Function graph_alloc_vertex

freebsd/kern/kern_lockf.c:2406–2433

* Allocate a vertex from the free list. Return ENOMEM if there are * none. */

 * none.
 */
static struct owner_vertex *
graph_alloc_vertex(struct owner_graph *g, struct lock_owner *lo)
{
	struct owner_vertex *v;

	sx_assert(&lf_owner_graph_lock, SX_XLOCKED);

	v = malloc(sizeof(struct owner_vertex), M_LOCKF, M_WAITOK);
	if (g->g_size == g->g_space) {
		g->g_vertices = realloc(g->g_vertices,
		    2 * g->g_space * sizeof(struct owner_vertex *),
		    M_LOCKF, M_WAITOK);
		free(g->g_indexbuf, M_LOCKF);
		g->g_indexbuf = malloc(2 * g->g_space * sizeof(int),
		    M_LOCKF, M_WAITOK);
		g->g_space = 2 * g->g_space;
	}
	v->v_order = g->g_size;
	v->v_gen = g->g_gen;
	g->g_vertices[g->g_size] = v;
	g->g_size++;

	LIST_INIT(&v->v_outedges);
	LIST_INIT(&v->v_inedges);
	v->v_owner = lo;

	return (v);
}

static void
graph_free_vertex(struct owner_graph *g, struct owner_vertex *v)