On 2014-02-01 07:35:44 +0000, Manu said:
On 1 February 2014 16:26, Adam Wilson <flybo...@gmail.com> wrote:
On Fri, 31 Jan 2014 21:29:04 -0800, Manu <turkey...@gmail.com> wrote:
On 26 December 2012 00:48, Sven Over <dl...@svenover.de> wrote:
std.typecons.RefCounted!T
core.memory.GC.disable();
Wow. That was easy.
I see, D's claim of being a multi-paradigm language is not false.
It's not a realistic suggestion. Everything you want to link uses the GC,
and the language its self also uses the GC. Unless you write software in
complete isolation and forego many valuable features, it's not a solution.
Phobos does rely on the GC to some extent. Most algorithms and ranges do
not though.
Running (library) code that was written with GC in mind and turning GC off
doesn't sound ideal.
But maybe this allows me to familiarise myself more with D. Who knows,
maybe I can learn to stop worrying and love garbage collection.
Thanks for your help!
I've been trying to learn to love the GC for as long as I've been around
here. I really wanted to break that mental barrier, but it hasn't happened.
In fact, I am more than ever convinced that the GC won't do. My current #1
wishlist item for D is the ability to use a reference counted collector in
place of the built-in GC.
You're not alone :)
I write realtime and memory-constrained software (console games), and for
me, I think the biggest issue that can never be solved is the
non-deterministic nature of the collect cycles, and the unknowable memory
footprint of the application. You can't make any guarantees or predictions
about the GC, which is fundamentally incompatible with realtime software.
Language-level ARC would probably do quite nicely for the miscellaneous
allocations. Obviously, bulk allocations are still usually best handled in
a context sensitive manner; ie, regions/pools/freelists/whatever, but the
convenience of the GC paradigm does offer some interesting and massively
time-saving features to D.
Everyone will always refer you to RefCounted, which mangles your types and
pollutes your code, but aside from that, for ARC to be useful, it needs to
be supported at the language-level, such that the language/optimiser is
able to optimise out redundant incref/decref calls, and also that it is
compatible with immutable (you can't manage a refcount if the object is
immutable).
The problem isn't GC's per se. But D's horribly naive implementation,
games are written on GC languages now all the time (Unity/.NET). And
let's be honest, games are kind of a speciality, games do things most
programs will never do.
You might want to read the GC Handbook. GC's aren't bad, but most, like
the D GC, are just to simplistic for common usage today.
Maybe a sufficiently advanced GC could address the performance
non-determinism to an acceptable level, but you're still left with the
memory non-determinism, and the conundrum that when your heap
approaches full (which is _always_ on a games console), the GC has to
work harder and harder, and more often to try and keep the tiny little
bit of overhead available.
A GC heap by nature expects you to have lots of memory, and also lots
of FREE memory.
No serious console game I'm aware of has ever been written in a
language with a GC. Casual games, or games that don't attempt to raise
the bar may get away with it, but that's not the industry I work in.
You can always force the GC to run between cycles in your game, and
turn off automatic sweeps. This is how most games operate nowadays.
It's also probably possible to create a drop-in replacement for the GC
to do something else. I could see if being *VERY* useful to make the
GC take a compile-time parameter to select which GC engine is used.