Nodes: fix threading issues with node ui storage

Calling BKE_nodetree_attribute_hint_add from multiple threads still
was not safe before..
One issue was that context_map embedded its values directly. So
when context_map grows, all NodeUIStorage would move as well.
I could patch around that by using std::unique_ptr in a few places,
but that just becomes too complex for now.
Instead I simplified the locking a bit by adding just locking a mutex
in NodeTreeUIStorage all the time while an attribute hint is added.

Differential Revision: https://developer.blender.org/D11399

1 files changed, 1 insertions, 9 deletions

diff --git a/source/blender/blenkernel/BKE_node_ui_storage.hh b/source/blender/blenkernel/BKE_node_ui_storage.hh
index 8bf89cd8f58..4ec165aad8c 100644
--- a/source/blender/blenkernel/BKE_node_ui_storage.hh
+++ b/source/blender/blenkernel/BKE_node_ui_storage.hh
@@ -95,21 +95,13 @@ struct AvailableAttributeInfo {
 };
 
 struct NodeUIStorage {
-  std::mutex mutex;
   blender::Vector<NodeWarning> warnings;
   blender::Set<AvailableAttributeInfo> attribute_hints;
-
-  NodeUIStorage() = default;
-  /* Needed because the mutex can't be moved or copied. */
-  NodeUIStorage(NodeUIStorage &&other)
-      : warnings(std::move(other.warnings)), attribute_hints(std::move(other.attribute_hints))
-  {
-  }
 };
 
 struct NodeTreeUIStorage {
+  std::mutex mutex;
   blender::Map<NodeTreeEvaluationContext, blender::Map<std::string, NodeUIStorage>> context_map;
-  std::mutex context_map_mutex;
 
   /**
    * Attribute search uses this to store the fake info for the string typed into a node, in order