RTOS pthread.h example

The device TMS320F28069
RTOS is bios_6_42_01_20

Hi Ken,

pthread for SYS/BIOS is documented here: http://processors.wiki.ti.com/index.php/SYS/BIOS_POSIX_Thread_%28pthread%29_Support

You need to add this to your .cfg file:

var Settings = xdc.useModule(‘ti.sysbios.posix.Settings’);

In the .c file, #include <ti/sysbios/posix/pthread.h>

To create a thread:

typedef void *(*ThreadFxn)(void *arg);

pthread_t       thread;
pthread_attr_t  pattrs;
int             threadArg = 1;

pthread_attr_init(&pattrs);

retc = pthread_create(&thread, &pattrs, (ThreadFxn)threadFxn,
                (void *)threadArg);

static void *threadFxn(void *arg)
{
    int n = (int)arg;

    ...
}

You can also look at posix examples on the web for pthread_create() examples.

Best regards,

    Janet

Hi Janet,

Does it need bios_start on at the end?

Ken

Hi Ken,

Yes, you still need to call BIOS_start() at the end of main().

Best regards,

    Janet

Can bios_start() be gated by a flag inside a while loop?

while()

{

xxxxx

if (bios_start_flag)

{

bios_start;

}

}

Hi Ken,
Is this while() loop in main()? You don't return from BIOS_start(). See the SYS/BIOS cdoc for BIOS_start() for a full description of the startup sequence. If you have Task enabled (which you would if you use pthread), calling BIOS_start() will invoke the Task scheduler and your highest priority task will start executing. You will never return back to main().

Best regards,
Janet

Hi Janet,

So it will have no while loop, all top level functions will be used as under pthread_create1 ,2 ..etc.
Is this correct?

Ken

Hi Ken,
Correct. You can also look at some of the BIOS examples, such as the Task mutex example. It doesn't use pthreads, but you can get an idea of how BIOS programs are structured.
Best regards,
Janet

Hi Janet,

Do you provide class training?
Can I attend some training class?

Ken

Hi Ken,
You might want to check out the SYS/BIOS online training here: processors.wiki.ti.com/.../BIOS_Online_Training
Best regards,
Janet

Hi Janet,

Thanks for the info.

I have read some of the online training material. I will read more.

For the pthread.h appoach, please verifiy the following

1. no while loop on top level

2. every function has to be run inside a thread

3. use thread_create for each thread open and execute.

4. add bios_start at the end

Ken

2.

Hi Ken,

The steps you describe above are correct for the main() function in BIOS, except I'm not sure exactly what you mean be "2. every function has to be run inside a thread".  There are some pthread functions that can only be run from threads, such as pthread_join().  The 'create' functions (e.g., pthread_create) can be called from main().  BIOS pthreads are built on top of BIOS Tasks, so the rules that apply to BIOS Tasks also apply to pthreads.  The link that I referred to in an earlier post, contains a table at the end of the page, listing the BIOS pthread APs and whether they can be called from main() or a BIOS task.

Best regards,

    Janet

Hi Janet,

Thanks for the verify.

When I say every function, it means the top level functions which will need to be called from thread_create.

Yes, I am aware of the thread_join. I will apply task rule and requirement.

Ken