GH-423 Avoid reuse of default value instances

src/script/instances/node_instance.cpp

@@ -27,3 +27,28 @@ Ref<OScriptNode> OScriptNodeInstance::get_base_node()
 {
     return { _base };
 }
+
+OScriptNodeInstance::~OScriptNodeInstance()
+{
+    if (input_pin_count > 0)
+    {
+        if (input_pins != nullptr)
+            memdelete_arr(input_pins);
+        if (input_default_stack_pos != nullptr)
+            memdelete_arr(input_default_stack_pos);
+    }
+
+    if (output_pin_count > 0)
+    {
+        if (output_pins != nullptr)
+            memdelete_arr(output_pins);
+    }
+
+    if (execution_output_pin_count > 0)
+    {
+        if (execution_output_pins != nullptr)
+            memdelete_arr(execution_output_pins);
+        if (execution_outputs != nullptr)
+            memdelete_arr(execution_outputs);
+    }
+}

src/script/instances/node_instance.h

@@ -86,6 +86,7 @@ class OScriptNodeInstance : public Object
     Vector<OScriptNodeInstance*> dependencies;           //! List of node instance dependencies for this node
     int* input_pins{ nullptr };                          //! Input pins
     int input_pin_count{ 0 };                            //! Input pin count
+    int* input_default_stack_pos{ nullptr };             //! Holds stack position references for default values
     int* output_pins{ nullptr };                         //! Output pins
     int output_pin_count{ 0 };                           //! Output pin count
     int working_memory_index{ 0 };                       //! Number of working memory slots
@@ -109,6 +110,9 @@ class OScriptNodeInstance : public Object
     /// @param p_context execution context
     /// @return the output port and bits
     virtual int step(OScriptExecutionContext& p_context) = 0;
+
+    /// Destructor
+    ~OScriptNodeInstance() override;
 };
 
 #endif  // ORCHESTRATOR_SCRIPT_NODE_INSTANCE_H

src/script/vm/execution_context.h

@@ -113,8 +113,13 @@ class OScriptExecutionContext
 
     /// Set the input value at the specified index to the default value
     /// @param p_index the input stack index to mutate
+    /// @param p_stack_index the stack position to write the value
     /// @param p_value the default value to use
-    _FORCE_INLINE_ void _set_input_from_default_value(int p_index, const Variant& p_value) { _inputs[p_index] = const_cast<Variant*>(&p_value); }
+    _FORCE_INLINE_ void _set_input_from_default_value(int p_index, int p_stack_index, const Variant& p_value)
+    {
+        _variant_stack[p_stack_index] = p_value.duplicate();
+        _inputs[p_index] = &_variant_stack[p_stack_index];
+    }
 
     /// Copies a variant stack value to the input stack at the given indices
     /// @param p_stack_index the variant stack index to copy from

src/script/vm/script_vm.cpp

@@ -75,20 +75,35 @@ static Ref<OScriptNodePin> get_data_pin_at_count_index(const Ref<OScriptNode>& p
     return nullptr;
 }
 
-void OScriptVirtualMachine::_set_unassigned_inputs(const Ref<OScriptNode>& p_node, const OScriptNodeInstance* p_instance)
+void OScriptVirtualMachine::_set_unassigned_inputs(const Ref<OScriptNode>& p_node, const OScriptNodeInstance* p_instance, Function& r_function)
 {
     for (int i = 0; i < p_instance->data_input_pin_count; i++)
     {
         // If the input pin is bound with a value of -1, it is unassigned.
         if (p_instance->input_pins[i] == -1)
         {
-            // Assign the default value index
-            p_instance->input_pins[i] = _default_values.size() | OScriptNodeInstance::INPUT_DEFAULT_VALUE_BIT;
-
             // Place the pin's effective default value on the default value list
             const Ref<OScriptNodePin> pin = get_data_pin_at_count_index(p_node, i, PD_Input);
-            if (pin.is_valid())
+            if (!pin.is_valid())
+                continue;
+
+            // Default values should be passed on the stack, assign a stack position for the value
+            int stack_pos = r_function.max_stack++;
+            p_instance->input_default_stack_pos[i] = stack_pos;
+
+            // Rather than duplicate default values for each node, reuse existing ones if possible.
+            int lookup_index = _default_values.find(pin->get_effective_default_value());
+            if (lookup_index != -1)
+            {
+                // Default value already exists, assign the stack position
+                p_instance->input_pins[i] = lookup_index | OScriptNodeInstance::INPUT_DEFAULT_VALUE_BIT;
+            }
+            else
+            {
+                // Default value doesn't exist, create a new entry
+                p_instance->input_pins[i] = _default_values.size() | OScriptNodeInstance::INPUT_DEFAULT_VALUE_BIT;
                 _default_values.push_back(pin->get_effective_default_value());
+            }
         }
     }
 }
@@ -198,8 +213,12 @@ bool OScriptVirtualMachine::_create_node_instance_pins(const Ref<OScriptNode>& p
         // Create the input array
         // Each defaults to -1, and if left as -1 triggers default value serialization
         p_instance->input_pins = memnew_arr(int, p_instance->data_input_pin_count);
+        p_instance->input_default_stack_pos = memnew_arr(int, p_instance->data_input_pin_count);
         for (int i = 0; i < p_instance->data_input_pin_count; i++)
+        {
             p_instance->input_pins[i] = -1;
+            p_instance->input_default_stack_pos[i] = -1;
+        }
     }
 
     if (p_instance->data_output_pin_count)
@@ -407,7 +426,7 @@ bool OScriptVirtualMachine::_build_function_node_graph(const Ref<OScriptFunction
         const Ref<OScriptNode>& node = p_function->get_orchestration()->get_node(E);
         const OScriptNodeInstance* instance = _nodes[E];
 
-        _set_unassigned_inputs(node, instance);
+        _set_unassigned_inputs(node, instance, r_function);
         _set_unassigned_outputs(node, instance, r_function.trash_pos);
     }
 
@@ -448,7 +467,7 @@ void OScriptVirtualMachine::_resolve_inputs(OScriptExecutionContext& p_context,
     {
         const int index = p_instance->input_pins[i] & OScriptNodeInstance::INPUT_MASK;
         if (p_instance->input_pins[i] & OScriptNodeInstance::INPUT_DEFAULT_VALUE_BIT)
-            p_context._set_input_from_default_value(i, _default_values[index]);
+            p_context._set_input_from_default_value(i, p_instance->input_default_stack_pos[i], _default_values[index]);
         else
             p_context._copy_stack_to_input(index, i);
     }
@@ -509,7 +528,7 @@ void OScriptVirtualMachine::_dependency_step(OScriptExecutionContext& p_context,
     {
         const int index = p_instance->input_pins[i] & OScriptNodeInstance::INPUT_MASK;
         if (p_instance->input_pins[i] & OScriptNodeInstance::INPUT_DEFAULT_VALUE_BIT)
-            p_context.set_input(i, &_default_values[index]);
+            p_context._set_input_from_default_value(i, p_instance->input_default_stack_pos[i], _default_values[index]);
         else
             p_context._copy_stack_to_input(index, i);
     }

src/script/vm/script_vm.h

@@ -80,7 +80,8 @@ class OScriptVirtualMachine
     /// Sets unassigned inputs on the specified node, if any exist.
     /// @param p_node the script node
     /// @param p_instance the node instance
-    void _set_unassigned_inputs(const Ref<OScriptNode>& p_node, const OScriptNodeInstance* p_instance);
+    /// @param r_function the function declaration
+    void _set_unassigned_inputs(const Ref<OScriptNode>& p_node, const OScriptNodeInstance* p_instance, Function& r_function);
 
     /// Sets unassigned outputs on the specified node, if any exist.
     /// @param p_node the script node