Function _can_nonblocking_tx

components/drivers/can/dev_can.c:338–376

* @internal * @brief Internal implementation of non-blocking CAN transmission. * * This function iterates through a buffer of CAN messages and attempts to send each one * using a non-blocking strategy. It first tries to send directly via hardware (fast path). * If the hardware is busy, it enqueues the message into a software ring buffer (slow path). * This function is thread-safe and ISR-saf

 * @return The number of bytes successfully sent or enqueued for later transmission.
 */
static rt_ssize_t _can_nonblocking_tx(struct rt_can_device *can, const struct rt_can_msg *pmsg, rt_size_t size)
{
    rt_ssize_t sent_size = 0;
    rt_base_t level;

    if (can->ops->sendmsg_nonblocking == RT_NULL)
    {
        return -RT_EINVAL;
    }

    while (sent_size < size)
    {
        if (can->ops->sendmsg_nonblocking(can, pmsg) == RT_EOK)
        {
            pmsg++;
            sent_size += sizeof(struct rt_can_msg);
            continue;
        }

        level = rt_hw_local_irq_disable();
        if (rt_ringbuffer_space_len(&can->nb_tx_rb) >= sizeof(struct rt_can_msg))
        {
            rt_ringbuffer_put(&can->nb_tx_rb, (rt_uint8_t *)pmsg, sizeof(struct rt_can_msg));
            rt_hw_local_irq_enable(level);

            pmsg++;
            sent_size += sizeof(struct rt_can_msg);
        }
        else
        {
            /* Buffer is full, cannot process this message or subsequent ones. */
            can->status.dropedsndpkg += (size - sent_size) / sizeof(struct rt_can_msg);
            rt_hw_local_irq_enable(level);
            break;
        }
    }

    return sent_size;
}

/**
 * @internal