[gclist] Real-Time GC for high-level languages

David Chase chase@world.std.com
Tue, 30 Jan 2001 12:56:37 -0500


At 03:19 PM 1/30/2001 +0100, Francois-Rene Rideau wrote:
>Notably, the Boehm GC, the RScheme GC (one of them), the Erlang GC (which?)
>are said to be "soft real-time". What does that mean? When do they fail?
>What if paging is disabled: will that make them "hard real-time"?
>What high-level language implementation can boast about real-time latency?

I think the Erlang people may have attained hard-real-time latency.

Another thing to consider is whether or not there are any constraints
on the memory-related behavior of the programs that you are running.
If, for instance, you can tell me that it never has more than X Mb
of live memory, then I can tell you how long a straightforward
copying-compacting collection will take (for small sets of data,
they are fast) after making some measurements.

On the other hand, if you've got no constraints on your running
program, you will find your hard-real-time GC choices exceedingly
limited.

>I have a feeling this is a FAQ. The FAQ doesn't seem to be maintained,
>however and its links are out of date.

The FAQ is only slightly maintained.  I will see what I can do about its
links.  Are you, perhaps, volunteering to help? :-)  I've been working on
getting more facile with cvs over the net (been using it in a canned way
for the last four years) so it might be possible to do something slightly
more organized.

David Chase