Far-Beyond-Pulsar/Pulsar-Native

Plugin system memory leak (`Arc<>` over FFI)

Open

#261 opened on Jun 16, 2026

View on GitHub
 (2 comments) (0 reactions) (3 assignees)Rust (29 forks)auto 404
Cleanupbugenhancementhelp wanted

Repository metrics

Stars
 (348 stars)
PR merge metrics
 (PR metrics pending)

Description

Intro

Arc<> is not at all FFI safe. Currently We have an issue in the plugin system where GPUI (WGPUI) unavoidably depends on Arc internally which cannot change.

The leak

  • On frame a plugin is told "render me a frame of your UI" where it returns a heavily nested data structure including Arc data internally.
  • This data is leaked across frames because when passed over FFI boundaries, the atomic counter disconnects creating a plugin-side and engine-side counter that never sync.

This means when the engine is done with the arc its atomic counter decrements, and so the memory deallocates. HOWEVER the plugin side counter is never updated and the memory is leaked on each render call.

Contributor guide

Research direction
Investigate how Arc references are passed across FFI boundaries. Consider using weak references or replacing Arc with a reference counted structure that is FFI safe, such as using raw pointers with manual reference counting.
Tech stack
rust
Domain
game dev
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
RustFFImemory management
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
20