Fix for issue #2080 where the GUI appears to hang when a chat with a large

model is deleted. There is no reason to save the context for a chat that
is being deleted.

Signed-off-by: Adam Treat <treat.adam@gmail.com>

gpt4all-chat/chat.cpp

@@ -286,6 +286,11 @@ void Chat::unloadAndDeleteLater()
     unloadModel();
 }
 
+void Chat::markForDeletion()
+{
+    m_llmodel->setMarkedForDeletion(true);
+}
+
 void Chat::unloadModel()
 {
     stopGenerating();

gpt4all-chat/chat.h

@@ -84,6 +84,7 @@ public:
     Q_INVOKABLE void forceReloadModel();
     Q_INVOKABLE void trySwitchContextOfLoadedModel();
     void unloadAndDeleteLater();
+    void markForDeletion();
 
     qint64 creationDate() const { return m_creationDate; }
     bool serialize(QDataStream &stream, int version) const;

gpt4all-chat/chatlistmodel.h

@@ -143,6 +143,8 @@ public:
             m_newChat = nullptr;
         }
 
+        chat->markForDeletion();
+
         const int index = m_chats.indexOf(chat);
         if (m_chats.count() < 3 /*m_serverChat included*/) {
             addChat();

gpt4all-chat/chatllm.cpp

@@ -64,6 +64,7 @@ ChatLLM::ChatLLM(Chat *parent, bool isServer)
     , m_isRecalc(false)
     , m_shouldBeLoaded(false)
     , m_forceUnloadModel(false)
+    , m_markedForDeletion(false)
     , m_shouldTrySwitchContext(false)
     , m_stopGenerating(false)
     , m_timer(nullptr)
@@ -690,7 +691,9 @@ void ChatLLM::unloadModel()
     else
         emit modelLoadingPercentageChanged(std::numeric_limits<float>::min()); // small non-zero positive value
 
-    saveState();
+    if (!m_markedForDeletion)
+        saveState();
+
 #if defined(DEBUG_MODEL_LOADING)
     qDebug() << "unloadModel" << m_llmThread.objectName() << m_llModelInfo.model;
 #endif

gpt4all-chat/chatllm.h

@@ -84,6 +84,7 @@ public:
     void setShouldBeLoaded(bool b);
     void setShouldTrySwitchContext(bool b);
     void setForceUnloadModel(bool b) { m_forceUnloadModel = b; }
+    void setMarkedForDeletion(bool b) { m_markedForDeletion = b; }
 
     QString response() const;
 
@@ -177,6 +178,7 @@ private:
     std::atomic<bool> m_shouldTrySwitchContext;
     std::atomic<bool> m_isRecalc;
     std::atomic<bool> m_forceUnloadModel;
+    std::atomic<bool> m_markedForDeletion;
     bool m_isServer;
     bool m_forceMetal;
     bool m_reloadingToChangeVariant;