Re: [lwip-users] Free LwIP resources

[Martin Velek]

Just FYI

Do not use netif_* functions with RTOS.
Use the netifapi_* variant.

Explanation is placed on the wiki or in this conference. Long story
short, do not modify lwip variables while the lwip tcpip task is
running.

Martin



On 8 September 2011 11:25, AMSN <address@hidden> wrote:
>
> Hi Richard, thanks a lot for your reply.
>
> Please excuse me if the previous message isn't clear.
>
> my application is built around graphical library and FreeRTOS, it contains
> many modules for each module I associated a demo (for example web server).
> I need to start, stop and restart again each module separately without
> stopping the whole application (without reset the microcontroller).
>
> For the web server demo, I implement the following functions:
>   - Webserver_start(): used to initialize the LwIP stack and create demo
> tasks
>   - Webserver_stop(): used to delete demo tasks and set down and remove the
> netif
>
> When I start the web server demo for the first time it works very well, but
> if I restart again the demo doesn't work correctly (the ping doesn’t work at
> all).
>
> Below the code of Webserver_stop function:
> Webserver_stop()
> {
>  // delete all tasks
>  ….
>
>  // Free LwIP resources
>  netif_set_down(&netif);
>  netif_remove(&netif);
> }
>
> Thank you very much !
> Regards
>
>
>
>
>
>
> FreeRTOS info wrote:
>>
>>
>>
>>
>> On 08/09/2011 07:34, AMSN wrote:
>>>
>>> Hi all,
>>>
>>> I am using lwIP v1.3.2 with FreeRTOS v6.1.0. My application is a web
>>> server
>>> based on netconn API.
>>> I have four tasks: tcpip, Ethernet interface, http and dhcp.
>>>
>>> I am looking for a method that allow the following:
>>> - delete all threads
>>> - free LwIP resources
>>> - set down and remove the netif
>>> Since I need to re-start the application again.
>>>
>>> Please give me some comments.
>>> Thank you very much !
>>
>>
>> First - I don't know exactly what you are doing, so this suggestion
>> might not be appropriate, but if you are truly restarting the entire
>> application, then the simplest thing to do would reset the
>> microcontroller (either hard reset using the watchdog, or a soft reset
>> in software).
>>
>> Second - I don't want to get into FreeRTOS support here.  This is an
>> lwIP list and FreeRTOS has its own support forum.  Superficially though,
>> as far as deleting FreeRTOS tasks go, then when you create a task using
>> xTaskCreate() you have the option of obtaining a handle to the task,
>> that can then be used to delete the task.  You must do that with care
>> though, if the task is blocked on a queue or such like.  You might also
>> want to delete the queues, etc.  So you don't get into memory
>> fragmentation problems though, it might be better to design your tasks
>> such that they can go back to their start rather than deleting them then
>> recreating them.
>>
>> Restarting the lwIP tasks will cause the lwIP init and MAC driver
>> functions to be called again, on the assumption they are not called from
>> main() before the scheduler is started.  The effect will probably be
>> different depending on the type of memory management you are using (for
>> example, you don't want malloc() memory leaks if malloc() is used).  I
>> will let the lwIP experts answer that fully though.
>>
>>
>> Regards,
>> Richard.
>>
>> + http://www.FreeRTOS.org
>> Designed for Microcontrollers.
>> More than 7000 downloads per month.
>>
>>
>>
>>
>>
>> _______________________________________________
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>> address@hidden
>> https://lists.nongnu.org/mailman/listinfo/lwip-users
>>
>>
>
>
> -----
> AMSN
> --
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> http://old.nabble.com/Free-LwIP-resources-tp32421345p32422235.html
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>
>
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