Manual GC Gen2 data allocation

Question

I'm prototyping some managed directx game engine before moving to c++ syntax horror. So let's say I've got some data (fe an array or a hashset of references) that I'm sure it'll stay alive throughout whole application's life. Since performance is crucial here and I'm trying to avoid any lag spikes on generation promotion, I'd like to ask if there's any way to initialize an object (allocate its memory) straight ahead in GC's generation 2? I couldn't find an answer for that, but I'm pretty sure I've seen someone doing that before.

Alternatively since there would be no real need to "manage" that piece of memory, would it be possible to allocate it with unmanaged code, but to expose it to the rest of the code as a .NET type?

Answer 1

You can't allocate directly in Gen 2. All allocations happen in either Gen 0 or on the large object heap (if they are 85000 bytes or larger). However, pushing something to Gen 2 is easy: Just allocate everything you want to go to Gen 2 and force GCs at that point. You can call GC.GetGeneration to inspect the generation of a given object.

Another thing to do is keep a pool of objects. Ie instead of releasing objects and thus making them eligible for GC, you return them to a pool. This reduces allocations and thus the number of GCs as well.