Function sys_timer_create

components/lwp/lwp_syscall.c:3037–3077

* @brief Creates a per-process timer. * * This system call creates a new timer associated with the specified clock, and * initializes the timer with the provided event notification attributes. * Once created, the timer can be started, stopped, or controlled as needed. * The timer will trigger when the specified expiration time or interval is reached. * * @param[in] clockid The clock to b

 *          unsupported notification types may result in unexpected behavior.
 */
sysret_t sys_timer_create(clockid_t clockid, struct sigevent *restrict sevp, timer_t *restrict timerid)
{
    int ret = 0;
#ifdef ARCH_MM_MMU
    struct sigevent sevp_k;
    timer_t timerid_k;
    int utimer;

    if (sevp == NULL)
    {
        sevp_k.sigev_notify = SIGEV_SIGNAL;
        sevp_k.sigev_signo = SIGALRM;
        sevp = &sevp_k;
    }
    else
    {
        /* clear extra bytes if any */
        if (sizeof(struct ksigevent) < sizeof(struct sigevent))
            memset(&sevp_k, 0, sizeof(sevp_k));

        /* musl passes `struct ksigevent` to kernel, we shoule only get size of that bytes */
        if (!lwp_get_from_user(&sevp_k, (void *)sevp, sizeof(struct ksigevent)))
        {
            return -EINVAL;
        }
    }

    ret = _SYS_WRAP(timer_create(clockid, &sevp_k, &timerid_k));

    if (ret != -RT_ERROR)
    {
        utimer = (rt_ubase_t)timerid_k;
        if (!lwp_put_to_user(sevp, (void *)&sevp_k, sizeof(struct ksigevent)) ||
            !lwp_put_to_user(timerid, (void *)&utimer, sizeof(utimer)))
            ret = -EINVAL;
    }
#else
    ret = _SYS_WRAP(timer_create(clockid, sevp, timerid));
#endif
    return ret;
}

/**
 * @brief Deletes a timer.