Ruby_C_ext_notes_JA_conf_RubyKaigi.md

Mark

Tell Garbage Collector which objects you use. Ruby takes care of object lifecycle; C doesn't. If you still need objects, mark them in use.

void mark(void* p) {
  auto* hash = reinterpret_cast<ruby_hash_t*>(p);
  for (auto& iter: *hash) {
    rb_gc_mark(iter.first);
    rb_gc_mark(iter.second);
  }
}

Garbage Collection in C Ruby

Mark and Sweep

If you don't mark, Ruby releases the memory. Nil starts to appear in random places. Might crash in worst case.

Basic Types in C Ruby

VALUE

Alias of a long, 64 bit integer (on 64 bit Linux).

RBasic

Struct with flags and class.

Every Ruby Variable in C is a VALUE

VALUE initialize(VALUE self) {
  return self;
}

---

def initialize
end