"Attempting to use an uninitialized RID" error is printed when opening the editor

[Calinou]

Tested versions

• Reproducible in: 4.4.dev e3213aa
• Not reproducible in: 4.3.stable, 4.4.dev1, 4.4.dev2

System information

Godot v4.4.dev (e3213aa) - Fedora Linux 40 (KDE Plasma) on X11 - X11 display driver, Multi-window, 1 monitor - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 4090 (nvidia; 560.35.03) - 13th Gen Intel(R) Core(TM) i9-13900K (32 threads)

Issue description

"Attempting to use an uninitialized RID" error is printed when opening the editor.

ERROR: Attempting to use an uninitialized RID
   at: get_or_null (./core/templates/rid_owner.h:199)
ERROR: Parameter "t" is null.
   at: texture_free (./servers/rendering/renderer_rd/storage_rd/texture_storage.cpp:726)

I bisected the regression from #96982. cc @dsnopek

According to @stuartcarnie, the issue comes from here:

Steps to reproduce

• Open the editor and look at the Output panel or terminal output.

Minimal reproduction project (MRP)

https://github.com/godotengine/godot-demo-projects/tree/master/3d/truck_town (this should be reproducible on an empty project, but I used Truck Town just in case)

[akien-mga]

Confirmed, also on Linux (Fedora 40).

[AThousandShips]

Encountered this on Windows as well

[darksylinc]

Full callstack:

1  RID_Alloc<RendererRD::TextureStorage::Texture, true>::get_or_null rid_owner.h                  196  0x55555e92a2db 
2  RID_Owner<RendererRD::TextureStorage::Texture, true>::get_or_null rid_owner.h                  448  0x55555e92a08f 
3  RendererRD::TextureStorage::texture_free                          texture_storage.cpp          719  0x55555ea66eab 
4  RendererRD::TextureStorage::free                                  texture_storage.cpp          548  0x55555ea6632c 
5  RendererRD::Utilities::free                                       utilities.cpp                100  0x55555ea84040 
6  RenderingServerDefault::_free                                     rendering_server_default.cpp 51   0x55555e7b9215 
7  RenderingServerDefault::free                                      rendering_server_default.h   1113 0x55555e7da553 
8  ExternalTexture::~ExternalTexture                                 external_texture.cpp         87   0x55555dba9dc1 
9  memdelete<Object>                                                 memory.h                     140  0x55555aa6ec0f 
10 ClassDB::class_get_default_property_value                         class_db.cpp                 2148 0x55555f371661 
11 get_documentation_default_value                                   doc_tools.cpp                391  0x55555bd304c6 
12 DocTools::generate                                                doc_tools.cpp                546  0x55555bd2cc45 
13 EditorHelp::generate_doc                                          editor_help.cpp              2996 0x55555be52d57 
14 call_with_variant_args_static<bool, 0ul>                          binder_common.h              778  0x55555be728e3 
15 call_with_variant_args_static<bool>                               binder_common.h              847  0x55555be72898 
16 CallableCustomStaticMethodPointer<void, bool>::call               callable_method_pointer.h    251  0x55555be727a3 
17 Callable::callp                                                   callable.cpp                 57   0x55555efe4328 
18 CallQueue::_call_function                                         message_queue.cpp            220  0x55555f3815c9 
19 CallQueue::flush                                                  message_queue.cpp            268  0x55555f3819e0 
20 SceneTree::physics_process                                        scene_tree.cpp               546  0x55555cee0e36 
21 Main::iteration                                                   main.cpp                     4354 0x55555aa6b57d 
22 OS_LinuxBSD::run                                                  os_linuxbsd.cpp              962  0x55555a9a9331 
23 main                                                              godot_linuxbsd.cpp           85   0x55555a9a0abe 

ERROR: Attempting to use an uninitialized RID
   at: get_or_null (./core/templates/rid_owner.h:196)

ERROR: Parameter "t" is null.
   at: texture_free (servers/rendering/renderer_rd/storage_rd/texture_storage.cpp:720)

This error looks like a race condition because it doesn't happen always.

A quick analysis shows that it is possible for ExternalTexture::ExternalTexture (I've not confirmed if this is what's happening) to call texture_external_create() from a worker thread, which will allocate, but not initialize, the RID.

The RID initialization will be queued.

My guess is that ExternalTexture::~ExternalTexture was called before RID initialization; which caused the error.

[darksylinc]

If we look at the creation function (FUNCRIDTEX3() it boils down to (simplified):

RID ret = RSG::texture_storage->texture_allocate();
if( we_are_in_main_thread )
{
    RSG::texture_storage->texture_external_initialize(ret, p1, p2, p3);
}
else
{
    command_queue.push(RSG::texture_storage, &RendererTextureStorage::texture_external_initialize, ret, p1, p2, p3);
}
return ret;

Now the problem is that doing:

RID ret = RSG::texture_storage->texture_allocate();
RenderingServer::get_singleton()->free(ret);

Will trigger the error because texture_external_initialize was never called.