Maximum service time for callback events (in microseconds).

C# |
public long callbackEventsMaximumServiceTime()

Maximum service time for callback events (in microseconds). This is the
high-water mark (i.e., the longest so far) for callback event service
durations measured from the point of de-queuement until the application has
finished servicing the event. Configuration option queue_service_time_enabled
must be activated.