Fix deadlock issue

Author: StephenSmith25

pythonfmu3/pythonfmu-export/src/pythonfmu/PySlaveInstance.cpp

@@ -57,7 +57,8 @@ std::string getClassName(PyObject * pModule)
                     className = classNameCandidate;
                     Py_DECREF(baseNameObj);
                     Py_DECREF(bases);
-                    break;
+                    Py_DECREF(keys);
+                    return className;
                     }
                 }
                 Py_DECREF(baseNameObj);
@@ -75,13 +76,27 @@ std::string getClassName(PyObject * pModule)
     return className;
 }
 
+class GILStateGuard {
+public:
+    GILStateGuard() : gil_state_(PyGILState_Ensure()) {}
+    ~GILStateGuard() { PyGILState_Release(gil_state_); }
+    
+    GILStateGuard(const GILStateGuard&) = delete;
+    GILStateGuard& operator=(const GILStateGuard&) = delete;
+    
+    PyGILState_STATE get() const { return gil_state_; }
+    
+private:
+    PyGILState_STATE gil_state_;
+};
+
 inline void py_safe_run(const std::function<void(PyGILState_STATE gilState)>& f)
 {
-    PyGILState_STATE gil_state = PyGILState_Ensure();
-    f(gil_state);
-    PyGILState_Release(gil_state);
+    GILStateGuard guard;
+    f(guard.get());
 }
 
+
 PySlaveInstance::PySlaveInstance(std::string instanceName, std::string resources, const cppfmu::Logger& logger, const bool visible, std::shared_ptr<IPyState> pyState)
     : pyState_{ std::move(pyState) }
     , instanceName_(std::move(instanceName))