Function luaC_barrier_

depends/lua/src/lgc.c:155–164

** barrier that moves collector forward, that is, mark the white object ** being pointed by a black object. (If in sweep phase, clear the black ** object to white [sweep it] to avoid other barrier calls for this ** same object.) */

** same object.)
*/
void luaC_barrier_ (lua_State *L, GCObject *o, GCObject *v) {
  global_State *g = G(L);
  lua_assert(isblack(o) && iswhite(v) && !isdead(g, v) && !isdead(g, o));
  if (keepinvariant(g))  /* must keep invariant? */
    reallymarkobject(g, v);  /* restore invariant */
  else {  /* sweep phase */
    lua_assert(issweepphase(g));
    makewhite(g, o);  /* mark main obj. as white to avoid other barriers */
  }
}


/*