Mysterious bug - MWE

Author: Zimamazim

python_host_node.py

@@ -0,0 +1,11 @@
+import depthai as dai
+import time
+
+class Printer(dai.HostNode):
+    def run(self):
+        print("hello world")
+
+p = dai.Pipeline()
+p.create(Printer)
+p.start()
+p.wait()

src/pipeline/PipelineBindings.cpp

@@ -116,29 +116,21 @@ void PipelineBindings::bind(pybind11::module& m, void* pCallstack){
         .def("setBoardConfig", &Pipeline::setBoardConfig, DOC(dai, Pipeline, setBoardConfig))
         .def("getBoardConfig", &Pipeline::getBoardConfig, DOC(dai, Pipeline, getBoardConfig))
         // 'Template' create function
-        //.def("create", &Pipeline::create<HostNode>)
-        /*
-        .def("test", [](py::object class_){
-             return py::module_::import("builtins").attr("issubclass")(
-                     class_.attr("__base__"),
-                     py::cast(HostNode)
-                     );
-            //return dynamic_cast<HostNode&>(py::cast(&class_)) == nullptr;
-            })*/
         .def("create", [](dai::Pipeline& p, py::object class_) {
-            //if (class_.attr("__base__")
-            //if (dynamic_cast<HostNode>(py::cast(class_)) != nullptr) {
-	    //if (py::cast<std::string>(class_.attr("__base__").attr("__name__")) == "HostNode") {
-	    	py::print("Detected HostNode");
+	    if (py::cast<std::string>(class_.attr("__base__").attr("__name__")) == "HostNode") {
+#if 0
 	        py::cast<std::shared_ptr<HostNode>>(class_())->run();
+#else
 	        auto host_node = py::cast<std::shared_ptr<HostNode>>(class_());
-		//Test
+	        //std::shared_ptr<HostNode> host_node = py::cast<std::shared_ptr<HostNode>>(class_());
+	        //std::shared_ptr<HostNode> host_node = class_().cast<std::shared_ptr<HostNode>>();
 		host_node->run();
-	    	py::print("Created HostNode");
-		p.add(host_node);
-	    	py::print("pipeline add");
-		return (std::shared_ptr<Node>) host_node;
-	    //}
+#endif
+		
+		//p.add(host_node);
+		//return (std::shared_ptr<Node>) host_node;
+		return (std::shared_ptr<Node>) nullptr;
+	    }
             auto node = createNode(p, class_);
             if(node == nullptr){
                 throw std::invalid_argument(std::string(py::str(class_)) + " is not a subclass of depthai.node");

src/pipeline/node/HostNodeBindings.cpp

@@ -1,65 +1,23 @@
 #include "NodeBindings.hpp"
 #include "Common.hpp"
 
-//#include "depthai/pipeline/Pipeline.hpp"
-//#include "depthai/pipeline/Node.hpp"
-//#include "depthai/pipeline/node/Script.hpp"
 #include "depthai/pipeline/HostNode.hpp"
 
 using namespace dai;
 
-// TODO(Zimamazim) Should be replaced with CRTP
-//class PyHostNode : public NodeCRTP<HostNode, PyHostNode> {
-class PyHostNode : public HostNode {
+class PyHostNode : public NodeCRTP<HostNode, PyHostNode> {
 public:
-    using HostNode::HostNode;
-
     void run() override {
         PYBIND11_OVERRIDE_PURE(
                 void,
                 HostNode,
                 run);
     }
-
-    // TODO(Zimamazim) Should be replaced with CRTP
-    const char* getName() const override {
-	return "PLACEHOLDER";
-    }
-
-    // TODO(Zimamazim) Should be replaced with CRTP
-    std::unique_ptr<Node> clone() const override {
-        return std::make_unique<PyHostNode>(*this);
-    }
-};
-
-class Pokus {
-public:
-	virtual void run() = 0;	
-};
-
-class PyPokus : public Pokus {
-public:
-	//using Pokus::Pokus;
-	void run() override {
-        PYBIND11_OVERRIDE_PURE(
-			void,
-			Pokus,
-			run
-			);}
-
 };
 
 void bind_hostnode(pybind11::module& m, void* pCallstack){
-
-    //using namespace dai::node;
-
-    // Node and Properties declare upfront
-    //py::class_<ScriptProperties> scriptProperties(m, "ScriptProperties", DOC(dai, ScriptProperties));
-    auto hostNode = py::class_<HostNode, PyHostNode, /*ThreadedNode,*/ std::shared_ptr<HostNode>>(m, "HostNode", DOC(dai, node, HostNode));
-    auto pokusNode = py::class_<Pokus, PyPokus, std::shared_ptr<Pokus>>(m, "Pokus");
-
-    //TODO(Zimamazim): Understand why shared_ptr<HostNode> is used
-    //TODO(Zimamazim): Understand why callstack is used
+    // declare upfront
+    auto hostNode = py::class_<HostNode, PyHostNode, ThreadedNode, std::shared_ptr<HostNode>>(m, "HostNode", DOC(dai, node, HostNode));
 
     ///////////////////////////////////////////////////////////////////////
     ///////////////////////////////////////////////////////////////////////
@@ -74,45 +32,8 @@ void bind_hostnode(pybind11::module& m, void* pCallstack){
     ///////////////////////////////////////////////////////////////////////
     ///////////////////////////////////////////////////////////////////////
 
-    pokusNode
-	.def(py::init<>())
-	.def("run", &Pokus::run)
-    ;
-    //m.def("pokus", [](Pokus *pokus){ pokus->run(); });
-    m.def("pokus", [](py::object o){ 
-	py::cast<std::shared_ptr<Pokus>>(o())->run();
-    });
     hostNode
         .def(py::init<>())
         .def("run", &HostNode::run)
     ;
-
-    m.def("testHost", [](py::object o){
-
-	py::cast<std::shared_ptr<HostNode>>(o())->run();
-        //return py::module_::import("builtins").attr("issubclass")(o, hostNode);
-        //return py::cast<std::string>(o.attr("__base__").attr("__name__")) == "HostNode";
-        });
-/*
-    // Properties
-    scriptProperties
-        .def_readwrite("scriptUri", &ScriptProperties::scriptUri, DOC(dai, ScriptProperties, scriptUri))
-        .def_readwrite("scriptName", &ScriptProperties::scriptName, DOC(dai, ScriptProperties, scriptName))
-        .def_readwrite("processor", &ScriptProperties::processor, DOC(dai, ScriptProperties, processor))
-    ;
-
-    // Node
-    script
-        .def_readonly("inputs", &Script::inputs)
-        .def_readonly("outputs", &Script::outputs)
-        .def("setScriptPath", &Script::setScriptPath, DOC(dai, node, Script, setScriptPath))
-        .def("setScript", py::overload_cast<const std::string&, const std::string&>(&Script::setScript), py::arg("script"), py::arg("name") = "", DOC(dai, node, Script, setScript))
-        .def("setScript", py::overload_cast<const std::vector<std::uint8_t>&, const std::string&>(&Script::setScript), py::arg("data"), py::arg("name") = "", DOC(dai, node, Script, setScript, 2))
-        .def("setScriptPath", &Script::setScriptPath, py::arg("path"), py::arg("name") = "", DOC(dai, node, Script, setScriptPath))
-        .def("getScriptName", &Script::getScriptName, DOC(dai, node, Script, getScriptName))
-        .def("setProcessor", &Script::setProcessor, DOC(dai, node, Script, setProcessor))
-        .def("getProcessor", &Script::getProcessor, DOC(dai, node, Script, getProcessor))
-        ;
-    daiNodeModule.attr("Script").attr("Properties") = scriptProperties;
-*/
 }