Fix deleting ogre2 when created (and deleted) in a thread

CMakeLists.txt

@@ -63,7 +63,9 @@ if ((NOT ${CMAKE_VERSION} VERSION_LESS 3.11) AND (NOT OpenGL_GL_PREFERENCE))
   set(OpenGL_GL_PREFERENCE "GLVND")
 endif()
 
-gz_find_package(OpenGL
+gz_find_package(OpenGL REQUIRED
+  COMPONENTS OpenGL
+  OPTIONAL_COMPONENTS EGL
   REQUIRED_BY ogre ogre2
   PKGCONFIG gl)
 

ogre2/src/CMakeLists.txt

@@ -47,6 +47,14 @@ target_link_libraries(${ogre2_target}
     terra
     GzOGRE2::GzOGRE2)
 
+if (TARGET OpenGL::EGL)
+  target_link_libraries(${ogre2_target}
+  PRIVATE
+      OpenGL::EGL
+  )
+  add_definitions(-DHAVE_EGL=1)
+endif()
+
 set (versioned ${CMAKE_SHARED_LIBRARY_PREFIX}${PROJECT_NAME_LOWER}-${engine_name}${CMAKE_SHARED_LIBRARY_SUFFIX})
 set (unversioned ${CMAKE_SHARED_LIBRARY_PREFIX}${PROJECT_NAME_NO_VERSION_LOWER}-${engine_name}${CMAKE_SHARED_LIBRARY_SUFFIX})
 

ogre2/src/Ogre2RenderEngine.cc

@@ -50,6 +50,10 @@
 # include <GL/glxext.h>
 #endif
 
+#if HAVE_EGL
+  #include <EGL/egl.h>
+#endif
+
 class GZ_RENDERING_OGRE2_HIDDEN
     gz::rendering::Ogre2RenderEnginePrivate
 {
@@ -146,6 +150,12 @@
 
   this->dataPtr->hlmsPbsTerraShadows.reset();
 
+  if (this->window)
+  {
+    this->window->destroy();
+    this->window = nullptr;
+  }
+
   if (this->ogreRoot)
   {
     // Clean up any textures that may still be in flight.
@@ -166,6 +176,7 @@
     }
     catch (...)
     {
+      gzerr << "Error deleting ogre root " << std::endl;
     }
     this->ogreRoot = nullptr;
   }
@@ -193,6 +204,12 @@
     }
   }
 #endif
+
+#if HAVE_EGL
+  // release egl per-thread state otherwise this causes a crash on exit if
+  // ogre is created and deleted in a thread
+  eglReleaseThread();
+#endif
 }
 
 //////////////////////////////////////////////////
@@ -391,6 +408,7 @@
   {
     this->CreateContext();
   }
+
   this->CreateRoot();
   this->CreateOverlay();
   this->LoadPlugins();
@@ -1043,7 +1061,7 @@
 {
   Ogre::StringVector paramsVector;
   Ogre::NameValuePairList params;
-  window = nullptr;
+  this->window = nullptr;
 
   if (this->dataPtr->graphicsAPI == GraphicsAPI::VULKAN)
   {
@@ -1103,19 +1121,18 @@
 #endif
 
   int attempts = 0;
-  while (window == nullptr && (attempts++) < 10)
+  while (this->window == nullptr && (attempts++) < 10)
   {
     try
     {
-      window = Ogre::Root::getSingleton().createRenderWindow(
+      this->window = Ogre::Root::getSingleton().createRenderWindow(
           stream.str(), _width, _height, false, &params);
-      this->RegisterHlms();
     }
     catch(const std::exception &_e)
     {
       gzerr << " Unable to create the rendering window: " << _e.what()
              << std::endl;
-      window = nullptr;
+      this->window = nullptr;
     }
   }
 
@@ -1126,12 +1143,14 @@
     return std::string();
   }
 
-  if (window)
+  this->RegisterHlms();
+
+  if (this->window)
   {
-    window->_setVisible(true);
+    this->window->_setVisible(true);
 
     // Windows needs to reposition the render window to 0,0.
-    window->reposition(0, 0);
+    this->window->reposition(0, 0);
   }
   return stream.str();
 }

test/integration/CMakeLists.txt

@@ -9,10 +9,11 @@ set(tests
   lidar_visual
   render_pass
   scene
-  segmentation_camera 
-  shadows 
+  segmentation_camera
+  shadows
   sky
   thermal_camera
+  load_unload
   wide_angle_camera
 )
 

test/integration/load_unload.cc

@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2023 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.
+ *
+ */
+
+#include <gtest/gtest.h>
+
+#include "CommonRenderingTest.hh"
+
+class LoadUnloadTest : public testing::Test
+{
+  /// \brief A thread that loads and unloads the render engine
+  public: void RenderThread()
+  {
+    gz::common::Console::SetVerbosity(4);
+
+    auto [envEngine, envBackend, envHeadless] = GetTestParams();
+
+    if (envEngine.empty())
+    {
+      GTEST_SKIP() << kEngineToTestEnv << " environment not set";
+    }
+
+    auto engineParams = GetEngineParams(envEngine, envBackend, envHeadless);
+    gz::rendering::RenderEngine *engine =
+        gz::rendering::engine(envEngine, engineParams);
+    if (!engine)
+    {
+      GTEST_SKIP() << "Engine '" << envEngine << "' could not be loaded"
+                   << std::endl;
+    }
+
+    gz::rendering::unloadEngine(envEngine);
+  }
+};
+
+/////////////////////////////////////////////////
+TEST_F(LoadUnloadTest, Thread)
+{
+  // verify that we can load and unload the render engine in a thread
+  std::thread renderThread = std::thread(&LoadUnloadTest::RenderThread, this);
+  EXPECT_TRUE(renderThread.joinable());
+  EXPECT_NO_THROW(renderThread.join());
+}
+
+