From 2cf20fde1b2f3494b8bd12e73fb9ccc17959f536 Mon Sep 17 00:00:00 2001
From: Campbell Barton <ideasman42@gmail.com>
Date: Fri, 25 Feb 2011 14:32:35 +0000
Subject: patch [#26215] Python weak reference (weakref) support for game
 objects by Alex Fraser (z0r)

---
 source/gameengine/Expressions/PyObjectPlus.cpp | 37 +++++++++++++++++++-------
 1 file changed, 27 insertions(+), 10 deletions(-)

(limited to 'source/gameengine/Expressions/PyObjectPlus.cpp')

diff --git a/source/gameengine/Expressions/PyObjectPlus.cpp b/source/gameengine/Expressions/PyObjectPlus.cpp
index a3c1e24cdf6..84d6a1cba4b 100644
--- a/source/gameengine/Expressions/PyObjectPlus.cpp
+++ b/source/gameengine/Expressions/PyObjectPlus.cpp
@@ -108,19 +108,26 @@ void PyObjectPlus::InvalidateProxy()		// check typename of each parent
 
 PyTypeObject PyObjectPlus::Type = {
 	PyVarObject_HEAD_INIT(NULL, 0)
-	"PyObjectPlus",			/*tp_name*/
+	"PyObjectPlus",					/*tp_name*/
 	sizeof(PyObjectPlus_Proxy),		/*tp_basicsize*/
-	0,				/*tp_itemsize*/
+	0,								/*tp_itemsize*/
 	/* methods */
-	py_base_dealloc,
-	0,
-	0,
-	0,
+	py_base_dealloc,				/* tp_dealloc */
+	0,								/* printfunc tp_print; */
+	0,								/* getattrfunc tp_getattr; */
+	0,								/* setattrfunc tp_setattr; */
+	0,								/* tp_compare */ /* DEPRECATED in python 3.0! */
+	py_base_repr,					/* tp_repr */
+	0,0,0,0,0,0,0,0,0,				/* Method suites for standard classes */
+	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,/* long tp_flags; */
+	0,0,0,0,
+	/* weak reference enabler */
+#ifdef USE_WEAKREFS
+	offsetof(PyObjectPlus_Proxy, in_weakreflist),	/* long tp_weaklistoffset; */
+#else
 	0,
-	py_base_repr,
-	0,0,0,0,0,0,0,0,0,
-	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,
-	0,0,0,0,0,0,0,
+#endif
+	0,0,
 	Methods,
 	0,
 	0,
@@ -209,8 +216,16 @@ PyObject * PyObjectPlus::py_base_new(PyTypeObject *type, PyObject *args, PyObjec
 	return (PyObject *)ret;
 }
 
+/**
+  * @param self A PyObjectPlus_Proxy
+  */
 void PyObjectPlus::py_base_dealloc(PyObject *self)				// python wrapper
 {
+#ifdef USE_WEAKREFS
+	if (BGE_PROXY_WKREF(self) != NULL)
+		PyObject_ClearWeakRefs((PyObject *) self);
+#endif
+
 	if (BGE_PROXY_PYREF(self)) {
 		PyObjectPlus *self_plus= BGE_PROXY_REF(self);
 		if(self_plus) {
@@ -1107,6 +1122,7 @@ PyObject *PyObjectPlus::GetProxyPlus_Ext(PyObjectPlus *self, PyTypeObject *tp, v
 		self->m_proxy = reinterpret_cast<PyObject *>PyObject_NEW( PyObjectPlus_Proxy, tp);
 		BGE_PROXY_PYOWNS(self->m_proxy) = false;
 		BGE_PROXY_PYREF(self->m_proxy) = true;
+		BGE_PROXY_WKREF(self->m_proxy) = NULL;
 	}
 	//PyObject_Print(self->m_proxy, stdout, 0);
 	//printf("ref %d\n", self->m_proxy->ob_refcnt);
@@ -1127,6 +1143,7 @@ PyObject *PyObjectPlus::NewProxyPlus_Ext(PyObjectPlus *self, PyTypeObject *tp, v
 		BGE_PROXY_PYOWNS(proxy) = py_owns;
 		BGE_PROXY_REF(proxy) = NULL; 
 		BGE_PROXY_PTR(proxy) = ptr;
+		BGE_PROXY_WKREF(self->m_proxy) = NULL;
 		return proxy;
 	}
 	if (self->m_proxy)
-- 
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