Ravenscar profile
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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]- Ada (programming language)
- High integrity software
- SPARK (programming language)
- From "Ada Reference Manual (Ada 202x Draft 19"): (D.13 The Ravenscar and Jorvik Profiles)
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
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