Applets: Reworked how the Applet update event is handled.

Applets are now cleaned up in AppletUpdateEvent after calling their respective Update method.

src/core/hle/applets/applet.cpp

@@ -31,9 +31,8 @@ namespace Applets {
 
 static std::unordered_map<Service::APT::AppletId, std::shared_ptr<Applet>> applets;
 static u32 applet_update_event = -1; ///< The CoreTiming event identifier for the Applet update callback.
-/// The interval at which the Applet update callback will be called.
-static const u64 applet_update_interval_microseconds = 16666;
-std::shared_ptr<Applet> g_current_applet = nullptr; ///< The applet that is currently executing
+/// The interval at which the Applet update callback will be called, 16.6ms
+static const u64 applet_update_interval_us = 16666;
 
 ResultCode Applet::Create(Service::APT::AppletId id) {
     switch (id) {
@@ -57,21 +56,38 @@ std::shared_ptr<Applet> Applet::Get(Service::APT::AppletId id) {
 }
 
 /// Handles updating the current Applet every time it's called.
-static void AppletUpdateEvent(u64, int cycles_late) {
-    if (g_current_applet && g_current_applet->IsRunning())
-        g_current_applet->Update();
+static void AppletUpdateEvent(u64 applet_id, int cycles_late) {
+    Service::APT::AppletId id = static_cast<Service::APT::AppletId>(applet_id);
+    std::shared_ptr<Applet> applet = Applet::Get(id);
+    ASSERT_MSG(applet != nullptr, "Applet doesn't exist! applet_id=%08X", id);
 
-    CoreTiming::ScheduleEvent(usToCycles(applet_update_interval) - cycles_late,
-        applet_update_event);
+    applet->Update();
+
+    // If the applet is still running after the last update, reschedule the event
+    if (applet->IsRunning()) {
+        CoreTiming::ScheduleEvent(usToCycles(applet_update_interval_us) - cycles_late,
+            applet_update_event, applet_id);
+    } else {
+        // Otherwise the applet has terminated, in which case we should clean it up
+        applets[id] = nullptr;
+    }
+}
+
+ResultCode Applet::Start(const Service::APT::AppletStartupParameter& parameter) {
+    ResultCode result = StartImpl(parameter);
+    if (result.IsError())
+        return result;
+    // Schedule the update event
+    CoreTiming::ScheduleEvent(usToCycles(applet_update_interval_us), applet_update_event, static_cast<u64>(id));
+    return result;
 }
 
 void Init() {
+    // Register the applet update callback
     applet_update_event = CoreTiming::RegisterEvent("HLE Applet Update Event", AppletUpdateEvent);
-    CoreTiming::ScheduleEvent(usToCycles(applet_update_interval), applet_update_event);
 }
 
 void Shutdown() {
-    CoreTiming::UnscheduleEvent(applet_update_event, 0);
 }
 
 }

src/core/hle/applets/applet.h

@@ -12,10 +12,10 @@
 namespace HLE {
 namespace Applets {
 
-class Applet : public std::enable_shared_from_this<Applet> {
+class Applet {
 public:
-    virtual ~Applet() {};
-    Applet(Service::APT::AppletId id) : id(id) {};
+    virtual ~Applet() { }
+    Applet(Service::APT::AppletId id) : id(id) { }
 
     /**
      * Creates an instance of the Applet subclass identified by the parameter.
@@ -37,25 +37,33 @@ public:
      * @param parameter Parameter data to handle.
      * @returns ResultCode Whether the operation was successful or not.
      */
-    virtual ResultCode ReceiveParameter(Service::APT::MessageParameter const& parameter) = 0;
+    virtual ResultCode ReceiveParameter(const Service::APT::MessageParameter& parameter) = 0;
 
     /**
      * Handles the Applet start event, triggered from the application.
      * @param parameter Parameter data to handle.
      * @returns ResultCode Whether the operation was successful or not.
      */
-    virtual ResultCode Start(Service::APT::AppletStartupParameter const& parameter) = 0;
+    ResultCode Start(const Service::APT::AppletStartupParameter& parameter);
 
     /**
      * Whether the applet is currently executing instead of the host application or not.
      */
-    virtual bool IsRunning() = 0;
+    virtual bool IsRunning() const = 0;
 
     /**
      * Handles an update tick for the Applet, lets it update the screen, send commands, etc.
      */
     virtual void Update() = 0;
 
+protected:
+    /**
+     * Handles the Applet start event, triggered from the application.
+     * @param parameter Parameter data to handle.
+     * @returns ResultCode Whether the operation was successful or not.
+     */
+    virtual ResultCode StartImpl(const Service::APT::AppletStartupParameter& parameter) = 0;
+
     Service::APT::AppletId id; ///< Id of this Applet
 };
 
@@ -65,6 +73,5 @@ void Init();
 /// Shuts down the HLE applets
 void Shutdown();
 
-extern std::shared_ptr<Applet> g_current_applet; ///< Applet that is currently executing
 }
 } // namespace

src/core/hle/applets/swkbd.cpp

@@ -4,6 +4,7 @@
 
 #include "common/assert.h"
 #include "common/logging/log.h"
+#include "common/string_util.h"
 
 #include "core/hle/applets/swkbd.h"
 #include "core/hle/service/hid/hid.h"
@@ -43,7 +44,9 @@ ResultCode SoftwareKeyboard::ReceiveParameter(Service::APT::MessageParameter con
     return RESULT_SUCCESS;
 }
 
-ResultCode SoftwareKeyboard::Start(Service::APT::AppletStartupParameter const& parameter) {
+ResultCode SoftwareKeyboard::StartImpl(Service::APT::AppletStartupParameter const& parameter) {
+    ASSERT_MSG(parameter.buffer_size == sizeof(config), "The size of the parameter (SoftwareKeyboardConfig) is wrong");
+
     memcpy(&config, parameter.data, parameter.buffer_size);
     text_memory = boost::static_pointer_cast<Kernel::SharedMemory, Kernel::Object>(parameter.object);
 
@@ -52,9 +55,7 @@ ResultCode SoftwareKeyboard::Start(Service::APT::AppletStartupParameter const& p
 
     DrawScreenKeyboard();
 
-    // Update the current applet so we can get update events
     started = true;
-    g_current_applet = shared_from_this();
     return RESULT_SUCCESS;
 }
 
@@ -98,8 +99,6 @@ void SoftwareKeyboard::Finalize() {
     Service::APT::SendParameter(message);
 
     started = false;
-    // Unset the current applet, we are not running anymore
-    g_current_applet = nullptr;
 }
 
 }

src/core/hle/applets/swkbd.h

@@ -42,17 +42,21 @@ struct SoftwareKeyboardConfig {
     INSERT_PADDING_BYTES(0x2B6);
 };
 
+/**
+ * The size of this structure (0x400) has been verified via reverse engineering of multiple games
+ * that use the software keyboard.
+ */
 static_assert(sizeof(SoftwareKeyboardConfig) == 0x400, "Software Keyboard Config size is wrong");
 
-class SoftwareKeyboard : public Applet {
+class SoftwareKeyboard final : public Applet {
 public:
     SoftwareKeyboard(Service::APT::AppletId id);
     ~SoftwareKeyboard() {}
 
-    ResultCode ReceiveParameter(Service::APT::MessageParameter const& parameter) override;
-    ResultCode Start(Service::APT::AppletStartupParameter const& parameter) override;
+    ResultCode ReceiveParameter(const Service::APT::MessageParameter& parameter) override;
+    ResultCode StartImpl(const Service::APT::AppletStartupParameter& parameter) override;
     void Update() override;
-    bool IsRunning() override { return started; }
+    bool IsRunning() const override { return started; }
 
     /**
      * Draws a keyboard to the current bottom screen framebuffer.
@@ -66,7 +70,7 @@ public:
     void Finalize();
 
     /// TODO(Subv): Find out what this is actually used for.
-    // It is believed that the application stores the current screen image here.
+    /// It is believed that the application stores the current screen image here.
     Kernel::SharedPtr<Kernel::SharedMemory> framebuffer_memory;
 
     /// SharedMemory where the output text will be stored

src/core/hle/service/apt/apt.cpp

@@ -44,7 +44,7 @@ static u32 cpu_percent; ///< CPU time available to the running application
 /// Parameter data to be returned in the next call to Glance/ReceiveParameter
 static MessageParameter next_parameter;
 
-void SendParameter(MessageParameter const& parameter) {
+void SendParameter(const MessageParameter& parameter) {
     next_parameter = parameter;
     // Signal the event to let the application know that a new parameter is ready to be read
     parameter_event->Signal();

src/core/hle/service/apt/apt.h

@@ -63,7 +63,7 @@ enum class AppletId : u32 {
 };
 
 /// Send a parameter to the currently-running application, which will read it via ReceiveParameter
-void SendParameter(MessageParameter const& parameter);
+void SendParameter(const MessageParameter& parameter);
 
 /**
  * APT::Initialize service function