From e9f0c6808740e405ca4d1c903d25188935b577f6 Mon Sep 17 00:00:00 2001
From: Oleksandr Poliakov <oleksandr.poliakov@mongodb.com>
Date: Wed, 12 Nov 2025 16:25:23 -0800
Subject: [PATCH] CSHARP-5743: version 3.5 causes delays and disruptions
 because it is trying to access a disposed semaphore slim

---
 src/MongoDB.Driver/Core/Connections/BinaryConnection.cs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/MongoDB.Driver/Core/Connections/BinaryConnection.cs b/src/MongoDB.Driver/Core/Connections/BinaryConnection.cs
index b2f35c6da36..2832cae67b9 100644
--- a/src/MongoDB.Driver/Core/Connections/BinaryConnection.cs
+++ b/src/MongoDB.Driver/Core/Connections/BinaryConnection.cs
@@ -543,6 +543,7 @@ public async Task<ResponseMessage> ReceiveMessageAsync(OperationContext operatio
 
         private void SendBuffer(OperationContext operationContext, IByteBuffer buffer)
         {
+            ThrowIfCancelledOrDisposed(operationContext);
             _sendLock.Wait(operationContext.RemainingTimeout, operationContext.CancellationToken);
             try
             {
@@ -571,6 +572,7 @@ private void SendBuffer(OperationContext operationContext, IByteBuffer buffer)
 
         private async Task SendBufferAsync(OperationContext operationContext, IByteBuffer buffer)
         {
+            ThrowIfCancelledOrDisposed(operationContext);
             await _sendLock.WaitAsync(operationContext.RemainingTimeout, operationContext.CancellationToken).ConfigureAwait(false);
             try
             {