Acquiring GIL in pywrapper.cpp

Author: ShikharJ

Diff for: symengine/lib/pywrapper.cpp

@@ -7,6 +7,12 @@
 
 namespace SymEngine {
 
+#if PY_MAJOR_VERSION >= 3
+if (!PyGILState_Check()) {
+    PyEval_AcquireLock();
+}
+#endif
+
 // PyModule
 PyModule::PyModule(PyObject* (*to_py)(const RCP<const Basic>), RCP<const Basic> (*from_py)(PyObject*),
                    RCP<const Number> (*eval)(PyObject*, long), RCP<const Basic> (*diff)(PyObject*, RCP<const Basic>)) :
@@ -274,4 +280,10 @@ int PyFunction::compare(const Basic &o) const {
     return unified_compare(arg_, s.arg_);
 }
 
+#if PY_MAJOR_VERSION >= 3
+if (PyGILState_Check()) {
+    PyEval_ReleaseLock();
+}
+#endif
+
 } // SymEngine