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Re: [lwip-users] recv and sent callbacks usage
From: |
narke |
Subject: |
Re: [lwip-users] recv and sent callbacks usage |
Date: |
Thu, 11 Aug 2011 22:10:17 +0800 |
On 11 August 2011 21:52, Kieran Mansley <address@hidden> wrote:
> On Thu, 2011-08-11 at 21:47 +0800, narke wrote:
>> For the 2nd question, if I called tcp_write 3 times, each time with a
>> 100 bytes pbuf, and I when I got the first call of sent callback with
>> a len argument equals to 100, should I prepare myself to resent the
>> last two 100 bytes pbuf again?
>
> No, you should never need to resend anything; lwIP will deal with the
> retransmission if necessary. You just have to retain the data you've
> sent until lwIP tells you (using the sent callback) that is has finished
> with it. You can then overwrite it or free it or do whatever you like.
> When you get the first callback with len=100 that tells you that you can
> release the first 100 bytes, but that the remaining 200 bytes must still
> be preserved.
>
Thanks, understood. If I used the TCP_WRITE_FLAG_COPY option, will
the situation change?
>> In above example, is that possible I got a sent callback with a len
>> that is not a multiple of 100?
>
> Yes, and this is actually quite likely once you have more data in
> flight.
>
> Kieran
>
>
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>
--
Life is the only flaw in an otherwise perfect nonexistence
-- Schopenhauer
narke
public key at http://subkeys.pgp.net:11371 (address@hidden)
- [lwip-users] lwip socket is stable, (continued)
- [lwip-users] lwip socket is stable, vincent cui, 2011/08/11
- Re: [lwip-users] lwip socket is stable, Kieran Mansley, 2011/08/11
- Re: [lwip-users] lwip socket is stable, vincent cui, 2011/08/11
- Re: [lwip-users] lwip socket is stable, Kieran Mansley, 2011/08/11
- Re: [lwip-users] lwip socket is stable, vincent cui, 2011/08/12
- Re: [lwip-users] lwip socket is stable, FreeRTOS Info, 2011/08/12
- Re: [lwip-users] lwip socket is stable, vincent cui, 2011/08/14
- Re: [lwip-users] lwip socket is stable, Felipe de Andrade Neves L., 2011/08/15
- Re: [lwip-users] lwip socket is stable, vincent cui, 2011/08/15
- Re: [lwip-users] lwip socket is stable, FreeRTOS Info, 2011/08/15
- Re: [lwip-users] recv and sent callbacks usage,
narke <=
- Re: [lwip-users] recv and sent callbacks usage, Kieran Mansley, 2011/08/11
- Re: [lwip-users] recv and sent callbacks usage, narke, 2011/08/11