[Bug] Thread-unsafe static service collection in PluginManager causes race conditions

[csharpfritz]

Summary

PluginManager uses static mutable collections (IServiceCollection and IServiceProvider?) without thread synchronization. Concurrent plugin loads or config changes cause race conditions.

Affected Files

File	Lines	Detail
src/SharpSite.Web/PluginManager.cs	25-26	Static _ServiceDescriptors and _ServiceProvider
src/SharpSite.Web/PluginManager.cs	134-144	Unsynchronized add/remove on config change
src/SharpSite.Plugins/PluginAssemblyManager.cs	12, 19-31	Unguarded dictionary

Risks

• Collection modified during enumeration
• Stale IServiceProvider during concurrent access
• Race conditions on concurrent plugin loads

Recommended Fix

Add lock or ReaderWriterLockSlim around all collection mutations. Use ConcurrentDictionary for PluginAssemblyManager. Use Interlocked.Exchange for provider swaps.

Estimated Effort

3-4 hours

[csharpfritz]

Triage: Bug

Routed to @river. Thread-safety issue in PluginManager static service collections without synchronization.

Priority: 3 (critical correctness)
Effort: 3-4 hours
Fix: Add lock or ReaderWriterLockSlim around mutations; use ConcurrentDictionary in PluginAssemblyManager.

[csharpfritz]

Fixed in commit d719ef9. ConcurrentDictionary for PluginAssemblyManager/ApplicationState, lock blocks on ServiceDescriptors, Interlocked.Exchange for provider swaps. Part of PR #352.