gras: figured out how to do the python reference

1 files changed, 46 insertions, 5 deletions

diff --git a/python/gras/GRAS_Block.i b/python/gras/GRAS_Block.i
index 82c5d78..e18476a 100644
--- a/python/gras/GRAS_Block.i
+++ b/python/gras/GRAS_Block.i
@@ -56,15 +56,53 @@
 %{
 #include <gras/block.hpp>
 #include <iostream>
+#include <boost/make_shared.hpp>
 %}
 
 %include <gras/element.i>
 %include <gras/block.i>
 
+%include "GRAS_Utils.i"
+
+////////////////////////////////////////////////////////////////////////
+// Create a reference holder for python objects
+////////////////////////////////////////////////////////////////////////
+%inline %{
+
+struct PyObjectRefHolder
+{
+    PyObjectRefHolder(PyObject *o):
+        o(o)
+    {
+        Py_INCREF(o);
+    }
+    ~PyObjectRefHolder(void)
+    {
+        PyGILPhondler phil;
+        Py_DECREF(o);
+    }
+    PyObject *o;
+};
+
+struct WeakElementPyObject : gras::WeakElement
+{
+    WeakElementPyObject(PyObject *o):
+        o(o)
+    {
+        //NOP
+    }
+    boost::shared_ptr<void> lock(void)
+    {
+        return boost::make_shared<PyObjectRefHolder>(o);
+    }
+    PyObject *o;
+};
+
+%}
+
 ////////////////////////////////////////////////////////////////////////
 // Make a special block with safe overloads
 ////////////////////////////////////////////////////////////////////////
-%include "GRAS_Utils.i"
 %inline %{
 
 namespace gras
@@ -84,6 +122,12 @@ struct BlockPython : Block
         this->reset();
     }
 
+    void _Py_set_ref(PyObject *o)
+     {
+         std::cout << o->ob_refcnt <<std::endl;
+         this->weak_self.reset(new WeakElementPyObject(o));
+     }
+
     void notify_active(void)
     {
         PyGILPhondler phil;
@@ -195,16 +239,13 @@ def sig_to_dtype_sig(sig):
     if sig is None: sig = ()
     return map(numpy.dtype, sig)
 
-#FIXME major kludge for ref holding
-blocks_ref_container = list()
-
 class Block(BlockPython):
     def __init__(self, name='Block', in_sig=None, out_sig=None):
         BlockPython.__init__(self, name)
         self.set_input_signature(in_sig)
         self.set_output_signature(out_sig)
-        blocks_ref_container.append(self)
         self.__prop_registry = dict();
+        self._Py_set_ref(self)
 
     def set_input_signature(self, sig):
         self.__in_sig = sig_to_dtype_sig(sig)