics.Vector2, System.Private.CoreLib, Version=7.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]], System.Private.CoreLib, Version=7.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]]..ctor(System.Linq.Expressions.Expression, System.Linq.Expressions.Expression, EBind.BindFlag, EBind.Configuration)
   at EBind.EqualityBindings.EqualityBindingFactory`1[[System.Nullable`1[[System.Numerics.Vector2, System.Private.CoreLib, Version=7.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]], System.Private.CoreLib, Version=7.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]].Create(System.Linq.Expressions.Expression, System.Linq.Expressions.Expression, EBind.BindFlag, EBind.Configuration)
   at EBind.EqualityBindings.EqualityBinding.Create[[System.Boolean, System.Private.CoreLib, Version=7.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.Linq.Expressions.Expression`1<System.Func`1<Boolean>>, EBind.BindFlag, EBind.Configuration)
   at EBind.ExpressionBinding.Create[[System.Boolean, System.Private.CoreLib, Version=7.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.Linq.Expressions.Expression`1<System.Func`1<Boolean>>, EBind.BindFlag, EBind.Configuration)
   at EBind.EBinding.Add[[System.Boolean, System.Private.CoreLib, Version=7.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e]](System.Linq.Expressions.Expression`1<System.Func`1<Boolean>>, Int32)
   at LifeSim.ViewModels.BuildMode.FurnitureTabViewModel..ctor(LifeSim.ViewModels.BuildMode.BuildModeActivityViewModel)
   at LifeSim.ViewModels.BuildMode.BuildModeActivityViewModel..ctor(LifeSim.ViewModels.GameViewModel)
   at LifeSim.ViewModels.GameViewModel.SwitchGameMode()
   at LifeSim.ViewModels.GameViewModel.Input_ActionPerformed(System.Object, LifeSim.ViewModels.ActionPerformedEventArgs)
   at LifeSim.Game.GameInputProvider.OnActionPerformed(LifeSim.ViewModels.ActionType)
   at LifeSim.Game.GameInputProvider.Input_KeyPressed(System.Object, Veldrid.KeyEvent)
   at LifeSim.Imago.Input.InputManager.UpdateFrameInput()
   at LifeSim.Imago.Application.Run()
   at LifeSim.Game.Program.Main(System.String[])

Of course I could use the classic PropertyChanged event here and subscribe manually to that change. It's not a big deal, just wanted to report the bug because it's a bit annoying.