From 7e0259f7a584e3bb7f38633c779f10a479a31791 Mon Sep 17 00:00:00 2001
From: ExMix <rahuba.youri@mapswithme.com>
Date: Wed, 28 Jan 2015 08:16:54 +0300
Subject: [PATCH] [drape] GLFunctions::Init must be called in thread with valid
 OGL context and executed only once

---
 drape/drape_tests/glfunctions.cpp    | 2 +-
 drape/glfunctions.cpp                | 6 ++++++
 drape_frontend/drape_engine.cpp      | 1 -
 drape_frontend/frontend_renderer.cpp | 1 +
 4 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drape/drape_tests/glfunctions.cpp b/drape/drape_tests/glfunctions.cpp
index 13ae00e13c..85a04553aa 100644
--- a/drape/drape_tests/glfunctions.cpp
+++ b/drape/drape_tests/glfunctions.cpp
@@ -239,7 +239,7 @@ int32_t GLFunctions::glGetInteger(glConst pname)
   return MOCK_CALL(glGetInteger(pname));
 }
 
-void CheckGLError() {}
+void CheckGLError(my::SrcPoint const & /*srcPt*/) {}
 
 // @TODO add actual unit tests
 void GLFunctions::glEnable(glConst mode) {}
diff --git a/drape/glfunctions.cpp b/drape/glfunctions.cpp
index 73d62e2918..1fede51b83 100644
--- a/drape/glfunctions.cpp
+++ b/drape/glfunctions.cpp
@@ -12,6 +12,7 @@
 #endif
 
 #include "std/cstring.hpp"
+#include "std/atomic.hpp"
 
 #if defined(OMIM_OS_WINDOWS)
 #define APIENTRY __stdcall
@@ -111,10 +112,15 @@ namespace
 
   int const GLCompileStatus = GL_COMPILE_STATUS;
   int const GLLinkStatus = GL_LINK_STATUS;
+
+  atomic_flag s_inited = ATOMIC_FLAG_INIT;
 }
 
 void GLFunctions::Init()
 {
+  if (s_inited.test_and_set())
+    return;
+
   /// VAO
 #if defined(OMIM_OS_MAC)
   glGenVertexArraysFn = &glGenVertexArraysAPPLE;
diff --git a/drape_frontend/drape_engine.cpp b/drape_frontend/drape_engine.cpp
index 0917cd3b55..58fdf71e0e 100644
--- a/drape_frontend/drape_engine.cpp
+++ b/drape_frontend/drape_engine.cpp
@@ -15,7 +15,6 @@ DrapeEngine::DrapeEngine(dp::RefPointer<dp::OGLContextFactory> contextfactory,
                          MapDataProvider const & model)
   : m_viewport(viewport)
 {
-  GLFunctions::Init();
   VisualParams::Init(viewport.GetPixelRatio(), df::CalculateTileSize(m_viewport.GetWidth(), m_viewport.GetHeight()));
 
   m_threadCommutator = dp::MasterPointer<ThreadsCommutator>(new ThreadsCommutator());
diff --git a/drape_frontend/frontend_renderer.cpp b/drape_frontend/frontend_renderer.cpp
index 55b8dcfa30..284169ef8b 100644
--- a/drape_frontend/frontend_renderer.cpp
+++ b/drape_frontend/frontend_renderer.cpp
@@ -385,6 +385,7 @@ void FrontendRenderer::Routine::Do()
 {
   dp::OGLContext * context = m_renderer.m_contextFactory->getDrawContext();
   context->makeCurrent();
+  GLFunctions::Init();
 
   my::Timer timer;
   //double processingTime = InitAvarageTimePerMessage; // By init we think that one message processed by 1ms