uint8_t ll_bit_compare_and_swap(uint8_t* b, uint8_t bit_number, uint8_t value) {
    uint8_t mask = s_mask[bit_number];
    uint8_t x_mask = ~mask;
    uint8_t new_bit_value = ((value) ? mask : 0);
    while (1) {
        uint8_t v = *b;
        if ((v & mask) == new_bit_value) {
            return 0;
        }
        uint8_t new_v = v;
        if (value) {
            new_v |= mask;
        } else {
            new_v &= x_mask;           
        }
        if (__sync_bool_compare_and_swap(b, v, new_v)) {
            return 1;
        }
    }
    return 0;
}