Run server and client in the same process

examples/worlds/minimal_scene.sdf

@@ -26,6 +26,23 @@ Missing for parity with GzScene3D:
 -->
 <sdf version="1.6">
   <world name="minimal_scene">
+    <physics name="1ms" type="ignored">
+      <max_step_size>0.001</max_step_size>
+      <real_time_factor>1.0</real_time_factor>
+    </physics>
+    <plugin
+      filename="ignition-gazebo-physics-system"
+      name="ignition::gazebo::systems::Physics">
+    </plugin>
+    <plugin
+      filename="ignition-gazebo-user-commands-system"
+      name="ignition::gazebo::systems::UserCommands">
+    </plugin>
+    <plugin
+      filename="ignition-gazebo-sensors-system"
+      name="ignition::gazebo::systems::Sensors">
+      <render_engine>ogre2</render_engine>
+    </plugin>
 
     <gui fullscreen="0">
 
@@ -131,9 +148,6 @@ Missing for parity with GzScene3D:
         <play_pause>true</play_pause>
         <step>true</step>
         <start_paused>true</start_paused>
-        <service>/world/buoyancy/control</service>
-        <stats_topic>/world/buoyancy/stats</stats_topic>
-
       </plugin>
 
       <!-- World statistics -->
@@ -157,7 +171,6 @@ Missing for parity with GzScene3D:
         <real_time>true</real_time>
         <real_time_factor>true</real_time_factor>
         <iterations>true</iterations>
-        <topic>/world/buoyancy/stats</topic>
       </plugin>
 
       <!-- Insert simple shapes -->

include/ignition/gazebo/Events.hh

@@ -58,6 +58,31 @@ namespace ignition
       /// the entity, which may contain multiple <plugin> tags.
       using LoadPlugins = common::EventT<void(Entity, sdf::ElementPtr),
           struct LoadPluginsTag>;
+
+      /// \brief Event used to emit a render event when running in one process.
+      /// This is required because we have two RenderUtil classes when there
+      /// is a render sensor in the scene (camera, depth sensor, etc).
+      /// We could only have one thread updating the render scene, with this
+      /// signal we are able to call from the GzSceneManager the render calls
+      /// required by the sensor
+      ///
+      /// For example:
+      /// \code
+      /// eventManager.Emit<ignition::gazebo::events::Render>();
+      /// \endcode
+      using Render = ignition::common::EventT<void(void), struct RenderTag>;
+
+      /// \brief Event used to emit render event when running in one process
+      using EnableSensors =
+        ignition::common::EventT<void(bool), struct EnableSensorsTag>;
+
+      /// \brief Event used to emit a render event when running in one process.
+      /// Some remove events are lost because of the rate when running in the
+      /// same process without sensors. This event is launched in the Simulation
+      /// runner when there is any new entity or entity marked to be removed
+      /// to remove/add entities in the renderUtil
+      using UpdateSystems =
+        ignition::common::EventT<void(void), struct UpdateSystemsTag>;
       }
     }  // namespace events
   }  // namespace gazebo

include/ignition/gazebo/Server.hh

@@ -116,6 +116,18 @@ namespace ignition
       /// \brief Destructor
       public: ~Server();
 
+      /// \brief Get the Entity Component Manager reference
+      /// \param[in] _worldIndex Index of the world in the simrunner
+      /// \return The Entity Component Manager reference
+      public: std::optional<std::reference_wrapper<EntityComponentManager>>
+        SharedEntityComponentManager(const unsigned int _worldIndex = 0) const;
+
+      /// \brief Get the Event Manager reference
+      /// \param[in] _worldIndex Index of the world in the simrunner
+      /// \return The Event Manager reference
+      public: std::optional<std::reference_wrapper<EventManager>>
+        SharedEventManager(const unsigned int _worldIndex = 0) const;
+
       /// \brief Set the update period. The update period is the wall-clock time
       /// between ECS updates.
       /// Note that this is different from the simulation update rate. ECS

include/ignition/gazebo/ServerConfig.hh

@@ -175,6 +175,16 @@ namespace ignition
       /// \return The full contents of the SDF string, or empty string.
       public: std::string SdfString() const;
 
+      /// \brief Set if the server and GUI should run in the same process.
+      /// \param[in] _sameProcessAsGUI True if the server and GUI will run in
+      /// the same process, False otherwise
+      public: void SetSameProcessAsGUI(bool _sameProcessAsGUI);
+
+      /// \brief Get if the server and GUI are running in the same process
+      /// \return  True if the server and GUI will run in
+      /// the same process, False otherwise
+      public: bool SameProcessAsGUI() const;
+
       /// \brief Set the update rate in Hertz. Value <=0 are ignored.
       /// \param[in] _hz The desired update rate of the server in Hertz.
       public: void SetUpdateRate(const double &_hz);

include/ignition/gazebo/components/SameProcess.hh

@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2021 Open Source Robotics Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+#ifndef IGNITION_GAZEBO_COMPONENTS_SAMEPROCESS_HH_
+#define IGNITION_GAZEBO_COMPONENTS_SAMEPROCESS_HH_
+
+#include <ignition/gazebo/components/Factory.hh>
+#include <ignition/gazebo/components/Component.hh>
+#include <ignition/gazebo/config.hh>
+
+namespace ignition
+{
+namespace gazebo
+{
+// Inline bracket to help doxygen filtering.
+inline namespace IGNITION_GAZEBO_VERSION_NAMESPACE {
+namespace components
+{
+  /// \brief A component used to hold if the server and gui are running in the
+  /// same process.
+  using SameProcess = Component<bool, class SameProcessTag>;
+
+  IGN_GAZEBO_REGISTER_COMPONENT("ign_gazebo_components.SameProcess",
+                                SameProcess)
+}
+}
+}
+}
+
+#endif

include/ignition/gazebo/gui/Gui.hh

@@ -22,6 +22,8 @@
 #include <ignition/gui/Application.hh>
 
 #include "ignition/gazebo/config.hh"
+#include "ignition/gazebo/EntityComponentManager.hh"
+#include "ignition/gazebo/EventManager.hh"
 #include "ignition/gazebo/gui/Export.hh"
 
 namespace ignition
@@ -35,20 +37,41 @@ namespace gui
   /// \brief Run GUI application
   /// \param[in] _argc Number of command line arguments (Used when running
   /// without ign-tools. Set to 1 if using ign-tools). Note: The object
-  /// referenced by this variable must continue to exist for the lifetime of the
-  /// application.
+  /// referenced by this variable must continue to exist for the lifetime of
+  /// the application.
   /// \param[in] _argv Command line arguments (Used when running without
   /// ign-tools. Set to the name of the application if using ign-tools)
   /// \param[in] _guiConfig The GUI configuration file. If nullptr, the default
   /// configuration from IGN_HOMEDIR/.ignition/gazebo/gui.config will be used.
-  IGNITION_GAZEBO_GUI_VISIBLE int runGui(int &_argc, char **_argv,
+  IGNITION_GAZEBO_GUI_VISIBLE int IGN_DEPRECATED(6) runGui(int &_argc,
+                                     char **_argv,
                                      const char *_guiConfig);
 
+  /// \brief Run GUI application
+  /// \param[in] _argc Number of command line arguments (Used when running
+  /// without ign-tools. Set to 1 if using ign-tools). Note: The object
+  /// referenced by this variable must continue to exist for the lifetime of
+  /// the application.
+  /// \param[in] _argv Command line arguments (Used when running without
+  /// ign-tools. Set to the name of the application if using ign-tools)
+  /// \param[in] _guiConfig The GUI configuration file. If nullptr, the default
+  /// configuration from IGN_HOMEDIR/.ignition/gazebo/gui.config will be used.
+  /// \param[in] _ecm Entity-component manager.
+  /// \param[in] _eventMgr Event manager
+  /// \param[in] _sameProcess Are the server and gui running in the same
+  /// process?
+  IGNITION_GAZEBO_GUI_VISIBLE int runGui(int &_argc,
+                                         char **_argv,
+                                         const char *_guiConfig,
+                                         EntityComponentManager &_ecm,
+                                         EventManager &_eventMgr,
+                                         bool _sameProcess);
+
   /// \brief Create a Gazebo GUI application
   /// \param[in] _argc Number of command line arguments (Used when running
   /// without ign-tools. Set to 1 if using ign-tools). Note: The object
-  /// referenced by this variable must continue to exist for the lifetime of the
-  /// application.
+  /// referenced by this variable must continue to exist for the lifetime of
+  /// the application.
   /// \param[in] _argv Command line arguments (Used when running without
   /// ign-tools. Set to the name of the application if using ign-tools)
   /// \param[in] _guiConfig The GUI configuration file. If nullptr, the default
@@ -61,9 +84,38 @@ namespace gui
   /// \param[in] _loadPluginsFromSdf If true, plugins specified in the world
   /// SDFormat file will get loaded.
   IGNITION_GAZEBO_GUI_VISIBLE
+  std::unique_ptr<ignition::gui::Application> IGN_DEPRECATED(6) createGui(
+     int &_argc, char **_argv, const char *_guiConfig,
+     const char *_defaultGuiConfig = nullptr, bool _loadPluginsFromSdf = true);
+
+  /// \brief Create a Gazebo GUI application
+  /// \param[in] _argc Number of command line arguments (Used when running
+  /// without ign-tools. Set to 1 if using ign-tools). Note: The object
+  /// referenced by this variable must continue to exist for the lifetime of the
+  /// application.
+  /// \param[in] _argv Command line arguments (Used when running without
+  /// ign-tools. Set to the name of the application if using ign-tools)
+  /// \param[in] _guiConfig The GUI configuration file. If nullptr, the default
+  /// configuration from IGN_HOMEDIR/.ignition/gazebo/gui.config will be used.
+  /// \param[in] _ecm Entity-component manager.
+  /// \param[in] _eventMgr Event manager
+  /// \param[in] _sameProcess are the server and gui running in the same
+  /// process ?
+  /// \param[in] _defaultGuiConfig The default GUI configuration file. If no
+  /// plugins were added from a world file or from _guiConfig, this
+  /// configuration file will be loaded. If this argument is a nullptr or if
+  /// the file does not exist, the default configuration from
+  /// IGN_HOMEDIR/.ignition/gazebo/gui.config will be used.
+  /// \param[in] _loadPluginsFromSdf If true, plugins specified in the world
+  /// SDFormat file will get loaded.
+  IGNITION_GAZEBO_GUI_VISIBLE
   std::unique_ptr<ignition::gui::Application> createGui(
       int &_argc, char **_argv, const char *_guiConfig,
-      const char *_defaultGuiConfig = nullptr, bool _loadPluginsFromSdf = true);
+      EntityComponentManager &_ecm,
+      EventManager &_eventMgr,
+      bool _sameProcess,
+      const char *_defaultGuiConfig = nullptr,
+      bool _loadPluginsFromSdf = true);
 
 }  // namespace gui
 }  // namespace IGNITION_GAZEBO_VERSION_NAMESPACE

include/ignition/gazebo/gui/GuiSystem.hh

@@ -21,6 +21,7 @@
 
 #include <ignition/gazebo/config.hh>
 #include <ignition/gazebo/EntityComponentManager.hh>
+#include <ignition/gazebo/EventManager.hh>
 #include <ignition/gazebo/gui/Export.hh>
 #include <ignition/gui/Plugin.hh>
 
@@ -53,6 +54,15 @@ namespace gazebo
     /// and write entities and their components.
     public: virtual void Update(const UpdateInfo &/*_info*/,
                                 EntityComponentManager &/*_ecm*/){}
+
+    /// \brief When running in the same process GUI and server we need to
+    /// configure the gui system plugins with the event manager to listen
+    /// ecm updates and set if we are running in the same process
+    /// \param[in] _ecm Mutable event manager
+    /// \param[in] _sameProcess are the server and gui running in the same
+    /// process ?
+    public: virtual void Configure(
+      EventManager &/*_event*/, bool /*sameProcess*/){}
   };
 }
 }

include/ignition/gazebo/rendering/RenderUtil.hh

@@ -27,8 +27,9 @@
 #include <ignition/gazebo/rendering/Export.hh>
 #include <ignition/gazebo/System.hh>
 
-#include "ignition/gazebo/rendering/SceneManager.hh"
+#include "ignition/gazebo/EventManager.hh"
 #include "ignition/gazebo/rendering/MarkerManager.hh"
+#include "ignition/gazebo/rendering/SceneManager.hh"
 
 
 namespace ignition
@@ -44,7 +45,7 @@ inline namespace IGNITION_GAZEBO_VERSION_NAMESPACE {
   class IGNITION_GAZEBO_RENDERING_VISIBLE RenderUtil
   {
     /// \brief Constructor
-    public: explicit RenderUtil();
+    public: RenderUtil();
 
     /// \brief Destructor
     public: ~RenderUtil();
@@ -62,6 +63,10 @@ inline namespace IGNITION_GAZEBO_VERSION_NAMESPACE {
     /// \brief Main update function. Must be called in the rendering thread.
     public: void Update();
 
+    /// brief Set the event Manager
+    /// \param[in] _eventMgr Reference to the event Manager
+    public: void SetEventManager(EventManager &_eventMgr);
+
     /// \brief Get a pointer to the scene
     /// \return Pointer to the scene
     public: rendering::ScenePtr Scene() const;

src/LevelManager.cc

@@ -51,6 +51,7 @@
 #include "ignition/gazebo/components/Pose.hh"
 #include "ignition/gazebo/components/RenderEngineGuiPlugin.hh"
 #include "ignition/gazebo/components/RenderEngineServerPlugin.hh"
+#include "ignition/gazebo/components/SameProcess.hh"
 #include "ignition/gazebo/components/Scene.hh"
 #include "ignition/gazebo/components/Wind.hh"
 #include "ignition/gazebo/components/World.hh"
@@ -151,6 +152,10 @@ void LevelManager::ReadLevelPerformerInfo()
       components::RenderEngineGuiPlugin(
       this->runner->serverConfig.RenderEngineGui()));
 
+  this->runner->entityCompMgr.CreateComponent(this->worldEntity,
+      components::SameProcess(
+      this->runner->serverConfig.SameProcessAsGUI()));
+
   auto worldElem = this->runner->sdfWorld->Element();
 
   // Create Wind

src/Server.cc

@@ -16,6 +16,7 @@
 */
 
 #include <numeric>
+#include <optional>
 
 #include <ignition/common/SystemPaths.hh>
 #include <ignition/fuel_tools/Interface.hh>
@@ -206,6 +207,30 @@ Server::Server(const ServerConfig &_config)
 /////////////////////////////////////////////////
 Server::~Server() = default;
 
+/////////////////////////////////////////////////
+std::optional<std::reference_wrapper<EntityComponentManager>>
+  Server::SharedEntityComponentManager(const unsigned int _worldIndex) const
+{
+  if (this->dataPtr->simRunners.size() > _worldIndex)
+  {
+    return std::reference_wrapper<EntityComponentManager>(
+      this->dataPtr->simRunners[_worldIndex]->EntityCompMgr());
+  }
+  return std::nullopt;
+}
+
+/////////////////////////////////////////////////
+std::optional<std::reference_wrapper<EventManager>>
+  Server::SharedEventManager(const unsigned int _worldIndex) const
+{
+  if (this->dataPtr->simRunners.size() > _worldIndex)
+  {
+    return std::reference_wrapper<EventManager>(
+      this->dataPtr->simRunners[_worldIndex]->EventMgr());
+  }
+  return std::nullopt;
+}
+
 /////////////////////////////////////////////////
 bool Server::Run(const bool _blocking, const uint64_t _iterations,
     const bool _paused)