[lwip-devel] [patch #8882] Vector improvements

[Joel Cunningham]

URL:
  <http://savannah.nongnu.org/patch/?8882>

                 Summary: Vector improvements
                 Project: lwIP - A Lightweight TCP/IP stack
            Submitted by: jcunningham
            Submitted on: Thu 21 Jan 2016 09:51:32 PM GMT
                Category: sockets/netconn
                Priority: 5 - Normal
                  Status: None
                 Privacy: Public
             Assigned to: jcunningham
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
         Planned Release: None

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Details:

Continuing my work with sendmsg(), I've got a couple more improvements:

1) Move struct iovec to def.h - This patch moves the LwIP provided definition
of struct iovec to def.h from sockets.h. This was done so that netconn code
can reference the type without having the socket layer enabled

This also switches to using a compiler guard of #if LWIP_IOVEC_PRIVATE because
#if !defined() on a structure doesn't actually work.  This also allows a port
to include <sys/uio.h> instead for struct iovec

2) Optimize sendmsg UDP pbuf chain creation - This patch optimizes the sendmsg
UDP pbuf chain creation by not allocating/freeing a netbuf per IO vector. 
This adds a new API (netbuf_ref_vectors()) which takes an array of struct
iovecs and creates a chain of PBUF_REFs in the provided netbuf. The logic is a
combination of netbuf_ref() and netbuf_chain()

3) Vectorize netconn_write for TCP - This patch adds support to the netconn
write APIs to take an input of vectors instead of a single data pointer.  This
allows vectors sent on a TCP connection via sendmsg to be treated atomically. 
The set of vectors is segmented into as much data as can fit into the send
buffer and then the TCP output function is called

Previously, each vector was passed to netconn_write_partly and tcp_write
segmented it into its own packet, which was then it was sent via tcp_output
(if not Nagleing)

This patch adds vector support to lwip_netconn_do_writemore() which is the
meat of the TCP write functionality from netconn/sockets layer. A new netconn
API netconn_write_vectors_partly() takes a set of vectors as input and hooks
up to do_writemore()

The patches have the follow dependency order:

0001-Move-struct-iovec-to-def.h.patch
0001-Optimzie-sendmsg-UDP-pbuf-chain-creation.patch
0001-Vectorize-netconn_write-for-TCP.patch



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File Attachments:


-------------------------------------------------------
Date: Thu 21 Jan 2016 09:51:32 PM GMT  Name:
0001-Move-struct-iovec-to-def.h.patch  Size: 2kB   By: jcunningham

<http://savannah.nongnu.org/patch/download.php?file_id=36123>
-------------------------------------------------------
Date: Thu 21 Jan 2016 09:51:32 PM GMT  Name:
0001-Vectorize-netconn_write-for-TCP.patch  Size: 12kB   By: jcunningham

<http://savannah.nongnu.org/patch/download.php?file_id=36124>
-------------------------------------------------------
Date: Thu 21 Jan 2016 09:51:32 PM GMT  Name:
0001-Optimzie-sendmsg-UDP-pbuf-chain-creation.patch  Size: 4kB   By:
jcunningham

<http://savannah.nongnu.org/patch/download.php?file_id=36125>

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