149 ** pointing to a white object as gray again. (Current implementation
156   black2gray(o);  /* make object gray (again) */  in luaC_barrierback_()
177     black2gray(obj2gco(p));  /* make prototype gray (again) */  in luaC_barrierproto_()
237 ** and turned black here. Other objects are marked gray and added
261         return;  /* open upvalues remain gray */  in reallymarkobject()
266       gco2lcl(o)->gclist = g->gray;  in reallymarkobject()
267       g->gray = o;  in reallymarkobject()
271       gco2ccl(o)->gclist = g->gray;  in reallymarkobject()
272       g->gray = o;  in reallymarkobject()
276       linktable(gco2t(o), &g->gray);  in reallymarkobject()
280       gco2th(o)->gclist = g->gray;  in reallymarkobject()
281       g->gray = o;  in reallymarkobject()
285       gco2p(o)->gclist = g->gray;  in reallymarkobject()
286       g->gray = o;  in reallymarkobject()
332 ** mark root set and reset all gray lists, to start a new
336   g->gray = g->grayagain = NULL;  in restartcollection()
440     black2gray(obj2gco(h));  /* keep table gray */  in traversetable()
516 ** traverse one gray object, turning it to black (except for threads,
517 ** which are always gray).
521   GCObject *o = g->gray;  in propagatemark()
527       g->gray = h->gclist;  /* remove from 'gray' list */  in propagatemark()
533       g->gray = cl->gclist;  /* remove from 'gray' list */  in propagatemark()
539       g->gray = cl->gclist;  /* remove from 'gray' list */  in propagatemark()
545       g->gray = th->gclist;  /* remove from 'gray' list */  in propagatemark()
554       g->gray = p->gclist;  /* remove from 'gray' list */  in propagatemark()
565   while (g->gray) propagatemark(g);  in propagateall()
570   lua_assert(g->gray == NULL);  /* no grays left */  in propagatelist()
571   g->gray = l;  in propagatelist()
576 ** retraverse all gray lists. Because tables may be reinserted in other
585   propagateall(g);  /* traverse main gray list */  in retraversegrays()
954     /* make sure gray lists are consistent */  in luaC_changemode()
1050       if (g->gray) {  in singlestep()
1055       else {  /* no more `gray' objects */  in singlestep()