dnn(ngraph): fix outputs handling, drop 'unconnected' logic

modules/dnn/src/dnn.cpp

@@ -1937,6 +1937,9 @@ struct Net::Impl : public detail::NetImplBase
 
 
 #ifdef HAVE_DNN_NGRAPH
+    /** mark input pins as outputs from other subnetworks
+     * FIXIT must be done by DNN engine not ngraph.
+     */
     void addNgraphOutputs(LayerData &ld)
     {
         CV_TRACE_FUNCTION();
@@ -1967,8 +1970,7 @@ struct Net::Impl : public detail::NetImplBase
                 if (layerNet != ieInpNode->net)
                 {
                     CV_LOG_DEBUG(NULL, "DNN/IE: pin output between subnets: " << ieInpNode->node->get_friendly_name());
-                    ieInpNode->net->addOutput(ieInpNode->node->get_friendly_name());
-                    ieInpNode->net->setUnconnectedNodes(ieInpNode);
+                    ieInpNode->net->addOutput(ieInpNode);
                 }
             }
         }
@@ -2118,7 +2120,7 @@ struct Net::Impl : public detail::NetImplBase
                         if (!inpNode.empty()) {
                             Ptr<InfEngineNgraphNode> ieNode = inpNode.dynamicCast<InfEngineNgraphNode>();
                             CV_Assert(!ieNode.empty());
-                            ieNode->net->setUnconnectedNodes(ieNode);
+                            ieNode->net->addOutput(ieNode);
                         }
                     }
                     continue;
@@ -2259,15 +2261,11 @@ struct Net::Impl : public detail::NetImplBase
             CV_Assert(!ieNode.empty());
             ieNode->net = net;
 
-            if (ld.consumers.empty()) {
-                // TF EAST_text_detection
-                ieNode->net->setUnconnectedNodes(ieNode);
-            }
             for (const auto& pin : blobsToKeep_)
             {
                 if (pin.lid == ld.id)
                 {
-                    ieNode->net->addOutput(ieNode->node->get_friendly_name());
+                    ieNode->net->addOutput(ieNode);
                     break;
                 }
             }
@@ -2298,7 +2296,7 @@ struct Net::Impl : public detail::NetImplBase
 
             if (!ieNode->net->isInitialized())
             {
-                ieNode->net->setUnconnectedNodes(ieNode);
+                ieNode->net->addOutput(ieNode);
                 ieNode->net->createNet((Target)preferableTarget);
                 ld.skip = false;
             }

modules/dnn/src/ie_ngraph.cpp

@@ -379,16 +379,21 @@ InfEngineNgraphNet::InfEngineNgraphNet(detail::NetImplBase& netImpl, InferenceEn
     device_name = "CPU";
 }
 
-void InfEngineNgraphNet::addOutput(const std::string& name)
+void InfEngineNgraphNet::addOutput(const Ptr<InfEngineNgraphNode>& node)
 {
-    requestedOutputs.push_back(name);
+    CV_Assert(node);
+    CV_Assert(node->node);
+    const std::string& name = node->node->get_friendly_name();
+    requestedOutputs.insert({name, node});
 }
 
 void InfEngineNgraphNet::setNodePtr(std::shared_ptr<ngraph::Node>* ptr) {
     all_nodes.emplace((*ptr)->get_friendly_name(), ptr);
 }
 
- void InfEngineNgraphNet::release() {
+ void InfEngineNgraphNet::release()
+ {
+     // FIXIT release should not be conditional, release ALL
      for (auto& node : components.back()) {
 #if INF_ENGINE_VER_MAJOR_GT(INF_ENGINE_RELEASE_2020_4)
          if (!(ngraph::op::is_parameter(node) || ngraph::op::is_output(node) || ngraph::op::is_constant(node)) ) {
@@ -397,7 +402,6 @@ void InfEngineNgraphNet::setNodePtr(std::shared_ptr<ngraph::Node>* ptr) {
 #endif
              auto it = all_nodes.find(node->get_friendly_name());
              if (it != all_nodes.end()) {
-                 unconnectedNodes.erase(*(it->second));
                  it->second->reset();
                  all_nodes.erase(it);
              }
@@ -422,7 +426,8 @@ void InfEngineNgraphNet::dfs(std::shared_ptr<ngraph::Node>& node,
     }
 }
 
-int InfEngineNgraphNet::getNumComponents() {
+int InfEngineNgraphNet::getNumComponents()
+{
     if (!components.empty()) {
         return components.size();
     }
@@ -445,12 +450,14 @@ int InfEngineNgraphNet::getNumComponents() {
 void InfEngineNgraphNet::createNet(Target targetId) {
     if (!hasNetOwner)
     {
-        CV_Assert(!unconnectedNodes.empty());
+        CV_Assert(!requestedOutputs.empty());
         ngraph::ResultVector outs;
-        for (auto& node : unconnectedNodes)
+
+        for (auto output_node_it = requestedOutputs.begin(); output_node_it != requestedOutputs.end(); ++output_node_it)
         {
-            CV_LOG_DEBUG(NULL, "DNN/IE: +network_output[" << outs.size() << "]: name='" << node->get_friendly_name() << "'");
-            auto out = std::make_shared<ngraph::op::Result>(node);
+            CV_LOG_DEBUG(NULL, "DNN/NGRAPH: Add 'Result' output: " << output_node_it->first);
+            CV_Assert(output_node_it->second);
+            auto out = std::make_shared<ngraph::op::Result>(output_node_it->second->node);
             outs.push_back(out);
         }
         CV_Assert_N(!inputs_vec.empty(), !outs.empty());
@@ -576,7 +583,7 @@ void InfEngineNgraphNet::init(Target targetId)
             auto node = ngraph_function->output(i).get_node();
             for (size_t j = 0; j < node->get_input_size(); ++j) {
                 std::string name = node->input_value(j).get_node()->get_friendly_name();
-                auto iter = std::find(requestedOutputs.begin(), requestedOutputs.end(), name);
+                auto iter = requestedOutputs.find(name);
                 if (iter != requestedOutputs.end()) {
                     requestedOutputs.erase(iter);
                     cnn.addOutput(name);
@@ -584,10 +591,6 @@ void InfEngineNgraphNet::init(Target targetId)
             }
         }
     }
-    for (const auto& name : requestedOutputs)
-    {
-        cnn.addOutput(name);
-    }
 
     for (const auto& it : cnn.getInputsInfo())
     {
@@ -632,9 +635,6 @@ ngraph::ParameterVector InfEngineNgraphNet::setInputs(const std::vector<cv::Mat>
     return current_inp;
 }
 
-void InfEngineNgraphNet::setUnconnectedNodes(Ptr<InfEngineNgraphNode>& node) {
-    unconnectedNodes.insert(node->node);
-}
 
 void InfEngineNgraphNet::initPlugin(InferenceEngine::CNNNetwork& net)
 {

modules/dnn/src/ie_ngraph.hpp

@@ -37,7 +37,7 @@ public:
     InfEngineNgraphNet(detail::NetImplBase& netImpl);
     InfEngineNgraphNet(detail::NetImplBase& netImpl, InferenceEngine::CNNNetwork& net);
 
-    void addOutput(const std::string& name);
+    void addOutput(const Ptr<InfEngineNgraphNode>& node);
 
     bool isInitialized();
     void init(Target targetId);
@@ -47,7 +47,6 @@ public:
     void initPlugin(InferenceEngine::CNNNetwork& net);
     ngraph::ParameterVector setInputs(const std::vector<cv::Mat>& inputs, const std::vector<std::string>& names);
 
-    void setUnconnectedNodes(Ptr<InfEngineNgraphNode>& node);
     void addBlobs(const std::vector<cv::Ptr<BackendWrapper> >& ptrs);
 
     void createNet(Target targetId);
@@ -88,8 +87,7 @@ public:
 
     InferenceEngine::CNNNetwork cnn;
     bool hasNetOwner;
-    std::vector<std::string> requestedOutputs;
-    std::unordered_set<std::shared_ptr<ngraph::Node>> unconnectedNodes;
+    std::unordered_map<std::string, Ptr<InfEngineNgraphNode> > requestedOutputs;
 
     std::map<std::string, InferenceEngine::TensorDesc> outputsDesc;
 };