Hi

Because AddPolicy method of AuthorizationOptions is not thread-safe, adding created policies to _options at run-time maybe cause error.
As a workaround, we can use LazyConcurrentDictionary that I use it in DNTFrameworkCore

public class AuthorizationPolicyProvider : DefaultAuthorizationPolicyProvider
{
    private readonly LazyConcurrentDictionary<string, AuthorizationPolicy> _policies =
        new LazyConcurrentDictionary<string, AuthorizationPolicy>(StringComparer.OrdinalIgnoreCase);

    public AuthorizationPolicyProvider(IOptions<AuthorizationOptions> options)
        : base(options)
    {
    }

    public override async Task<AuthorizationPolicy> GetPolicyAsync(string policyName)
    {
        if (!policyName.StartsWith(PermissionConstant.PolicyPrefix, StringComparison.OrdinalIgnoreCase))
        {
            return await base.GetPolicyAsync(policyName);
        }

        var policy = _policies.GetOrAdd(policyName, name =>
        {
            var permissions = policyName.ExtractPermissionsFromPolicyName();

            return new AuthorizationPolicyBuilder()
                .AddRequirements(new PermissionAuthorizationRequirement(permissions))
                .Build();
        });

        return policy;
    }
}

Hi Jon,

I transferred the discussion to GitHub as per your request. Thank you for the quick response.

So, run down of what I've done up to now:

• Created and ASP.NET Core application (NetCoreApp 2.2 Framework) without authorization
• Scaffolded Identity into the project
• Transferred the database from in memory to Azure Hosted SQL
• Customized the IdentityUser and added additional roles in a separate class library which is used for setting up the database
• Migrated and updated the database
• Updated the StartupExtensions code to reference to the User Class Library (this enables me to change the IdentityUser to the CustomUser - without this the StartupExtensions through an error as no instance of IdentityUser is used in the main startup)
• Test the coding without seeding the database, it all runs smoothly and I can register new users and sign in.
• Changed the Program Main to Async and added the StartupExtention there (as per your updated TestWebApp)
• When running the code the following error occurs:

Pop-up in code (In Main App Program.cs at "await webHost.Services.AddUsersAndExtraAuthAsync()":
System.InvalidOperationException: 'A second operation started on this context before a previous operation completed. This is usually caused by different threads using the same instance of DbContext, however instance members are not guaranteed to be thread safe. This could also be caused by a nested query being evaluated on the client, if this is the case rewrite the query avoiding nested invocations.'

On Prompt:
fail: Microsoft.EntityFrameworkCore.Update[10000]
An exception occurred in the database while saving changes for context type 'User.Models.IdentityContext'. (DbContext of Asp Identity)
System.InvalidOperationException: A second operation started on this context before a previous operation completed. This is usually caused by different threads using the same instance of DbContext, however instance members are not guaranteed to be thread safe. This could also be caused by a nested query being evaluated on the client, if this is the case rewrite the query avoiding nested invocations.
at Microsoft.EntityFrameworkCore.Internal.ConcurrencyDetector.EnterCriticalSection()
at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(IReadOnlyList1 entriesToSave, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.DbContext.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken) System.InvalidOperationException: A second operation started on this context before a previous operation completed. This is usually caused by different threads using the same instance of DbContext, however instance members are not guaranteed to be thread safe. This could also be caused by a nested query being evaluated on the client, if this is the case rewrite the query avoiding nested invocations. at Microsoft.EntityFrameworkCore.Internal.ConcurrencyDetector.EnterCriticalSection() at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(IReadOnlyList1 entriesToSave, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.DbContext.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)