Re: D's New GC and Object Allocation Pools

[Damian via Digitalmars-d]

On Sunday, 26 October 2014 at 03:37:47 UTC, Maxime 
Chevalier-Boisvert wrote:
Hello,

I was wondering if there have been updates regarding Andrei's 
announcement that he would rewrite the D garbage collector. Is 
there any kind of timeline for when a new version of the GC can 
be expected?

I also wanted to ask if there was an implementation of an 
object pool in the standard library. If not, I'm wondering what 
the best way to implement this is. Is there any way to overload 
new and destroy?

I was thinking of using the templated emplace operator from 
std.conv to allocate class objects into a large flat array, and 
to derive pool-allocated classes from a PoolObject base class. 
This base class would contain linked list pointers to implement 
a free list, as well as templated static methods to allocate 
and free the objects. Any advice welcome.

For your object pool, why not just create functions, alloc and 
free, instead of trying to override them - something like below

version (USE_GC)
{
  import core.memory;
}
else
{
  import core.stdc.stdlib: malloc, free;
}

struct MemPool
{
  void* alloc(size_t size, bool usePool = true) nothrow
  {
    version (USE_GC) return GC.malloc(size);
    else malloc(size);
  }

  void Free(void* p) nothrow
  {
    version (USE_GC) GC.free(p);
    else free(p);
  }
}