The Ravenscar profile is a subset of the
Ada
Ada may refer to:
Places
Africa
* Ada Foah, a town in Ghana
* Ada (Ghana parliament constituency)
* Ada, Osun, a town in Nigeria
Asia
* Ada, Urmia, a village in West Azerbaijan Province, Iran
* Ada, Karaman, a village in Karaman Province, T ...
tasking features designed for
safety-critical
A safety-critical system (SCS) or life-critical system is a system whose failure or malfunction may result in one (or more) of the following outcomes:
* death or serious injury to people
* loss or severe damage to equipment/property
* environme ...
hard
real-time computing
Real-time computing (RTC) is the computer science term for hardware and software systems subject to a "real-time constraint", for example from event to system response. Real-time programs must guarantee response within specified time constrai ...
. 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
A Ravenscar Ada application uses the following
compiler directive
In computer programming, a directive or pragma (from "pragmatic") is a language construct that specifies how a compiler (or other translator) should process its input. Directives are not part of the grammar of a programming language, and may v ...
:
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
*
Ada (programming language)
Ada is a structured, statically typed, imperative, and object-oriented high-level programming language, extended from Pascal and other languages. It has built-in language support for '' design by contract'' (DbC), extremely strong typing, ex ...
*
High integrity software High-integrity software is software whose failure may cause serious damage with possible "life-threatening consequences." “Integrity is important as it demonstrates the safety, security, and maintainability of… code.” Examples of high-integri ...
*
SPARK (programming language)
SPARK is a formally defined computer programming language based on the Ada programming language, intended for the development of high integrity software used in systems where predictable and highly reliable operation is essential. It facilita ...
* From "Ada Reference Manual (Ada 202x Draft 19"):
D.13 The Ravenscar and Jorvik Profiles
References
*
*
*
External links
A Ravenscar runtime for ARM processorsDiscussion about implementation Ravenscar Profile for ARM's
Ada (programming language)
Ada programming language family
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