Document some deadlocks in the physics server code #108495
Open
+8
−0
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| @@ -136,6 +136,9 @@ void GodotSoftBody3D::set_mesh(RID p_mesh) { | |||
| return; | |||
| } | |||
|
|
|||
| // TODO: calling RenderingServer::mesh_surface_get_arrays() from the physics thread | |||
| // is not safe and can deadlock. This method blocks on the main thread to return data, | |||
There was a problem hiding this comment.
Suggested change
| // is not safe and can deadlock. This method blocks on the main thread to return data, | |
| // is not safe and can deadlock. This method blocks on the main thread to return data, |
| @@ -128,6 +128,9 @@ bool JoltSoftBody3D::_ref_shared_data() { | |||
| if (iter_shared_data == mesh_to_shared.end()) { | |||
| RenderingServer *rendering = RenderingServer::get_singleton(); | |||
|
|
|||
| // TODO: calling RenderingServer::mesh_surface_get_arrays() from the physics thread | |||
| // is not safe and can deadlock. This method blocks on the main thread to return data, | |||
There was a problem hiding this comment.
Suggested change
| // is not safe and can deadlock. This method blocks on the main thread to return data, | |
| // is not safe and can deadlock. This method blocks on the main thread to return data, |
|
It seems pertinent to mention |
Add some comments documenting locations where PhysicsServer3D::soft_body_set_mesh() can deadlock. godotengine/godot-proposals#12670 has a proposal for some alternate thread-safe soft body APIs. In the meantime it seems worth at least documenting some of the current pitfalls in the code.
simpkins
force-pushed
the
deadlock_comments
branch
from
a04deb8 to
cb25b93
Compare
|
Applied the review feedback. |
mihe
approved these changes
Jul 14, 2025
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Add some comments documenting locations where
PhysicsServer3D::soft_body_set_mesh()can deadlock.godotengine/godot-proposals#12670 has a proposal for some alternate thread-safe soft body APIs. In the meantime it seems worth at least documenting some of the current pitfalls in the code.
Note that most people typically won't run into this deadlock today because they will crash in
PhysicsServer3D::soft_body_update_rendering_server()first if trying to use SoftBody3D with a separate physics thread.