ActivationGroupImpl

Creates a default activation group implementation.

The group's activeObject method is called when an object is exported (either by Activatable object construction or an explicit call to Activatable.exportObject. The group must inform its ActivationMonitor that the object is active (via the monitor's activeObject method) if the group hasn't already done so.

The group's inactiveObject method is called indirectly via a call to the Activatable.inactive method. A remote object implementation must call Activatable's inactive method when that object deactivates (the object deems that it is no longer active). If the object does not call Activatable.inactive when it deactivates, the object will never be garbage collected since the group keeps strong references to the objects it creates.

The group's inactiveObject method unexports the remote object from the RMI runtime so that the object can no longer receive incoming RMI calls. This call will only succeed if the object has no pending/executing calls. If the object does have pending/executing RMI calls, then false will be returned. If the object has no pending/executing calls, the object is removed from the RMI runtime and the group informs its ActivationMonitor (via the monitor's inactiveObject method) that the remote object is not currently active so that the remote object will be re-activated by the activator upon a subsequent activation request.

Creates a new instance of an activatable remote object. The Activator calls this method to create an activatable object in this group. This method should be idempotent; a call to activate an already active object should return the previously activated object. Note: this method assumes that the Activator will only invoke newInstance for the same object in a serial fashion (i.e., the activator will not allow the group to see concurrent requests to activate the same object.