On Thursday, 27 February 2014 at 12:32:36 UTC, Namespace wrote:
On Thursday, 27 February 2014 at 12:25:49 UTC, Szymon Gatner
wrote:
On Thursday, 27 February 2014 at 11:13:17 UTC, bearophile
wrote:
Szymon Gatner:
I just want them to do their cleanup first as they should.
Why? Perhaps if you explain what's behind your needs better,
people can help better.
Bye,
bearophile
In my specific example I am creating OpenGL Renderer. Renderer
class instance holds GLContext instance. After context
creation GL objects are created like textures and vertex
buffers. Those are Texture and VertexBuffer class instances
too. It is critical that those child resources are freed
before GL context is destroyed. Thing is, even tho Renderer
keeps list of Textures , VertexBuffers and Context object,
order of their destruction is completely undefined making
Context d-tor called first and then child resources d-tors
which ends in catastrophe.
In C++ (which has a LOT of problems) this is a no-brainer.
Order of d-tors is fully defined. Sub-objects are destroyed
before parent d-tor is called so only thing to worry about is
the order of definition of members.
This is just an example but I would think that it is something
rather important to have... What about child objects
un-registering themselves in d-tors from a list that parent
object holds and parent is destroyed first? What about
asynchronous completion handler object that should notify some
other object that it finished/not finished a job but a notifee
is already destroyed because application is being shut-down? I
honestly can't imagine how to reason about object graph
lifetimes in GC world and I am sure I am missing something
very basic. Probably a very different mindset.
I had the same problem in Dgame. Therefore I use shared
pointers
(https://github.com/Dgame/Dgame/blob/master/Graphics/Surface.d#L90)
or if I have to use classes, I use this:
https://github.com/Dgame/Dgame/blob/master/Window/Window.d#L44
https://github.com/Dgame/Dgame/blob/master/Window/Window.d#L177
I put the instances in a module global array and the module
dtor finalize the data.
Module d-tor() looks like a pretty good solution, thanks.
shared_ptr tho... I was really hoping that I am moving away from
it to a better place...
Still, this feels like working around a language issue, if c-tor
order is defined why d-tor isn't? I am ok with non-deterministic
time of execution of d-tors/finalizers but not-having
parent-child d-tor order defined? That is weird.
