n = tree->trb_alloc->libavl_malloc (tree->trb_alloc, sizeof *n); if (n == NULL) return NULL; tree->trb_count++; n->trb_data = item; n->trb_tag[0] = n->trb_tag[1] = TRB_THREAD; n->trb_link[dir] = p->trb_link[dir]; if (tree->trb_root != NULL) { p->trb_tag[dir] = TRB_CHILD; n->trb_link[!dir] = p; } else n->trb_link[1] = NULL; p->trb_link[dir] = n; n->trb_color = TRB_RED;