Files
LEDMatrix/docs
ChuckandClaude Opus 5.5 26d697b5ef fix(plugins): one hung plugin no longer stops every plugin from updating
The single update worker took each plugin's lock with a blocking acquire(),
and the render thread holds that lock while it runs the plugin's display().
A display() that never returned -- or a first frame still running on the
executor's lingering thread after its 30s timeout -- parked the worker for
good, and no plugin updated again.

- The worker waits at most PLUGIN_LOCK_TIMEOUT (5s, the bound unload_plugin
  already uses), skips the busy plugin and records it through the normal
  update-failure path as a hang (PluginBusyError), so repeats open its
  circuit breaker. Log lines about it are rate-limited per plugin.
- display() is timed on every frame (two monotonic reads). Calls of 2s or
  more are logged once a minute and counted in plugin health
  (slow_call_count, last_slow_call); calls past the executor timeout, and a
  first frame still running at it, are recorded as hangs (hang_count,
  last_hang) and no longer as successes. An update() still running after
  its timeout is recorded as a hang too.
- on_config_change() runs under the plugin's lock via
  PluginManager.apply_config_change(); if the lock stays busy the latest
  change is deferred to the update worker, applied as soon as the lock
  frees and before the plugin's next update() at the latest. The plugin API
  is unchanged. Which thread runs each hook is documented in
  PluginManager.__init__.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-09-29 13:58:16 -04:00
..

LEDMatrix Documentation

This directory contains guides, references, and architectural notes for the LEDMatrix project. If you are setting up a Pi for the first time, start with the project root README — it covers hardware, OS imaging, and the one-shot installer. The pages here go deeper.

I'm a new user

  1. GETTING_STARTED.md — first-time setup walkthrough
  2. WEB_INTERFACE_GUIDE.md — using the web UI
  3. PLUGIN_STORE_GUIDE.md — installing and managing plugins
  4. WIFI_NETWORK_SETUP.md — WiFi and AP-mode setup
  5. TROUBLESHOOTING.md — common issues and fixes (PERMISSIONS.md for "Permission denied")
  6. SSH_UNAVAILABLE_AFTER_INSTALL.md — recovering SSH after install
  7. CONFIG_DEBUGGING.md — diagnosing config problems
  8. LOW_MEMORY_BOARDS.md — Pi Zero 2 W / 3B+ / 1GB Pi 4 memory limits

I want to write a plugin

Start here:

  1. PLUGIN_DEVELOPMENT_GUIDE.md — end-to-end workflow
  2. PLUGIN_QUICK_REFERENCE.md — cheat sheet
  3. PLUGIN_API_REFERENCE.md — display, cache, and plugin-manager APIs
  4. PLUGIN_ERROR_HANDLING.md — error-handling patterns
  5. DEV_PREVIEW.md — preview plugins on your dev machine without a Pi
  6. EMULATOR_SETUP_GUIDE.md — running the matrix emulator

Going deeper:

Configuring plugins

Advanced features

Reference

Contributing to LEDMatrix itself

Audits

Contributing to the docs

  • Markdown only, professional tone, minimal emoji.
  • Prefer adding to an existing page over creating a new one. If you add a new page, link it from this index in the section it belongs to.
  • If a page becomes obsolete, delete it (it stays in the repository history) and fix the links to it; test/test_doc_links.py fails on broken relative links.
  • Keep examples runnable — paths, commands, and config keys here should match what's actually in the repo.