Some tasks have entries. An entry of a task can be called by other tasks. A task accepts a call of one of its entries by executing an accept statement for the entry. Synchronization is achieved by rendezvous between a task issuing an entry call and a task accepting the call. The properties of each task are defined by a corresponding task unit which consists of a task specification and a task body.
Task units are one of the four forms of program unit of which programs can be composed.
The other forms are subprograms, packages and generic units.