Separate utility code for cyobjects

Cython/Utility/CyObjects.cpp

+/////////////// CyObjects.proto ///////////////
+
+#if !defined(__GNUC__)
+#define GCC_VERSION (__GNUC__ * 10000 \
+                     + __GNUC_MINOR__ * 100 \
+                     + __GNUC_PATCHLEVEL__)
+/* Test for GCC > 4.9.0 */
+#if GCC_VERSION < 40900
+#error atomic.h works only with GCC newer than version 4.9
+#endif /* GNUC >= 4.9 */
+
+#endif /* Has GCC */
+
+#ifdef __cplusplus
+  #if __cplusplus >= 201103L
+    #include <atomic>
+    using namespace std;
+    #define CyObject_ATOMIC_REFCOUNT_TYPE atomic_int
+
+    class CyObject {
+        private:
+          CyObject_ATOMIC_REFCOUNT_TYPE ob_refcnt;
+        public:
+          CyObject(): ob_refcnt(1) {}
+          virtual ~CyObject() {}
+          void CyObject_INCREF();
+          int CyObject_DECREF();
+    };
+
+    static inline int _Cy_DECREF(CyObject *op) {
+        return op->CyObject_DECREF();
+    }
+
+    static inline void _Cy_INCREF(CyObject *op) {
+        op->CyObject_INCREF();
+    }
+
+    /* Cast argument to CyObject* type. */
+    #define _CyObject_CAST(op) op
+
+    #define Cy_INCREF(op) do {if (op != NULL) {_Cy_INCREF(_CyObject_CAST(op));}} while(0)
+    #define Cy_DECREF(op) do {if (_Cy_DECREF(_CyObject_CAST(op))) {op = NULL;}} while(0)
+    #define Cy_XDECREF(op) do {if (op != NULL) {Cy_DECREF(op);}} while(0)
+    #define Cy_GOTREF(op)
+    #define Cy_XGOTREF(op)
+    #define Cy_GIVEREF(op)
+    #define Cy_XGIVEREF(op)
+  #endif
+#endif
+
+
+/////////////// CyObjects ///////////////
+
+#ifdef __cplusplus
+  #include <cstdlib>
+  #include <cstddef>
+// atomic is already included in ModuleSetupCode
+//  #include <atomic>
+#else
+  #error C++ needed for cython+ nogil classes
+#endif /* __cplusplus */
+
+void CyObject::CyObject_INCREF()
+{
+  atomic_fetch_add(&(this->ob_refcnt), 1);
+}
+
+int CyObject::CyObject_DECREF()
+{
+  if (atomic_fetch_sub(&(this->ob_refcnt), 1) == 1) {
+    delete this;
+    return 1;
+  }
+  return 0;
+}