A simple action has a name and a body consisting of a block. The body contains the executable code of the action. There are no parameters.

The action names onload(), onunload(), ondie(), onBeginRecovery(), and onConcludeRecovery() are special. These actions are invoked automatically when certain events in a monitor’s life cycle occur.

A block must follow the action name. Note that there are no formal parameters in this form of action definition and the action cannot return a value.

The onload() action is invoked immediately after a monitor has been loaded. This action must be present in every monitor.

The ondie() action, if present, is invoked by the correlator when a monitor instance terminates.

The onunload() action, if present, is invoked by the correlator after all instances of a monitor have terminated, just before the last monitor instance is unloaded.

The onBeginRecovery() action, if present, is invoked by the correlator during recovery of a persistence-enabled correlator. The correlator executes onBeginRecovery() on monitors and any live events after it reinjects source code and restores state in persistent monitors.

The onConcludeRecovery() action, if present, is invoked by the correlator during recovery of a persistence-enabled correlator. The correlator executes onConcludeRecovery() on monitors and any live events before it begins to send clock ticks.