GRND_NONBLOCK
error = read_random_uio(&auio, (flags & GRND_NONBLOCK) != 0);
#define GRND_VALIDFLAGS (GRND_NONBLOCK | GRND_RANDOM | GRND_INSECURE)
flags |= GRND_NONBLOCK;
EXPECT_OK(getrandom_(buffer, sizeof(buffer), GRND_NONBLOCK));
EXPECT_OK(getrandom_(buffer2, sizeof(buffer2), GRND_NONBLOCK));
static const unsigned valid_flags[] = { 0, GRND_NONBLOCK, GRND_RANDOM,
GRND_NONBLOCK | GRND_RANDOM };
if (ret < 0 && (mode & GRND_NONBLOCK) != 0 &&