Provides timers that asynchronously notify an application after an interval or at a specific time.
The User class in the
System Static Functions API provides simple functions to suspend a
thread for a given interval or until a specific time.
The API has three key concepts: simple timer, periodic timer, and heartbeat timer.
The simple timer produces an event at a given system
time or after a given interval. It is provided by RTimer. This service is wrapped in an active object by CTimer.
A periodic timer produces a sequence
of events at a specified interval. The application is called through
a callback (TCallBack) when they occur. It is provided
by CPeriodic.
A heartbeat timer is similar to a periodic timer. However, if the application is busy handling another event when the timer event occurs, a periodic timer simple delays delivering the event, while a heartbeat timer will inform the application that it has missed the event.
It is provided by CHeartbeat. Applications are alerted to timer events through implementing an
interface MBeating.