Trying to findout actual bug which causing CI failures.

Author: jadhavrohit924

src/app/InteractionModelEngine.cpp

@@ -198,8 +198,6 @@ void InteractionModelEngine::Shutdown()
 
     mTimedHandlers.ReleaseAll();
 
-    mReadHandlers.ReleaseAll();
-
 #if CHIP_CONFIG_ENABLE_READ_CLIENT
     // Shut down any subscription clients that are still around.  They won't be
     // able to work after this point anyway, since we're about to drop our refs
@@ -220,6 +218,7 @@ void InteractionModelEngine::Shutdown()
         readClient->mpImEngine = nullptr;
         auto * tmpClient       = readClient->GetNextClient();
         readClient->SetNextClient(nullptr);
+        readClient->Close(CHIP_NO_ERROR);
         readClient = tmpClient;
     }
 
@@ -229,6 +228,7 @@ void InteractionModelEngine::Shutdown()
     mpActiveReadClientList = nullptr;
 #endif // CHIP_CONFIG_ENABLE_READ_CLIENT
 
+    mReadHandlers.ReleaseAll();
     for (auto & writeHandler : mWriteHandlers)
     {
         if (!writeHandler.IsFree())
@@ -1865,14 +1865,17 @@ Protocols::InteractionModel::Status InteractionModelEngine::CheckCommandExistenc
 
 DataModel::Provider * InteractionModelEngine::SetDataModelProvider(DataModel::Provider * model)
 {
-    // Altering data model should not be done while IM is actively handling requests.
-    VerifyOrDie(mReadHandlers.begin() == mReadHandlers.end());
-
+    printf("SetDataModelProvider called with data model provider: %p\n", model);
     if (model == mDataModelProvider)
     {
         // no-op, just return
         return model;
     }
+    printf("mReadHandlers.begin(): %p and mReadHandlers.end(): %p\n", static_cast<void *>(*mReadHandlers.begin()),
+           static_cast<void *>(*mReadHandlers.end()));
+
+    // Altering data model should not be done while IM is actively handling requests.
+    VerifyOrDie(mReadHandlers.begin() == mReadHandlers.end());
 
     DataModel::Provider * oldModel = mDataModelProvider;
     if (oldModel != nullptr)