fixed race conditions on current graphics::Overlay object.

map/basic_tiling_render_policy.cpp

@@ -118,8 +118,6 @@ void BasicTilingRenderPolicy::DrawFrame(shared_ptr<PaintEvent> const & e, Screen
 
   if (curCvg)
   {
-    SetOverlay(curCvg->GetOverlay());
-
     curCvg->Draw(pDrawer->screen().get(), s);
 
     m_DrawScale = curCvg->GetDrawScale();
@@ -255,6 +253,21 @@ size_t BasicTilingRenderPolicy::TileSize() const
   return m_TileSize;
 }
 
+void BasicTilingRenderPolicy::FrameLock()
+{
+  m_CoverageGenerator->Mutex().Lock();
+}
+
+void BasicTilingRenderPolicy::FrameUnlock()
+{
+  m_CoverageGenerator->Mutex().Unlock();
+}
+
+shared_ptr<graphics::Overlay> const BasicTilingRenderPolicy::FrameOverlay() const
+{
+  return m_CoverageGenerator->CurrentCoverage()->GetOverlay();
+}
+
 int BasicTilingRenderPolicy::InsertBenchmarkFence()
 {
   return m_CoverageGenerator->InsertBenchmarkFence();

map/basic_tiling_render_policy.hpp

@@ -79,6 +79,10 @@ public:
   size_t ScaleEtalonSize() const;
   size_t TileSize() const;
 
+  void FrameLock();
+  void FrameUnlock();
+  shared_ptr<graphics::Overlay> const FrameOverlay() const;
+
   /// benchmarking protocol
   int InsertBenchmarkFence();
   void JoinBenchmarkFence(int fenceID);

map/framework.cpp

@@ -1411,6 +1411,8 @@ shared_ptr<graphics::OverlayElement> const GetClosestToPivot(list<shared_ptr<gra
 
 bool Framework::GetVisiblePOI(m2::PointD const & pxPoint, m2::PointD & pxPivot, AddressInfo & info) const
 {
+  m_renderPolicy->FrameLock();
+
   m2::PointD const pt = m_navigator.ShiftPoint(pxPoint);
   double const halfSize = TOUCH_PIXEL_RADIUS * GetVisualScale();
 
@@ -1419,12 +1421,14 @@ bool Framework::GetVisiblePOI(m2::PointD const & pxPoint, m2::PointD & pxPivot,
   list<shared_ptr<ElementT> > candidates;
   m2::RectD rect(pt.x - halfSize, pt.y - halfSize,
                  pt.x + halfSize, pt.y + halfSize);
-  m_renderPolicy->GetOverlay()->selectOverlayElements(rect, candidates);
+  m_renderPolicy->FrameOverlay()->selectOverlayElements(rect, candidates);
 
-  shared_ptr<ElementT> res = GetClosestToPivot(candidates, pt);
-  if (res)
+  bool res = false;
+
+  shared_ptr<ElementT> elem = GetClosestToPivot(candidates, pt);
+  if (elem)
   {
-    ElementT::UserInfo const & ui = res->userInfo();
+    ElementT::UserInfo const & ui = elem->userInfo();
     if (ui.IsValid())
     {
       Index::FeaturesLoaderGuard guard(m_model.GetIndex(), ui.m_mwmID);
@@ -1439,11 +1443,12 @@ bool Framework::GetVisiblePOI(m2::PointD const & pxPoint, m2::PointD & pxPivot,
       GetAddressInfo(ft, center, info);
 
       pxPivot = GtoP(center);
-      return true;
+      res = true;
     }
   }
 
-  return false;
+  m_renderPolicy->FrameUnlock();
+  return res;
 }
 
 Animator & Framework::GetAnimator()

map/render_policy.cpp

@@ -239,14 +239,20 @@ void RenderPolicy::SetAnimController(anim::Controller * controller)
   m_controller = controller;
 }
 
-void RenderPolicy::SetOverlay(shared_ptr<graphics::Overlay> const & overlay)
+void RenderPolicy::FrameLock()
 {
-  m_overlay = overlay;
+  LOG(LWARNING, ("unimplemented method called."));
 }
 
-shared_ptr<graphics::Overlay> const RenderPolicy::GetOverlay() const
+void RenderPolicy::FrameUnlock()
 {
-  return m_overlay;
+  LOG(LWARNING, ("unimplemented method called"));
+}
+
+shared_ptr<graphics::Overlay> const RenderPolicy::FrameOverlay() const
+{
+  LOG(LWARNING, ("unimplemented method called"));
+  return shared_ptr<graphics::Overlay>();
 }
 
 graphics::Color const RenderPolicy::GetBgColor() const

map/render_policy.hpp

@@ -71,8 +71,6 @@ protected:
   anim::Controller * m_controller;
   shared_ptr<graphics::Overlay> m_overlay;
 
-  void SetOverlay(shared_ptr<graphics::Overlay> const & overlay);
-
   void InitCacheScreen();
 
 public:
@@ -149,11 +147,25 @@ public:
   double VisualScale() const;
   string const & SkinName() const;
 
+  /// This function is used when we need to prevent race
+  /// conditions on some resources, which could be modified
+  /// from another threads.
+  /// One example of such resource is a current graphics::Overlay
+  /// object
+  /// @{
+  virtual void FrameLock();
+  virtual void FrameUnlock();
+  /// @}
+
+  /// Get current graphics::Overlay object.
+  /// Access to this resource should be synchronized using
+  /// FrameLock/FrameUnlock methods
+  virtual shared_ptr<graphics::Overlay> const FrameOverlay() const;
+
   /// Benchmarking protocol
   virtual int InsertBenchmarkFence();
   virtual void JoinBenchmarkFence(int fenceID);
 
-  virtual shared_ptr<graphics::Overlay> const GetOverlay() const;
   graphics::Color const GetBgColor() const;
 
   shared_ptr<graphics::Screen> const & GetCacheScreen() const;