Allow new future batcher for stateless session (for all AbstractSessionImpl based classes)

Author: bahusoid

src/NHibernate.Test/Async/Futures/LinqFutureFixture.cs

@@ -176,6 +176,36 @@ public async Task CanUseFutureQueryAsync()
 			}
 		}
 
+		[Test]
+		public async Task CanUseFutureQueryAndQueryOverForSatelessSessionAsync()
+		{
+			IgnoreThisTestIfMultipleQueriesArentSupportedByDriver();
+
+			using (var s = Sfi.OpenStatelessSession())
+			{
+				var persons10 = s.Query<Person>()
+					.Take(10)
+					.ToFuture();
+				var persons5 = s.QueryOver<Person>()
+					.Take(5)
+					.Future();
+
+				using (var logSpy = new SqlLogSpy())
+				{
+					foreach (var person in await (persons5.GetEnumerableAsync()))
+					{
+					}
+
+					foreach (var person in await (persons10.GetEnumerableAsync()))
+					{
+					}
+
+					var events = logSpy.Appender.GetEvents();
+					Assert.AreEqual(1, events.Length);
+				}
+			}
+		}
+
 		[Test]
 		public async Task CanUseFutureQueryWithAnonymousTypeAsync()
 		{

src/NHibernate.Test/Futures/LinqFutureFixture.cs

@@ -165,6 +165,36 @@ public void CanUseFutureQuery()
 			}
 		}
 
+		[Test]
+		public void CanUseFutureQueryAndQueryOverForSatelessSession()
+		{
+			IgnoreThisTestIfMultipleQueriesArentSupportedByDriver();
+
+			using (var s = Sfi.OpenStatelessSession())
+			{
+				var persons10 = s.Query<Person>()
+					.Take(10)
+					.ToFuture();
+				var persons5 = s.QueryOver<Person>()
+					.Take(5)
+					.Future();
+
+				using (var logSpy = new SqlLogSpy())
+				{
+					foreach (var person in persons5.GetEnumerable())
+					{
+					}
+
+					foreach (var person in persons10.GetEnumerable())
+					{
+					}
+
+					var events = logSpy.Appender.GetEvents();
+					Assert.AreEqual(1, events.Length);
+				}
+			}
+		}
+
 		[Test]
 		public void CanUseFutureQueryWithAnonymousType()
 		{

src/NHibernate/Impl/AbstractSessionImpl.cs

@@ -30,6 +30,9 @@ public abstract partial class AbstractSessionImpl : ISessionImplementor
 		private ISessionFactoryImplementor _factory;
 		private FlushMode _flushMode;
 
+		[NonSerialized]
+		private IMultiAnyQueryBatch _futureMultiBatch;
+
 		private bool closed;
 
 		/// <summary>Get the current NHibernate transaction.</summary>
@@ -280,10 +283,9 @@ public virtual IQuery GetNamedSQLQuery(string name)
 		public abstract FutureCriteriaBatch FutureCriteriaBatch { get; protected internal set; }
 		public abstract FutureQueryBatch FutureQueryBatch { get; protected internal set; }
 
-		//TODO 6.0: Make abstract
 		public virtual IMultiAnyQueryBatch FutureMultiBatch
 		{
-			get => throw new NotImplementedException();
+			get => _futureMultiBatch ?? (_futureMultiBatch = new MultiAnyQueryBatch(this));
 		}
 
 		public virtual IInterceptor Interceptor { get; protected set; }

src/NHibernate/Impl/SessionImpl.cs

@@ -53,8 +53,6 @@ public sealed partial class SessionImpl : AbstractSessionImpl, IEventSource, ISe
 		private FutureCriteriaBatch futureCriteriaBatch;
 		[NonSerialized]
 		private FutureQueryBatch futureQueryBatch;
-		[NonSerialized]
-		private IMultiAnyQueryBatch _futureMultiBatch;
 
 		[NonSerialized]
 		private readonly EventListeners listeners;
@@ -239,11 +237,6 @@ protected internal set
 			}
 		}
 
-		public override IMultiAnyQueryBatch FutureMultiBatch
-		{
-			get => _futureMultiBatch ?? (_futureMultiBatch = new MultiAnyQueryBatch(this));
-		}
-
 		public ConnectionReleaseMode ConnectionReleaseMode
 		{
 			get { return connectionReleaseMode; }

src/NHibernate/Impl/StatelessSessionImpl.cs

@@ -867,11 +867,6 @@ public override FutureQueryBatch FutureQueryBatch
 			protected internal set { throw new NotSupportedException("future queries are not supported for stateless session"); }
 		}
 
-		public override IMultiAnyQueryBatch FutureMultiBatch
-		{
-			get { throw new NotSupportedException("future queries are not supported for stateless session"); }
-		}
-
 		public override IEntityPersister GetEntityPersister(string entityName, object obj)
 		{
 			using (BeginProcess())