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TCP data can be safely referenced as PBUF_ROM instead of PBUF_REF.

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likewise 2003-04-07 21:28:16 +00:00
parent a3087737bd
commit a4a7a7a47e
1 changed files with 10 additions and 6 deletions
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16
src/core/tcp_out.c
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@ -167,14 +167,14 @@ tcp_enqueue(struct tcp_pcb *pcb, void *arg, u16_t len,
and data copied into pbuf, otherwise data comes from and data copied into pbuf, otherwise data comes from
ROM or other static memory, and need not be copied. If ROM or other static memory, and need not be copied. If
optdata is != NULL, we have options instead of data. */ optdata is != NULL, we have options instead of data. */
if(optdata != NULL) { if (optdata != NULL) {
if((seg->p = pbuf_alloc(PBUF_TRANSPORT, optlen, PBUF_RAM)) == NULL) { if((seg->p = pbuf_alloc(PBUF_TRANSPORT, optlen, PBUF_RAM)) == NULL) {
goto memerr; goto memerr;
} }
++queuelen; ++queuelen;
seg->dataptr = seg->p->payload; seg->dataptr = seg->p->payload;
} }
else if(copy) { else if (copy) {
if((seg->p = pbuf_alloc(PBUF_TRANSPORT, seglen, PBUF_RAM)) == NULL) { if((seg->p = pbuf_alloc(PBUF_TRANSPORT, seglen, PBUF_RAM)) == NULL) {
DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_enqueue: could not allocate memory for pbuf copy size %u\n", seglen)); DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_enqueue: could not allocate memory for pbuf copy size %u\n", seglen));
goto memerr; goto memerr;
@ -185,12 +185,16 @@ tcp_enqueue(struct tcp_pcb *pcb, void *arg, u16_t len,
} }
seg->dataptr = seg->p->payload; seg->dataptr = seg->p->payload;
} }
/* do not copy data */
else { else {
/* Do not copy the data. */
/* First, allocate a pbuf for holding the data. */ /* first, allocate a pbuf for holding the data.
if((p = pbuf_alloc(PBUF_TRANSPORT, seglen, PBUF_REF)) == NULL) { * since the referenced data is available at least until it is sent out on the
DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_enqueue: could not allocate memory for pbuf non-copy\n")); * link (as it has to be ACKed by the remote party) we can safely use PBUF_ROM
* instead of PBUF_REF here.
*/
if((p = pbuf_alloc(PBUF_TRANSPORT, seglen, PBUF_ROM)) == NULL) {
DEBUGF(TCP_OUTPUT_DEBUG, ("tcp_enqueue: could not allocate memory for zero-copy pbuf\n"));
goto memerr; goto memerr;
} }
++queuelen; ++queuelen;