February 23, 2012
I am looking for the details on D Garbage Collection implementation. I will much appreciate if someone suggests the answers or give some links to existing documentation clarifying the following points:

1. Is it Mark-n-Sweep or copy or generational collector or simple reference counting? Or anything else? Any documentation on this would be very helpful

2. Sun/Oracle JVM publishes a number of counters in shared memory so that user may easily monitor the memory usage and the GC statistics real-time without affecting the application (and without modifying the application). Is there anything similar for D GC?

3. Is there any performance tests of D GC efficiency? Is it possible to write GC-predictable code (without manual allocate/free) or at least do something like System.gc()?
February 24, 2012
On 24 February 2012 12:49, Vadim <vadim.goryunov@gmail.com> wrote:
> I am looking for the details on D Garbage Collection implementation. I will much appreciate if someone suggests the answers or give some links to existing documentation clarifying the following points:
>
> 1. Is it Mark-n-Sweep or copy or generational collector or simple reference counting? Or anything else? Any documentation on this would be very helpful
>
> 2. Sun/Oracle JVM publishes a number of counters in shared memory so that user may easily monitor the memory usage and the GC statistics real-time without affecting the application (and without modifying the application). Is there anything similar for D GC?
>
> 3. Is there any performance tests of D GC efficiency? Is it possible to
> write GC-predictable code (without manual allocate/free) or at least do
> something like System.gc()?

I don't know the answers to 1 or 2, but I know that there is a GC class with a bunch of methods on it for controlling the GC, including enabling and disabling it and getting GC-allocated memory. Whether that helps you write GC predictable code - I don't know, garbage collection is mostly a black art to me :-)

--
James Miller
February 24, 2012
On Feb 23, 2012 6:50 PM, "Vadim" <vadim.goryunov@gmail.com> wrote:
>
> I am looking for the details on D Garbage Collection implementation. I
will much appreciate if someone suggests the answers or give some links to existing documentation clarifying the following points:
>
> 1. Is it Mark-n-Sweep or copy or generational collector or simple
reference counting? Or anything else? Any documentation on this would be very helpful
>
> 2. Sun/Oracle JVM publishes a number of counters in shared memory so that
user may easily monitor the memory usage and the GC statistics real-time without affecting the application (and without modifying the application). Is there anything similar for D GC?
>
> 3. Is there any performance tests of D GC efficiency? Is it possible to
write GC-predictable code (without manual allocate/free) or at least do
something like System.gc

There is quite a lot of info in the mailing list.  Off of the top of my head I know it is a mark and sweep.  There is someone who did their Phd on GC in D and he did a fairly good analysis of the current situation.

And as the fellow before me said, there is a garbage collector control.


February 24, 2012
Le 24/02/2012 00:49, Vadim a écrit :
> I am looking for the details on D Garbage Collection implementation. I
> will much appreciate if someone suggests the answers or give some links
> to existing documentation clarifying the following points:
>
> 1. Is it Mark-n-Sweep or copy or generational collector or simple
> reference counting? Or anything else? Any documentation on this would be
> very helpful
>

Mark and sweep, but do not copy and isn't generationnal.

> 2. Sun/Oracle JVM publishes a number of counters in shared memory so
> that user may easily monitor the memory usage and the GC statistics
> real-time without affecting the application (and without modifying the
> application). Is there anything similar for D GC?
>

You should ask the system for thoses infos.

> 3. Is there any performance tests of D GC efficiency? Is it possible to
> write GC-predictable code (without manual allocate/free) or at least do
> something like System.gc()?

Its performance are quite poor ATM, it is getting better, but still not as effeiscient as java's GC for example. You could disable it using the class GC on critical period of time, so you'd know when it run and when it cannot trigger itself. D allow also to manage memory manually, and if you don't generate garbage, GC will not trigger.
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