Handle sharing of ExtensibleRate among copies of ReactionRateDelegator

Cantera · Sep 11, 2022 · d198841 · d198841
1 parent bf1e2b4
commit d198841
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Showing 3 changed files with 28 additions and 13 deletions.
diff --git a/include/cantera/base/Delegator.h b/include/cantera/base/Delegator.h
@@ -8,6 +8,7 @@
 
 #include "cantera/base/global.h"
 #include "cantera/base/ctexceptions.h"
+#include "cantera/base/ExtensionManager.h"
 #include <array>
 #include <list>
 
@@ -101,12 +102,6 @@ namespace Cantera
 class Delegator
 {
 public:
-    ~Delegator() {
-        for (auto& func : m_cleanup_funcs) {
-            func();
-        }
-    }
-
     //! Set delegates for member functions with the signature `void()`.
     void setDelegate(const std::string& name, const std::function<void()>& func,
                      const std::string& when)
@@ -249,8 +244,8 @@ class Delegator
         *m_funcs_sz_csr[name] = makeDelegate(func, when, m_base_sz_csr[name]);
     }
 
-    void addCleanupFunc(const std::function<void()>& func) {
-        m_cleanup_funcs.push_back(func);
+    void holdExternalHandle(const shared_ptr<ExternalHandle>& handle) {
+        m_handles.push_back(handle);
     }
 
 protected:
@@ -490,7 +485,7 @@ class Delegator
     //! @}
 
     //! Cleanup functions to be called from the destructor
-    std::list<std::function<void()>> m_cleanup_funcs;
+    std::list<shared_ptr<ExternalHandle>> m_handles;
 };
 
 }

diff --git a/include/cantera/base/ExtensionManager.h b/include/cantera/base/ExtensionManager.h
@@ -24,6 +24,14 @@ class ExtensionManager
     };
 };
 
+//! A base class for managing the lifetime of an external object, such as a Python
+//! object used by a Delegator
+class ExternalHandle
+{
+public:
+    virtual ~ExternalHandle() = default;
+};
+
 }
 
 #endif
diff --git a/src/extensions/PythonExtensionManager.cpp b/src/extensions/PythonExtensionManager.cpp
@@ -16,6 +16,20 @@ using namespace std;
 
 namespace {
 
+class PythonHandle : public Cantera::ExternalHandle
+{
+public:
+    explicit PythonHandle(PyObject* obj) : m_obj(obj) {}
+
+    ~PythonHandle() {
+        Py_XDECREF(m_obj);
+    }
+
+private:
+    PyObject* m_obj;
+};
+
+
 std::string getPythonExceptionInfo()
 {
     if (!PyErr_Occurred()) {
@@ -126,10 +140,8 @@ void PythonExtensionManager::registerPythonRateBuilder(
         //! Call setParameters after the delegated functions have been connected
         delegator->setParameters(params, units);
 
-        // Make the delegator responsible for eventually deleting the Python object
-        Py_IncRef(extRate);
-        delegator->addCleanupFunc([extRate]() { Py_DecRef(extRate); });
-
+        // The delegator is responsible for eventually deleting the Python object
+        delegator->holdExternalHandle(make_shared<PythonHandle>(extRate));
         return delegator.release();
     };
     ReactionRateFactory::factory()->reg(rateName, builder);