CCS: [CC3220SD/SDK4.10] Create detached pthread will keep occupying heap memory?

Eric Hsieh3

Intellectual 780 points

Tool/software: Code Composer Studio

Hi TI,

Following is my sample code to create detached pthread, why it keep occupying heap memory when it finished its task?

Please help. Thanks.

pthread_t create_thread(const int priority, callback cb, void *args)

{

pthread_t pid = NULL;

pthread_attr_t attrs;

struct sched_param schedule;

do {

pthread_attr_init(&attrs);

schedule.sched_priority = priority;

pthread_attr_setschedparam(&attrs, &schedule);

if (pthread_attr_setdetachstate(&attrs, PTHREAD_CREATE_DETACHED) != 0) {

error("fail to setdetachstate\n");

break;

}

if (pthread_attr_setstacksize(&attrs, 4096) != 0) {

error("fail to setstacksize\n");

break;

}

if (pthread_create(&pid, &attrs, cb, args) != 0) {

error("fail to create thread\n");

break;

}

} while (false);

pthread_attr_destroy(&attrs);

return pid;

}

over 5 years ago

0 ToddMullanix over 5 years ago

TI__Guru* 96960 points

Hi Eric,

How is the thread terminating? Is it being deleted or just falling out of the thread entry function? What is the underlying OS...FreeRTOS or TI-RTOS?

Todd

0 Eric Hsieh3 over 5 years ago in reply to ToddMullanix

Intellectual 780 points

Hi ToddMullanix,

I am using TI-RTOS. And following code is how the thread terminate. Thanks.

void *my_thread_task(void *args)
{
    info("enter thread\n");
    pthread_exit(NULL);
    return NULL;
}

0 ToddMullanix over 5 years ago in reply to Eric Hsieh3

TI__Guru* 96960 points

Hi Eric,

The pthread memory is cleaned up when Idle runs. Take a look in Tools->Runtime Object View->Idle and you can see the function (_pthread_cleanupFxn) that will do the actual deletion of the pthread (and underlying Task).

Todd

0 Eric Hsieh3 over 5 years ago in reply to ToddMullanix

Intellectual 780 points

Hi ToddMullanix,

Yes, I can see _pthread_cleanupFxn running when I tested my code.

And at the same time, I checked the heap when pthread finished its task.

Check again.

Heap continue occupying by pthread. How to fix this issue? Any wrong with my sample code? Thanks.

0 ToddMullanix over 5 years ago in reply to Eric Hsieh3

TI__Guru* 96960 points

Hi Eric,

Can you put a breakpoint in _pthread_cleanupFxn and confirm it is being hit? If Idle never runs, the memory will not be cleaned up.

Another thing you can try is to use HeapTrack to see who (and when) is allocating memory. Take a look at https://training.ti.com/debugging-common-application-issues-ti-rtos. It covers how to use HeapTrack in the last section. There is a pdf on the page in case you don't want to watch the video.

Note: for the SimpleLink SDK, the debug kernel project enables HeapTrack. Take a look at the SimpleLink SDK's User Guide to see how to use the debug kernel project (instead of the default release kernel project).

Todd

0 Eric Hsieh3 over 5 years ago in reply to ToddMullanix

Intellectual 780 points

Hi ToddMullanix,

Set up a breakpoint at _pthread_cleanupFxn, looks like it never to be called. Why? Thanks.

0 ToddMullanix over 5 years ago in reply to Eric Hsieh3

TI__Guru* 96960 points

Eric,

Take a look at ROV->Task Detailed. Is there a task that never gives up the processor and thus never allows Idle to run?

Todd

0 Eric Hsieh3 over 5 years ago in reply to ToddMullanix

Intellectual 780 points

Hi ToddMullanix,

Something interesting, before running services_thread, I can observe _pthread_cleanupFxn was called.

I double check the code of services_thread, it always blocked at select function for HTTP connection.

More tips to debug? Thanks.

0 Eric Hsieh3 over 5 years ago in reply to Eric Hsieh3

Intellectual 780 points

Hi ToddMullanix,

Thanks. I figure out the problem. Because we use UART_readPolling which it keep thread running on the background.

Now, we use UART_read/write instead of Polling, anything looks good. Thanks.

Code Composer Studio™︎

Code Composer Studio forum

CCS: [CC3220SD/SDK4.10] Create detached pthread will keep occupying heap memory?