soft reset nios won't deallocate memory

The following is a simplified version of my main function. It works fine until I asserted Nios' soft reset input several times. After asserting Nios' reset input several times, there was not enough memory to get allocated.

I tried to put free() function right before return(1) at the end of main function and it didn't do anything.

Any suggestion?

Thanks.

------------------------------------------------------------

int main()

{

ITEMS *my_items;

int command;

if ((my_items = (ITEMS *) malloc(sizeof(ITEMS) * MAX_ITEMS)) == NULL) {

printf("failed to allocate memory\r\n");

exit(-1);

}

// tight loop to wait user's input to do something with ITEMS

while (1)

{

command = IORD_BLA_AVALON_COMMAND (BLA_0_BASE));

switch (command)

{

case 1: set (my_items); break;

case 2: save (my_items); break;

case 3: read (my_items); break;

default: break;

}

}

return (1);

}