[gclist] Language behaviour wrt GC
Henry G. Baker
Thu, 5 Dec 1996 06:56:34 -0800 (PST)
> Geert Bosch wrote:
> > It's a little bit sad that a modern language [Ada-95] that actually
> > *needs* a garbage collector if you don't want to use
> > Unchecked_Deallocation, has no good [Ada-95] implementations that have
> > one. As a small survey has indicated the main property of such a
> > collector would be safety, which is why not m any people are interested
> > in a conservative collector.
> I think the main property would be ease of development and maintenance.
> A conservative collector would be quite safe enough for most of the
> applications I'm interested in.
> Your surveyees have tunnel vision, IMHO.
> Fergus Henderson <firstname.lastname@example.org> | "I have always known that the pursuit
Having spent some time in the Ada world, I tried to understand what their
concerns were. Part of the problem with Ada is that it is no longer
conceived by the Ada world as a 'general purpose' language (whatever that
means), but has retreated into being a 'controller' language for embedded
real-time systems (never mind the fact that it isn't particularly good
for that purpose, either :-). For example, I understand that some of the
systems of the Boeing 777 are programmed in Ada, but Boeing and many DoD
folks use a 'stripped-down' Ada in which dynamic allocation and
exception-handling are disallowed. In some of other applications, a
traditional real-time OS (not written in Ada) partitions and manages the
memory using memory-mapping HW, and a somewhat traditional time-slicing
multiple process approach, so Ada's vaunted synchronization primitives
are rarely -- if ever -- used.
If you do a search of the Ada repository, you will find that most, if not
all, of the 'pretty-printers' for Ada use a C-based parser, so Ada cannot
even parse itself!
The bottom line is that most in the DoD community wish that Ada would
simply go quietly away, so they could go back to hiring off-the-shelf
college graduates and use off-the-shelf $99 C/C++ compilers.
Ada is the poster child for a government bureaucracy gone haywire.