Fix issue in recent bugfix, did not work with multiple sessions (preview render).

intern/cycles/blender/blender_object.cpp

@@ -516,7 +516,7 @@ void BlenderSync::sync_objects(BL::SpaceView3D b_v3d, int motion)
 		mesh_motion_synced.clear();
 }
 
-void BlenderSync::sync_motion(BL::SpaceView3D b_v3d, BL::Object b_override)
+void BlenderSync::sync_motion(BL::SpaceView3D b_v3d, BL::Object b_override, void **python_thread_state)
 {
 	if(scene->need_motion() == Scene::MOTION_NONE)
 		return;
@@ -535,9 +535,9 @@ void BlenderSync::sync_motion(BL::SpaceView3D b_v3d, BL::Object b_override)
 		/* we need to set the python thread state again because this
 		 * function assumes it is being executed from python and will
 		 * try to save the thread state */
-		python_thread_state_restore();
+		python_thread_state_restore(python_thread_state);
 		b_scene.frame_set(frame + motion, 0.0f);
-		python_thread_state_save();
+		python_thread_state_save(python_thread_state);
 
 		/* camera object */
 		if(b_cam)
@@ -550,9 +550,9 @@ void BlenderSync::sync_motion(BL::SpaceView3D b_v3d, BL::Object b_override)
 	/* we need to set the python thread state again because this
 	 * function assumes it is being executed from python and will
 	 * try to save the thread state */
-	python_thread_state_restore();
+	python_thread_state_restore(python_thread_state);
 	b_scene.frame_set(frame, 0.0f);
-	python_thread_state_save();
+	python_thread_state_save(python_thread_state);
 
 	/* tag camera for motion update */
 	if(scene->camera->motion_modified(prevcam))

intern/cycles/blender/blender_python.cpp

@@ -35,17 +35,15 @@
 
 CCL_NAMESPACE_BEGIN
 
-static PyThreadState *python_thread_state = NULL;
+void python_thread_state_save(void **python_thread_state)
-
-void python_thread_state_save()
 {
-	python_thread_state = PyEval_SaveThread();
+	*python_thread_state = (void*)PyEval_SaveThread();
 }
 
-void python_thread_state_restore()
+void python_thread_state_restore(void **python_thread_state)
 {
-	PyEval_RestoreThread(python_thread_state);
+	PyEval_RestoreThread((PyThreadState*)*python_thread_state);
-	python_thread_state = NULL;
+	*python_thread_state = NULL;
 }
 
 static PyObject *init_func(PyObject *self, PyObject *args)
@@ -100,8 +98,6 @@ static PyObject *create_func(PyObject *self, PyObject *args)
 	/* create session */
 	BlenderSession *session;
 
-	python_thread_state_save();
-
 	if(rv3d) {
 		/* interactive viewport session */
 		int width = region.width();
@@ -122,7 +118,11 @@ static PyObject *create_func(PyObject *self, PyObject *args)
 		session = new BlenderSession(engine, userpref, data, scene);
 	}
 
-	python_thread_state_restore();
+	python_thread_state_save(&session->python_thread_state);
+
+	session->create();
+
+	python_thread_state_restore(&session->python_thread_state);
 
 	return PyLong_FromVoidPtr(session);
 }
@@ -136,12 +136,13 @@ static PyObject *free_func(PyObject *self, PyObject *value)
 
 static PyObject *render_func(PyObject *self, PyObject *value)
 {
-	python_thread_state_save();
-
 	BlenderSession *session = (BlenderSession*)PyLong_AsVoidPtr(value);
+
+	python_thread_state_save(&session->python_thread_state);
+
 	session->render();
 
-	python_thread_state_restore();
+	python_thread_state_restore(&session->python_thread_state);
 
 	Py_RETURN_NONE;
 }
@@ -183,23 +184,24 @@ static PyObject *reset_func(PyObject *self, PyObject *args)
 	RNA_id_pointer_create((ID*)PyLong_AsVoidPtr(pyscene), &sceneptr);
 	BL::Scene b_scene(sceneptr);
 
-	python_thread_state_save();
+	python_thread_state_save(&session->python_thread_state);
 
 	session->reset_session(b_data, b_scene);
 
-	python_thread_state_restore();
+	python_thread_state_restore(&session->python_thread_state);
 
 	Py_RETURN_NONE;
 }
 
 static PyObject *sync_func(PyObject *self, PyObject *value)
 {
-	python_thread_state_save();
-
 	BlenderSession *session = (BlenderSession*)PyLong_AsVoidPtr(value);
+
+	python_thread_state_save(&session->python_thread_state);
+
 	session->synchronize();
 
-	python_thread_state_restore();
+	python_thread_state_restore(&session->python_thread_state);
 
 	Py_RETURN_NONE;
 }

intern/cycles/blender/blender_session.cpp

@@ -40,7 +40,7 @@ CCL_NAMESPACE_BEGIN
 BlenderSession::BlenderSession(BL::RenderEngine b_engine_, BL::UserPreferences b_userpref_,
 	BL::BlendData b_data_, BL::Scene b_scene_)
 : b_engine(b_engine_), b_userpref(b_userpref_), b_data(b_data_), b_render(b_engine_.render()), b_scene(b_scene_),
-  b_v3d(PointerRNA_NULL), b_rv3d(PointerRNA_NULL)
+  b_v3d(PointerRNA_NULL), b_rv3d(PointerRNA_NULL), python_thread_state(NULL)
 {
 	/* offline render */
 
@@ -50,15 +50,13 @@ BlenderSession::BlenderSession(BL::RenderEngine b_engine_, BL::UserPreferences b
 	background = true;
 	last_redraw_time = 0.0;
 	start_resize_time = 0.0;
-
-	create_session();
 }
 
 BlenderSession::BlenderSession(BL::RenderEngine b_engine_, BL::UserPreferences b_userpref_,
 	BL::BlendData b_data_, BL::Scene b_scene_,
 	BL::SpaceView3D b_v3d_, BL::RegionView3D b_rv3d_, int width_, int height_)
 : b_engine(b_engine_), b_userpref(b_userpref_), b_data(b_data_), b_render(b_scene_.render()), b_scene(b_scene_),
-  b_v3d(b_v3d_), b_rv3d(b_rv3d_)
+  b_v3d(b_v3d_), b_rv3d(b_rv3d_), python_thread_state(NULL)
 {
 	/* 3d view render */
 
@@ -67,9 +65,6 @@ BlenderSession::BlenderSession(BL::RenderEngine b_engine_, BL::UserPreferences b
 	background = false;
 	last_redraw_time = 0.0;
 	start_resize_time = 0.0;
-
-	create_session();
-	session->start();
 }
 
 BlenderSession::~BlenderSession()
@@ -77,6 +72,14 @@ BlenderSession::~BlenderSession()
 	free_session();
 }
 
+void BlenderSession::create()
+{
+	create_session();
+
+	if(b_v3d)
+		session->start();
+}
+
 void BlenderSession::create_session()
 {
 	SceneParams scene_params = BlenderSync::get_scene_params(b_scene, background);
@@ -102,7 +105,7 @@ void BlenderSession::create_session()
 
 	if(b_v3d) {
 		/* full data sync */
-		sync->sync_data(b_v3d, b_engine.camera_override());
+		sync->sync_data(b_v3d, b_engine.camera_override(), &python_thread_state);
 		sync->sync_view(b_v3d, b_rv3d, width, height);
 	}
 	else {
@@ -389,7 +392,7 @@ void BlenderSession::render()
 
 		/* update scene */
 		sync->sync_camera(b_render, b_engine.camera_override(), width, height);
-		sync->sync_data(b_v3d, b_engine.camera_override(), b_rlay_name.c_str());
+		sync->sync_data(b_v3d, b_engine.camera_override(), &python_thread_state, b_rlay_name.c_str());
 
 		/* update number of samples per layer */
 		int samples = sync->get_layer_samples();
@@ -506,7 +509,7 @@ void BlenderSession::synchronize()
 	}
 
 	/* data and camera synchronize */
-	sync->sync_data(b_v3d, b_engine.camera_override());
+	sync->sync_data(b_v3d, b_engine.camera_override(), &python_thread_state);
 
 	if(b_rv3d)
 		sync->sync_view(b_v3d, b_rv3d, width, height);

intern/cycles/blender/blender_session.h

@@ -40,6 +40,8 @@ public:
 
 	~BlenderSession();
 
+	void create();
+
 	/* session */
 	void create_session();
 	void free_session();
@@ -90,6 +92,8 @@ public:
 	int width, height;
 	double start_resize_time;
 
+	void *python_thread_state;
+
 protected:
 	void do_write_update_render_result(BL::RenderResult b_rr, BL::RenderLayer b_rlay, RenderTile& rtile, bool do_update_only);
 	void do_write_update_render_tile(RenderTile& rtile, bool do_update_only);

intern/cycles/blender/blender_sync.cpp

@@ -135,7 +135,7 @@ bool BlenderSync::sync_recalc()
 	return recalc;
 }
 
-void BlenderSync::sync_data(BL::SpaceView3D b_v3d, BL::Object b_override, const char *layer)
+void BlenderSync::sync_data(BL::SpaceView3D b_v3d, BL::Object b_override, void **python_thread_state, const char *layer)
 {
 	sync_render_layers(b_v3d, layer);
 	sync_integrator();
@@ -143,7 +143,7 @@ void BlenderSync::sync_data(BL::SpaceView3D b_v3d, BL::Object b_override, const
 	sync_shaders();
 	sync_curve_settings();
 	sync_objects(b_v3d);
-	sync_motion(b_v3d, b_override);
+	sync_motion(b_v3d, b_override, python_thread_state);
 }
 
 /* Integrator */

intern/cycles/blender/blender_sync.h

@@ -53,7 +53,7 @@ public:
 
 	/* sync */
 	bool sync_recalc();
-	void sync_data(BL::SpaceView3D b_v3d, BL::Object b_override, const char *layer = 0);
+	void sync_data(BL::SpaceView3D b_v3d, BL::Object b_override, void **python_thread_state, const char *layer = 0);
 	void sync_render_layers(BL::SpaceView3D b_v3d, const char *layer);
 	void sync_integrator();
 	void sync_camera(BL::RenderSettings b_render, BL::Object b_override, int width, int height);
@@ -72,7 +72,7 @@ private:
 	void sync_lamps(bool update_all);
 	void sync_materials(bool update_all);
 	void sync_objects(BL::SpaceView3D b_v3d, int motion = 0);
-	void sync_motion(BL::SpaceView3D b_v3d, BL::Object b_override);
+	void sync_motion(BL::SpaceView3D b_v3d, BL::Object b_override, void **python_thread_state);
 	void sync_film();
 	void sync_view();
 	void sync_world(bool update_all);

intern/cycles/blender/blender_util.h

@@ -37,8 +37,8 @@ float *BKE_image_get_float_pixels_for_frame(void *image, int frame);
 
 CCL_NAMESPACE_BEGIN
 
-void python_thread_state_save();
+void python_thread_state_save(void **python_thread_state);
-void python_thread_state_restore();
+void python_thread_state_restore(void **python_thread_state);
 
 static inline BL::Mesh object_to_mesh(BL::BlendData data, BL::Object object, BL::Scene scene, bool apply_modifiers, bool render, bool calc_undeformed)
 {