SYSBIOS: Dynamically created task fails memory allocation for task stack

Andy Sifferman1

Part Number: SYSBIOS
Other Parts Discussed in Thread: 66AK2G12,

Hi,

I'm using:

66AK2G12
CCS 10.2.0
Processor SDK RTOS K2G 6.03.00.106, including PDK K2G 1.0.16
XDCtools 3.61.02.27
SYS/BIOS 6.76.03.01

In main() I am doing this:

int main(void)
{
    Task_Params task_params;
    Task_Handle task0 = NULL;
    Error_Block task0_eb;
    EDMA3_DRV_Handle edma_handle = NULL;

    // Initialize DMA driver
    edma_handle = DmaDriverInit();
    assert(edma_handle);

    //**** Create Draw Task ****

    Task_Params_init(&task_params);
    task_params.priority = 7;
    task_params.stackSize = 2048;

    // Pass DMA driver handle into the task
    task_params.arg0 = (uintptr_t) edma_handle;

    task0 = Task_create(DrawTask, &task_params, &task0_eb);
    assert(!Error_check(&task0_eb));    // FAILS THIS ASSERTION!!!

    BIOS_start();
    return (0);
}

On execution, the console prints the following error message:

[CortexA15] assertion "!Error_check(&task0_eb)" failed: file "../main_arm.cpp", line 339, function: int main()

Using the debugger, I stepped into the Task_create() function, and found that the problem occurs when the code tries to allocate memory for the 2048-byte task stack. Specifically, the sysbios kernel function Task_Instance_init() does this:

    /* deal with undefined Task_Params defaults */
    if (params->stackHeap == NULL) {
        tsk->stackHeap = Task_defaultStackHeap;
    }

but the variable Task_defaultStackHeap contains 0. Further down, Memory_alloc() is called:

    tsk->stack = (Char *)Memory_alloc(tsk->stackHeap, tsk->stackSize, align, eb);

but the first parameter, tsk->stackHeap, is NULL. I believe this causes Memory_alloc() to return with a null pointer (and an error in eb).

How do I solve this?

over 3 years ago

0 Aravind Batni over 2 years ago

TI__Expert 8885 points

Hi Andy,

Can you try providing the

1. Task stack pointer (stack variable) and

2. the appropriate size (stackSize) for the Task Create ()?

Please refer to below:

http://software-dl.ti.com/dsps/dsps_public_sw/sdo_sb/targetcontent/sysbios/6_50_00_10/exports/bios_6_50_00_10/docs/cdoc/ti/sysbios/knl/Task.html#per-instance_config_parameters

Example:

/* provide 16k Stack, this can be changed as per the application need */

#define APP_TSK_STACK_MAIN (16U * 1024U)

/* Test application stack */
static uint8_t gAppTskStackMain[APP_TSK_STACK_MAIN] __attribute__((aligned(32)));

TaskP_Params taskParams;
Error_Block eb;
TaskP_Params_init(&taskParams);

taskParams.stack = gAppTskStackMain;
taskParams.stacksize = sizeof (gAppTskStackMain);
taskParams.pErrBlk = &eb;

TaskP_create(App_Test_Task, &taskParams);

Thanks

+1 Andy Sifferman1 over 2 years ago in reply to Aravind Batni

Prodigy 200 points

I did the following:

#include "ti/osal/TaskP.h"
#include "assert.h"

void App_Test_Task(UArg a0, UArg a1)
{
}

#define APP_TSK_STACK_MAIN              (16U * 1024U)

/* Test application stack */
static uint8_t gAppTskStackMain[APP_TSK_STACK_MAIN] __attribute__((aligned(32)));

int main(void)
{
    TaskP_Params taskParams;
    Error_Block eb;
    TaskP_Params_init(&taskParams);

    taskParams.stack = gAppTskStackMain;
    taskParams.stacksize = sizeof (gAppTskStackMain);
    taskParams.pErrBlk = &eb;

    TaskP_Handle taskH = TaskP_create(App_Test_Task, &taskParams);
    assert(taskH);
}

The following error occurs during compile:

../main_arm.cpp:490:65: error: invalid conversion from 'void (*)(UArg, UArg) {aka void (*)(unsigned int, unsigned int)}' to 'void*' [-fpermissive]

I then tried this:

#include "ti/sysbios/knl/Task.h"
#include "assert.h"

void App_Test_Task(UArg a0, UArg a1)
{
}

#define APP_TSK_STACK_MAIN              (16U * 1024U)

/* Test application stack */
static uint8_t gAppTskStackMain[APP_TSK_STACK_MAIN] __attribute__((aligned(32)));

int main(void)
{
    Task_Params taskParams;
    Error_Block eb;
    Task_Params_init(&taskParams);

    taskParams.stack = gAppTskStackMain;
    taskParams.stackSize = sizeof (gAppTskStackMain);

    Task_Handle taskH = Task_create(App_Test_Task, &taskParams, &eb);
    assert(taskH);
}

This builds without error. On execution, Task_create() returns a valid handle.

Is this the solution you recommend? Most of the example programs I have seen did not need to provide a block of allocated memory to Task_create() (e.g. those in SPRUEX3V).

0 Aravind Batni over 2 years ago

TI__Expert 8885 points

Andy Sifferman1 said:
found that the problem occurs when the code tries to allocate memory for the 2048-byte task stack.

Hi Andy,

Glad that you now have resolved the issue. I recommended the solution I proposed earlier to make sure you have memory reserved for the task stack. If you do not provide the memory it would be from the heap.

The approach I suggested makes sure there is sufficient memory for application task stack.

Thanks

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SYSBIOS: Dynamically created task fails memory allocation for task stack