FIG migration state = state +
The state is the object of a certain moment in its life cycle, including simple state, complex state, the initial state, termination, and the state, the history of the state.
entry: is triggered automatically when entering a state of time.
do: execute do activities when the state is active.
exit: is automatically triggered when leaving a state.
Migration caused by events: 1) the signal event 2) change events 3) Time Event 4) calling event
Migration text label: 1) trigger shows the trigger, specify what conditions can lead to migration. 2) guard represented alert condition, refer to the alert in order to allow the occurrence of a Boolean expression that must be true. 3) behavior refers to the act performed in response to an event, the migration behavior means that when a non-interruptible activities performed by the migration occurred.
FIG operation Activity = activity + + + side of the active node activity
The conduct of activities is composed of one or more actions. Action is a step in activity, but not the smallest unit, but in terms of relative activity.
Side activities associated information flow can be divided into two categories: a control stream and stream objects.