Use a stored SerializedStepMap message instead of passing it as a f…

…unction argument

Signed-off-by: Addisu Z. Taddese <[email protected]>

src/gui/GuiRunner.cc

@@ -15,7 +15,9 @@
  *
 */
 
+#include <optional>
 #include <memory>
+#include <mutex>
 #include <utility>
 #include <vector>
 
@@ -45,10 +47,6 @@
 using namespace gz;
 using namespace sim;
 
-// Register SerializedStepMap to the Qt meta type system so we can pass objects
-// of this type in QMetaObject::invokeMethod
-Q_DECLARE_METATYPE(msgs::SerializedStepMap)
-
 /////////////////////////////////////////////////
 class gz::sim::GuiRunner::Implementation
 {
@@ -64,15 +62,6 @@ class gz::sim::GuiRunner::Implementation
   /// \brief Latest update info
   public: UpdateInfo updateInfo;
 
-  /// \brief Flag used to end the updateThread.
-  public: bool running{false};
-
-  /// \brief Mutex to protect the plugin update.
-  public: std::mutex updateMutex;
-
-  /// \brief The plugin update thread..
-  public: std::thread updateThread;
-
   /// \brief True if the initial state has been received and processed.
   public: bool receivedInitialState{false};
 
@@ -103,14 +92,15 @@ class gz::sim::GuiRunner::Implementation
 
   /// \brief Manager of all events.
   public: EventManager eventMgr;
+
+  public: std::optional<msgs::SerializedStepMap> lastStateMsg;
+  public: std::mutex stateMsgMutex;
 };
 
 /////////////////////////////////////////////////
 GuiRunner::GuiRunner(const std::string &_worldName)
   : dataPtr(utils::MakeUniqueImpl<Implementation>())
 {
-  qRegisterMetaType<msgs::SerializedStepMap>();
-
   this->setProperty("worldName", QString::fromStdString(_worldName));
 
   // Allow for creation of entities on GUI side.
@@ -262,8 +252,11 @@ void GuiRunner::OnStateAsyncService(const msgs::SerializedStepMap &_res)
   // OnStateQt function to the queue so that its called from the Qt thread. This
   // ensures that only one thread has access to the ecm and updateInfo
   // variables.
-  QMetaObject::invokeMethod(this, "OnStateQt", Qt::QueuedConnection,
-                            Q_ARG(msgs::SerializedStepMap, _res));
+  {
+    std::lock_guard<std::mutex> lock(this->dataPtr->stateMsgMutex);
+    this->dataPtr->lastStateMsg = _res;
+  }
+  QMetaObject::invokeMethod(this, "OnStateQt", Qt::QueuedConnection);
   this->dataPtr->receivedInitialState = true;
 
   // todo(anyone) store reqSrv string in a member variable and use it here
@@ -284,23 +277,32 @@ void GuiRunner::OnState(const msgs::SerializedStepMap &_msg)
   if (!this->dataPtr->receivedInitialState)
     return;
 
+  {
+    std::lock_guard<std::mutex> lock(this->dataPtr->stateMsgMutex);
+    this->dataPtr->lastStateMsg = _msg;
+  }
   // Since this function may be called from a transport thread, we push the
   // OnStateQt function to the queue so that its called from the Qt thread. This
   // ensures that only one thread has access to the ecm and updateInfo
   // variables.
-  QMetaObject::invokeMethod(this, "OnStateQt", Qt::QueuedConnection,
-                            Q_ARG(msgs::SerializedStepMap, _msg));
+  QMetaObject::invokeMethod(this, "OnStateQt", Qt::QueuedConnection);
 }
 
 /////////////////////////////////////////////////
-void GuiRunner::OnStateQt(const msgs::SerializedStepMap &_msg)
+void GuiRunner::OnStateQt()
 {
   GZ_PROFILE_THREAD_NAME("Qt thread");
   GZ_PROFILE("GuiRunner::Update");
-  this->dataPtr->ecm.SetState(_msg.state());
+  {
+    std::lock_guard<std::mutex> lock(this->dataPtr->stateMsgMutex);
+    if (this->dataPtr->lastStateMsg.has_value())
+    {
+      this->dataPtr->ecm.SetState(this->dataPtr->lastStateMsg->state());
+    }
 
-  // Update all plugins
-  this->dataPtr->updateInfo = convert<UpdateInfo>(_msg.stats());
+    // Update all plugins
+    this->dataPtr->updateInfo = convert<UpdateInfo>(this->dataPtr->lastStateMsg->stats());
+  }
   this->UpdatePlugins();
 }
 

src/gui/GuiRunner.hh

@@ -28,10 +28,12 @@
 #include "gz/sim/EventManager.hh"
 #include "gz/sim/gui/Export.hh"
 
+
 namespace gz
 {
 namespace sim
 {
+
 // Inline bracket to help doxygen filtering.
 inline namespace GZ_SIM_VERSION_NAMESPACE {
 /// \brief Responsible for running GUI systems as new states are received from
@@ -67,7 +69,7 @@ class GZ_SIM_GUI_VISIBLE GuiRunner : public QObject
 
   /// \brief Called by the Qt thread to update the ECM with new state
   /// \param[in] _msg New state message.
-  private: Q_INVOKABLE void OnStateQt(const msgs::SerializedStepMap &_msg);
+  private: Q_INVOKABLE void OnStateQt();
 
   /// \brief Update the plugins.
   private: Q_INVOKABLE void UpdatePlugins();