RTOS/OMAPL138C6748: Task is not switching with using sprintf()

Andy Fung

Intellectual 875 points

Part Number: OMAPL138C6748

Tool/software: TI-RTOS

My dev board is OMAP-L138/C6748 LC Dev Kit.

Tried to run Example 3-1 Time-Slice Scheduling in the document SPRUEX3Q—June 2016.

In the hiPriTask while loop, I added the code as following:

if(TRUE == Semaphore_pend(sem, BIOS_WAIT_FOREVER))
{

for(i=0;i<100;i++)
{
sprintf(tempStr, "%.6f,", fArray[i]);

}

System_printf("TestFloatArray() is done!\n");
}

hiPriTask is ran once and never switch back again. If I remove sprintf(), the task switching is running normally.

Please advise. Thanks.

over 7 years ago

Yordan Kovachev over 7 years ago

TI__Guru**** 161600 points

Hi Andy,

I've notified the RTOS team. Their feedback will be posted here.

Best Regards,
Yordan

Rahul Prabhu over 7 years ago

TI__Guru** 114410 points

Have you also tried increasing the heap size? C I/O routines such as sprintf tend to use a lot of heap as well, and having insufficient heap size is usually a common source of these routines failing.
processors.wiki.ti.com/.../Tips_for_using_printf

Regards,
Rahul

Andy Fung over 7 years ago in reply to Rahul Prabhu

Intellectual 875 points

In the .cfg file, I set the heap and stack size as following:

Program.stack = 0x5000;

Program.heap = 0x5000;

Task.defaultStackSection = ".far:taskStackSection";
Memory.defaultHeapSize = 0x5000;

In tthe code, I set the stack size to 8k:

taskParams.stackSize = 8192;

The problem is still exist.

Vincent W. over 7 years ago in reply to Andy Fung

TI__Genius 12865 points

Hi Andy,

Is the size of tempStr large enough to hold the result? I am just wondering if memory is corrupted as a result of the output buffer being too small.

Best regards,
Vincent

Andy Fung over 7 years ago in reply to Vincent W.

Intellectual 875 points

Hello Vincent,

I defined tempStr as

char tempStr[100];

The size should not be a problem.

I found that I have to set "Level of printf/scanf support required" to minimal instead of full so the example run properly. Is there any way that sprintf can support "full" formal?

Thanks,

Vincent W. over 7 years ago in reply to Andy Fung

TI__Genius 12865 points

Hi Andy,

Which version of the compiler are you using? Does sprintf return correctly in other contexts of this program (i.e. main(), other Tasks)? Any warnings regarding sprintf when you build the code?

I know you have increased the system stack/heap sizes and Task Stack size already, but as a sanity check it probably wouldn't hurt to bring up the ROV (Tools->RTOS Object View) to check out how much stack and heap you are using when sprintf fails to return.

Also note that there is also an sprintf equivalent named System_sprintf() in the XDC runtime that you can use, given you are already using the System module: rtsc.eclipse.org/.../System.html. You may want to check if it works better for you.

Best regards,
Vincent

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RTOS/OMAPL138C6748: Task is not switching with using sprintf()