Are Queue elements placed on heap or system stack?

My target is an OMAPL138

Tools:

CCS version = 5.1.0

TI compiler = 7.3.1

SYSBIOS = 6.33.1.25

XDCtools = 3.23.0.32

Code snippets

#include <ti/sysbios/BIOS.h>

#include <ti/sysbios/knl/Queue.h>

Queue_Handle m_dataQueHandle;

typedef struct

{

Queue_Elem _elem;

uint32_t timeStamp;

uint16_t stepNumber;

uint16_t numberOfDataSamples;

int32_t acValue[500];

int32_t dcValue[500];

uint16_t lightIntensity[500];

}detectorDataType;

void myInitFunction()

{

m_dataQueHandle = Queue_create(NULL, NULL);

}

void mySwiFxn()

{

detectorDataType foo;

/** enqueue test data **/

int i;

foo.timeStamp = 1;

foo.stepNumber = 1;

foo.numberOfDataSamples = 1;

for (i = 0; i < 500; i++)

{

foo.acValue[i] = i;

foo.dcValue[i] = i;

foo.lightIntensity[i] = i;

}

Queue_put(m_dataQueHandle, &foo._elem);

} 

void myProcessingFxn()

{

detectorDataType* foo2;

foo2 = Queue_get(m_dataQueHandle);

}

Here is what I'm seeing.  During mySwiFxn() I try to put foo into the queue.  I can see the contents of foo on the system stack, which I would expect.  I assume the call to Queue_put() will copy the contents of foo to the heap, but I suspect this is not happening.  Later when myProcessingFxn() calls Queue_get(), foo2 points to the system stack where foo from mySwiFxn resided.  That looks like incorrect behavior to me.

I assumed the queue will allocate and free memory from the heap, is this correct?

Thanks in advance for your help!