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.
