=== PyNodes ===

* Make PyNodes work with threaded renderer. This patch is by Willian. He has worked hard on getting this sorted out - now you should be able to render with PyNodes AND multiple threads.

7 files changed, 367 insertions, 67 deletions

diff --git a/source/blender/nodes/intern/SHD_nodes/SHD_dynamic.c b/source/blender/nodes/intern/SHD_nodes/SHD_dynamic.c
index 1d1cf3d7e23..ec3a9f3e5d6 100644
--- a/source/blender/nodes/intern/SHD_nodes/SHD_dynamic.c
+++ b/source/blender/nodes/intern/SHD_nodes/SHD_dynamic.c
@@ -43,11 +43,19 @@
 
 static void node_dynamic_setup(bNode *node);
 static void node_dynamic_exec_cb(void *data, bNode *node, bNodeStack **in, bNodeStack **out);
+static void node_dynamic_free_storage_cb(bNode *node);
 
 static PyObject *init_dynamicdict(void) {
-	PyObject *newscriptdict= PyDict_New();
+	PyObject *newscriptdict;
+	PyGILState_STATE gilstate = PyGILState_Ensure();
+
+	newscriptdict= PyDict_New();
+
 	PyDict_SetItemString(newscriptdict, "__builtins__", PyEval_GetBuiltins());
 	EXPP_dict_set_item_str(newscriptdict, "__name__", PyString_FromString("__main__"));
+
+	PyGILState_Release(gilstate);
+
 	return newscriptdict;
 }
 
@@ -228,12 +236,8 @@ static void node_dynamic_rem_all_links(bNodeType *tinfo)
 }
 
 /* node_dynamic_reset: clean a pynode, getting rid of all
- * data dynamically created for it.
- * ntree is used only in a special case: for working pynodes
- * that were saved on a .blend but fail for some reason when
- * the file is opened. We need it because pynodes are initialized
- * before G.main. */
-static void node_dynamic_reset(bNode *node, bNodeTree *ntree)
+ * data dynamically created for it. */
+static void node_dynamic_reset(bNode *node, int unlink_text)
 {
 	bNodeType *tinfo, *tinfo_default;
 	Material *ma;
@@ -244,16 +248,6 @@ static void node_dynamic_reset(bNode *node, bNodeTree *ntree)
 	node_dynamic_rem_all_links(tinfo);
 	node_dynamic_free_typeinfo_sockets(tinfo);
 
-	if (!ntree) { node_dynamic_free_sockets(node); }
-
-	//wnode_dynamic_update_socket_links(node, ntree);
-	node_dynamic_free_storage_cb(node);
-
-	/* XXX hardcoded for shaders: */
-	if (node->typeinfo->id) { BLI_remlink(&node_all_shaders, tinfo); }
-
-	node->typeinfo = tinfo_default;
-
 	/* reset all other XXX shader nodes sharing this typeinfo */
 	for (ma= G.main->mat.first; ma; ma= ma->id.next) {
 		if (ma->nodetree) {
@@ -263,45 +257,129 @@ static void node_dynamic_reset(bNode *node, bNodeTree *ntree)
 					node_dynamic_free_storage_cb(nd);
 					node_dynamic_free_sockets(nd);
 					nd->typeinfo = tinfo_default;
+					if (unlink_text) {
+						nd->id = NULL;
+						nd->custom1 = 0;
+						nd->custom1 = BSET(nd->custom1, NODE_DYNAMIC_NEW);
+						BLI_strncpy(nd->name, "Dynamic", 8);
+					}
 				}
 			}
 		}
 	}
 
+	/* XXX hardcoded for shaders: */
+	if (tinfo->id) { BLI_remlink(&node_all_shaders, tinfo); }
+	node_dynamic_free_typeinfo(tinfo);
+}
+
+/* Special case of the above function: for working pynodes
+ * that were saved on a .blend but fail for some reason when
+ * the file is opened. We need this because pynodes are initialized
+ * before G.main. */
+static void node_dynamic_reset_loaded(bNode *node)
+{
+	bNodeType *tinfo = node->typeinfo;
+
+	node_dynamic_rem_all_links(tinfo);
+	node_dynamic_free_typeinfo_sockets(tinfo);
+	node_dynamic_free_storage_cb(node);
+	/* XXX hardcoded for shaders: */
+	if (tinfo->id) { BLI_remlink(&node_all_shaders, tinfo); }
+
 	node_dynamic_free_typeinfo(tinfo);
+	node->typeinfo = node_dynamic_find_typeinfo(&node_all_shaders, NULL);
 }
 
 int nodeDynamicUnlinkText(ID *txtid) {
 	Material *ma;
-	int unlinked= 0;
+	bNode *nd;
 
+	/* find one node that uses this text */
 	for (ma= G.main->mat.first; ma; ma= ma->id.next) {
 		if (ma->nodetree) {
-			bNode *nd, *nd2 = NULL;
 			for (nd= ma->nodetree->nodes.first; nd; nd = nd->next) {
 				if ((nd->type == NODE_DYNAMIC) && (nd->id == txtid)) {
-					nd->id = NULL;
+					node_dynamic_reset(nd, 1); /* found, reset all */
+					return 1;
+				}
+			}
+		}
+	}
+	return 0; /* no pynodes used this text */
+}
+
+/*
+static void node_dynamic_free_all_typeinfos(ListBase *list)
+{
+	bNodeType *ntype, *ntnext;
+
+	ntype = list->first;
+
+	while (ntype) {
+		ntnext = ntype->next;
+		if (ntype->type == NODE_DYNAMIC && ntype->id) {
+			BLI_remlink(list, ntype);
+			node_dynamic_free_typeinfo_sockets(ntype);
+			node_dynamic_free_typeinfo(ntype);
+		}
+		ntype = ntnext;
+	}
+}
+*/
+/* Unload all pynodes: since the Game Engine restarts Python, we need
+ * to recreate pynodes dicts and objects. First we get rid of them here: */
+/*
+void nodeDynamicUnloadAll(void)
+{
+	Material *ma;
+	bNode *nd;
+	PyGILState_STATE gilstate = PyGILState_Ensure();
+
+	for (ma= G.main->mat.first; ma; ma= ma->id.next) {
+		if (ma->nodetree) {
+			for (nd= ma->nodetree->nodes.first; nd; nd = nd->next) {
+				if ((nd->type == NODE_DYNAMIC) && nd->id) {
+					node_dynamic_free_storage_cb(nd);
+					nd->typeinfo = NULL;
 					nd->custom1 = 0;
-					nd->custom1 = BSET(nd->custom1, NODE_DYNAMIC_NEW);
-					BLI_strncpy(nd->name, "Dynamic", 8);
-					nd2 = nd; /* so we have a ptr to one of them */
-					unlinked++;
+					nd->custom1 = BSET(nd->custom1, NODE_DYNAMIC_LOADED);
 				}
 			}
-			/* clean uneeded dynamic data from all nodes that shared
-			 * this text: */
-			if (nd2) node_dynamic_reset(nd2, NULL);
 		}
 	}
 
-	return unlinked;
+	node_dynamic_free_all_typeinfos(&node_all_shaders);
+
+	PyGILState_Release(gilstate);
+}
+
+void nodeDynamicReloadAll(void)
+{
+	Material *ma;
+	bNode *nd;
+
+	for (ma= G.main->mat.first; ma; ma= ma->id.next) {
+		if (ma->nodetree) {
+			for (nd= ma->nodetree->nodes.first; nd; nd = nd->next) {
+				if ((nd->type == NODE_DYNAMIC) && nd->id) {
+					node_dynamic_setup(nd);
+				}
+			}
+		}
+	}
 }
+*/
 
 static void node_dynamic_pyerror_print(bNode *node)
 {
+	PyGILState_STATE gilstate = PyGILState_Ensure();
+
 	fprintf(stderr, "\nError in dynamic node script \"%s\":\n", node->name);
 	if (PyErr_Occurred()) { PyErr_Print(); }
 	else { fprintf(stderr, "Not a valid dynamic node Python script.\n"); }
+
+	PyGILState_Release(gilstate);
 }
 
 static int node_dynamic_parse(struct bNode *node)
@@ -316,6 +394,7 @@ static int node_dynamic_parse(struct bNode *node)
 	char *buf = NULL;
 	Py_ssize_t pos = 0;
 	int is_valid_script = 0;
+	PyGILState_STATE gilstate;
 
 	if (!node->id || !node->storage)
 		return 0;
@@ -324,6 +403,9 @@ static int node_dynamic_parse(struct bNode *node)
 	if (BTST(node->custom1, NODE_DYNAMIC_READY))
 		return 0;
 
+	/* for threading */
+	gilstate = PyGILState_Ensure();
+
 	nsd = (NodeScriptDict *)node->storage;
 
 	dict = (PyObject *)(nsd->dict);
@@ -336,6 +418,7 @@ static int node_dynamic_parse(struct bNode *node)
 	if (!pyresult) {
 		node_dynamic_disable(node);
 		node_dynamic_pyerror_print(node);
+		PyGILState_Release(gilstate);
 		return -1;
 	}
 
@@ -365,7 +448,8 @@ static int node_dynamic_parse(struct bNode *node)
 					node->typeinfo->pydict = dict;
 					node->typeinfo->pynode = pynode;
 					node->typeinfo->id = node->id;
-					nodeAddSockets(node, node->typeinfo);
+					if (BNTST(node->custom1, NODE_DYNAMIC_LOADED))
+						nodeAddSockets(node, node->typeinfo);
 					if (BNTST(node->custom1, NODE_DYNAMIC_REPARSE)) {
 						nodeRegisterType(&node_all_shaders, node->typeinfo);
 						/* nodeRegisterType copied it to a new one, so we
@@ -386,6 +470,8 @@ static int node_dynamic_parse(struct bNode *node)
 		}
 	}
 
+	PyGILState_Release(gilstate);
+
 	if (!is_valid_script) { /* not a valid pynode script */
 		node_dynamic_disable(node);
 		node_dynamic_pyerror_print(node);
@@ -402,6 +488,7 @@ static void node_dynamic_setup(bNode *node)
 	NodeScriptDict *nsd = NULL;
 	bNodeTree *nodetree = NULL;
 	bNodeType *ntype = NULL;
+	PyGILState_STATE gilstate;
 
 	/* Possible cases:
 	 * NEW
@@ -423,9 +510,12 @@ static void node_dynamic_setup(bNode *node)
 	if (BTST(node->custom1, NODE_DYNAMIC_READY))
 		return;
 
+	gilstate = PyGILState_Ensure();
+
 	/* ERROR, reset to (empty) defaults */
 	if (BCLR(node->custom1, NODE_DYNAMIC_ERROR) == 0) {
-		node_dynamic_reset(node, NULL);
+		node_dynamic_reset(node, 0);
+		PyGILState_Release(gilstate);
 		return;
 	}
 
@@ -459,6 +549,7 @@ static void node_dynamic_setup(bNode *node)
 			node->storage = nsd;
 			/* prepared, now reparse: */
 			node_dynamic_parse(node);
+			PyGILState_Release(gilstate);
 			return;
 		}
 	}
@@ -492,8 +583,9 @@ static void node_dynamic_setup(bNode *node)
 			nodeMakeDynamicType(node);
 			nsd->dict = init_dynamicdict();
 			if ((node_dynamic_parse(node) == -1) && nodetree) {
-				node_dynamic_reset(node, nodetree);
+				node_dynamic_reset_loaded(node);
 			}
+			PyGILState_Release(gilstate);
 			return;
 		}
 	}
@@ -502,6 +594,7 @@ static void node_dynamic_setup(bNode *node)
 	 * we just reuse existing py dict and pynode */
 	nsd->dict = node->typeinfo->pydict;
 	nsd->node = node->typeinfo->pynode;
+
 	Py_INCREF((PyObject *)(nsd->dict));
 	Py_INCREF((PyObject *)(nsd->node));
 
@@ -513,6 +606,8 @@ static void node_dynamic_setup(bNode *node)
 	node->custom1 = BCLR(node->custom1, NODE_DYNAMIC_ADDEXIST);
 	node->custom1 = BSET(node->custom1, NODE_DYNAMIC_READY);
 
+	PyGILState_Release(gilstate);
+
 	return;
 }
 
@@ -546,16 +641,21 @@ static void node_dynamic_init_cb(bNode *node) {
 static void node_dynamic_copy_cb(bNode *orig_node, bNode *new_node)
 {
 	NodeScriptDict *nsd;
+	PyGILState_STATE gilstate;
 
 	if (!orig_node->storage) return;
 
 	nsd = (NodeScriptDict *)(orig_node->storage);
 	new_node->storage = MEM_dupallocN(orig_node->storage);
 
+	gilstate = PyGILState_Ensure();
+
 	if (nsd->node)
 		Py_INCREF((PyObject *)(nsd->node));
 	if (nsd->dict)
 		Py_INCREF((PyObject *)(nsd->dict));
+
+	PyGILState_Release(gilstate);
 }
 
 /* node_dynamic_exec_cb: the execution callback called per pixel
@@ -566,12 +666,13 @@ static void node_dynamic_exec_cb(void *data, bNode *node, bNodeStack **in, bNode
 	PyObject *pyresult = NULL;
 	PyObject *args = NULL;
 	ShadeInput *shi;
+	PyGILState_STATE gilstate;
 
 	if (!node->id)
 		return;
 
-	if (G.scene->r.threads > 1)
-		return;
+	/*if (G.scene->r.threads > 1)
+		return;*/
 
 	if (BTST2(node->custom1, NODE_DYNAMIC_NEW, NODE_DYNAMIC_REPARSE)) {
 		node_dynamic_setup(node);
@@ -585,9 +686,13 @@ static void node_dynamic_exec_cb(void *data, bNode *node, bNodeStack **in, bNode
 
 	if (BTST(node->custom1, NODE_DYNAMIC_READY)) {
 		nsd = (NodeScriptDict *)node->storage;
-
 		mynode = (BPy_Node *)(nsd->node);
+
+
 		if (mynode && PyCallable_Check((PyObject *)mynode)) {
+
+			gilstate = PyGILState_Ensure();
+
 			mynode->node = node;
 			shi = ((ShaderCallData *)data)->shi;
 
@@ -600,12 +705,14 @@ static void node_dynamic_exec_cb(void *data, bNode *node, bNodeStack **in, bNode
 			Py_DECREF(args);
 
 			if (!pyresult) {
+				PyGILState_Release(gilstate);
 				node_dynamic_disable_all_by_id(node->id);
 				node_dynamic_pyerror_print(node);
 				node_dynamic_setup(node);
 				return;
 			}
 			Py_DECREF(pyresult);
+			PyGILState_Release(gilstate);
 		}
 	}
 }
@@ -627,3 +734,4 @@ bNodeType node_dynamic_typeinfo = {
 	/* id          */	NULL
 };
 
+
diff --git a/source/blender/python/BPY_interface.c b/source/blender/python/BPY_interface.c
index 9d28e8f9e38..b1fd48d87e6 100644
--- a/source/blender/python/BPY_interface.c
+++ b/source/blender/python/BPY_interface.c
@@ -182,6 +182,7 @@ PyObject *traceback_getFilename( PyObject * tb );
 ****************************************************************************/
 void BPY_start_python( int argc, char **argv )
 {
+	PyThreadState *py_tstate = NULL;
 	static int argc_copy = 0;
 	static char **argv_copy = NULL;
 	int first_time = argc;
@@ -227,6 +228,9 @@ void BPY_start_python( int argc, char **argv )
 	Py_Initialize(  );
 	PySys_SetArgv( argc_copy, argv_copy );
 
+	/* Initialize thread support (also acquires lock) */
+	PyEval_InitThreads();
+
 	//Overrides __import__
 	init_ourImport(  );
 	init_ourReload(  );
@@ -237,6 +241,10 @@ void BPY_start_python( int argc, char **argv )
 	//Look for a python installation
 	init_syspath( first_time ); /* not first_time: some msgs are suppressed */
 
+	//PyEval_ReleaseLock();
+	py_tstate = PyGILState_GetThisThreadState();
+	PyEval_ReleaseThread(py_tstate);
+
 	return;
 }
 
@@ -247,6 +255,8 @@ void BPY_end_python( void )
 {
 	Script *script = NULL;
 
+	PyGILState_Ensure(); /* finalizing, no need to grab the state */
+
 	if( bpy_registryDict ) {
 		Py_DECREF( bpy_registryDict );
 		bpy_registryDict = NULL;
@@ -392,7 +402,6 @@ void init_syspath( int first_time )
 	}
 }
 
-
 void BPY_rebuild_syspath( void )
 {
 	PyObject *mod, *dict, *syspath;
@@ -444,6 +453,7 @@ void BPY_rebuild_syspath( void )
 	}
 	
 	Py_DECREF(mod);
+
 }
 
 /****************************************************************************
@@ -457,8 +467,12 @@ that dir info is available.
 ****************************************************************************/
 void BPY_post_start_python( void )
 {
+	PyGILState_STATE gilstate = PyGILState_Ensure();
+
 	BPY_rebuild_syspath();
 	BPyMenu_Init( 0 );	/* get dynamic menus (registered scripts) data */
+
+	PyGILState_Release(gilstate);
 }
 
 /****************************************************************************
@@ -599,6 +613,7 @@ int BPY_txt_do_python_Text( struct Text *text )
 	BPy_constant *info;
 	char textname[24];
 	Script *script = G.main->script.first;
+	PyGILState_STATE gilstate;
 
 	if( !text )
 		return 0;
@@ -639,10 +654,13 @@ int BPY_txt_do_python_Text( struct Text *text )
 	script->py_button = NULL;
 	script->py_browsercallback = NULL;
 
+	gilstate = PyGILState_Ensure();
+
 	py_dict = CreateGlobalDictionary(  );
 
 	if( !setup_armature_weakrefs()){
 		printf("Oops - weakref dict\n");
+		PyGILState_Release(gilstate);
 		return 0;
 	}
 
@@ -667,7 +685,7 @@ int BPY_txt_do_python_Text( struct Text *text )
 		script->py_globaldict = NULL;
 		if( G.main->script.first )
 			free_libblock( &G.main->script, script );
-
+		PyGILState_Release(gilstate);
 		return 0;
 	} else {
 		Py_DECREF( py_result );
@@ -679,6 +697,8 @@ int BPY_txt_do_python_Text( struct Text *text )
 		}
 	}
 
+	PyGILState_Release(gilstate);
+
 	return 1;		/* normal return */
 }
 
@@ -759,12 +779,15 @@ int BPY_menu_do_python( short menutype, int event )
 	char scriptname[21];
 	Script *script = NULL;
 	int len;
+	PyGILState_STATE gilstate;
 
 	pym = BPyMenu_GetEntry( menutype, ( short ) event );
 
 	if( !pym )
 		return 0;
 
+	gilstate = PyGILState_Ensure();
+
 	if( pym->version > G.version )
 		notice( "Version mismatch: script was written for Blender %d. "
 			"It may fail with yours: %d.", pym->version,
@@ -787,8 +810,10 @@ int BPY_menu_do_python( short menutype, int event )
 				while( arg-- )
 					pysm = pysm->next;
 				pyarg = PyString_FromString( pysm->arg );
-			} else
+			} else {
+				PyGILState_Release(gilstate);
 				return 0;
+			}
 		}
 	}
 
@@ -810,6 +835,7 @@ int BPY_menu_do_python( short menutype, int event )
 
 		if (!scriptsdir) {
 			printf("Error loading script: can't find default scripts dir!");
+			PyGILState_Release(gilstate);
 			return 0;
 		}
 
@@ -820,6 +846,7 @@ int BPY_menu_do_python( short menutype, int event )
 	if( !fp ) {
 		printf( "Error loading script: couldn't open file %s\n",
 			filestr );
+		PyGILState_Release(gilstate);
 		return 0;
 	}
 
@@ -838,6 +865,7 @@ int BPY_menu_do_python( short menutype, int event )
 	if( !script ) {
 		printf( "couldn't allocate memory for Script struct!" );
 		fclose( fp );
+		PyGILState_Release(gilstate);
 		return 0;
 	}
 
@@ -944,6 +972,7 @@ int BPY_menu_do_python( short menutype, int event )
 	if( !setup_armature_weakrefs()){
 		printf("Oops - weakref dict\n");
 		MEM_freeN( buffer );
+		PyGILState_Release(gilstate);
 		return 0;
 	}
 
@@ -962,6 +991,7 @@ int BPY_menu_do_python( short menutype, int event )
 			free_libblock( &G.main->script, script );
 		error( "Python script error: check console" );
 
+		PyGILState_Release(gilstate);
 		return 0;
 	} else {
 		Py_DECREF( py_res );
@@ -983,6 +1013,8 @@ int BPY_menu_do_python( short menutype, int event )
 		}
 	}
 
+	PyGILState_Release(gilstate);
+
 	return 1;		/* normal return */
 }
 
@@ -1005,14 +1037,20 @@ void BPY_free_compiled_text( struct Text *text )
 *****************************************************************************/
 void BPY_free_finished_script( Script * script )
 {
+	PyGILState_STATE gilstate;
+
 	if( !script )
 		return;
 
+	gilstate = PyGILState_Ensure();
+
 	if( PyErr_Occurred(  ) ) {	/* if script ended after filesel */
 		PyErr_Print(  );	/* eventual errors are handled now */
 		error( "Python script error: check console" );
 	}
 
+	PyGILState_Release(gilstate);
+
 	free_libblock( &G.main->script, script );
 	return;
 }
@@ -1047,13 +1085,17 @@ static void unlink_script( Script * script )
 void BPY_clear_script( Script * script )
 {
 	PyObject *dict;
+	PyGILState_STATE gilstate;
 
 	if( !script )
 		return;
 
+	gilstate = PyGILState_Ensure();
+
 	if (!Py_IsInitialized()) {
 		printf("\nError: trying to free script data after finalizing Python!");
 		printf("\nScript name: %s\n", script->id.name+2);
+		PyGILState_Release(gilstate);
 		return;
 	}
 
@@ -1074,6 +1116,8 @@ void BPY_clear_script( Script * script )
 		script->py_globaldict = NULL;
 	}
 
+	PyGILState_Release(gilstate);
+
 	unlink_script( script );
 }
 
@@ -1229,11 +1273,14 @@ void BPY_pyconstraint_update(Object *owner, bConstraint *con)
 		/* script does exist. it is assumed that this is a valid pyconstraint script */
 		PyObject *globals;
 		PyObject *retval, *gval;
+		PyGILState_STATE gilstate;
 		int num, i;
 		
 		/* clear the relevant flags first */
 		data->flag = 0;
-				
+
+		gilstate = PyGILState_Ensure();
+
 		/* populate globals dictionary */
 		globals = CreateGlobalDictionary();
 		retval = RunPython(data->text, globals);
@@ -1242,6 +1289,7 @@ void BPY_pyconstraint_update(Object *owner, bConstraint *con)
 			BPY_Err_Handle(data->text->id.name);
 			ReleaseGlobalDictionary(globals);
 			data->flag |= PYCON_SCRIPTERROR;
+			PyGILState_Release(gilstate);
 			return;
 		}
 		
@@ -1297,6 +1345,10 @@ void BPY_pyconstraint_update(Object *owner, bConstraint *con)
 			
 			/* clear globals */
 			ReleaseGlobalDictionary(globals);
+
+			PyGILState_Release(gilstate);
+
+			return;
 		}
 		else {
 			/* NUM_TARGETS is not defined or equals 0 */
@@ -1307,6 +1359,8 @@ void BPY_pyconstraint_update(Object *owner, bConstraint *con)
 			data->tarnum = 0;
 			data->flag &= ~PYCON_USETARGETS;
 			
+			PyGILState_Release(gilstate);
+
 			return;
 		}
 	}
@@ -1335,10 +1389,13 @@ void BPY_pyconstraint_eval(bPythonConstraint *con, bConstraintOb *cob, ListBase
 	bConstraintTarget *ct;
 	MatrixObject *retmat;
 	int row, col, index;
-	
+	PyGILState_STATE gilstate;
+
 	if (!con->text) return;
 	if (con->flag & PYCON_SCRIPTERROR) return;
-	
+
+	gilstate = PyGILState_Ensure();
+
 	globals = CreateGlobalDictionary();
 	
 	/* wrap blender-data as PyObjects for evaluation 
@@ -1357,6 +1414,8 @@ void BPY_pyconstraint_eval(bPythonConstraint *con, bConstraintOb *cob, ListBase
 	
 	if (!setup_armature_weakrefs()) {
 		fprintf(stderr, "Oops - weakref dict setup\n");
+		PyGILState_Release(gilstate);
+
 		return;
 	}
 	
@@ -1372,7 +1431,9 @@ void BPY_pyconstraint_eval(bPythonConstraint *con, bConstraintOb *cob, ListBase
 		Py_XDECREF(tarmats);
 		
 		ReleaseGlobalDictionary(globals);
-		
+
+		PyGILState_Release(gilstate);
+
 		return;
 	}
 
@@ -1389,7 +1450,9 @@ void BPY_pyconstraint_eval(bPythonConstraint *con, bConstraintOb *cob, ListBase
 		Py_XDECREF(tarmats);
 		
 		ReleaseGlobalDictionary(globals);
-		
+
+		PyGILState_Release(gilstate);
+
 		return;
 	}
 	
@@ -1408,7 +1471,9 @@ void BPY_pyconstraint_eval(bPythonConstraint *con, bConstraintOb *cob, ListBase
 		Py_XDECREF(tarmats);
 		
 		ReleaseGlobalDictionary(globals);
-		
+
+		PyGILState_Release(gilstate);
+
 		return;
 	}
 	
@@ -1422,7 +1487,9 @@ void BPY_pyconstraint_eval(bPythonConstraint *con, bConstraintOb *cob, ListBase
 		Py_XDECREF(tarmats);
 		
 		ReleaseGlobalDictionary(globals);
-		
+
+		PyGILState_Release(gilstate);
+
 		return;
 	}
 	
@@ -1437,7 +1504,9 @@ void BPY_pyconstraint_eval(bPythonConstraint *con, bConstraintOb *cob, ListBase
 		Py_XDECREF(retval);
 		
 		ReleaseGlobalDictionary(globals);
-		
+
+		PyGILState_Release(gilstate);
+
 		return;
 	}
 	
@@ -1452,7 +1521,9 @@ void BPY_pyconstraint_eval(bPythonConstraint *con, bConstraintOb *cob, ListBase
 		Py_XDECREF(retval);
 		
 		ReleaseGlobalDictionary(globals);
-		
+
+		PyGILState_Release(gilstate);
+
 		return;
 	}	
 
@@ -1471,6 +1542,8 @@ void BPY_pyconstraint_eval(bPythonConstraint *con, bConstraintOb *cob, ListBase
 	
 	/* clear globals */
 	ReleaseGlobalDictionary(globals);
+
+	PyGILState_Release(gilstate);
 }
 
 /* This evaluates the target matrix for each target the PyConstraint uses.
@@ -1485,11 +1558,14 @@ void BPY_pyconstraint_target(bPythonConstraint *con, bConstraintTarget *ct)
 	PyObject *pyargs, *retval;
 	MatrixObject *retmat;
 	int row, col;
-	
+	PyGILState_STATE gilstate;
+
 	if (!con->text) return;
 	if (con->flag & PYCON_SCRIPTERROR) return;
 	if (!ct) return;
 	
+	gilstate = PyGILState_Ensure();
+
 	globals = CreateGlobalDictionary();
 	
 	tar = Object_CreatePyObject(ct->tar);
@@ -1506,6 +1582,7 @@ void BPY_pyconstraint_target(bPythonConstraint *con, bConstraintTarget *ct)
 	
 	if (!setup_armature_weakrefs()) {
 		fprintf(stderr, "Oops - weakref dict setup\n");
+		PyGILState_Release(gilstate);
 		return;
 	}
 	
@@ -1522,7 +1599,9 @@ void BPY_pyconstraint_target(bPythonConstraint *con, bConstraintTarget *ct)
 		Py_XDECREF(tarmat);
 		
 		ReleaseGlobalDictionary(globals);
-		
+
+		PyGILState_Release(gilstate);
+
 		return;
 	}
 
@@ -1539,7 +1618,9 @@ void BPY_pyconstraint_target(bPythonConstraint *con, bConstraintTarget *ct)
 		Py_XDECREF(tarmat);
 		
 		ReleaseGlobalDictionary(globals);
-		
+
+		PyGILState_Release(gilstate);
+
 		return;
 	}
 	
@@ -1559,6 +1640,9 @@ void BPY_pyconstraint_target(bPythonConstraint *con, bConstraintTarget *ct)
 		Py_XDECREF(tarmat);
 		
 		ReleaseGlobalDictionary(globals);
+
+		PyGILState_Release(gilstate);
+
 		return;
 	}
 	
@@ -1574,6 +1658,9 @@ void BPY_pyconstraint_target(bPythonConstraint *con, bConstraintTarget *ct)
 		Py_XDECREF(tarmat);
 		
 		ReleaseGlobalDictionary(globals);
+
+		PyGILState_Release(gilstate);
+
 		return;
 	}
 	
@@ -1587,6 +1674,9 @@ void BPY_pyconstraint_target(bPythonConstraint *con, bConstraintTarget *ct)
 		Py_XDECREF(retval);
 		
 		ReleaseGlobalDictionary(globals);
+
+		PyGILState_Release(gilstate);
+
 		return;
 	}
 	
@@ -1602,6 +1692,9 @@ void BPY_pyconstraint_target(bPythonConstraint *con, bConstraintTarget *ct)
 		Py_XDECREF(retval);
 		
 		ReleaseGlobalDictionary(globals);
+
+		PyGILState_Release(gilstate);
+
 		return;
 	}	
 
@@ -1621,6 +1714,8 @@ void BPY_pyconstraint_target(bPythonConstraint *con, bConstraintTarget *ct)
 	
 	/* clear globals */
 	ReleaseGlobalDictionary(globals);
+
+	PyGILState_Release(gilstate);
 }
 
 /* This draws+handles the user-defined interface for editing pyconstraints idprops */
@@ -1631,6 +1726,7 @@ void BPY_pyconstraint_settings(void *arg1, void *arg2)
 	PyObject *globals;
 	PyObject *gval;
 	PyObject *retval;
+	PyGILState_STATE gilstate;
 	
 	if (!con->text) return;
 	if (con->flag & PYCON_SCRIPTERROR) return;
@@ -1648,6 +1744,9 @@ void BPY_pyconstraint_settings(void *arg1, void *arg2)
 	
 		/* free temp objects */
 		Py_XDECREF(idprop);
+
+		PyGILState_Release(gilstate);
+
 		return;
 	}
 
@@ -1661,6 +1760,9 @@ void BPY_pyconstraint_settings(void *arg1, void *arg2)
 		/* free temp objects */
 		ReleaseGlobalDictionary( globals );
 		Py_XDECREF(idprop);
+
+		PyGILState_Release(gilstate);
+
 		return;
 	}
 	
@@ -1673,6 +1775,9 @@ void BPY_pyconstraint_settings(void *arg1, void *arg2)
 		ReleaseGlobalDictionary( globals );
 		
 		Py_XDECREF(idprop);
+
+		PyGILState_Release(gilstate);
+
 		return;
 	}
 	
@@ -1683,6 +1788,9 @@ void BPY_pyconstraint_settings(void *arg1, void *arg2)
 		/* free temp objects */
 		ReleaseGlobalDictionary(globals);
 		Py_XDECREF(idprop);
+
+		PyGILState_Release(gilstate);
+
 		return;
 	}
 	else {
@@ -1692,6 +1800,9 @@ void BPY_pyconstraint_settings(void *arg1, void *arg2)
 		/* free temp objects */
 		Py_XDECREF(idprop);
 		Py_DECREF(retval);
+
+		PyGILState_Release(gilstate);
+
 		return;
 	}
 }
@@ -1702,12 +1813,16 @@ void BPY_pyconstraint_settings(void *arg1, void *arg2)
  * updates in it reach pydriver evaluation. */
 void BPY_pydriver_update(void)
 {
+	PyGILState_STATE gilstate = PyGILState_Ensure();
+
 	if (bpy_pydriver_Dict) { /* free the global dict used by pydrivers */
 		PyDict_Clear(bpy_pydriver_Dict);
 		Py_DECREF(bpy_pydriver_Dict);
 		bpy_pydriver_Dict = NULL;
 	}
 
+	PyGILState_Release(gilstate);
+
 	return;
 }
 
@@ -1750,15 +1865,19 @@ float BPY_pydriver_eval(IpoDriver *driver)
 	PyObject *retval, *bpy_ob = NULL;
 	float result = 0.0f; /* default return */
 	int setitem_retval;
+	PyGILState_STATE gilstate;
 
 	if (!driver) return result;
 
 	expr = driver->name; /* the py expression to be evaluated */
 	if (!expr || expr[0]=='\0') return result;
 
+	gilstate = PyGILState_Ensure();
+
 	if (!bpy_pydriver_Dict) {
 		if (bpy_pydriver_create_dict() != 0) {
 			fprintf(stderr, "Pydriver error: couldn't create Python dictionary");
+			PyGILState_Release(gilstate);
 			return result;
 		}
 	}
@@ -1775,6 +1894,7 @@ float BPY_pydriver_eval(IpoDriver *driver)
 
 	if( !setup_armature_weakrefs()){
 		fprintf( stderr, "Oops - weakref dict setup\n");
+		PyGILState_Release(gilstate);
 		return result;
 	}
 
@@ -1782,13 +1902,18 @@ float BPY_pydriver_eval(IpoDriver *driver)
 		bpy_pydriver_Dict);
 
 	if (retval == NULL) {
-		return pydriver_error(driver);
+		result = pydriver_error(driver);
+		PyGILState_Release(gilstate);
+		return result;
 	}
 
 	result = ( float )PyFloat_AsDouble( retval );
 	
-	if (result == -1 && PyErr_Occurred()) 
-		return pydriver_error(driver);
+	if (result == -1 && PyErr_Occurred()) {
+		result = pydriver_error(driver);
+		PyGILState_Release(gilstate);
+		return result;
+	}
 
 	/* remove 'self', since this dict is also used by py buttons */
 	if (setitem_retval == 0) PyDict_DelItemString(bpy_pydriver_Dict, "self");
@@ -1796,6 +1921,8 @@ float BPY_pydriver_eval(IpoDriver *driver)
 	/* all fine, make sure the "invalid expression" flag is cleared */
 	driver->flag &= ~IPO_DRIVER_FLAG_INVALID;
 
+	PyGILState_Release(gilstate);
+
 	return result;
 }
 
@@ -1832,15 +1959,20 @@ static int bpy_button_eval_error(char *expr) {
 int BPY_button_eval(char *expr, double *value)
 {
 	PyObject *retval, *floatval;
+	PyGILState_STATE gilstate;
+	int ret;
 
 	if (!value || !expr || expr[0]=='\0') return -1;
 
 	*value = 0.0; /* default value */
 
+	gilstate = PyGILState_Ensure();
+
 	if (!bpy_pydriver_Dict) {
 		if (bpy_pydriver_create_dict() != 0) {
 			fprintf(stderr,
 				"Button Python Eval error: couldn't create Python dictionary");
+			PyGILState_Release(gilstate);
 			return -1;
 		}
 	}
@@ -1848,6 +1980,7 @@ int BPY_button_eval(char *expr, double *value)
 
 	if( !setup_armature_weakrefs()){
 		fprintf(stderr, "Oops - weakref dict\n");
+		PyGILState_Release(gilstate);
 		return -1;
 	}
 
@@ -1855,20 +1988,26 @@ int BPY_button_eval(char *expr, double *value)
 		bpy_pydriver_Dict);
 
 	if (retval == NULL) {
-		return bpy_button_eval_error(expr);
+		ret = bpy_button_eval_error(expr);
+		PyGILState_Release(gilstate);
+		return ret;
 	}
 	else {
 		floatval = PyNumber_Float(retval);
 		Py_DECREF(retval);
 	}
 
-	if (floatval == NULL) 
-		return bpy_button_eval_error(expr);
-	else {
+	if (floatval == NULL) {
+		ret = bpy_button_eval_error(expr);
+		PyGILState_Release(gilstate);
+		return ret;
+	} else {
 		*value = (float)PyFloat_AsDouble(floatval);
 		Py_DECREF(floatval);
 	}
 
+	PyGILState_Release(gilstate);
+
 	return 0; /* successful exit */
 }
 
@@ -1973,19 +2112,24 @@ void BPY_do_pyscript( ID * id, short event )
 		PyObject *dict;
 		PyObject *ret;
 		int index, during_slink = during_scriptlink(  );
+		PyGILState_STATE gilstate;
 
 		/* invalid scriptlinks (new .blend was just loaded), return */
 		if( during_slink < 0 )
 			return;
-		
+
+		gilstate = PyGILState_Ensure();
+
 		if( !setup_armature_weakrefs()){
 			printf("Oops - weakref dict, this is a bug\n");
+			PyGILState_Release(gilstate);
 			return;
 		}
 		
 		value = GetPyObjectFromID( id );
 		if( !value){
 			printf("Oops - could not get a valid python object for Blender.link, this is a bug\n");
+			PyGILState_Release(gilstate);
 			return;
 		}
 		
@@ -2039,6 +2183,8 @@ void BPY_do_pyscript( ID * id, short event )
 		PyDict_SetItemString(g_blenderdict, "bylink", Py_False);
 		PyDict_SetItemString( g_blenderdict, "link", Py_None );
 		EXPP_dict_set_item_str( g_blenderdict, "event", PyString_FromString( "" ) );
+
+		PyGILState_Release(gilstate);
 	}
 }
 
@@ -2190,6 +2336,7 @@ int BPY_do_spacehandlers( ScrArea *sa, unsigned short event,
 {
 	ScriptLink *scriptlink;
 	int retval = 0;
+	PyGILState_STATE gilstate;
 	
 	if (!sa || !(G.f & G_DOSCRIPTLINKS)) return 0;
 	
@@ -2213,8 +2360,11 @@ int BPY_do_spacehandlers( ScrArea *sa, unsigned short event,
 			disable_where_scriptlink( (short)during_slink );
 		}
 
+		gilstate = PyGILState_Ensure();
+
 		if( !setup_armature_weakrefs()){
 			printf("Oops - weakref dict, this is a bug\n");
+			PyGILState_Release(gilstate);
 			return 0;
 		}
 		
@@ -2290,6 +2440,8 @@ int BPY_do_spacehandlers( ScrArea *sa, unsigned short event,
 	 * space_event is of type DRAW:
 	 * 0 always */
 
+	PyGILState_Release(gilstate);
+
 	return retval;
 }
 
diff --git a/source/blender/python/api2_2x/Draw.c b/source/blender/python/api2_2x/Draw.c
index fc84c9a1445..da8a87ad218 100644
--- a/source/blender/python/api2_2x/Draw.c
+++ b/source/blender/python/api2_2x/Draw.c
@@ -672,6 +672,7 @@ void BPY_spacescript_do_pywin_draw( SpaceScript * sc )
 	uiBlock *block;
 	char butblock[20];
 	Script *script = sc->script;
+	PyGILState_STATE gilstate = PyGILState_Ensure();
 
 	sprintf( butblock, "win %d", curarea->win );
 	block = uiNewBlock( &curarea->uiblocks, butblock, UI_EMBOSSX,
@@ -696,6 +697,8 @@ void BPY_spacescript_do_pywin_draw( SpaceScript * sc )
 	uiDrawBlock( block );
 
 	curarea->win_swap = WIN_BACK_OK;
+
+	PyGILState_Release(gilstate);
 }
 
 static void spacescript_do_pywin_buttons( SpaceScript * sc,
@@ -709,6 +712,8 @@ static void spacescript_do_pywin_buttons( SpaceScript * sc,
 void BPY_spacescript_do_pywin_event( SpaceScript * sc, unsigned short event,
 	short val, char ascii )
 {
+	PyGILState_STATE gilstate = PyGILState_Ensure();
+
 	if( event == QKEY && G.qual & ( LR_ALTKEY | LR_CTRLKEY ) ) {
 		/* finish script: user pressed ALT+Q or CONTROL+Q */
 		Script *script = sc->script;
@@ -717,6 +722,8 @@ void BPY_spacescript_do_pywin_event( SpaceScript * sc, unsigned short event,
 
 		script->flags &= ~SCRIPT_GUI;	/* we're done with this script */
 
+		PyGILState_Release(gilstate);
+
 		return;
 	}
 
@@ -729,6 +736,9 @@ void BPY_spacescript_do_pywin_event( SpaceScript * sc, unsigned short event,
 			 * read the comment before check_button_event() below to understand */
 			if (val >= EXPP_BUTTON_EVENTS_OFFSET && val < 0x4000)
 				spacescript_do_pywin_buttons(sc, val - EXPP_BUTTON_EVENTS_OFFSET);
+
+			PyGILState_Release(gilstate);
+
 			return;
 		}
 	}
@@ -749,6 +759,8 @@ void BPY_spacescript_do_pywin_event( SpaceScript * sc, unsigned short event,
 			EXPP_dict_set_item_str(g_blenderdict, "event",
 					PyString_FromString(""));
 	}
+
+	PyGILState_Release(gilstate);
 }
 
 static void exec_but_callback(void *pyobj, void *data)
@@ -869,9 +881,13 @@ void BPy_Free_DrawButtonsList(void)
 {
 	/*Clear the list.*/
 	if (M_Button_List) {
+		PyGILState_STATE gilstate = PyGILState_Ensure();
+
 		PyList_SetSlice(M_Button_List, 0, PyList_Size(M_Button_List), NULL);
 		Py_DECREF(M_Button_List);
 		M_Button_List = NULL;
+
+		PyGILState_Release(gilstate);
 	}
 }
 
diff --git a/source/blender/python/api2_2x/Window.c b/source/blender/python/api2_2x/Window.c
index 73edcb2df9c..7d346ed9cd9 100644
--- a/source/blender/python/api2_2x/Window.c
+++ b/source/blender/python/api2_2x/Window.c
@@ -1,5 +1,5 @@
 /* 
- * $Id: Window.c 12813 2007-12-07 09:51:02Z campbellbarton $
+ * $Id$
  *
  * ***** BEGIN GPL/BL DUAL LICENSE BLOCK *****
  *
@@ -512,6 +512,8 @@ static void getSelectedFile( char *name )
 	pycallback = script->py_browsercallback;
 
 	if (pycallback) {
+		PyGILState_STATE gilstate = PyGILState_Ensure();
+
 		result = PyObject_CallFunction( pycallback, "s", name );
 
 		if (!result) {
@@ -525,6 +527,8 @@ static void getSelectedFile( char *name )
 		/* else another call to selector was made inside pycallback */
 
 		Py_DECREF(pycallback);
+
+		PyGILState_Release(gilstate);
 	}
 
 	return;
diff --git a/source/blender/src/drawnode.c b/source/blender/src/drawnode.c
index 54475eb362e..d85e3199fb3 100644
--- a/source/blender/src/drawnode.c
+++ b/source/blender/src/drawnode.c
@@ -798,11 +798,6 @@ static int node_shader_buts_dynamic(uiBlock *block, bNodeTree *ntree, bNode *nod
 				ui_rasterpos_safe(butr->xmin + xoff, butr->ymin + 5, snode->aspect);
 				snode_drawstring(snode, "Error! Check console...", butr->xmax - butr->xmin);
 			}
-			else if (G.scene->r.threads > 1) {
-				BIF_ThemeColor(TH_REDALERT);
-				ui_rasterpos_safe(butr->xmin + xoff, butr->ymin + 5, snode->aspect);
-				snode_drawstring(snode, "Set threads to 1", butr->xmax - butr->xmin);
-			}
 		}
 	}
 	return 20+19; 
diff --git a/source/blender/src/space.c b/source/blender/src/space.c
index 55faa4650df..1994a2fcb7f 100644
--- a/source/blender/src/space.c
+++ b/source/blender/src/space.c
@@ -544,9 +544,14 @@ void start_game(void)
 	RestoreState();
 
 	/* Restart BPY - unload the game engine modules. */
+
+	/* Commented out: testing before Blender 2.46 if it's ok to keep
+	 * these modules around, they give access to relevant info for
+	 * exporters to other engines...
 	BPY_end_python();
-	BPY_start_python(0, NULL); /* argc, argv stored there already */
-	BPY_post_start_python(); /* userpref path and menus init */
+	BPY_start_python(0, NULL); 
+	BPY_post_start_python();
+	*/
 
 	restore_all_scene_cfra(scene_cfra_store);
 	set_scene_bg(startscene);
@@ -615,10 +620,16 @@ void start_RBSimulation(void)
 	SaveState();
 	StartKetsjiShellSimulation(curarea, startscene->id.name+2, G.main,G.sipo, 1);
 	RestoreState();
+
 	/* Restart BPY - unload the game engine modules. */
+
+	/* Commented out: testing before Blender 2.46 if it's ok to keep
+	 * these modules around, they give access to relevant info for
+	 * exporters to other engines...
 	BPY_end_python();
-	BPY_start_python(0, NULL); /* argc, argv stored there already */
-	BPY_post_start_python(); /* userpref path and menus init */
+	BPY_start_python(0, NULL); 
+	BPY_post_start_python();
+	*/
 
 	restore_all_scene_cfra(scene_cfra_store);
 	set_scene_bg(startscene);
diff --git a/source/gameengine/BlenderRoutines/BL_KetsjiEmbedStart.cpp b/source/gameengine/BlenderRoutines/BL_KetsjiEmbedStart.cpp
index e89c78614cc..e412fcdf748 100644
--- a/source/gameengine/BlenderRoutines/BL_KetsjiEmbedStart.cpp
+++ b/source/gameengine/BlenderRoutines/BL_KetsjiEmbedStart.cpp
@@ -135,6 +135,10 @@ extern "C" void StartKetsjiShell(struct ScrArea *area,
 	STR_String exitstring = "";
 	BlendFileData *bfd= NULL;
 
+	// Acquire Python's GIL (global interpreter lock)
+	// so we can safely run Python code and API calls
+	PyGILState_STATE gilstate = PyGILState_Ensure();
+
 	bgl::InitExtensions(1);
 	
 	do
@@ -464,6 +468,9 @@ extern "C" void StartKetsjiShell(struct ScrArea *area,
 	} while (exitrequested == KX_EXIT_REQUEST_RESTART_GAME || exitrequested == KX_EXIT_REQUEST_START_OTHER_GAME);
 
 	if (bfd) BLO_blendfiledata_free(bfd);
+
+	// Release Python's GIL
+	PyGILState_Release(gilstate);
 }
 
 extern "C" void StartKetsjiShellSimulation(struct ScrArea *area,
@@ -482,6 +489,10 @@ extern "C" void StartKetsjiShellSimulation(struct ScrArea *area,
 	STR_String exitstring = "";
 	BlendFileData *bfd= NULL;
 
+	// Acquire Python's GIL (global interpreter lock)
+	// so we can safely run Python code and API calls
+	PyGILState_STATE gilstate = PyGILState_Ensure();
+
 	bgl::InitExtensions(1);
 
 	do
@@ -669,4 +680,7 @@ extern "C" void StartKetsjiShellSimulation(struct ScrArea *area,
 
 	} while (exitrequested == KX_EXIT_REQUEST_RESTART_GAME || exitrequested == KX_EXIT_REQUEST_START_OTHER_GAME);
 	if (bfd) BLO_blendfiledata_free(bfd);
+
+	// Release Python's GIL
+	PyGILState_Release(gilstate);
 }