Garbage Collector : Ignoring a reference

[Guillaume Piolat via Digitalmars-d-learn]

On Tuesday, 26 April 2016 at 09:07:59 UTC, Begah wrote:
> I am trying to create an asset manager for my textures. I had 
> the idea ( it may be a wrong idea ) to create a hashmap of my 
> textures with a string as the key. When the program request a 
> texture, it firts check if it is in the hashmap and then 
> returns if it is :
>
> Texture[string] textures;
>
> Texture loadTexture(string filename) {
>   if(filename in textures)
>     return textures[filename]
>   else
>     // Load image and put it in hashmap
> }
>
> Warning : I haven't tested if it actually doesn't work, but 
> thinking about it, i think it should not.
> My problem is that i return a reference of the texture to the 
> program, but i keep one to myself and i want to free the 
> texture if my program isn't using it anymore ( no more 
> reference to it ). The problem i see, is that i will always 
> have atleast one reference to the texture in my hashmap, but i 
> want the garbage collector to ignore that reference and to free 
> the texture if there are no more references anywhere in my 
> program ( except in the hashmap ).
>
> How could i tell the garbage collector to ignore the reference 
> in the hashmap and to free it if there isn't any other 
> reference that in my hashmap?

You should avoid to rely on the garbage collector to free 
non-memory resources anyway. This is accidental correctness. You 
are not guaranteed to get called by the GC, or by the appropriate 
thread.

You can call .destroy() on these textures when in the texture 
manager destructor.