Fix crash happening in DAG_pose_sort() due to threading issues

This function used ugly hack with static variable which was
preventing some type checks in DAG nodes. Using this variable
form multiple threads is not considered safe, apparently.

Solved by moving this variable inside the DAGForest structure.
so it's global for the graph now, but different graphs does not
run into conflicts.

This required passing the forest to some functions, which doesn't
look so much nice, but don't want to spend time on making this
code look beautiful because it is really to be replaced by the
new dependency graph.

This is really bad bug actually which is must go to 'a'.

source/blender/blenkernel/BKE_depsgraph.h

@@ -157,7 +157,7 @@ void DAG_print_dependencies(struct Main *bmain, struct Scene *scene, struct Obje
 /* ************************ DAG querying ********************* */
 
 struct Object *DAG_get_node_object(void *node_v);
-const char *DAG_get_node_name(void *node_v);
+const char *DAG_get_node_name(struct Scene *scene, void *node_v);
 short DAG_get_eval_flags_for_object(struct Scene *scene, void *object);
 bool DAG_is_acyclic(struct Scene *scene);
 

source/blender/blenkernel/depsgraph_private.h

@@ -129,6 +129,7 @@ typedef struct DagForest {
 	int numNodes;
 	bool is_acyclic;
 	int time;  /* for flushing/tagging, compare with node->lasttime */
+	bool ugly_hack_sorry;  /* prevent type check */
 } DagForest;
 
 // queue operations

source/blender/blenkernel/intern/depsgraph.c

@@ -305,6 +305,7 @@ DagForest *dag_init(void)
 	DagForest *forest;
 	/* use callocN to init all zero */
 	forest = MEM_callocN(sizeof(DagForest), "DAG root");
+	forest->ugly_hack_sorry = true;
 	return forest;
 }
 
@@ -995,7 +996,6 @@ DagNode *dag_find_node(DagForest *forest, void *fob)
 	return NULL;
 }
 
-static int ugly_hack_sorry = 1;         /* prevent type check */
 static int dag_print_dependencies = 0;  /* debugging */
 
 /* no checking of existence, use dag_find_node first or dag_get_node */
@@ -1008,7 +1008,7 @@ DagNode *dag_add_node(DagForest *forest, void *fob)
 		node->ob = fob;
 		node->color = DAG_WHITE;
 
-		if (ugly_hack_sorry) node->type = GS(((ID *) fob)->name);  /* sorry, done for pose sorting */
+		if (forest->ugly_hack_sorry) node->type = GS(((ID *) fob)->name);  /* sorry, done for pose sorting */
 		if (forest->numNodes) {
 			((DagNode *) forest->DagNode.last)->next = node;
 			forest->DagNode.last = node;
@@ -1116,28 +1116,28 @@ void dag_add_relation(DagForest *forest, DagNode *fob1, DagNode *fob2, short rel
 	fob1->child = itA;
 }
 
-static const char *dag_node_name(DagNode *node)
+static const char *dag_node_name(DagForest *dag, DagNode *node)
 {
 	if (node->ob == NULL)
 		return "null";
-	else if (ugly_hack_sorry)
+	else if (dag->ugly_hack_sorry)
 		return ((ID *)(node->ob))->name + 2;
 	else
 		return ((bPoseChannel *)(node->ob))->name;
 }
 
-static void dag_node_print_dependencies(DagNode *node)
+static void dag_node_print_dependencies(DagForest *dag, DagNode *node)
 {
 	DagAdjList *itA;
 
-	printf("%s depends on:\n", dag_node_name(node));
+	printf("%s depends on:\n", dag_node_name(dag, node));
 
 	for (itA = node->parent; itA; itA = itA->next)
-		printf("  %s through %s\n", dag_node_name(itA->node), itA->name);
+		printf("  %s through %s\n", dag_node_name(dag, itA->node), itA->name);
 	printf("\n");
 }
 
-static int dag_node_print_dependency_recurs(DagNode *node, DagNode *endnode)
+static int dag_node_print_dependency_recurs(DagForest *dag, DagNode *node, DagNode *endnode)
 {
 	DagAdjList *itA;
 
@@ -1150,8 +1150,8 @@ static int dag_node_print_dependency_recurs(DagNode *node, DagNode *endnode)
 		return 1;
 
 	for (itA = node->parent; itA; itA = itA->next) {
-		if (dag_node_print_dependency_recurs(itA->node, endnode)) {
-			printf("  %s depends on %s through %s.\n", dag_node_name(node), dag_node_name(itA->node), itA->name);
+		if (dag_node_print_dependency_recurs(dag, itA->node, endnode)) {
+			printf("  %s depends on %s through %s.\n", dag_node_name(dag, node), dag_node_name(dag, itA->node), itA->name);
 			return 1;
 		}
 	}
@@ -1166,8 +1166,8 @@ static void dag_node_print_dependency_cycle(DagForest *dag, DagNode *startnode,
 	for (node = dag->DagNode.first; node; node = node->next)
 		node->color = DAG_WHITE;
 
-	printf("  %s depends on %s through %s.\n", dag_node_name(endnode), dag_node_name(startnode), name);
-	dag_node_print_dependency_recurs(startnode, endnode);
+	printf("  %s depends on %s through %s.\n", dag_node_name(dag, endnode), dag_node_name(dag, startnode), name);
+	dag_node_print_dependency_recurs(dag, startnode, endnode);
 	printf("\n");
 }
 
@@ -1201,7 +1201,7 @@ static void dag_check_cycle(DagForest *dag)
 	/* debugging print */
 	if (dag_print_dependencies)
 		for (node = dag->DagNode.first; node; node = node->next)
-			dag_node_print_dependencies(node);
+			dag_node_print_dependencies(dag, node);
 
 	/* tag nodes unchecked */
 	for (node = dag->DagNode.first; node; node = node->next)
@@ -2838,7 +2838,7 @@ void DAG_pose_sort(Object *ob)
 	int skip = 0;
 	
 	dag = dag_init();
-	ugly_hack_sorry = 0;  /* no ID structs */
+	dag->ugly_hack_sorry = false;  /* no ID structs */
 
 	rootnode = dag_add_node(dag, NULL);  /* node->ob becomes NULL */
 	
@@ -2965,8 +2965,6 @@ void DAG_pose_sort(Object *ob)
 	
 	free_forest(dag);
 	MEM_freeN(dag);
-	
-	ugly_hack_sorry = 1;
 }
 
 /* ************************  DAG FOR THREADED UPDATE  ********************* */
@@ -3085,14 +3083,14 @@ Object *DAG_get_node_object(void *node_v)
 }
 
 /* Returns node name, used for debug output only, atm. */
-const char *DAG_get_node_name(void *node_v)
+const char *DAG_get_node_name(Scene *scene, void *node_v)
 {
 	DagNode *node = node_v;
 
-	return dag_node_name(node);
+	return dag_node_name(scene->theDag, node);
 }
 
-short DAG_get_eval_flags_for_object(struct Scene *scene, void *object)
+short DAG_get_eval_flags_for_object(Scene *scene, void *object)
 {
 	DagNode *node;
 

source/blender/blenkernel/intern/scene.c

@@ -1340,7 +1340,7 @@ static void scene_update_object_func(TaskPool *pool, void *taskdata, int threadi
 	}
 	else {
 		PRINT("Threda %d: update node %s\n", threadid,
-		      DAG_get_node_name(node));
+		      DAG_get_node_name(scene, node));
 	}
 
 	/* Update will decrease child's valency and schedule child with zero valency. */