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author | patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3> | 2007-12-06 23:10:31 +0000 |
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committer | patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3> | 2007-12-06 23:10:31 +0000 |
commit | c9c4a58af6383cc524f4ebdbfaea3a117ebaf8c3 (patch) | |
tree | 952a99a56375ea4591f2d44aee065e7f02601b83 /nuttx/net | |
parent | bedbe4f4b09fc925b7c204cc358bc32d5b48064c (diff) | |
download | px4-nuttx-c9c4a58af6383cc524f4ebdbfaea3a117ebaf8c3.tar.gz px4-nuttx-c9c4a58af6383cc524f4ebdbfaea3a117ebaf8c3.tar.bz2 px4-nuttx-c9c4a58af6383cc524f4ebdbfaea3a117ebaf8c3.zip |
Improved read-ahead buffer management
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@430 42af7a65-404d-4744-a932-0658087f49c3
Diffstat (limited to 'nuttx/net')
-rw-r--r-- | nuttx/net/uip/uip-tcpcallback.c | 100 |
1 files changed, 76 insertions, 24 deletions
diff --git a/nuttx/net/uip/uip-tcpcallback.c b/nuttx/net/uip/uip-tcpcallback.c index d96e97981..7c7fb2209 100644 --- a/nuttx/net/uip/uip-tcpcallback.c +++ b/nuttx/net/uip/uip-tcpcallback.c @@ -60,6 +60,45 @@ ****************************************************************************/ /**************************************************************************** + * Function: uip_readahead + * + * Description: + * Copy as much received data as possible into the readahead buffer + * + * Assumptions: + * This function is called at the interrupt level with interrupts disabled. + * + ****************************************************************************/ + +#if CONFIG_NET_NTCP_READAHEAD_BUFFERS > 0 +static int uip_readahead(struct uip_readahead_s *readahead, uint8 *buf, int len) +{ + int available = CONFIG_NET_TCP_READAHEAD_BUFSIZE - readahead->rh_nbytes; + int recvlen = 0; + + if (len > 0 && available > 0) + { + /* Get the length of the data to buffer. */ + + if (len > available) + { + recvlen = available; + } + else + { + recvlen = len; + } + + /* Copy the new appdata into the read-ahead buffer */ + + memcpy(&readahead->rh_buffer[readahead->rh_nbytes], buf, recvlen); + readahead->rh_nbytes += recvlen; + } + return recvlen; +} +#endif + +/**************************************************************************** * Function: uip_dataevent * * Description: @@ -74,10 +113,6 @@ static inline uint8 uip_dataevent(struct uip_driver_s *dev, struct uip_conn *conn, uint8 flags) { -#if CONFIG_NET_NTCP_READAHEAD_BUFFERS > 0 - struct uip_readahead_s *readahead; - uint16 recvlen; -#endif uint8 ret = flags; /* Is there new data? With non-zero length? (Certain connection events @@ -87,39 +122,56 @@ uip_dataevent(struct uip_driver_s *dev, struct uip_conn *conn, uint8 flags) if ((flags & UIP_NEWDATA) != 0 && dev->d_len > 0) { #if CONFIG_NET_NTCP_READAHEAD_BUFFERS > 0 - /* Allocate a read-ahead buffer to hold the newly received data */ + struct uip_readahead_s *readahead1; + struct uip_readahead_s *readahead2 = NULL; + uint16 recvlen = 0; + uint8 *buf = dev->d_appdata; + int buflen = dev->d_len; + + /* First, we need to determine if we have space to buffer the data. This + * needs to be verified before we actually begin buffering the data. We + * will use any remaining space in the last allocated readahead buffer + * plus as much one additional buffer. It is expected that the size of + * readahead buffers are tuned so that one full packet will always fit + * into one readahead buffer (for example if the buffer size is 420, then + * a readahead buffer of 366 will hold a full packet of TCP data). + */ - readahead = uip_tcpreadaheadalloc(); - if (readahead) + readahead1 = (struct uip_readahead_s*)conn->readahead.tail; + if ((readahead1 && + (CONFIG_NET_TCP_READAHEAD_BUFSIZE - readahead1->rh_nbytes) > buflen) || + (readahead2 = uip_tcpreadaheadalloc()) != NULL) { - /* Get the length of the data to buffer. If the sizes of the - * read-ahead buffers are picked correct, they should always - * hold the full received packet.\ + /* We have buffer space. Now try to append add as much data as possible + * to the last readahead buffer attached to this connection. */ - if (dev->d_len > CONFIG_NET_TCP_READAHEAD_BUFSIZE) - { - recvlen = CONFIG_NET_TCP_READAHEAD_BUFSIZE; - } - else + if (readahead1) { - recvlen = dev->d_len; + recvlen = uip_readahead(readahead1, buf, buflen); + if (recvlen > 0) + { + buf += recvlen; + buflen -= recvlen; + } } - /* Copy the new appdata into the read-ahead buffer */ + /* Do we need to buffer into the newly allocated buffer as well? */ - memcpy(readahead->rh_buffer, dev->d_appdata, recvlen); - readahead->rh_nbytes = recvlen; - nvdbg("Buffered %d bytes (of %d)\n", recvlen, dev->d_len); + if (readahead2) + { + (void)uip_readahead(readahead2, buf, buflen); - /* Save the readahead buffer in the connection structure where - * it can be found with recv() is called. - */ + /* Save the readahead buffer in the connection structure where + * it can be found with recv() is called. + */ - sq_addlast(&readahead->rh_node, &conn->readahead); + sq_addlast(&readahead2->rh_node, &conn->readahead); + } /* Indicate that all of the data in the buffer has been consumed */ + nvdbg("Buffered %d bytes\n", dev->d_len); dev->d_len = 0; } else |