Merge pull request #305 from allywarner/viewer_race_condition

Viewer race condition

Author: allywarner

src/Core/RenderResources/RenderResources.cc

@@ -27,6 +27,10 @@
  */
 
 #include <GL/glew.h>
+#include <atomic>
+#include <chrono>
+#include <boost/logic/tribool.hpp>
+#include <boost/logic/tribool_io.hpp>
 
 #ifdef _WIN32
 #include <Windows.h>
@@ -54,9 +58,13 @@ class RenderResourcesPrivate
   // initialize_gl:
   // Initialize GLEW and check required OpenGL version and extensions.
   void initialize_gl();
+
+  //Error checking for GL initialization.
+  void initialize_gl_log_error(const std::string&);
 
   // Query available video memory size.
   void query_video_memory_size();
+  std::atomic<bool> videoDone_{ false };
 
   // A Handle to resource that generated the contexts
   RenderResourcesContextHandle resources_context_;
@@ -75,37 +83,48 @@ class RenderResourcesPrivate
   boost::mutex thread_mutex_;
   boost::condition_variable thread_condition_variable_;
 
-  bool gl_capable_;
+  std::atomic<boost::tribool> gl_capable_{ boost::logic::indeterminate };
   unsigned long vram_size_;
+
+  bool wait_for_render_resources()
+  {
+    return boost::logic::indeterminate(gl_capable_) || !videoDone_;
+  }
+
 };
-  
+
+void RenderResourcesPrivate::initialize_gl_log_error(const std::string& error_string)
+{
+	this->gl_capable_ = false;
+	CORE_LOG_ERROR(error_string);
+}
+
 void RenderResourcesPrivate::initialize_gl()
 {
-  this->gl_capable_ = true;
-  
-  int err = glewInit();
-  if ( err != GLEW_OK )
-  {
-    this->gl_capable_ = false;
-    CORE_LOG_ERROR( "glewInit failed with error code " + Core::ExportToString( err ) );
-  }
-  
-  // Check OpenGL capabilities
-  if ( !GLEW_VERSION_2_0 )
-  {
-    this->gl_capable_ = false;
-    CORE_LOG_ERROR( "OpenGL 2.0 required but not found." );
-  }
-  if ( !GLEW_EXT_framebuffer_object )
-  {
-    this->gl_capable_ = false;
-    CORE_LOG_ERROR( "GL_EXT_framebuffer_object required but not found." );
-  }
-  if ( !GLEW_ARB_pixel_buffer_object )
-  {
-    this->gl_capable_ = false;
-    CORE_LOG_ERROR( "GL_ARB_pixel_buffer_object required but not found." );
-  }
+	//refactor error checks into a function to avoid misuse
+	int err = glewInit();
+	if (err != GLEW_OK)
+	{
+		initialize_gl_log_error("glewInit failed with error code " + Core::ExportToString(err));
+	}
+
+	// Check OpenGL capabilities
+	else if (!GLEW_VERSION_2_0)
+	{
+		initialize_gl_log_error("OpenGL 2.0 required but not found.");
+	}
+	else if (!GLEW_EXT_framebuffer_object)
+	{
+		initialize_gl_log_error("GL_EXT_framebuffer_object required but not found.");
+	}
+	else if (!GLEW_ARB_pixel_buffer_object)
+	{
+		initialize_gl_log_error("GL_ARB_pixel_buffer_object required but not found.");
+	}
+	else
+	{
+		this->gl_capable_ = true;
+	}
 }
 
 void RenderResourcesPrivate::query_video_memory_size()
@@ -214,12 +233,14 @@ void RenderResourcesPrivate::query_video_memory_size()
   {
     CORE_LOG_MESSAGE( "Video Memory Size: " + ExportToString( vram_size_MB ) + " MB." );
   }
+
+  videoDone_ = true;
 }
 
 RenderResources::RenderResources() :
   private_( new RenderResourcesPrivate )
 {
-  this->private_->gl_capable_ = false;
+  
 }
 
 RenderResources::~RenderResources()
@@ -280,12 +301,32 @@ void RenderResources::install_resources_context( RenderResourcesContextHandle re
   this->initialize_on_event_thread();
 }
 
+//#define LOG_RENDER_RESOURCE_INIT
+
 bool RenderResources::valid_render_resources()
 {
-  return ( this->private_->resources_context_ && 
-         this->private_->resources_context_->valid_render_resources() && 
-         this->private_->delete_context_ &&
-         this->private_->gl_capable_ );
+  if (!this->private_->gl_capable_)
+  {
+    return false;
+  }
+
+  while (this->private_->wait_for_render_resources())
+  {
+#ifdef LOG_RENDER_RESOURCE_INIT
+	  std::cout << "Waiting..." << std::endl;
+	  std::cout << std::boolalpha << "resources context: " << (this->private_->resources_context_ != nullptr) << " "
+		  << "valid render resources: " << this->private_->resources_context_->valid_render_resources() << " "
+		  << "delete context: " << (this->private_->delete_context_ != nullptr) << " "
+		  << "GL capable: " << this->private_->gl_capable_ << std::endl;
+#endif
+
+	  boost::this_thread::sleep_for(boost::chrono::milliseconds(100));
+  }
+
+  return (this->private_->resources_context_ &&
+		  this->private_->resources_context_->valid_render_resources() &&
+		  this->private_->delete_context_ &&
+		  this->private_->gl_capable_);	
 }
 
 void RenderResources::initialize_on_event_thread()