Query: Allow non static methods in top level projection

Under a specific condition, disposed context’s are not being released with a GC. In production it is rapidly increasing memory usage.

Memory Analysis done with Jetbrains dotMemory.

Attached working project: ReproduceEFCoreMemoryLeakNonStaticHelperMethods.zip

Sample from attached code:

            Console.WriteLine("Take 1st snapshot!");
            Console.ReadLine();

            for(var i=0; i<10; i++)
            using (var context = new TestContextSql())
            {
                var repo = new Repository(context); // <--- The non static helper will leave 10 instances TestContextSql in memory.
                //var repo = new RepositoryStatic(context); // <--- The static helper will leave 1 instances TestContextSql in memory.

                var query = repo.GetInt();

                var list = query.ToList();
            }

            Console.WriteLine("Force GC");
            GC.Collect();
            Console.WriteLine("Take 2nd snapshot");
            Console.ReadLine();

        public IQueryable<int> GetInt()
        {
            return _context.TestEntities.Select(t => HashCode(t.DateRange1));
        }

        private int HashCode(string dateRange1)
        {
            return dateRange1.GetHashCode();
        }

Occurs in: EF Core 2.0.1 EF Core 2.1.1

[ajcvickers]

@ksmithRenweb Sorry, I should have said that we know what the issue is. Deciding what to do about it is a different matter–it plays into #12795 because behavior is a consequence of how we evaluate the opaque method call on the client. We’re considering changing some of this in 3.0.

[roji]

@LucasLopesr see @smitpatel’s comment just above - which version of EF Core are you using?