Game Loop System

The game loop runs on a dedicated background thread and drives packet dispatch, timers, and outbound flush.

Loop Responsibilities

Per iteration, GameLoopService does:

1. DrainPacketQueue()
2. _timerService.UpdateTicksDelta(timestampMilliseconds)
3. DrainOutgoingPacketQueue()

If idle CPU throttling is enabled and no work was done, it sleeps for IdleSleepMilliseconds.

Timing Model

• Loop timestamp is derived from Stopwatch.GetTimestamp() converted to milliseconds.
• Timer progression is delta-based (not fixed-sleep-tick based).
• TimerWheelService accumulates elapsed milliseconds and processes due slots.

Timer Wheel

TimerWheelService features:

• hashed wheel buckets
• named timers
• register/unregister by id and by name
• repeating and one-shot timers
• callback execution metrics and error counting

Used by persistence for autosave timer db_save.

Outbound Flush

Outbound network send is intentionally inside the game loop:

• dequeue OutgoingGamePacket
• resolve session from IGameNetworkSessionService
• call IOutboundPacketSender.Send(...)

This keeps outbound ordering tied to loop progression.

Metrics

GameLoopService exposes:

• tick count
• uptime
• average/max tick duration
• idle sleep count
• average work units
• outbound queue depth
• total outbound packets

Timer metrics are exposed separately by ITimerMetricsSource.

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