28 entries tagged with #Tasking
This blog entry shows how to define protected types that extend the language-defined priority inheritance for protected actions to the separate statements outside those protected actions. We create a mutex type for illustration.
Every year the GNAT Pro product family acquires new members and capabilities, to help our customers develop safer, more secure and more efficient code on newer hardware and software platforms. Moving forward, our goal is to offer a clear view on the future development of our technology. As part of this effort, we have made available a public roadmap for AdaCore products on our documentation platform.
AdaCore has partnered closely with Lynx to deliver Ada language support alongside its LYNX MOSA.ic software framework that comprises a real-time operating system (LynxOS-178), Linux and hypervisor (LynxSecure) technology.
A few months ago I was reading this article about coroutines in game development and how they are great tools for writing scripts (as in movie scripts) in the same language as the game engine. Until then I heard about coroutines but never really gave them a thought, this piqued my curiosity.
A retrospective on learning Ada and developing a tool with it in 2021 from 2021 Ada Crate of the Year Winner Paul Jarrett.
This blog entry shows how to define an abstract data type that allows tasks to block on objects of the type, waiting for resumption signals from other components, for at most a specified amount of time per object. This "timeout" capability has been available in Ada from the beginning, via select statements containing timed entry calls. But what about developers working within the Ravenscar and Jorvik tasking subsets? Select statements and timed calls are not included within either profile. This new abstraction will provide some of the functionality of timed entry calls, with an implementation consistent with the Ravenscar and Jorvik subsets.
We are happy to announce that the GNAT Community 2021 release is now available via https://www.adacore.com/download. Here are some release highlights:
The Ada 2022 draft defines a new tasking profile named Jorvik (pronounced “Yourvick”), based directly on the standard Ravenscar profile. Jorvik relaxes certain restrictions in order to increase expressive power for real-time/embedded Ada and SPARK applications. We will explore the details in this blog entry.
Ada has a concurrency construct known as “entry families” that, in some cases, is just what we need to express a concise, clear solution.
In this blog post I want to present a new tool that allows one to very quickly and easily start Ada programming on any ARM Cortex-M or RISC-V microcontroller.
News from the Ada front The next revision of the Ada standard is now almost ready, so it's time for a status update on where GNAT and AdaCore stand on this front!
John Singleton's The SmartBase makes your existing adjustable bed safer and easier to use by adding voice control and safe (and fun!) LED underbed lighting! Additionally, this project won first place prize in the 2019/20 Make with Ada competition.
Last year, I started evaluating programming languages for a formally-verified operating system. I've been developing software for a while, but only recently began work in high integrity software development and formal methods. There are several operating system projects, like the SeL4 microkernel and the Muen separation kernel, that make use of formal verification. But I was interested in using a formally-verified language to write a general-purpose OS - an environment for abstracting the underlying hardware while acting as an arbiter for running the normal applications we're used to.
As a demonstration for the use of Ada and SPARK in very small embedded targets, I created a remote-controlled (RC) car using Lego NXT Mindstorms motors and sensors but without using the Lego computer or Lego software. I used an ARM Cortex System-on-Chip board for the computer, and all the code -- the control program, the device drivers, everything -- is written in Ada. Over time, I’ve upgraded some of the code to be in SPARK. This blog post describes the hardware, the software, the SPARK upgrades, and the repositories that are used and created for this purpose.
In this blog post, I will present one of the most interesting additions to the community 2019 version of SPARK: pointer support. One of the core assumption in SPARK has always been the absence of aliasing, so adding pointers without breaking this assumption was quite a challenge. I will explain how this was achieved using an ownership model for pointers (like is done in Rust) through small examples.
The Danish Technical University has a yearly RoboCup where autonomous vehicles solve a number of challenges. We participated with RoadRunner, a 3D printed robot with wheel suspension, based on the BeagleBone Blue ARM-based board and the Pixy 1 camera with custom firmware enabling real-time line detection. Code is written in Ada and formally proved correct with SPARK at Silver level.
In Part 1 of this blog post I discussed why I chose to implement this application using the Ada Web Server to serve the computed fractal to a web browser. In this part I will discuss a bit more about the backend of the application, the Ada part.
I was looking for a topic for my master thesis in embedded systems engineering when one of my advisor proposed the idea of programming a control system for autonomous trains in Ada. Since I am fascinated by the idea of autonomous vehicles I agreed immediately without knowing Ada.
The first thing that struck me when I started to learn about the Ada programing language was the tasking support. In Ada, creating tasks, synchronizing them, sharing access to resources, are part of the language
This project involves the design of a software platform that provides a good basis when developing motor controllers for brushless DC motors (BLDC/PMSM). It consist of a basic but clean and readable implementation of a sensored field oriented control algorithm. Included is a logging feature that will simplify development and allows users to visualize what is happening. The project shows that Ada successfully can be used for a bare-metal project that requires fast execution.
Updated July 2018
This post describes the new GNATCOLL.Strings package, and the various optimizations it performs to provide improved performance.
This post has been updated in March 2017 and was originally posted in March 2016.
One of us got hooked on the promise of a credit-card-size programmable pocket game under the name of Arduboy and participated in its kickstarter in 2015. The kickstarter was successful (but late) and delivered the expected working board in mid 2016. Of course, the idea from the start was to program it in Ada , but this is an 8-bits AVR microcontroller (the ATmega32u4 by Atmel) not supported anymore by GNAT Pro. One solution would have been to rebuild our own GNAT compiler for 8-bit AVR from the GNAT FSF repository and use the AVR-Ada project. Another solution, which we explore in this blog post, is to use the SPARK-to-C compiler that we developed at AdaCore to turn our Ada code into C and then use the Arduino toolchain to compile for the Arduboy board.
Tasking was one of the big features introduced in the previous release of SPARK 2014. However, GNATprove only supported tasking-related constructs allowed by the Ravenscar profile. Now it also supports the more relaxed GNAT Extended Ravenscar profile.
I started this project more than a year ago. It was supposed to be the first Make with Ada project but it became the most challenging from both, the hardware and software side.
The SPARK tools now support yet another feature that allows users to better specify the intended behavior of their programs. This new feature enables users to declare that specific variables can only be updated during the elaboration of their enclosing package. Read on if you want to know more...
Tetris is a well-known game from the 80's, which has been ported in many versions to all game platforms since then. There are even versions of Tetris written in Ada. But there was no version of Tetris written in SPARK, so we've repaired that injustice. Also, there was no version of Tetris for the Atmel SAM4S ARM processor, another injustice we've repaired.