Fix T38332, Fix T38607: cycles render crash with motion blur.

It wasn't working together well with the python thread state changes after the
depsgraph multithreading.

3 files changed, 34 insertions, 8 deletions

diff --git a/intern/cycles/blender/blender_object.cpp b/intern/cycles/blender/blender_object.cpp
index 0df8939bc18..c8a2f080bba 100644
--- a/intern/cycles/blender/blender_object.cpp
+++ b/intern/cycles/blender/blender_object.cpp
@@ -532,7 +532,12 @@ void BlenderSync::sync_motion(BL::SpaceView3D b_v3d, BL::Object b_override)
 	int frame = b_scene.frame_current();
 
 	for(int motion = -1; motion <= 1; motion += 2) {
+		/* 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();
 		b_scene.frame_set(frame + motion, 0.0f);
+		python_thread_state_save();
 
 		/* camera object */
 		if(b_cam)
@@ -542,7 +547,12 @@ void BlenderSync::sync_motion(BL::SpaceView3D b_v3d, BL::Object b_override)
 		sync_objects(b_v3d, motion);
 	}
 
+	/* 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();
 	b_scene.frame_set(frame, 0.0f);
+	python_thread_state_save();
 
 	/* tag camera for motion update */
 	if(scene->camera->motion_modified(prevcam))
diff --git a/intern/cycles/blender/blender_python.cpp b/intern/cycles/blender/blender_python.cpp
index 22c425aa332..6c9f1dc080f 100644
--- a/intern/cycles/blender/blender_python.cpp
+++ b/intern/cycles/blender/blender_python.cpp
@@ -35,6 +35,19 @@
 
 CCL_NAMESPACE_BEGIN
 
+static PyThreadState *python_thread_state = NULL;
+
+void python_thread_state_save()
+{
+	python_thread_state = PyEval_SaveThread();
+}
+
+void python_thread_state_restore()
+{
+	PyEval_RestoreThread(python_thread_state);
+	python_thread_state = NULL;
+}
+
 static PyObject *init_func(PyObject *self, PyObject *args)
 {
 	const char *path, *user_path;
@@ -87,7 +100,7 @@ static PyObject *create_func(PyObject *self, PyObject *args)
 	/* create session */
 	BlenderSession *session;
 
-	Py_BEGIN_ALLOW_THREADS
+	python_thread_state_save();
 
 	if(rv3d) {
 		/* interactive viewport session */
@@ -109,7 +122,7 @@ static PyObject *create_func(PyObject *self, PyObject *args)
 		session = new BlenderSession(engine, userpref, data, scene);
 	}
 
-	Py_END_ALLOW_THREADS
+	python_thread_state_restore();
 
 	return PyLong_FromVoidPtr(session);
 }
@@ -123,12 +136,12 @@ static PyObject *free_func(PyObject *self, PyObject *value)
 
 static PyObject *render_func(PyObject *self, PyObject *value)
 {
-	Py_BEGIN_ALLOW_THREADS
+	python_thread_state_save();
 
 	BlenderSession *session = (BlenderSession*)PyLong_AsVoidPtr(value);
 	session->render();
 
-	Py_END_ALLOW_THREADS
+	python_thread_state_restore();
 
 	Py_RETURN_NONE;
 }
@@ -170,23 +183,23 @@ static PyObject *reset_func(PyObject *self, PyObject *args)
 	RNA_id_pointer_create((ID*)PyLong_AsVoidPtr(pyscene), &sceneptr);
 	BL::Scene b_scene(sceneptr);
 
-	Py_BEGIN_ALLOW_THREADS
+	python_thread_state_save();
 
 	session->reset_session(b_data, b_scene);
 
-	Py_END_ALLOW_THREADS
+	python_thread_state_restore();
 
 	Py_RETURN_NONE;
 }
 
 static PyObject *sync_func(PyObject *self, PyObject *value)
 {
-	Py_BEGIN_ALLOW_THREADS
+	python_thread_state_save();
 
 	BlenderSession *session = (BlenderSession*)PyLong_AsVoidPtr(value);
 	session->synchronize();
 
-	Py_END_ALLOW_THREADS
+	python_thread_state_restore();
 
 	Py_RETURN_NONE;
 }
diff --git a/intern/cycles/blender/blender_util.h b/intern/cycles/blender/blender_util.h
index cb0f7b76d56..c9048cd8a28 100644
--- a/intern/cycles/blender/blender_util.h
+++ b/intern/cycles/blender/blender_util.h
@@ -37,6 +37,9 @@ float *BKE_image_get_float_pixels_for_frame(void *image, int frame);
 
 CCL_NAMESPACE_BEGIN
 
+void python_thread_state_save();
+void python_thread_state_restore();
+
 static inline BL::Mesh object_to_mesh(BL::BlendData data, BL::Object object, BL::Scene scene, bool apply_modifiers, bool render, bool calc_undeformed)
 {
 	return data.meshes.new_from_object(scene, object, apply_modifiers, (render)? 2: 1, true, calc_undeformed);