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fix(FileWatcher): gracefully handle inotify instance exhaustion#679

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Score2 wants to merge 1 commit intoTabooLib:dev/6.2.3from
Score2:fix/filewatcher-inotify-exhaustion
Open

fix(FileWatcher): gracefully handle inotify instance exhaustion#679
Score2 wants to merge 1 commit intoTabooLib:dev/6.2.3from
Score2:fix/filewatcher-inotify-exhaustion

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@Score2 Score2 commented Mar 16, 2026

Problem

On Linux, when the OS inotify instance limit is reached (fs.inotify.max_user_instances), FileWatcher constructor throws a RuntimeException, causing ExceptionInInitializerError during <clinit>. Since JVM permanently marks the class as failed after a <clinit> error, FileWatcher.INSTANCE becomes inaccessible for the entire ClassLoader lifetime.

This causes ConfigLoader to crash mid-visit before writing to files[name], so all subsequent @ConfigNode fields report "xxx.yml not defined" — affecting every plugin with autoReload = true loaded after the limit is hit.

Fix

  • Catch IOException in FileWatcher(int) constructor; set watchService = null and emit a PrimitiveIO.warning instead of throwing
  • Skip scheduler registration and DISABLE lifecycle callback when watchService is null
  • addSimpleListener returns early (no-op) when watchService is null
  • INSTANCE is always a valid object (degraded mode), so callers are unaffected

…shing

When the OS inotify instance limit is reached, FileWatcher constructor
threw RuntimeException causing ExceptionInInitializerError on <clinit>.
This permanently broke FileWatcher.INSTANCE for the ClassLoader lifetime,
causing ConfigLoader to crash before registering config files, which then
triggered false "@ConfigNode file not defined" warnings for all plugins
using autoReload=true on the same server.

- Catch IOException in constructor, set watchService=null with a warning
- Skip scheduling and DISABLE callback when watchService is null
- addSimpleListener is a no-op when watchService is null
- INSTANCE is always a valid (possibly degraded) object
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