Ravenscar profile

The Ravenscar profile is a subset of the Ada tasking features designed for safety-critical hard real-time systems.

Restrictions of the profile

A Ravenscar Ada application uses the following compiler directive:

pragma Profile (Ravenscar);

This is the same as writing the following set of configuration pragmas:

pragma Task_Dispatching_Policy (FIFO_Within_Priorities);

pragma Locking_Policy (Ceiling_Locking);

pragma Detect_Blocking;

pragma Restrictions (
                No_Abort_Statements,
                No_Dynamic_Attachment,
                No_Dynamic_Priorities,
                No_Implicit_Heap_Allocations,
                No_Local_Protected_Objects,
                No_Local_Timing_Events,
                No_Protected_Type_Allocators,
                No_Relative_Delay,
                No_Requeue_Statements,
                No_Select_Statements,
                No_Specific_Termination_Handlers,
                No_Task_Allocators,
                No_Task_Hierarchy,
                No_Task_Termination,
                Simple_Barriers,
                Max_Entry_Queue_Length => 1,
                Max_Protected_Entries  => 1,
                Max_Task_Entries       => 0,
                No_Dependence => Ada.Asynchronous_Task_Control,
                No_Dependence => Ada.Calendar,
                No_Dependence => Ada.Execution_Time.Group_Budget,
                No_Dependence => Ada.Execution_Time.Timers,
                No_Dependence => Ada.Task_Attributes);

See also

• Ada
• SPARK

References

• Alan Burns (December 1999). "The Ravenscar Profile". ACM SIGAda Ada Letters XIX (4): 49–52. doi:10.1145/340396.340450. http://polaris.dit.upm.es/~str/proyectos/ork/documents/RP_spec.pdf. 
• Alan Burns, Brian Dobbing and Tullio Vardanega (June 2004). "Guide for the use of the Ada Ravenscar Profile in high integrity systems". ACM SIGAda Ada Letters XXIV (2): 1–74. doi:10.1145/997119.997120. http://www.sigada.org/ada_letters/jun2004/ravenscar_article.pdf. 
• Template:Cite techreport

External links

• The Ravenscar Profile, by Paul Parkinson