Garbage Collector : Ignoring a reference

[Marco Leise via Digitalmars-d-learn]

Am Tue, 26 Apr 2016 13:35:37 +0000
schrieb Begah <mathieu.roux222 at gmail.com>:

> When the screen switches to another screen ie from menu to the 
> game,
> I want that the "button.png" texture is automaticly destroyed by 
> the gc.

My ideological point of view is that you must not use
non-deterministic garbage collection for resources. Neither
for files, GUI widgets or textures. The garbage collector
cannot look past its own confined environment (heap memory
allocated by the D program and loaded D libraries) and will
not have enough information to tell if the process is running
out of file handles, backing buffer for widgets or texture
memory on the graphics card. It only takes action, when its own
heap is filling up or when you manually call GC.collect().
All the convenient 100% GC languages from Java to Python
require the user to call ".close()" for files,
".dispose()/.Destroy()" for widgets, etc.
Reference counting is the correct approach. It makes using
external resources safe and convenient by removing the need
for manual lifetime management. Cyclic references cannot
exist in the D code in this scenario.

The texture constructor:
- sets ref count to 1
- adds texture to hash map
The copy constructor:
- increments the ref count
The destructor:
- decrements the ref count
- if ref count reaches 0:
  - removes the texture from the hash table
  - destroys the texture data

-- 
Marco