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Disabled pbuf_dechain() as it not currently in use. Fixed comment position.

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likewise 2003-04-14 11:37:12 +00:00
parent 445a64d933
commit f9538c9395
1 changed files with 36 additions and 33 deletions
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69
src/core/pbuf.c
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@ -657,39 +657,7 @@ pbuf_chain(struct pbuf *h, struct pbuf *t)
DEBUGF(PBUF_DEBUG | DBG_FRESH | 2, ("pbuf_chain: referencing tail %p\n", (void *) t));
}
/**
* Dechains the first pbuf from its succeeding pbufs in the chain.
*
* Makes p->tot_len field equal to p->len.
* @param p pbuf to dechain
* @return remainder of the pbuf chain, or NULL if it was de-allocated.
*/
struct pbuf *
pbuf_dechain(struct pbuf *p)
{
struct pbuf *q;
u8_t tail_gone = 1;
/* tail */
q = p->next;
/* pbuf has successor in chain? */
if (q != NULL) {
/* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */
LWIP_ASSERT("p->tot_len == p->len + q->tot_len", q->tot_len == p->tot_len - p->len);
/* enforce invariant if assertion is disabled */
q->tot_len = p->tot_len - p->len;
/* decouple pbuf from remainder */
p->next = NULL;
/* total length of pbuf p is its own length only */
p->tot_len = p->len;
/* q is no longer referenced by p, free it */
DEBUGF(PBUF_DEBUG | DBG_STATE, ("pbuf_dechain: unreferencing %p\n", (void *) q));
tail_gone = pbuf_free(q);
/* return remaining tail or NULL if deallocated */
}
/* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */
LWIP_ASSERT("p->tot_len == p->len", p->tot_len == p->len);
return (tail_gone > 0? NULL: q);
}
/**
*
@ -795,3 +763,38 @@ pbuf_take(struct pbuf *p)
return head;
}
#if 0 /* expected to enabled again, once needed (multiple chain queueing comes to mind) */
/**
* Dechains the first pbuf from its succeeding pbufs in the chain.
*
* Makes p->tot_len field equal to p->len.
* @param p pbuf to dechain
* @return remainder of the pbuf chain, or NULL if it was de-allocated.
*/
struct pbuf *
pbuf_dechain(struct pbuf *p)
{
struct pbuf *q;
u8_t tail_gone = 1;
/* tail */
q = p->next;
/* pbuf has successor in chain? */
if (q != NULL) {
/* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */
LWIP_ASSERT("p->tot_len == p->len + q->tot_len", q->tot_len == p->tot_len - p->len);
/* enforce invariant if assertion is disabled */
q->tot_len = p->tot_len - p->len;
/* decouple pbuf from remainder */
p->next = NULL;
/* total length of pbuf p is its own length only */
p->tot_len = p->len;
/* q is no longer referenced by p, free it */
DEBUGF(PBUF_DEBUG | DBG_STATE, ("pbuf_dechain: unreferencing %p\n", (void *) q));
tail_gone = pbuf_free(q);
/* return remaining tail or NULL if deallocated */
}
/* assert tot_len invariant: (p->tot_len == p->len + (p->next? p->next->tot_len: 0) */
LWIP_ASSERT("p->tot_len == p->len", p->tot_len == p->len);
return (tail_gone > 0? NULL: q);
}
#endif /* pbuf_dechain() */