Stopped metaline processing in background

drape_frontend/backend_renderer.cpp

@@ -490,6 +490,7 @@ void BackendRenderer::OnContextCreate()
   GLFunctions::Init(m_apiVersion);
 
   m_readManager->Start();
+  m_metalineManager->Start();
   InitGLDependentResource();
 }
 
@@ -498,6 +499,7 @@ void BackendRenderer::OnContextDestroy()
   LOG(LINFO, ("On context destroy."));
   m_readManager->Stop();
   m_batchersPool.reset();
+  m_metalineManager->Stop();
   m_texMng->Release();
   m_overlays.clear();
   m_trafficGenerator->ClearGLDependentResources();

drape_frontend/metaline_manager.cpp

@@ -13,14 +13,31 @@ namespace df
 MetalineManager::MetalineManager(ref_ptr<ThreadsCommutator> commutator, MapDataProvider & model)
   : m_model(model)
   , m_tasksPool(4, ReadMetalineTaskFactory(m_model))
-  , m_threadsPool(make_unique_dp<threads::ThreadPool>(2, std::bind(&MetalineManager::OnTaskFinished,
-                                                                   this, std::placeholders::_1)))
   , m_commutator(commutator)
-{}
+{
+  Start();
+}
 
 MetalineManager::~MetalineManager()
 {
-  m_threadsPool->Stop();
+  Stop();
+}
+
+void MetalineManager::Start()
+{
+  if (m_threadsPool != nullptr)
+    return;
+
+  using namespace std::placeholders;
+  uint8_t constexpr kThreadsCount = 2;
+  m_threadsPool = make_unique_dp<threads::ThreadPool>(
+      kThreadsCount, std::bind(&MetalineManager::OnTaskFinished, this, _1));
+}
+
+void MetalineManager::Stop()
+{
+  if (m_threadsPool != nullptr)
+    m_threadsPool->Stop();
   m_threadsPool.reset();
 }
 

drape_frontend/metaline_manager.hpp

@@ -20,6 +20,9 @@ public:
   MetalineManager(ref_ptr<ThreadsCommutator> commutator, MapDataProvider & model);
   ~MetalineManager();
 
+  void Start();
+  void Stop();
+
   void Update(std::set<MwmSet::MwmId> const & mwms);
 
   m2::SharedSpline GetMetaline(FeatureID const & fid) const;

drape_frontend/read_metaline_task.cpp

@@ -108,6 +108,9 @@ void ReadMetalineTask::Do()
   auto metalines = ReadMetalinesFromFile(m_mwmId);
   for (auto const & metaline : metalines)
   {
+    if (IsCancelled())
+      return;
+
     bool failed = false;
     for (auto const & fid : metaline.m_features)
     {