Much better memory mgmt for multi-threaded model loading/unloading.

gpt4all-chat/chatllm.h

@@ -3,9 +3,23 @@
 
 #include <QObject>
 #include <QThread>
+#include <QFileInfo>
 
 #include "../gpt4all-backend/llmodel.h"
 
+enum LLModelType {
+    MPT_,
+    GPTJ_,
+    LLAMA_
+};
+
+struct LLModelInfo {
+    LLModel *model = nullptr;
+    QFileInfo fileInfo;
+    // NOTE: This does not store the model type or name on purpose as this is left for ChatLLM which
+    // must be able to serialize the information even if it is in the unloaded state
+};
+
 class Chat;
 class ChatLLM : public QObject
 {
@@ -17,12 +31,6 @@ class ChatLLM : public QObject
     Q_PROPERTY(QString generatedName READ generatedName NOTIFY generatedNameChanged)
 
 public:
-    enum ModelType {
-        MPT_,
-        GPTJ_,
-        LLAMA_
-    };
-
     ChatLLM(Chat *parent);
     virtual ~ChatLLM();
 
@@ -33,6 +41,9 @@ public:
 
     void stopGenerating() { m_stopGenerating = true; }
 
+    bool shouldBeLoaded() const { return m_shouldBeLoaded; }
+    void setShouldBeLoaded(bool b);
+
     QString response() const;
     QString modelName() const;
 
@@ -52,10 +63,12 @@ public Q_SLOTS:
     bool loadDefaultModel();
     bool loadModel(const QString &modelName);
     void modelNameChangeRequested(const QString &modelName);
+    void forceUnloadModel();
     void unloadModel();
-    void reloadModel(const QString &modelName);
+    void reloadModel();
     void generateName();
     void handleChatIdChanged();
+    void handleShouldBeLoadedChanged();
 
 Q_SIGNALS:
     void isModelLoadedChanged();
@@ -71,6 +84,7 @@ Q_SIGNALS:
     void generatedNameChanged();
     void stateChanged();
     void threadStarted();
+    void shouldBeLoadedChanged();
 
 protected:
     LLModel::PromptContext m_ctx;
@@ -89,16 +103,17 @@ private:
     void restoreState();
 
 private:
-    LLModel *m_llmodel;
+    LLModelInfo m_modelInfo;
+    LLModelType m_modelType;
     std::string m_response;
     std::string m_nameResponse;
     quint32 m_responseLogits;
     QString m_modelName;
-    ModelType m_modelType;
     Chat *m_chat;
     QByteArray m_state;
     QThread m_llmThread;
     std::atomic<bool> m_stopGenerating;
+    std::atomic<bool> m_shouldBeLoaded;
     bool m_isRecalc;
 };