[ECOS] strange behavior with single thread

[ECOS] strange behavior with single thread

[Mandeep Sandhu]

Hi All,

I have a _very_ simple thread app which I've modified from the
"twothreads.c" example.

It does nothing except start a thread in which I simply print a debug
message and declare
a var of "struct sockaddr_in". But on starting the app, it stops after a call to
cyg_thread_resume(), i.e the thread does not start!

I had originally written a limited DHCP server implementation (which
was not working)!
So on debugging I narrowed down the problem to a declaration of
"struct sockaddr_in"
variable.

So I thought I'd make a simple thread which just declares this var and
does nothing. And
even in this sample app (test.c) I saw the same problem. I've
allocated a big enough stack
for the thread - 4KB. Also, increasing the stack size does not help.
The source is pasted
below.

I know this is only some minor oversight from my side, but any
pointers will be very helpful

Thanks,
-mandeep

test.c:

#include <cyg/kernel/kapi.h>
#include <network.h>

cyg_thread test_s;
cyg_handle_t test_thread;
cyg_thread_entry_t test_start;
char stack[4096];


void test_start(cyg_addrword_t data)
{
    diag_printf("TEST!\n");
    struct sockaddr_in addr;
    cyg_test_exit();
}

void cyg_user_start(void)
{
    diag_printf("Configuring test thread...\n");
    cyg_thread_create( 4,
                       test_start,
                       (cyg_addrword_t) 0,
                       "TEST Thread",
                       (void *) &stack,
                       4096,
                       &test_thread,
                       &test_s );


    diag_printf("Starting test...\n");
    cyg_thread_resume(test_thread);
}

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[ECOS] Re: strange behavior with single thread

[Mandeep Sandhu]

Just to add to the rest of the info, I'm using i386-elf (that comes
with ecos) to compile my
program.

I have another program that too has a single thread and it uses TWO
struct sockaddr_in var's.
That program works just fine!

Running strace on the prog shows a lot of Seg faults happening. I'm
pretty clueless right now
as to why one works while the other does not! :(

-mandeep

On Mon, Aug 3, 2009 at 2:53 PM, Mandeep
Sandhu<mandeepsandhu.chd@gmail.com> wrote:
> Hi All,
>
> I have a _very_ simple thread app which I've modified from the
> "twothreads.c" example.
>
> It does nothing except start a thread in which I simply print a debug
> message and declare
> a var of "struct sockaddr_in". But on starting the app, it stops after a call to
> cyg_thread_resume(), i.e the thread does not start!
>
> I had originally written a limited DHCP server implementation (which
> was not working)!
> So on debugging I narrowed down the problem to a declaration of
> "struct sockaddr_in"
> variable.
>
> So I thought I'd make a simple thread which just declares this var and
> does nothing. And
> even in this sample app (test.c) I saw the same problem. I've
> allocated a big enough stack
> for the thread - 4KB. Also, increasing the stack size does not help.
> The source is pasted
> below.
>
> I know this is only some minor oversight from my side, but any
> pointers will be very helpful
>
> Thanks,
> -mandeep
>
> test.c:
>
> #include <cyg/kernel/kapi.h>
> #include <network.h>
>
> cyg_thread test_s;
> cyg_handle_t test_thread;
> cyg_thread_entry_t test_start;
> char stack[4096];
>
>
> void test_start(cyg_addrword_t data)
> {
>    diag_printf("TEST!\n");
>    struct sockaddr_in addr;
>    cyg_test_exit();
> }
>
> void cyg_user_start(void)
> {
>    diag_printf("Configuring test thread...\n");
>    cyg_thread_create( 4,
>                       test_start,
>                       (cyg_addrword_t) 0,
>                       "TEST Thread",
>                       (void *) &stack,
>                       4096,
>                       &test_thread,
>                       &test_s );
>
>
>    diag_printf("Starting test...\n");
>    cyg_thread_resume(test_thread);
> }
>

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