How does Ruby manage native extension memory ownership safely?

CRuby enforces explicit ownership rules using VALUE handles and GC marking APIs.

Native extensions must treat Ruby objects as GC-managed handles (VALUE). They must register references using GC marking APIs and avoid raw pointer retention. If C code stores a VALUE without marking it, GC may reclaim it, leading to use-after-free bugs. This design enforces cooperative memory safety between Ruby and C layers.