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Lots of clearing up comments and use of new debugging features.

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This commit is contained in:
likewise 2003-03-24 15:15:18 +00:00
parent cea002a088
commit 80b961df60
1 changed files with 84 additions and 72 deletions
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156
src/core/pbuf.c
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@ -266,7 +266,7 @@ pbuf_alloc(pbuf_layer l, u16_t size, pbuf_flag flag)
rsize = size - p->len; rsize = size - p->len;
while(rsize > 0) { while(rsize > 0) {
q = pbuf_pool_alloc(); q = pbuf_pool_alloc();
if(q == NULL) { if (q == NULL) {
DEBUGF(PBUF_DEBUG | 2, ("pbuf_alloc: Out of pbufs in pool.\n")); DEBUGF(PBUF_DEBUG | 2, ("pbuf_alloc: Out of pbufs in pool.\n"));
#ifdef PBUF_STATS #ifdef PBUF_STATS
++lwip_stats.pbuf.err; ++lwip_stats.pbuf.err;
@ -281,9 +281,9 @@ pbuf_alloc(pbuf_layer l, u16_t size, pbuf_flag flag)
q->payload = (void *)((u8_t *)q + sizeof(struct pbuf)); q->payload = (void *)((u8_t *)q + sizeof(struct pbuf));
r = q; r = q;
q->ref = 1; q->ref = 1;
/*q = q->next; DJH: Appears to be an unnecessary statement*/
rsize -= PBUF_POOL_BUFSIZE; rsize -= PBUF_POOL_BUFSIZE;
} }
/* end of chain */
r->next = NULL; r->next = NULL;
LWIP_ASSERT("pbuf_alloc: pbuf->payload properly aligned", LWIP_ASSERT("pbuf_alloc: pbuf->payload properly aligned",
@ -304,14 +304,17 @@ pbuf_alloc(pbuf_layer l, u16_t size, pbuf_flag flag)
LWIP_ASSERT("pbuf_alloc: pbuf->payload properly aligned", LWIP_ASSERT("pbuf_alloc: pbuf->payload properly aligned",
((u32_t)p->payload % MEM_ALIGNMENT) == 0); ((u32_t)p->payload % MEM_ALIGNMENT) == 0);
break; break;
case PBUF_ROM: /* pbuf references existing ROM payload? */
case PBUF_REF: case PBUF_ROM:
/* If the pbuf should point to ROM, we only need to allocate /* pbuf references existing (externally allocated) RAM payload? */
memory for the pbuf structure. */ case PBUF_REF:
/* only allocate memory for the pbuf structure */
p = memp_mallocp(MEMP_PBUF); p = memp_mallocp(MEMP_PBUF);
if(p == NULL) { if(p == NULL) {
DEBUGF(PBUF_DEBUG | DBG_TRACE | 2, ("pbuf_alloc: Could not allocate MEMP_PBUF for PBUF_REF.\n"));
return NULL; return NULL;
} }
/* caller must set this field properly, afterwards */
p->payload = NULL; p->payload = NULL;
p->len = p->tot_len = size; p->len = p->tot_len = size;
p->next = NULL; p->next = NULL;
@ -535,70 +538,71 @@ pbuf_free(struct pbuf *p)
struct pbuf *q; struct pbuf *q;
u8_t count = 0; u8_t count = 0;
SYS_ARCH_DECL_PROTECT(old_level); SYS_ARCH_DECL_PROTECT(old_level);
if(p == NULL) { if(p == NULL) {
return 0; return 0;
} }
PERF_START; PERF_START;
LWIP_ASSERT("pbuf_free: sane flags", p->flags == PBUF_FLAG_POOL || LWIP_ASSERT("pbuf_free: sane flags", p->flags == PBUF_FLAG_POOL ||
p->flags == PBUF_FLAG_ROM || p->flags == PBUF_FLAG_ROM ||
p->flags == PBUF_FLAG_RAM || p->flags == PBUF_FLAG_RAM ||
p->flags == PBUF_FLAG_REF ); p->flags == PBUF_FLAG_REF );
/* Since decrementing ref cannot be guarranteed to be a single machine operation /* Since decrementing ref cannot be guarranteed to be a single machine operation
we must protect it. Also, the later test of ref must be protected. we must protect it. Also, the later test of ref must be protected.
*/ */
SYS_ARCH_PROTECT(old_level); SYS_ARCH_PROTECT(old_level);
/* Decrement reference count. */ /* Decrement reference count. */
for (q = p; q != NULL; q = q->next) { for (q = p; q != NULL; q = q->next) {
LWIP_ASSERT("pbuf_free: q->ref == 0", q->ref > 0); LWIP_ASSERT("pbuf_free: q->ref > 0", q->ref > 0);
q->ref--; q->ref--;
} }
/*q = NULL; DJH: Unnecessary statement*/
/* If reference count == 0, actually deallocate pbuf. */ /* If reference count == 0, actually deallocate pbuf. */
if(p->ref == 0) { if(p->ref == 0) {
SYS_ARCH_UNPROTECT(old_level); SYS_ARCH_UNPROTECT(old_level);
while(p != NULL) { while(p != NULL) {
/* Check if this is a pbuf from the pool. */ /* this is a pbuf from the pool? */
if(p->flags == PBUF_FLAG_POOL) { if(p->flags == PBUF_FLAG_POOL) {
p->len = p->tot_len = PBUF_POOL_BUFSIZE; p->len = p->tot_len = PBUF_POOL_BUFSIZE;
p->payload = (void *)((u8_t *)p + sizeof(struct pbuf)); p->payload = (void *)((u8_t *)p + sizeof(struct pbuf));
q = p->next; q = p->next;
PBUF_POOL_FREE(p); PBUF_POOL_FREE(p);
} else { /* not a pbuf from the pool */
if(p->flags == PBUF_FLAG_ROM || p->flags == PBUF_FLAG_REF) {
q = p->next;
memp_freep(MEMP_PBUF, p);
} else {
q = p->next;
mem_free(p);
}
}
p = q;
/* Only free the next one in a chain if it's reference count is 0.
This allows buffer chains to have multiple headers pointing to them. */
if (p)
{
p->ref--;
if (p->ref > 0)
break;
}
++count;
} }
pbuf_refresh(); else {
} if(p->flags == PBUF_FLAG_ROM || p->flags == PBUF_FLAG_REF) {
q = p->next;
memp_freep(MEMP_PBUF, p);
}
else {
q = p->next;
mem_free(p);
}
}
p = q;
/* Only free the next one in a chain if it's reference count is 0.
This allows buffer chains to have multiple headers pointing to them. */
if (p)
{
p->ref--;
if (p->ref > 0)
break;
}
++count;
}
pbuf_refresh();
}
else else
SYS_ARCH_UNPROTECT(old_level); SYS_ARCH_UNPROTECT(old_level);
PERF_STOP("pbuf_free"); PERF_STOP("pbuf_free");
return count; return count;
} }
/*-----------------------------------------------------------------------------------*/ /*-----------------------------------------------------------------------------------*/
@ -699,47 +703,54 @@ pbuf_dechain(struct pbuf *p)
return q; return q;
} }
/** Replace any pbufs of type PBUF_FLAG_REF with PBUF_POOL buffers. /**
*
Go through pbuf chain and replace any PBUF_REF buffers with PBUF_POOL * Replace any PBUF_REF pbufs of a chain into PBUF_POOL/RAM buffers.
buffers. This is generally done for buffer chains which need to be queued *
in some way (either on an output queue or on the arp queue). All pbufs * Go through pbuf chain and replace any PBUF_REF buffers with PBUF_POOL
replaced will be freed immediately. * (or PBUF_RAM) buffers.
*
@param f Head of pbuf chain to process * Used to queue packets on behalf of the lwIP stack, such as ARP based
* queueing.
@return Pointer to new head of pbuf chain. *
*/ * @param f Head of pbuf chain to process
*
* @return Pointer to new head of pbuf chain.
*/
struct pbuf * struct pbuf *
pbuf_unref(struct pbuf *f) pbuf_unref(struct pbuf *f)
{ {
struct pbuf *p, *prev, *top; struct pbuf *p, *prev, *top;
DEBUGF(PBUF_DEBUG | DBG_TRACE, ("pbuf_unref: %p\n", (void*)f)); LWIP_ASSERT("pbuf_unref: f != NULL", f != NULL);
DEBUGF(PBUF_DEBUG | DBG_TRACE | 3, ("pbuf_unref(%p)\n", (void*)f));
prev = NULL; prev = NULL;
p = f; p = f;
top = f; top = f;
/* iterate through pbuf chain */
do do
{ {
/* pbuf is of type PBUF_REF? */ /* pbuf is of type PBUF_REF? */
if (p->flags == PBUF_FLAG_REF) if (p->flags == PBUF_FLAG_REF)
{ {
/* the replacement pbuf */
struct pbuf *q; struct pbuf *q;
q = NULL; q = NULL;
DEBUGF(PBUF_DEBUG | DBG_TRACE, ("pbuf_unref: encountered PBUF_REF %p\n", (void *)p));
/* allocate a pbuf (w/ payload) fully in RAM */ /* allocate a pbuf (w/ payload) fully in RAM */
/* PBUF_POOL buffers are faster if we can use them */ /* PBUF_POOL buffers are faster if we can use them */
if (p->len <= PBUF_POOL_BUFSIZE) { if (p->len <= PBUF_POOL_BUFSIZE) {
q = pbuf_alloc(PBUF_RAW, p->len, PBUF_POOL); q = pbuf_alloc(PBUF_RAW, p->len, PBUF_POOL);
if (q == NULL) DEBUGF(PBUF_DEBUG | DBG_TRACE, ("pbuf_unref: Could not allocate PBUF_RAW\n")); if (q == NULL) DEBUGF(PBUF_DEBUG | DBG_TRACE | 2, ("pbuf_unref: Could not allocate PBUF_RAW\n"));
} }
/* no (large enough) PBUF_POOL was available? retry with PBUF_RAM */ /* no (large enough) PBUF_POOL was available? retry with PBUF_RAM */
if (q == NULL) { if (q == NULL) {
q = pbuf_alloc(PBUF_RAW, p->len, PBUF_RAM); q = pbuf_alloc(PBUF_RAW, p->len, PBUF_RAM);
if (q == NULL) DEBUGF(PBUF_DEBUG | DBG_TRACE, ("pbuf_unref: Could not allocate PBUF_POOL\n")); if (q == NULL) DEBUGF(PBUF_DEBUG | DBG_TRACE | 2, ("pbuf_unref: Could not allocate PBUF_POOL\n"));
} }
if (q != NULL) if (q != NULL)
{ {
/* copy pbuf struct */ /* copy successor */
q->next = p->next; q->next = p->next;
if (prev != NULL) if (prev != NULL)
/* Break chain and insert new pbuf instead */ /* Break chain and insert new pbuf instead */
@ -751,26 +762,27 @@ pbuf_unref(struct pbuf *f)
memcpy(q->payload, p->payload, p->len); memcpy(q->payload, p->payload, p->len);
q->tot_len = p->tot_len; q->tot_len = p->tot_len;
q->len = p->len; q->len = p->len;
/* do not copy ref, since someone else might be using the old buffer */
/* Don't copy ref, since someone else might be using the old buffer */ /* pbuf is not freed, as this is the responsibility of the application */
DEBUGF(PBUF_DEBUG, ("pbuf_unref: replaced PBUF_REF %p with %q\n", (void *)p, (void *)q));
/* de-allocate PBUF_REF */
/* pbuf is not freed because it is assumed that some upper level
program has a direct pointer to this pbuf and will free it. */
p = q; p = q;
DEBUGF(PBUF_DEBUG, ("pbuf_unref: succesful %p \n", (void *)p));
} }
else else
{ {
/* deallocate chain */ /* deallocate chain */
pbuf_free(top); pbuf_free(top);
DEBUGF(PBUF_DEBUG | 2, ("pbuf_unref: failed\n")); DEBUGF(PBUF_DEBUG | 2, ("pbuf_unref: failed to allocate replacement pbuf for %p\n", (void *)p));
return NULL; return NULL;
} }
} }
else {
DEBUGF(PBUF_DEBUG | DBG_TRACE | 1, ("pbuf_unref: not PBUF_REF"));
}
prev = p; prev = p;
p = p->next; p = p->next;
} while (p); } while (p);
DEBUGF(PBUF_DEBUG | DBG_TRACE | 1, ("pbuf_unref: end of chain reached."));
return top; return top;
} }