Thread Safety

This document summarizes thread-safety guarantees and configuration rules for XenoAtom.Logging.

Runtime usage

LogManager static APIs are thread-safe.
Logger instances are safe for concurrent log calls.
LogWriter implementations may receive concurrent calls depending on processor mode and configuration.

Error propagation by processor mode

Synchronous mode: writer exceptions propagate to the caller thread.
Asynchronous mode: writer/dispatch exceptions are handled on the background thread and do not propagate to caller threads.
Configure LogManagerConfig.AsyncErrorHandler to observe async failures, and use LogManager.GetDiagnostics() (ErrorCount, DroppedMessages) for runtime visibility.

Configuration mutation

Treat LogManagerConfig, LoggerConfig.Writers, and writer filter collections as single-threaded configuration objects.
Build or update configuration from one thread, then call LogManagerConfig.ApplyChanges() to refresh logger/writer snapshots.
Avoid mutating configuration collections concurrently with heavy logging traffic.

`LogProperties` ownership

LogProperties is a mutable value type that rents pooled buffers.
Avoid copying populated LogProperties values.
Dispose only the original owner instance.
If you need to merge properties, create a new instance and call AddRange.

Writer-specific notes

StreamLogWriter serializes stream writes internally and can optionally own/dispose its stream.
FileLogWriter serializes file operations internally and is safe for concurrent logging.
TerminalLogWriter writes through XenoAtom.Terminal; TerminalLogStyleConfiguration should be treated as startup-time configuration (not thread-safe for concurrent mutation/read).