Detect running server on startup (#2828)

Signed-off-by: GauravKumar9920 <[email protected]>
Signed-off-by: Gaurav Kumar <[email protected]>
Co-authored-by: Arjo Chakravarty <[email protected]>

Author: GauravKumar9920

src/SimulationRunner.cc

@@ -192,6 +192,14 @@ SimulationRunner::SimulationRunner(const sdf::World &_world,
 
   this->node = std::make_unique<transport::Node>(opts);
 
+  std::vector<transport::MessagePublisher> pubs;
+  std::vector<transport::MessagePublisher> subs;
+  this->node->TopicInfo("/world/" + this->worldName + "/stats", pubs, subs);
+  if (!pubs.empty())
+  {
+    gzerr << "Another world of the same name is running" << std::endl;
+  }
+
   // Create the system manager
   this->systemMgr = std::make_unique<SystemManager>(
       _systemLoader, &this->entityCompMgr, &this->eventMgr, validNs,

src/gui/Gui_TEST.cc

@@ -252,6 +252,8 @@ TEST_F(GuiTest, GZ_UTILS_TEST_ENABLED_ONLY_ON_LINUX(QuickStart))
     // Close the quick start window
     gzdbg << "Closing the quickstart window" << std::endl;
     ASSERT_EQ(1, gui::App()->allWindows().count());
+    while (!gui::App()->allWindows()[0]->isExposed())
+    std::this_thread::sleep_for(std::chrono::milliseconds(100));
     gui::App()->allWindows()[0]->close();
 
     gzdbg << "Waiting for main window" << std::endl;

src/gui/QuickStartHandler.cc

@@ -18,10 +18,23 @@
 #include "QuickStartHandler.hh"
 
 #include "gz/sim/InstallationDirectories.hh"
+#include <gz/transport/Node.hh>
+#include <gz/common/Console.hh>
 
 using namespace gz;
 using namespace sim::gui;
 
+QuickStartHandler::QuickStartHandler()
+{
+  std::vector<transport::MessagePublisher> publishers;
+  std::vector<transport::MessagePublisher> subscribers;
+  this->node.TopicInfo("/stats", publishers, subscribers);
+  if (!publishers.empty())
+  {
+    gzerr << "Detected an already running world on start" << std::endl;
+  }
+}
+
 /////////////////////////////////////////////////
 QString QuickStartHandler::WorldsPath() const
 {

src/gui/QuickStartHandler.hh

@@ -23,6 +23,12 @@
 #include "gz/sim/config.hh"
 #include "gz/sim/gui/Export.hh"
 
+#include <gz/transport/Node.hh>
+#include <gz/common/Console.hh>
+
+#include <memory>
+#include <vector>
+
 namespace gz
 {
 namespace sim
@@ -36,6 +42,9 @@ class GZ_SIM_GUI_VISIBLE QuickStartHandler : public QObject
 {
   Q_OBJECT
 
+  // Explicitly declare the constructor
+  public: QuickStartHandler();
+
   /// \brief Get worlds path
   /// \return worlds directory path
   public: Q_INVOKABLE QString WorldsPath() const;
@@ -69,6 +78,9 @@ class GZ_SIM_GUI_VISIBLE QuickStartHandler : public QObject
 
   /// \brief Get starting world url.
   private: std::string startingWorld{""};
+
+  // Add a member for the transport node
+  private: gz::transport::Node node;
 };
 }
 }