Ravenscar profile

The Ravenscar profile is a subset of the Ada tasking features designed for safety-critical hard real-time computing. It was defined by a separate technical report in Ada 95; it is now part of the Ada 2012 Standard. It has been named after the English village of Ravenscar, the location of the 8th International Real-Time Ada Workshop (IRTAW 8).

Restrictions of the profile[edit]

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_Calendar,                  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[edit]

References[edit]

  • Alan Burns (December 1999). "The Ravenscar Profile" (PDF). ACM SIGAda Ada Letters. XIX (4): 49–52. doi:10.1145/340396.340450. S2CID 29367277.
  • Alan Burns, Brian Dobbing and Tullio Vardanega (June 2004). "Guide for the use of the Ada Ravenscar Profile in high integrity systems" (PDF). ACM SIGAda Ada Letters. XXIV (2): 1–74. doi:10.1145/997119.997120. S2CID 36061649.
  • Ravenscar profile for high-integrity systems (Technical report). ISO/WG9 Ada Rapporteur Group. AI95-00249.

External links[edit]