From 4faab55dc683021f5254de5458a4e14b1864b26e Mon Sep 17 00:00:00 2001
From: rykalov <rykalov@skbkontur.ru>
Date: Sat, 14 Feb 2026 00:14:02 +0500
Subject: [PATCH 1/3] Create TaskCompletionSource with
 TaskCreationOptions.RunContinuationsAsynchronously in
 TcsMetricsRequestResultHandler for netstandard

---
 .../Core/SessionExecuteAsyncTests.cs          | 27 +++++++++++++++++++
 .../TcsMetricsRequestResultHandler.cs         |  4 +++
 2 files changed, 31 insertions(+)

diff --git a/src/Cassandra.IntegrationTests/Core/SessionExecuteAsyncTests.cs b/src/Cassandra.IntegrationTests/Core/SessionExecuteAsyncTests.cs
index f1867b39b..f05ce28c6 100644
--- a/src/Cassandra.IntegrationTests/Core/SessionExecuteAsyncTests.cs
+++ b/src/Cassandra.IntegrationTests/Core/SessionExecuteAsyncTests.cs
@@ -14,7 +14,9 @@
 //   limitations under the License.
 //
 using System;
+using System.Diagnostics;
 using System.Linq;
+using System.Threading;
 using System.Threading.Tasks;
 
 using NUnit.Framework;
@@ -93,5 +95,30 @@ public void SessionExecuteAsyncCQLQueriesParallel()
             Assert.NotNull(task2.Result.First().GetValue<string>("key"));
             Assert.NotNull(task3.Result.First().GetValue<string[]>("tokens"));
         }
+
+        [Test]
+        public async Task SessionExecuteAsyncCQLQueriesParallelAndSlowResponseProcessingInUserThread()
+        {
+            const int sleepTimeMs = 3_000;
+            const int maxExpectedWaitingTimeMs = 5_000;
+            for (var i = 0; i < 3; i++)
+            {
+                var sw = Stopwatch.StartNew();
+                
+                var tasks = Enumerable.Range(0, 10)
+                                      .Select(_ => Task.Run(async () =>
+                                      {
+                                          var statement = new SimpleStatement("SELECT * FROM system.local");
+                                          await Session.ExecuteAsync(statement).ConfigureAwait(false);
+                                          Thread.Sleep(sleepTimeMs);
+                                      }))
+                                      .ToArray();
+                await Task.WhenAll(tasks).ConfigureAwait(false);
+                
+                sw.Stop();  
+                    
+                Assert.Less(sw.ElapsedMilliseconds, maxExpectedWaitingTimeMs);
+            }
+        }
     }
 }
\ No newline at end of file
diff --git a/src/Cassandra/Requests/TcsMetricsRequestResultHandler.cs b/src/Cassandra/Requests/TcsMetricsRequestResultHandler.cs
index 1e2c008d3..7aa26e4e6 100644
--- a/src/Cassandra/Requests/TcsMetricsRequestResultHandler.cs
+++ b/src/Cassandra/Requests/TcsMetricsRequestResultHandler.cs
@@ -30,7 +30,11 @@ internal class TcsMetricsRequestResultHandler : IRequestResultHandler
         public TcsMetricsRequestResultHandler(IRequestObserver requestObserver)
         {
             _requestObserver = requestObserver;
+#if NET452
             _taskCompletionSource = new TaskCompletionSource<RowSet>();
+#else
+            _taskCompletionSource = new TaskCompletionSource<RowSet>(TaskCreationOptions.RunContinuationsAsynchronously);
+#endif
         }
 
         public async Task TrySetResultAsync(RowSet result, SessionRequestInfo sessionRequestInfo)

From 6361f6dbf7f79cc8ca034d77e248ffcf20b73e65 Mon Sep 17 00:00:00 2001
From: rykalov <rykalov@skbkontur.ru>
Date: Thu, 19 Feb 2026 13:40:29 +0500
Subject: [PATCH 2/3] Configure ThreadPool to pass test
 SessionExecuteAsyncCQLQueriesParallelAndSlowResponseProcessingInUserThread

---
 .../Core/SessionExecuteAsyncTests.cs                      | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/Cassandra.IntegrationTests/Core/SessionExecuteAsyncTests.cs b/src/Cassandra.IntegrationTests/Core/SessionExecuteAsyncTests.cs
index f05ce28c6..ab0fff211 100644
--- a/src/Cassandra.IntegrationTests/Core/SessionExecuteAsyncTests.cs
+++ b/src/Cassandra.IntegrationTests/Core/SessionExecuteAsyncTests.cs
@@ -25,6 +25,14 @@ namespace Cassandra.IntegrationTests.Core
 {
     public class SessionExecuteAsyncTests : SimulacronTest
     {
+        public override void OneTimeSetUp()
+        {
+            base.OneTimeSetUp();
+            
+            const int minThreads = 32;
+            ThreadPool.SetMinThreads(minThreads, minThreads);
+        }
+
         [Test]
         public void SessionExecuteAsyncCQLQueryToSync()
         {

From 1b10c8938e553431d0f44fff545b31c90136b2ec Mon Sep 17 00:00:00 2001
From: rykalov <rykalov@skbkontur.ru>
Date: Thu, 19 Feb 2026 14:07:22 +0500
Subject: [PATCH 3/3] Add description of PR 622 to changelog

---
 CHANGELOG.md | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e11d8c004..877025751 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,13 @@
 # ChangeLog - DataStax C# Driver
 
+## 3.23.0
+
+TBD
+
+### New Features
+
+*   [[PR 622](https://github.com/datastax/csharp-driver/pull/622)] Fix some freezes caused by the application running slowly after a request execution
+
 ## 3.22.0
 
 2024-09-30