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by lispm 4004 days ago
LispWorks has a lot of features in its GC. Years ago it was used in a demanding telco application, an ATM switch. It was also used on a space mission experiment. Generally the runtime is very very nice.

Franz Inc uses Allegro CL in a large database. They tuned the GC quite a bit for that. But there were also other GC demanding applications on Allegro CL, for example in CAD and 3D design. They are now working on a concurrent GC, something which is still rare in the Lisp world.
2 comments
aidenn0 4003 days ago
Who used lispworks in an ATM switch? My very first job was working on ATM/IMA switches.
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lispm 4003 days ago
Lucent. The switching nodes were running LispWorks and the control system was running Allegro CL + OO database. That's quite some time ago... ;-)
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lambdaelite 4004 days ago
Why are concurrent GCs rare?
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lispm 4004 days ago
Mostly because there are very very few people in the world who are able to develop such a complex thing for Lisp (or similar runtimes). Since the market is relatively small and many applications are not overly concurrent, there is very little money to support the development.
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0xCMP 4004 days ago
I am guessing[1] that GCs are easier to code correctly without the concurrency and that a GC language is already expected to be slower so it doesn't make sense to do a concurrent GC. Also possibly, the language doesn't support concurrency well. Like a Python or Ruby.

[1] just an educated guess. I have no real knowledge of GCs other than skimming how they work in articles and runtime/language docs.

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vseloved 4004 days ago
are there many platforms, besides JVM and .Net, that have good-quality concurrent GCs?
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fredyr 4003 days ago
The Erlang Vm (BEAM), is another one at least.
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the_why_of_y 4003 days ago
It doesn't actually implement concurrent GC, although what it does implement is far simpler and has a similar effect (low latencies) as concurrent GC.

Each Erlang process has a separate heap that is collected independently; because the process heap is usually small a stop-the-process collection does not take much time.

The downside is that sending messages between processes requires copying all the data that is sent between process heaps.

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