python service wrapper: add state management for blocking IO in python

pyiec61850/iec61850.i

@@ -154,3 +154,9 @@ void CommParameters_setDstAddress(CommParameters *gooseCommParameters,
                                   uint8_t dst_mac_4,
                                   uint8_t dst_mac_5);
 
+
+/* Wrapper for synchronous functions */
+%{
+#include "servicePythonWrapper.hpp"
+%}
+%include "servicePythonWrapper.hpp"

pyiec61850/servicePythonWrapper.hpp

@@ -0,0 +1,63 @@
+#ifndef PYIEC61850_SERVICEPYTHONWRAPPER_HPP
+#define PYIEC61850_SERVICEPYTHONWRAPPER_HPP
+
+#include "iec61850_client.h"
+#include <Python.h>
+
+
+class PyThreadStateSave
+{
+public:
+    PyThreadStateSave(void)
+    {
+        if (PyGILState_Check())
+            state = PyEval_SaveThread();
+        else
+            state = nullptr;
+    }
+
+    ~PyThreadStateSave(void)
+    {
+        if (state)
+            PyEval_RestoreThread(state);
+    }
+
+private:
+    PyThreadState* state;
+};
+
+/*
+Wrapping of synchronous functions to prevent deadlocks
+*/
+static MmsValue* 
+pyWrap_IedConnection_readObject(IedConnection con, IedClientError* error, const char* objRef, FunctionalConstraint fc)
+{
+    PyThreadStateSave gilStateSave;
+    return IedConnection_readObject(con, error, objRef, fc);
+}
+
+static void
+pyWrap_IedConnection_writeObject(IedConnection con, IedClientError* error, const char* objectReference,
+        FunctionalConstraint fc, MmsValue* value)
+{
+    PyThreadStateSave gilStateSave;
+    IedConnection_writeObject(con, error, objectReference, fc, value);
+}
+
+static void 
+pyWrap_IedConnection_setRCBValues(IedConnection con, IedClientError* error, ClientReportControlBlock rcb, uint32_t parametersMask, 
+        bool singleRequest)
+{
+    PyThreadStateSave gilStateSave;
+    IedConnection_setRCBValues(con, error, rcb, parametersMask, singleRequest);
+}
+
+static ClientReportControlBlock 
+pyWrap_IedConnection_getRCBValues(IedConnection con, IedClientError* error, const char* rcbReference,
+        ClientReportControlBlock updateRcb)
+{
+    PyThreadStateSave gilStateSave;
+    return IedConnection_getRCBValues(con, error, rcbReference, updateRcb);
+}
+
+#endif