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Documentation and comment clearifications.

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likewise 2003-11-18 00:31:30 +00:00
parent eb84532b3a
commit c8303f2fde
1 changed files with 13 additions and 12 deletions
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21
src/core/pbuf.c
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@ -636,9 +636,10 @@ pbuf_ref(struct pbuf *p)
/** /**
* Concatenate two pbufs (each may be a pbuf chain) and take over * Concatenate two pbufs (each may be a pbuf chain) and take over
* the reference of the tail pbuf. * the caller's reference of the tail pbuf.
* *
* @note The caller MAY NOT reference the tail pbuf afterwards. * @note The caller MAY NOT reference the tail pbuf afterwards.
* Use pbuf_chain() for that purpose.
* *
* @see pbuf_chain() * @see pbuf_chain()
*/ */
@ -650,16 +651,14 @@ pbuf_cat(struct pbuf *h, struct pbuf *t)
LWIP_ASSERT("h != NULL", h != NULL); LWIP_ASSERT("h != NULL", h != NULL);
LWIP_ASSERT("t != NULL", t != NULL); LWIP_ASSERT("t != NULL", t != NULL);
if ((h = NULL) || (t == NULL)) return;
if (t == NULL)
return;
/* proceed to last pbuf of chain */ /* proceed to last pbuf of chain */
for (p = h; p->next != NULL; p = p->next) { for (p = h; p->next != NULL; p = p->next) {
/* add total length of second chain to all totals of first chain */ /* add total length of second chain to all totals of first chain */
p->tot_len += t->tot_len; p->tot_len += t->tot_len;
} }
/* p is last pbuf of first h chain */ /* { p is last pbuf of first h chain, p->next == NULL } */
LWIP_ASSERT("p->tot_len == p->len (of last pbuf in chain)", p->tot_len == p->len); LWIP_ASSERT("p->tot_len == p->len (of last pbuf in chain)", p->tot_len == p->len);
/* add total length of second chain to last pbuf total of first chain */ /* add total length of second chain to last pbuf total of first chain */
p->tot_len += t->tot_len; p->tot_len += t->tot_len;
@ -668,13 +667,15 @@ pbuf_cat(struct pbuf *h, struct pbuf *t)
} }
/** /**
* Chain two pbufs (or pbuf chains) together. They must belong to the same packet. * Chain two pbufs (or pbuf chains) together.
* It's the same as pbuf_cat with the addition that it increases the reference count *
* of the tail. * The caller MUST call pbuf_free(t) once it has stopped
* using it. Use pbuf_cat() instead if you no longer use t.
* *
* @param h head pbuf (chain) * @param h head pbuf (chain)
* @param t tail pbuf (chain) * @param t tail pbuf (chain)
* @note May not be called on a packet queue. * @note The pbufs MUST belong to the same packet.
* @note MAY NOT be called on a packet queue.
* *
* The ->tot_len fields of all pbufs of the head chain are adjusted. * The ->tot_len fields of all pbufs of the head chain are adjusted.
* The ->next field of the last pbuf of the head chain is adjusted. * The ->next field of the last pbuf of the head chain is adjusted.
@ -685,7 +686,7 @@ void
pbuf_chain(struct pbuf *h, struct pbuf *t) pbuf_chain(struct pbuf *h, struct pbuf *t)
{ {
pbuf_cat(h, t); pbuf_cat(h, t);
/* t is now referenced to one more time */ /* t is now referenced by h */
pbuf_ref(t); pbuf_ref(t);
LWIP_DEBUGF(PBUF_DEBUG | DBG_FRESH | 2, ("pbuf_chain: %p references %p\n", (void *)h, (void *)t)); LWIP_DEBUGF(PBUF_DEBUG | DBG_FRESH | 2, ("pbuf_chain: %p references %p\n", (void *)h, (void *)t));
} }