Use std::unique_ptr for message queue memory management

src/guiengine/engine.cpp

@@ -838,7 +838,6 @@ namespace GUIEngine
         needsUpdate.clearWithoutDeleting();
 
         gui_messages.clear();
-        MessageQueue::clear();
     }   // clear
 
     // ------------------------------------------------------------------------

src/guiengine/message_queue.cpp

@@ -25,6 +25,7 @@
 
 #include "GlyphLayout.h"
 #include <atomic>
+#include <memory>
 
 using namespace GUIEngine;
 
@@ -32,8 +33,8 @@ namespace MessageQueue
 {
 // ============================================================================
 /** The label widget used to show the current message. */
-SkinWidgetContainer* g_container = NULL;
-SkinWidgetContainer* g_static_container = NULL;
+std::unique_ptr<SkinWidgetContainer> g_container;
+std::unique_ptr<SkinWidgetContainer> g_static_container;
 
 /** Stores the height of an static container to allow showing both. */
 int s_msg_raise = 0;
@@ -77,8 +78,6 @@ public:
     }
     // ------------------------------------------------------------------------
     bool canBeRemoved() const                { return m_display_timer < 0.0f; }
-    // ------------------------------------------------------------------------
-    virtual void remove() {}
 
 };
 
@@ -110,7 +109,7 @@ public:
         Message(5.0f, message)
     {
         m_font = NULL;
-        m_container = g_container;
+        m_container = g_container.get();
         m_message_type = mt;
         assert(mt != MessageQueue::MT_PROGRESS);
         if (mt == MessageQueue::MT_ACHIEVEMENT)
@@ -190,7 +189,7 @@ public:
         m_text_rect = core::recti(x, y, x + left_icon_size + total_width,
             y + dim.Height);
 
-        if (m_container == g_static_container)
+        if (m_container == g_static_container.get())
             s_msg_raise = int(dim.Height) + m_font->getHeightPerLine() / 10;
     }
     // ------------------------------------------------------------------------
@@ -208,7 +207,7 @@ public:
         if (m_font != GUIEngine::getFont())
             init();
         int pos_transform = 0;
-        if (m_container == g_container)
+        if (m_container == g_container.get())
             pos_transform = s_msg_raise;
         core::position2di raise = core::position2di(0,
             irr_driver->getDevice()->getOnScreenKeyboardHeight() -
@@ -218,8 +217,6 @@ public:
         GUIEngine::getFont()->draw(m_gls, m_text_rect - raise,
             GUIEngine::getSkin()->getColor("text::neutral"), true/*hcenter*/);
     }
-    // ------------------------------------------------------------------------
-    virtual void remove()                                      { delete this; }
 
 };   // class TextMessage
 
@@ -229,7 +226,7 @@ public:
     StaticTextMessage(MessageQueue::MessageType mt, const core::stringw &message) :
         TextMessage(mt, message)
     {
-        m_container = g_static_container;
+        m_container = g_static_container.get();
         m_message_type = mt;
         assert(mt != MessageQueue::MT_PROGRESS);
         if (mt == MessageQueue::MT_ACHIEVEMENT)
@@ -252,7 +249,6 @@ public:
         TextMessage::draw(dt);
         m_display_timer = 9999999.9f;
     }
-    // ------------------------------------------------------------------------
 };
 
 // ============================================================================
@@ -263,7 +259,8 @@ public:
     /** Used to sort messages by priority in the priority queue. Achievement
      * messages (1) need to have a higher priority than friend messages
      * (value 0), and errors (3) the highest priority. */
-    bool operator() (const Message *a, const Message *b) const
+    bool operator() (const std::unique_ptr<Message>& a,
+                     const std::unique_ptr<Message>& b) const
     {
         return a->getMessageType() < b->getMessageType();
     }   // operator ()
@@ -271,12 +268,12 @@ public:
 
 // ============================================================================
 /** List of all messages. */
-Synchronised<std::priority_queue<Message*, std::vector<Message*>,
-                   CompareMessages> > g_all_messages;
+Synchronised<std::priority_queue<std::unique_ptr<Message>,
+    std::vector<std::unique_ptr<Message> >, CompareMessages> > g_all_messages;
 
 // ============================================================================
 /** The Storage for a Static Message */
-StaticTextMessage* g_static_message = NULL;
+std::unique_ptr<StaticTextMessage> g_static_message;
 
 // ============================================================================
 /** Add any message to the message queue.
@@ -285,7 +282,7 @@ StaticTextMessage* g_static_message = NULL;
 void privateAdd(Message* m)
 {
     g_all_messages.lock();
-    g_all_messages.getData().push(m);
+    g_all_messages.getData().emplace(std::unique_ptr<Message>(m));
     g_all_messages.unlock();
 }   // privateAdd
 
@@ -337,8 +334,6 @@ public:
         if (g_progress.load() >= 100)
             m_display_timer = -1.0f;
     }
-    // ------------------------------------------------------------------------
-    virtual void remove()                                      { delete this; }
 
 };   // class ProgressBarMessage
 
@@ -347,7 +342,7 @@ public:
  *  position of the message. */
 void updatePosition()
 {
-    if (g_static_message != 0)
+    if (g_static_message)
         g_static_message->init();
 }   // updatePosition
 
@@ -377,9 +372,7 @@ void addStatic(MessageType mt, const irr::core::stringw &message)
 #ifndef SERVER_ONLY
     if (GUIEngine::isNoGraphics())
         return;
-    delete g_static_message;
-    g_static_message = NULL;
-    g_static_message = new StaticTextMessage(mt, message);
+    g_static_message.reset(new StaticTextMessage(mt, message));
 #endif
 }   // addStatic
 
@@ -396,29 +389,17 @@ void update(float dt)
     if (GUIEngine::isNoGraphics())
         return;
 
-    if (!g_container)
-    {
-        g_container = new SkinWidgetContainer();
-    }
-    if (!g_static_container)
-    {
-        g_static_container = new SkinWidgetContainer();
-    }
-
-    if (g_static_message != 0)
+    if (g_static_message)
         g_static_message->draw(dt);
 
     g_all_messages.lock();
     if (!g_all_messages.getData().empty())
     {
-        Message* current = g_all_messages.getData().top();
+        auto& current = g_all_messages.getData().top();
         current->draw(dt);
 
         if (current->canBeRemoved())
-        {
             g_all_messages.getData().pop();
-            current->remove();
-        }
     }
     g_all_messages.unlock();
 #endif
@@ -456,32 +437,20 @@ void discardStatic()
     if (GUIEngine::isNoGraphics())
         return;
 
-    delete g_static_message;
-    g_static_message = NULL;
+    g_static_message.reset();
     s_msg_raise = 0;
 #endif
 }    // discardStatic
 
-// ----------------------------------------------------------------------------
-/** Clear all message, called when destroying the GUIEngine.
- */
-void clear()
-{
-#ifndef SERVER_ONLY
-    delete g_static_message;
-    g_static_message = NULL;
-#endif
-}
-
 // ----------------------------------------------------------------------------
 /** Reset global variables (for clear starting in android).
  */
 void resetGlobalVariables()
 {
 #ifndef SERVER_ONLY
-    g_container = NULL;
-    g_static_container = NULL;
-    g_static_message = NULL;
+    g_container.reset(new SkinWidgetContainer());
+    g_static_container.reset(new SkinWidgetContainer());
+    g_static_message.reset();
     s_msg_raise = 0;
     while (!g_all_messages.getData().empty())
         g_all_messages.getData().pop();

src/guiengine/message_queue.hpp

@@ -49,7 +49,6 @@ namespace MessageQueue
     void updatePosition();
     void update(float dt);
     void discardStatic();
-    void clear();
     void resetGlobalVariables();
 };   // namespace GUIEngine
 #endif