Thread-safe MessageBus collections + perf#33
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The handler and log-listener collections derive from Collection<T>, which is not thread-safe. Post iterates the collection while Subscribe/Unsubscribe mutate it, so concurrent use (the default path when RunPostOnSeperateTask is set or via PostAsync) could throw "Collection was modified" or read torn state. - Add a SyncRoot lock to both collections; guard all iteration and snapshot the result so handlers are invoked outside the lock (avoids reentrancy deadlock when a handler re-subscribes or posts). - Lock the service's compound check-then-act Subscribe/Unsubscribe/StopListening operations on the same root. - Make LogListernersCollection.FindAll snapshot eagerly (was lazy LINQ that enumerated after the lock released). - Optimise HandlersForEvent: drop per-handler ToLower allocations for OrdinalIgnoreCase compare, single-pass with no result alloc when no match. - Add ConcurrencyTest covering parallel Subscribe/Unsubscribe/Post (10 DataRow repeats) and parallel-post delivery count. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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Summary
Collection<T>(not thread-safe), soPostiterating whileSubscribe/Unsubscribemutate — the default path underRunPostOnSeperateTaskorPostAsync— could throw "Collection was modified" or read torn state.SyncRootlock to both collections; guard all iteration and snapshot the result so handlers run outside the lock (no reentrancy deadlock when a handler re-subscribes or posts).Subscribe/Unsubscribe/StopListeningops on the same root.LogListernersCollection.FindAllnow snapshots eagerly (was lazy LINQ enumerating after the lock released).HandlersForEvent: drop per-handlerToLowerallocations for anOrdinalIgnoreCasecompare; single pass, no result allocation when nothing matches.Tests
ConcurrencyTest: parallel Subscribe/Unsubscribe/Post (10DataRowrepeats) + parallel-post delivery count.🤖 Generated with Claude Code