[ECOS] ecos + lwip
Tue Sep 1 15:32:00 GMT 2009
Mandeep Sandhu wrote:
> On Tue, Sep 1, 2009 at 7:08 PM, Simon Kallweit<firstname.lastname@example.org> 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
"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."
This message should pop up unless you have asserts disabled?!?
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.
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