On Mon, Oct 19, 2009 at 2:24 AM, Gerrit Renker <gerrit@xxxxxxxxxxxxxx> wrote:
>
> | +static struct tfrc_tx_hist_entry*
> | + tfrc_sp_seek_tx_entry(struct tfrc_tx_hist_entry *head,
> | + u64 seqno, u32 backward)
> | +{
> | + if (head == NULL)
> | + return NULL;
> | +
> | + while (head->seqno != seqno) {
> | + head = head->next;
> | +
> | + if (head == NULL)
> | + return NULL;
> | + }
> | +
> | + while (backward-- > 0) {
> | + head = head->next;
> | +
> | + if (head == NULL)
> | + return NULL;
> | + }
> | +
> | + return head;
> | +}
> | +
> | +/*
> | + * tfrc_sp_p_from_loss_intervals_opt - calcs p from loss interval option
> | + * li_data: data parsed from options
> | + * head: contains ccval info
> | + * curr_ccval: current ccval
> | + * seqno: last acked seqno
> | + */
> | +u32 tfrc_sp_p_from_loss_intervals_opt(struct tfrc_tx_li_data *li_data,
> | + struct tfrc_tx_hist_entry *head,
> | + u8 curr_ccval, u64 seqno)
> | +{
> <snip>
> | +
> | + for (i = 1; i <= k; i++) {
> | + i_i = li_data->loss_interval_data[i];
> | + i_totl += i_i;
> | + ccval = tfrc_sp_seek_tx_entry(head, seqno, i_totl - 1)->ccval;
>
> tfrc_sp_seek_tx_entry() can return NULL (as per above implementation). Then this
> will crash/panic.
>
Thanks for observing this.
> <snip>
> | +
> | + if (i > 1)
> | + i_tot1 += i_i * tfrc_lh_weights[i-2];
> | + }
> | +
> | + ccval = tfrc_sp_seek_tx_entry(head, seqno,
> | + li_data->loss_interval_data[1] - 1)->ccval;
> Here it can also crash.
Thanks, will be fixed.
>
> Getting a sender-based implementation right is complex, since it requires to
> enforce consistency and garbage collection for so many data structures.
>
Yes, it can take time.
> That is why I think it would be easier to start with a receiver-based implementation
> and then grow it into a sender-based implementation if it shows promise.
Agreed.
--
Ivo Augusto Andrade Rocha Calado
MSc. Candidate
Embedded Systems and Pervasive Computing Lab - http://embedded.ufcg.edu.br
Systems and Computing Department - http://www.dsc.ufcg.edu.br
Electrical Engineering and Informatics Center - http://www.ceei.ufcg.edu.br
Federal University of Campina Grande - http://www.ufcg.edu.br
PGP: 0x03422935
Quidquid latine dictum sit, altum viditur.
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