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Re: [lwip-users] lwIP reentrancy issues and TCP
From: |
Simon Goldschmidt |
Subject: |
Re: [lwip-users] lwIP reentrancy issues and TCP |
Date: |
Sat, 25 Jun 2011 09:26:43 +0200 |
Peter Montgomery <address@hidden> wrote:
> You say that lwIP was designed to be run entirely from foreground (FG for
> short) code, with the Ethernet hardware interrupt handler merely setting a
> flag that the FG code polls. So the entire system was designed to be run in
> a polled mode? I guess this presupposes that the FG would never get stuck
> doing something that took a little too long, and fail to poll in a timely
> manner. That seems awfully hard to guarantee.
Well, I should have mentioned that an ISR may pull packets off the hardware and
put them into a queue which is then processed by FG code. You can do this by
either preallocating pbufs for RX packets or by correctly implementing
SYS_LIGHTWEIGHT_PROT and calling pbuf_alloc(PBUF_POOL) from the ISR.
> You also say Stellaris is a bad example of an lwIP implementation.
I didn't mean to say that Stellaris is bad. It's a perfectly working way to use
lwIP (as far as I know: I haven't been using it, only had a quick look at the
freely downloadable code and heard what users said on this list). However,
using lwIP this way is a bit confusing for lwIP beginners, that's all I meant
to say.
> Since Stellaris has lwIP running completely in interrupts, what's the best
> way for me to get messages from the FG to lwIP's interrupt code?
And this question is the reason I said it's "a bit confusing for lwIP
beginners".
Hmm, the easiest way might be to disable the ethernet interrupt while calling
into lwIP from FG code. However, I can't really help you here as I don't really
know the implementation detailed enough to guide you.
Simon
>
- [lwip-users] Data sending problem over TCP, Sanchayan, 2011/06/22
- Re: [lwip-users] Data sending problem over TCP, Tim Lambrix, 2011/06/22
- Re: [lwip-users] Data sending problem over TCP, Sanchayan, 2011/06/22
- Re: [lwip-users] Data sending problem over TCP, Tim Lambrix, 2011/06/22
- Re: [lwip-users] Data sending problem over TCP, Sanchayan, 2011/06/22
- [lwip-users] lwIP reentrancy issues and TCP, Peter Montgomery, 2011/06/24
- Re: [lwip-users] lwIP reentrancy issues and TCP, Simon Goldschmidt, 2011/06/24
- Re: [lwip-users] lwIP reentrancy issues and TCP, Peter Montgomery, 2011/06/24
- Re: [lwip-users] lwIP reentrancy issues and TCP,
Simon Goldschmidt <=
- Re: [lwip-users] lwIP reentrancy issues and TCP, FreeRTOS Info, 2011/06/25
- Re: [lwip-users] lwIP reentrancy issues and TCP, FreeRTOS Info, 2011/06/25
- Re: [lwip-users] lwIP reentrancy issues and TCP, AjK, 2011/06/25
- Re: [lwip-users] lwIP reentrancy issues and TCP, FreeRTOS Info, 2011/06/27
- Re: [lwip-users] lwIP reentrancy issues and TCP, AjK, 2011/06/27
Re: [lwip-users] Data sending problem over TCP, Kieran Mansley, 2011/06/23