watcher started only when needed

src/modelmanager.cpp

@@ -196,7 +196,7 @@ Status ModelManager::start(const Config& config) {
         SPDLOG_LOGGER_ERROR(modelmanager_logger, "Couldn't start model manager");
         return status;
     }
-    startWatcher(isStartedWithConfigFile());
+    evaluatePollingState();
     if (resourcesCleanupIntervalMillisec > 0)
         startCleaner();
 
@@ -212,6 +212,38 @@ void ModelManager::startWatcher(bool watchConfigFile) {
     }
 }
 
+void ModelManager::evaluatePollingState() {
+    static const std::set<std::string> singleFileExtensions = {
+        ".xml", ".onnx", ".pdmodel", ".pdiparams", ".pb", ".tflite"};
+
+    versionPollingNeeded = false;
+    for (const auto& [name, config] : servedModelConfigs) {
+        const std::string& basePath = config.getBasePath();
+        auto ext = std::filesystem::path(basePath).extension().string();
+        if (singleFileExtensions.count(ext) == 0) {
+            SPDLOG_LOGGER_TRACE(modelmanager_logger, "Model {} with path {} requires version polling", name, basePath);
+            versionPollingNeeded = true;
+            break;
+        }
+    }
+
+    if (watcherStarted) {
+        return;
+    }
+
+    bool needWatcher = versionPollingNeeded || isStartedWithConfigFile();
+    if (needWatcher && watcherIntervalMillisec > 0) {
+        if (versionPollingNeeded) {
+            SPDLOG_LOGGER_DEBUG(modelmanager_logger, "Filesystem version polling enabled - at least one model uses version directories");
+        } else {
+            SPDLOG_LOGGER_DEBUG(modelmanager_logger, "Filesystem version polling disabled - no model uses version directories");
+        }
+        startWatcher(isStartedWithConfigFile());
+    } else {
+        SPDLOG_LOGGER_DEBUG(modelmanager_logger, "Filesystem version polling disabled - no model uses version directories");
+    }
+}
+
 void ModelManager::startCleaner() {
     if ((!cleanerStarted)) {
         std::future<void> exitSignal = cleanerExitTrigger.get_future();
@@ -1047,18 +1079,22 @@ Status ModelManager::configFileReloadNeeded(bool& isNeeded) {
 void ModelManager::watcher(std::future<void> exitSignal, bool watchConfigFile) {
     SPDLOG_LOGGER_INFO(modelmanager_logger, "Started model manager thread");
     while (exitSignal.wait_for(std::chrono::milliseconds(this->watcherIntervalMillisec)) == std::future_status::timeout) {
-        SPDLOG_LOGGER_TRACE(modelmanager_logger, "Models configuration and filesystem check cycle begin");
         std::unique_lock<std::recursive_mutex> loadingLock(configMtx);
         if (watchConfigFile) {
+            SPDLOG_LOGGER_TRACE(modelmanager_logger, "Checking if config file changed");
             bool isNeeded;
             configFileReloadNeeded(isNeeded);
             if (isNeeded) {
                 loadConfig();
+                evaluatePollingState();
             }
         }
-        updateConfigurationWithoutConfigFile();
+        if (versionPollingNeeded) {
+            SPDLOG_LOGGER_TRACE(modelmanager_logger, "Models configuration and filesystem check cycle begin");
+            updateConfigurationWithoutConfigFile();
+            SPDLOG_LOGGER_TRACE(modelmanager_logger, "Models configuration and filesystem check cycle end");
+        }
         loadingLock.unlock();
-        SPDLOG_LOGGER_TRACE(modelmanager_logger, "Models configuration and filesystem check cycle end");
     }
     SPDLOG_LOGGER_INFO(modelmanager_logger, "Stopped model manager thread");
 }

src/modelmanager.hpp

@@ -96,6 +96,7 @@ class ModelManager : public ServableNameChecker, public MetricProvider, public M
 private:
     bool watcherStarted = false;
     bool cleanerStarted = false;
+    bool versionPollingNeeded = false;
 
     ModelManager(const ModelManager&) = delete;
 
@@ -128,6 +129,12 @@ class ModelManager : public ServableNameChecker, public MetricProvider, public M
      */
     void watcher(std::future<void> exitSignal, bool watchConfigFile);
 
+    /**
+     * @brief Evaluates whether filesystem version polling is needed
+     * and starts the watcher thread if at least one model uses version directories
+     */
+    void evaluatePollingState();
+
     /**
      * @brief Cleaner thread for resources cleanup
      */

src/test/configs/config_string.json

@@ -3,6 +3,7 @@
         {"config": {
                 "name": "passthrough",
                 "base_path": "/ovms/src/test/passthrough_string",
-                "shape": "(-1)"}}
+                "shape": "(-1)",
+                "target_device": "CPU"}}
     ]
 }