Concurrent Ada Programming

By Thomas Løcke | Published: May 17, 2012

I wrote a short article about concurrent Ada programming, and a mere handful of minutes after I put it online a reader had found a bug in it.

You gotta love the interwebz! :D

It’s definitely an article for beginners, and I do plan on adding it to the Ada-DK Wiki as soon as possible. Feel free to let me know what you think about it, and don’t hold back on suggestions for improvements.

 
Posted in Ada Programming | Tagged , | Leave a comment

AdaIC Survey

By Thomas Løcke | Published: May 17, 2012

The adaic.org website is one of the better online Ada resources, and with the latest survey they’ve put up, it seems they are aiming even higher. We got this from Randy Brukardt:

As part of our ongoing efforts to improve the AdaIC website, we’re conducting a short survey of Ada users to guide possible improvements to the site. Find the survey at:

http://www.adaic.org/survey/

Thanks in advance for your time.

Randy Brukardt, (former) AdaIC webmaster

P.S. You’ll need to have Javascript enabled to access the survey, as I found out when I tried it. :-)

Personally I’d like to see some more code on the website, and a tight integration with Google+.

 
Posted in General | Tagged | Leave a comment

Ada Industrial Control Widget Library v1.3 Released

By Thomas Løcke | Published: May 17, 2012

The Ada Industrial Control Widget library provide high-quality industrial control widgets for Ada applications. Version 1.3 is a bug-fix release with no new features:

  • A sample of asynchronous plotting added, based on the contribution by Yogeshwarsing Calleecharan, who generously provided his code solving a differential equation of a generator’s rotor movement. The sample illustrates ploting data on-line, as they are computed by a separate Ada task.
  • Memory leak while drawing graph paper annotations fixed.
  • Graph paper annotations formatting flag to enable or disable superscript numbers.

You can read the release announcement here and get to the code here. Fedora and Debian packages are available and source for the rest of us.

 
Posted in Ada Libraries | Tagged | Leave a comment

GtkAda Contributions v2.13 Released

By Thomas Løcke | Published: May 17, 2012

Just a small fix compared to version 2.12:

  • The procedure Send of Generic_Message has now the Timeout parameter to break possible deadlocks when messages are posted upon application completion.

Read the release announcement here and get the code here. Fedora and Debian packages are available and source for the rest of us.

 
Posted in Ada Libraries | Tagged | Leave a comment

Ada Server Faces 0.4.0 Released

By Thomas Løcke | Published: May 17, 2012

Ada Server Faces is moving ahead at a steady pace with the latest 0.4.0 release. It is, as you might remember from earlier Ada-DK posts about it, a framework for making web-applications using the same methodology as Java Server Faces:

Ada Server Faces allows to create web applications using the same pattern a the Java Server Faces (See JSR 252, JSR 314 or JSR 344).

ASF provides a security framework which allows to protect web pages according to some security policy. This framework allows users to authenticate by using OpenID Authentication 2.0.

You can get the latest version here or you can grab the dev version from the SVN repository:

svn checkout http://ada-asf.googlecode.com/svn/trunk/ ada-asf-read-only

New in version 0.4.0 is:

  • Support for shared or static build configuration.
  • Support for file upload.
  • New components , , , .
  • New EL function util:hasMessage.
  • ASF now Implements the JSF phase events and phase listeners.
  • Implements the JSF/Ruby on Rails flash context.
  • Adds the pre-defined JSF beans: initParam, flash.
  • Support for locales and honors the Accept-Language.
  • New demos are available in French and English

There’s a live online demo available. You can read the full release announcement here.

 
Posted in Uncategorized | Tagged | Leave a comment

Ada Database Objects 0.3.0 Released

By Thomas Løcke | Published: May 17, 2012

Ada Database Objects is a library that facilitates access to MySQL and SQLite databases and the mapping of database objects into Ada records, AKA an ORM.

New in this version is:

  • Support to update database records when a field is really modified.
  • Customization of the SQLite database connection by using SQLite PRAGMAs.
  • Escape of MySQL or SQLite reserved keywords.
  • Support for blob type.

You can get to the code here, or you can grab the latest dev version from SVN:

svn checkout http://ada-ado.googlecode.com/svn/trunk/ ada-ado-read-only

The full release announcement can be read here.

 
Posted in Ada Libraries | Tagged | Leave a comment

Abusing Operator Overloading for Fun and Profit

By Thomas Løcke | Published: May 17, 2012

You know there’s a good chance of a programming article being interesting/fun if it starts out like this:

“Preserve the conventional meaning of overloaded operators” — Ada Quality & Style, Overloaded Operators

Mmmmm, bite me.

And he means it! The Worried Programmer goes on to write an excellent piece on how to abusively overload operators. The article is full of great examples, like this one:

procedure Impsel is
   Which : Boolean := True;
   Letter_Choice : Natural := 2;
 
begin
   Put_Line(("This here" or "That there") and Which); -- "That there"
 
   Put_Line(("A" or "B" or "C") and Letter_Choice);  -- "C" (0-based indexing)
 
   Put_Line(("A" or "B" or "C") and False);   -- Constraint_Error!
end Impsel;

Yes, really. The section of the article containing the above marvel was rightly dubbed “Losing Myself” by the author. It might not be pretty, or very Ada-like, but it sure as heck is fun!

Be sure to read the Abusing Operator Overloading for Fun and Profit article. Don’t miss out on this one!

 
Posted in Ada Programming | Tagged | Leave a comment

Spawning Processes From Ada Using The Ada Spawn Manager

By Thomas Løcke | Published: May 10, 2012

The codelabs.ch project is steadily growing their collection of nice Ada projects, the latest being the Ada Spawn Manager:

The Ada spawn manager implements the concept described in the GNAT GPL package System.OS_Lib. It is used to solve the problem of spawning processes at arbitrary times from multitasking Ada programs:

If the parent is using tasking, and needs to spawn subprocesses at arbitrary times, one technique is for the parent to spawn (very early) a particular spawn-manager subprocess whose job is to spawn other processes. The spawn-manager avoids tasking. The parent sends messages to the spawn-manager requesting it to spawn processes, using whatever inter-process communication mechanism you like, such as sockets.

SYSTEM.OS_LIB specification
— GNAT COMPILER COMPONENTS

The Ada spawn manager uses UNIX domain sockets provided by the Anet library to implement fast and simple IPC.

Fun!

Currently there’s no official release version, but you can git clone the development version:

git clone http://git.codelabs.ch/git/spawn-manager.git

I wonder how this compares to spawning processes using the Florist POSIX package found at libre.adacore.com?

 
Posted in Ada Libraries | Tagged | 2 Comments

Stephane Carrez Releases Ada Utility Library 1.5.0

By Thomas Løcke | Published: May 10, 2012

It’s been a while since I’ve posted anything from Stephane Carrez’ excellent Java2Ada blog, but today that drought is ended with the release of Stephane’s Ada Utility Library v1.5.0. As the name implies the library provides a bunch of Ada utilities, chief among those being concurrent fifo queues and arrays, process creation/spawning and SHA1/HMAC encoding. There’s lots more in there, so be sure to check it out.

You can read the full release announcement here or you could simply svn clone it and get to the goodies immediately:

svn checkout http://ada-util.googlecode.com/svn/trunk/ ada-util-read-only

What I’d really like to see in this package is a standalone implementation of Stephane’s OpenID stuff. I’ve got a project that needs OpenID, and it would be really nice to be able to do “with Util.OpenID” and then make it fly. One can dream!

 
Posted in Ada Libraries | Tagged , | Leave a comment

Another Round of Dmitry Kazakov Updates

By Thomas Løcke | Published: May 10, 2012

The productivity of Dmitry Kazakov continues to amaze me. Not only is he producing some rather large libraries and projects, he is also very actively updating and maintaining them.

I could probably learn a lot from this guy. :)

Today we’ve got updates to the following projects:

Simple components for Ada v3.16:

Changes in version 3.16 (and 3.15, since I forgot to report those):

  • Bug fix in the package Storage_Streams. The bug was caused by an overflow in index computations.
  • Parsers now have a mechanism to disallow an operation outside brackets.
  • Closing brackets can be returned back when misplaced switching to infix context. For example, it is now possible to parse expressions like f(|a|+1|x), where | is both |·|-brackets and an infix operation.
  • Association checks are performed on all operations and brackets.

Simple components provides…

…implementations of smart pointers, directed graphs, sets, maps, stacks, tables, string editing, unbounded arrays, expression analyzers, lock-free data structures, synchronization primitives (events, race condition free pulse events, arrays of events, reentrant mutexes, deadlock-free arrays of mutexes), pseudo-random non-repeating numbers, symmetric encoding and decoding, IEEE 754 representations support. Tables management and strings editing are described in separate documents see Tables and Strings edit. The library is kept conform to both Ada 95 and Ada 2005 language standards.

The next contender is the Ada industrial widget library v1.2:

Changes to the previous version:

  • Bug fix in waveform sampling which had the effect that sometimes the amplifier get permanently rescaled when in auto-scale mode.
  • Rendering waveform annotations was changed to prevent values shown as xxx*10**0.

The key features of the Ada industrial widget library are..

…widgets composed of transparent layers drawn by cairo, fully scalable graphics, support of time controlled refresh policy for real-time and heavy-duty applications, caching graphical operations, stream I/O support for serialization and deserialization, ready-to-use gauge, meter, oscilloscope widgets, editor widget for WYSIWYG design of complex dashboards.

Go get ‘em while they are hot!

 
Posted in Ada Libraries | Tagged , | Leave a comment