C++ (Cpp) vhci_put_user示例

示例#1

static ssize_t vhci_read(struct file *file,
				char __user *buf, size_t count, loff_t *pos)
{
	struct vhci_data *data = file->private_data;
	struct sk_buff *skb;
	ssize_t ret = 0;

	while (count) {
		skb = skb_dequeue(&data->readq);
		if (skb) {
			ret = vhci_put_user(data, skb, buf, count);
			if (ret < 0)
				skb_queue_head(&data->readq, skb);
			else
				kfree_skb(skb);
			break;
		}

		if (file->f_flags & O_NONBLOCK) {
			ret = -EAGAIN;
			break;
		}

		ret = wait_event_interruptible(data->read_wait,
					!skb_queue_empty(&data->readq));
		if (ret < 0)
			break;
	}

	return ret;
}

示例#2

文件： hci_vhci.c 项目： johnny/CobraDroidBeta

static ssize_t vhci_read(struct file *file,
                         char __user *buf, size_t count, loff_t *pos)
{
    DECLARE_WAITQUEUE(wait, current);
    struct vhci_data *data = file->private_data;
    struct sk_buff *skb;
    ssize_t ret = 0;

    add_wait_queue(&data->read_wait, &wait);
    while (count) {
        set_current_state(TASK_INTERRUPTIBLE);

        skb = skb_dequeue(&data->readq);
        if (!skb) {
            if (file->f_flags & O_NONBLOCK) {
                ret = -EAGAIN;
                break;
            }

            if (signal_pending(current)) {
                ret = -ERESTARTSYS;
                break;
            }

            schedule();
            continue;
        }

        if (access_ok(VERIFY_WRITE, buf, count))
            ret = vhci_put_user(data, skb, buf, count);
        else
            ret = -EFAULT;

        kfree_skb(skb);
        break;
    }
    set_current_state(TASK_RUNNING);
    remove_wait_queue(&data->read_wait, &wait);

    return ret;
}