Service logic moved to kernel (#554)

+ fix BT service file paths

Tactility/Include/Tactility/service/Service.h

@@ -1,15 +1,12 @@
 #pragma once
 
+#include <tactility/service/service_instance.h>
+
 #include <memory>
 
 namespace tt::service {
 
-enum class State {
-    Starting,
-    Started,
-    Stopping,
-    Stopped
-};
+using State = ::ServiceState;
 
 // Forward declaration
 class ServiceContext;
@@ -26,6 +23,6 @@ public:
 };
 
 template<typename T>
-std::shared_ptr<Service> create() { return std::shared_ptr<T>(new T); }
+void* create(const ::ServiceManifest* /*manifest*/) { return new std::shared_ptr<Service>(std::shared_ptr<T>(new T)); }
 
 }

Tactility/Include/Tactility/service/ServiceContext.h

@@ -1,6 +1,9 @@
 #pragma once
 
 #include <memory>
+#include <tactility/service/service_manifest.h>
+
+struct ServiceInstance;
 
 namespace tt::service {
 
@@ -8,23 +11,23 @@ struct ServiceManifest;
 class ServicePaths;
 
 /**
- * The public representation of a service instance.
+ * Thin, non-owning wrapper around the running TactilityKernel service instance
+ * (ServiceInstance, which the kernel API also calls ServiceContext).
  * @warning Do not store references or pointers to these! You can retrieve them via the Loader service.
  */
-class ServiceContext {
+class ServiceContext final {
 
-protected:
-
-    virtual ~ServiceContext() = default;
+    ::ServiceInstance* service_instance;
 
 public:
 
+    explicit ServiceContext(::ServiceInstance* instance) : service_instance(instance) {}
+
     /** @return a reference to the service's manifest */
-    virtual const ServiceManifest& getManifest() const = 0;
+    const ::ServiceManifest* getManifest() const;
 
     /** Retrieve the paths that are relevant to this service */
-    virtual std::unique_ptr<ServicePaths> getPaths() const = 0;
+    std::unique_ptr<ServicePaths> getPaths() const;
 };
 
-
 } // namespace

Tactility/Include/Tactility/service/ServiceManifest.h

@@ -9,7 +9,7 @@ namespace tt::service {
 // Forward declarations
 class ServiceContext;
 
-typedef std::shared_ptr<Service>(*CreateService)();
+using CreateService = ::ServiceCreate;
 
 /** A ledger that describes the main parts of a service. */
 struct ServiceManifest {

Tactility/Include/Tactility/service/ServicePaths.h

@@ -1,45 +1,67 @@
 #pragma once
 
+#include <tactility/check.h>
+#include <tactility/error.h>
+#include <tactility/service/service_manifest.h>
+#include <tactility/service/service_paths.h>
+
+#include <cassert>
 #include <string>
-#include <memory>
 
 namespace tt::service {
 
-// Forward declarations
-class ServiceManifest;
+constexpr size_t PATH_BUFFER_SIZE = 255;
 
 class ServicePaths {
 
-    std::shared_ptr<const ServiceManifest> manifest;
+    const ::ServiceManifest* manifest;
 
 public:
 
-    explicit ServicePaths(std::shared_ptr<const ServiceManifest> manifest) : manifest(std::move(manifest)) {}
+    explicit ServicePaths(const ::ServiceManifest* manifest) : manifest(manifest) {}
 
     /**
      * The user data directory is intended to survive OS upgrades.
      * The path will not end with a "/".
      */
-    std::string getUserDataDirectory() const;
+    std::string getUserDataDirectory() const {
+        char buffer[PATH_BUFFER_SIZE];
+        check(service_paths_get_user_data_directory(manifest->id, buffer, sizeof(buffer)) == ERROR_NONE);
+        return buffer;
+    }
 
     /**
      * The user data directory is intended to survive OS upgrades.
      * Configuration data should be stored here.
      * @param[in] childPath the path without a "/" prefix
      */
-    std::string getUserDataPath(const std::string& childPath) const;
+    std::string getUserDataPath(const std::string& childPath) const {
+        assert(!childPath.starts_with('/'));
+        char buffer[PATH_BUFFER_SIZE];
+        check(service_paths_get_user_data_path(manifest->id, childPath.c_str(), buffer, sizeof(buffer)) == ERROR_NONE);
+        return buffer;
+    }
 
     /**
      * You should not store configuration data here.
      * The path will not end with a "/".
      */
-    std::string getAssetsDirectory() const;
+    std::string getAssetsDirectory() const {
+        char buffer[PATH_BUFFER_SIZE];
+        check(service_paths_get_assets_directory(manifest->id, buffer, sizeof(buffer)) == ERROR_NONE);
+        return buffer;
+    }
 
     /**
      * You should not store configuration data here.
      * @param[in] childPath the path without a "/" prefix
      */
-    std::string getAssetsPath(const std::string& childPath) const;
+    std::string getAssetsPath(const std::string& childPath) const {
+        assert(!childPath.starts_with('/'));
+        char buffer[PATH_BUFFER_SIZE];
+        check(service_paths_get_assets_path(manifest->id, childPath.c_str(), buffer, sizeof(buffer)) == ERROR_NONE);
+        return buffer;
+    }
 };
 
-}
+}

Tactility/Include/Tactility/service/ServiceRegistration.h

@@ -40,7 +40,7 @@ State getState(const std::string& id);
  * @param[in] id the id as defined in the manifest
  * @return the matching manifest or nullptr when it wasn't found
  */
-std::shared_ptr<const ServiceManifest> findManifestById(const std::string& id);
+const ::ServiceManifest* findManifestById(const std::string& id);
 
 /** Find a ServiceContext by its manifest id.
  * @param[in] id the id as defined in the manifest

Tactility/Private/Tactility/service/ServiceInstance.h

@@ -1,36 +0,0 @@
-#pragma once
-
-#include <Tactility/service/ServiceContext.h>
-#include <Tactility/service/Service.h>
-#include <Tactility/Mutex.h>
-
-#include <memory>
-
-namespace tt::service {
-
-class ServiceInstance final : public ServiceContext {
-
-    Mutex mutex;
-    std::shared_ptr<const ServiceManifest> manifest;
-    std::shared_ptr<Service> service;
-    State state = State::Stopped;
-
-public:
-
-    explicit ServiceInstance(std::shared_ptr<const ServiceManifest> manifest);
-    ~ServiceInstance() override = default;
-
-    /** @return a reference to the service's manifest */
-    const ServiceManifest& getManifest() const override;
-
-    /** Retrieve the paths that are relevant to this service */
-    std::unique_ptr<ServicePaths> getPaths() const override;
-
-    std::shared_ptr<Service> getService() const { return service; }
-
-    State getState() const { return state; }
-
-    void setState(State newState) { state = newState; }
-};
-
-}

Tactility/Source/bluetooth/BluetoothPairedDevice.cpp

@@ -1,5 +1,7 @@
 #include <Tactility/bluetooth/BluetoothPairedDevice.h>
 
+#include "Tactility/Paths.h"
+
 #include <Tactility/file/File.h>
 #include <Tactility/file/PropertiesFile.h>
 #include <tactility/log.h>
@@ -16,13 +18,16 @@ namespace tt::bluetooth::settings {
 constexpr auto* TAG = "BluetoothPairedDevice";
 
 // Use the same directory as the old service for backward compatibility.
-constexpr auto* DATA_DIR               = "/data/service/bluetooth";
 constexpr auto* DEVICE_SETTINGS_FORMAT = "{}/{}.device.properties";
 constexpr auto* KEY_NAME        = "name";
 constexpr auto* KEY_ADDR        = "addr";
 constexpr auto* KEY_AUTO_CONNECT = "autoConnect";
 constexpr auto* KEY_PROFILE_ID  = "profileId";
 
+static std::string getSettingsFilePath() {
+    return getUserDataPath() + "/service/bluetooth";
+}
+
 std::string addrToHex(const std::array<uint8_t, 6>& addr) {
     std::stringstream stream;
     stream << std::hex;
@@ -52,7 +57,7 @@ static bool hexToAddr(const std::string& hex, std::array<uint8_t, 6>& addr) {
 }
 
 static std::string getFilePath(const std::string& addr_hex) {
-    return std::format(DEVICE_SETTINGS_FORMAT, DATA_DIR, addr_hex);
+    return std::format(DEVICE_SETTINGS_FORMAT, getSettingsFilePath(), addr_hex);
 }
 
 bool hasFileForDevice(const std::string& addr_hex) {
@@ -102,7 +107,10 @@ bool remove(const std::string& addr_hex) {
 
 std::vector<PairedDevice> loadAll() {
     std::vector<dirent> entries;
-    file::scandir(DATA_DIR, entries, [](const dirent* entry) -> int {
+    if (!file::isDirectory(getSettingsFilePath())) {
+        return {};
+    }
+    file::scandir(getSettingsFilePath(), entries, [](const dirent* entry) -> int {
         if (entry->d_type != file::TT_DT_REG && entry->d_type != file::TT_DT_UNKNOWN) return -1;
         std::string name = entry->d_name;
         return name.ends_with(".device.properties") ? 0 : -1;

Tactility/Source/lvgl/Lvgl.cpp

@@ -102,7 +102,7 @@ void attachDevices() {
     // We search for the manifest first, because during the initial start() during boot
     // the service won't be registered yet.
     if (service::findManifestById("Gui") != nullptr) {
-        if (service::getState("Gui") == service::State::Stopped) {
+        if (service::getState("Gui") == SERVICE_STATE_STOPPED) {
             service::startService("Gui");
         } else {
             LOG_E(TAG, "Gui service is not in Stopped state");
@@ -112,7 +112,7 @@ void attachDevices() {
     // We search for the manifest first, because during the initial start() during boot
     // the service won't be registered yet.
     if (service::findManifestById("Statusbar") != nullptr) {
-        if (service::getState("Statusbar") == service::State::Stopped) {
+        if (service::getState("Statusbar") == SERVICE_STATE_STOPPED) {
             service::startService("Statusbar");
         } else {
             LOG_E(TAG, "Statusbar service is not in Stopped state");

Tactility/Source/service/ServiceContext.cpp

@@ -0,0 +1,17 @@
+#include <Tactility/service/ServiceContext.h>
+
+#include <Tactility/service/ServicePaths.h>
+
+#include <tactility/service/service_instance.h>
+
+namespace tt::service {
+
+const ::ServiceManifest* ServiceContext::getManifest() const {
+    return service_instance_get_manifest(service_instance);
+}
+
+std::unique_ptr<ServicePaths> ServiceContext::getPaths() const {
+    return std::make_unique<ServicePaths>(getManifest());
+}
+
+} // namespace

Tactility/Source/service/ServiceInstance.cpp

@@ -1,19 +0,0 @@
-#include <Tactility/service/ServiceInstance.h>
-
-#include <Tactility/service/ServiceManifest.h>
-#include <Tactility/service/ServicePaths.h>
-
-namespace tt::service {
-
-ServiceInstance::ServiceInstance(std::shared_ptr<const ServiceManifest> manifest) :
-    manifest(manifest),
-    service(manifest->createService())
-{}
-
-const ServiceManifest& ServiceInstance::getManifest() const { return *manifest; }
-
-std::unique_ptr<ServicePaths> ServiceInstance::getPaths() const {
-    return std::make_unique<ServicePaths>(manifest);
-}
-
-}

Tactility/Source/service/ServicePaths.cpp

@@ -1,29 +0,0 @@
-#include <Tactility/service/ServicePaths.h>
-
-#include <Tactility/service/ServiceManifest.h>
-#include <Tactility/Paths.h>
-
-#include <cassert>
-#include <format>
-
-namespace tt::service {
-
-std::string ServicePaths::getUserDataDirectory() const {
-    return std::format("{}/service/{}", tt::getUserDataPath(), manifest->id);
-}
-
-std::string ServicePaths::getUserDataPath(const std::string& childPath) const {
-    assert(!childPath.starts_with('/'));
-    return std::format("{}/{}", getUserDataDirectory(), childPath);
-}
-
-std::string ServicePaths::getAssetsDirectory() const {
-    return std::format("{}/service/{}/assets", tt::getUserDataPath(), manifest->id);
-}
-
-std::string ServicePaths::getAssetsPath(const std::string& childPath) const {
-    assert(!childPath.starts_with('/'));
-    return std::format("{}/{}", getAssetsDirectory(), childPath);
-}
-
-}

Tactility/Source/service/ServiceRegistration.cpp

@@ -1,43 +1,68 @@
 #include <Tactility/service/ServiceRegistration.h>
 
-#include <Tactility/Mutex.h>
-#include <Tactility/service/ServiceInstance.h>
+#include <Tactility/service/ServiceContext.h>
 #include <Tactility/service/ServiceManifest.h>
 
-#include <string>
-
+#include <tactility/error.h>
 #include <tactility/log.h>
+#include <tactility/service/service_manager.h>
+
+#include <cassert>
+#include <memory>
 
 namespace tt::service {
 
 constexpr auto* TAG = "ServiceRegistration";
 
-typedef std::unordered_map<std::string, std::shared_ptr<const ServiceManifest>> ManifestMap;
-typedef std::unordered_map<std::string, std::shared_ptr<ServiceInstance>> ServiceInstanceMap;
+// Bridges the kernel's C ServiceManifest/Service callbacks to the C++ Service
+// instances they wrap. Declared extern "C" to match the linkage of the C
+// function-pointer types they're assigned to (see e.g. gpio_controller.cpp).
+extern "C" {
 
-static ManifestMap service_manifest_map;
-static ServiceInstanceMap service_instance_map;
+static void cppDestroyServiceTrampoline(const ::ServiceManifest* /*manifest*/, void* data) {
+    delete static_cast<std::shared_ptr<Service>*>(data);
+}
 
-static Mutex manifest_mutex;
-static Mutex instance_mutex;
+static error_t cppOnStartTrampoline(::ServiceInstance* instance, void* data) {
+    auto& servicePtr = *static_cast<std::shared_ptr<Service>*>(data);
+    ServiceContext context(instance);
+    return servicePtr->onStart(context) ? ERROR_NONE : ERROR_RESOURCE;
+}
+
+static void cppOnStopTrampoline(::ServiceInstance* instance, void* data) {
+    auto& servicePtr = *static_cast<std::shared_ptr<Service>*>(data);
+    ServiceContext context(instance);
+    servicePtr->onStop(context);
+}
+
+} // extern "C"
 
 void addService(std::shared_ptr<const ServiceManifest> manifest, bool autoStart) {
     assert(manifest != nullptr);
-    // We'll move the manifest pointer, but we'll need to id later
     const auto& id = manifest->id;
 
     LOG_I(TAG, "Adding %s", id.c_str());
 
-    manifest_mutex.lock();
-    if (service_manifest_map[id] == nullptr) {
-        service_manifest_map[id] = std::move(manifest);
-    } else {
+    if (service_manager_find_manifest(id.c_str()) != nullptr) {
         LOG_E(TAG, "Service id in use: %s", id.c_str());
+        return;
     }
-    manifest_mutex.unlock();
 
-    if (autoStart) {
-        startService(id);
+    // Intentionally never freed: services are registered once and live for the
+    // process lifetime (there is no removeService()). Keeps id's backing string
+    // alive for cManifest.id below.
+    auto* persistentManifest = new std::shared_ptr(manifest);
+    auto* cManifest = new ::ServiceManifest {
+        .id = (*persistentManifest)->id.c_str(),
+        .create_service = (*persistentManifest)->createService,
+        .destroy_service = cppDestroyServiceTrampoline,
+        .on_start = cppOnStartTrampoline,
+        .on_stop = cppOnStopTrampoline,
+    };
+
+    error_t error = service_manager_add(cManifest, autoStart);
+    if (error != ERROR_NONE) {
+        LOG_E(TAG, "Failed to add service %s: %s", id.c_str(), error_to_string(error));
     }
 }
 
@@ -45,94 +70,50 @@ void addService(const ServiceManifest& manifest, bool autoStart) {
     addService(std::make_shared<const ServiceManifest>(manifest), autoStart);
 }
 
-std::shared_ptr<const ServiceManifest> findManifestById(const std::string& id) {
-    manifest_mutex.lock();
-    auto iterator = service_manifest_map.find(id);
-    auto manifest = iterator != service_manifest_map.end() ? iterator->second : nullptr;
-    manifest_mutex.unlock();
-    return manifest;
+const ::ServiceManifest* findManifestById(const std::string& id) {
+    return service_manager_find_manifest(id.c_str());
 }
 
-static std::shared_ptr<ServiceInstance> findServiceInstanceById(const std::string& id) {
-    manifest_mutex.lock();
-    auto iterator = service_instance_map.find(id);
-    auto service = iterator != service_instance_map.end() ? iterator->second : nullptr;
-    manifest_mutex.unlock();
-    return service;
-}
-
-// TODO: Return proper error/status instead of BOOL?
 bool startService(const std::string& id) {
     LOG_I(TAG, "Starting %s", id.c_str());
-    auto manifest = findManifestById(id);
-    if (manifest == nullptr) {
-        LOG_E(TAG, "manifest not found for service %s", id.c_str());
+    const error_t error = service_manager_start(id.c_str());
+    if (error != ERROR_NONE) {
+        LOG_E(TAG, "Starting %s failed: %s", id.c_str(), error_to_string(error));
         return false;
     }
-
-    auto service_instance = std::make_shared<ServiceInstance>(manifest);
-
-    // Register first, so that a service can retrieve itself during onStart()
-    instance_mutex.lock();
-    service_instance_map[manifest->id] = service_instance;
-    instance_mutex.unlock();
-
-    service_instance->setState(State::Starting);
-    if (service_instance->getService()->onStart(*service_instance)) {
-        service_instance->setState(State::Started);
-    } else {
-        LOG_E(TAG, "Starting %s failed", id.c_str());
-        service_instance->setState(State::Stopped);
-        instance_mutex.lock();
-        service_instance_map.erase(manifest->id);
-        instance_mutex.unlock();
-    }
-
     LOG_I(TAG, "Started %s", id.c_str());
-
     return true;
 }
 
 std::shared_ptr<ServiceContext> findServiceContextById(const std::string& id) {
-    return findServiceInstanceById(id);
+    auto* instance = service_manager_find_instance(id.c_str());
+    if (instance == nullptr) {
+        return nullptr;
+    }
+    return std::make_shared<ServiceContext>(instance);
 }
 
 std::shared_ptr<Service> findServiceById(const std::string& id) {
-    auto instance = findServiceInstanceById(id);
-    return instance != nullptr ? instance->getService() : nullptr;
+    auto* instance = service_manager_find_instance(id.c_str());
+    if (instance == nullptr) {
+        return nullptr;
+    }
+    return *static_cast<std::shared_ptr<Service>*>(instance->data);
 }
 
 bool stopService(const std::string& id) {
     LOG_I(TAG, "Stopping %s", id.c_str());
-    auto service_instance = findServiceInstanceById(id);
-    if (service_instance == nullptr) {
+    error_t error = service_manager_stop(id.c_str());
+    if (error != ERROR_NONE) {
         LOG_W(TAG, "Service not running: %s", id.c_str());
         return false;
     }
-
-    service_instance->setState(State::Stopping);
-    service_instance->getService()->onStop(*service_instance);
-    service_instance->setState(State::Stopped);
-
-    instance_mutex.lock();
-    service_instance_map.erase(id);
-    instance_mutex.unlock();
-
-    if (service_instance.use_count() > 1) {
-        LOG_W(TAG, "Possible memory leak: service %s still has %d references", service_instance->getManifest().id.c_str(), (int)(service_instance.use_count() - 1));
-    }
-
     LOG_I(TAG, "Stopped %s", id.c_str());
-
     return true;
 }
 
 State getState(const std::string& id) {
-    auto service_instance = findServiceInstanceById(id);
-    if (service_instance == nullptr) {
-        return State::Stopped;
-    }
-    return service_instance->getState();
+    return service_manager_get_state(id.c_str());
 }
 
 } // namespace