Is it safe to override SaveChanges and SaveChangesAsync like this?

Question

I have some custom logic that is performed around the SaveChangesAsync method. The problem is that I have some legacy code that calls SaveChanges instead. I have determined that the code below could be fine, but I'm afraid of any possible side-effect (deadlocks). I have had problems trying to turn asynchronous calls into synchronous calls.

class SomeDbContext : DbContext
{
    public override async Task<int> SaveChangesAsync(CancellationToken cancellationToken = new CancellationToken())
    {
        BeforeSaveChanges();
        var result = await base.SaveChangesAsync(cancellationToken);
        await DispatchDomainEvents();
        return result;
    }

    public override int SaveChanges()
    {
        return SaveChangesAsync().GetAwaiter().GetResult();
    }
}

Answer 1

You should copy the same implemenetation in the sync SaveChanges method:

class SomeDbContext : DbContext
{
    public override async Task<int> SaveChangesAsync(CancellationToken cancellationToken = new CancellationToken())
    {
        BeforeSaveChanges();
        var result = await base.SaveChangesAsync(cancellationToken);
        await DispatchDomainEvents();
        return result;
    }

    public override int SaveChanges()
    {
        BeforeSaveChanges();
        var result = base.SaveChanges();
        DispatchDomainEvents().Wait(); // Ideally, you should have a sync version for this method too
        return result;
    }
}

Blocking the current thread to wait for an async method to finish may lead to thread starvation in some scenarios.