Re: [ECOS] ecos + lwip

[Mandeep Sandhu <mandeepsandhu dot chd at gmail dot com>]

On Tue, Sep 1, 2009 at 9:07 PM, Simon Kallweit<simon.kallweit@intefo.ch> wrote:
> Mandeep Sandhu wrote:
>>
>> On Tue, Sep 1, 2009 at 7:08 PM, Simon Kallweit<simon.kallweit@intefo.ch>
>> wrote:
>>>
>>> Mandeep Sandhu wrote:
>>> sys_thread_new() will use preallocated memory for the stack, while
>>> cyg_lwip_thread_new() will take the stack as an argument. Therefore by
>>> default you should use cyg_lwip_thread_new(). When using sys_thread_new()
>>> the ecos should fail when all preallocated memory is used.
>>
>> But sys_thread_new() also takes stacksize as an argument. It passes
>> the same value
>> to cyg_lwip_thread_new() after validating it. So I guess it should be ok.
>
> Yes, sys_thread_new() takes a stacksize argument, but no pointer to the
> actual memory. The current code uses a statically allocated buffer for all
> lwip's internal stacks, but it is not large enough to hold additional stacks
> from users, hence the cyg_lwip_thread_new() API where the user can provide a
> pointer to the actual stack memory to be used.
>
> Your application should FAIL when using sys_thread_new() with the following
> message:
>
> "Not enough memory to allocate the thread's stack. You may want to use
> cyg_lwip_thread_new() instead of sys_thread_new() so you can provide
> external stack memory."

I dont see this message.
>
> This message should pop up unless you have asserts disabled?!?

No. They're enabled.
>
> Maybe I should add an option in the CDL to enlarge the statically allocated
> internal stack memory so users could allocate threads with sys_thread_new().
> But I don't personally like it, as you may waste memory.
> cyg_lwip_thread_new() does solve this problem by forcing you to allocate the
> stack memory yourself.
>
> Please try to use cyg_lwip_thread_new() and tell me if that works.

I'll do that now. Thanks for tips.

Also I noted one more thing.

My thread which calls netif_find() is executed _BEFORE_ I see the netif_add()
messages!!!
Could this be a thread synchronization issue? Should I wait for the
netif init() to
complete?

Regards,
-mandeep

>
> Simon
>

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