Create a new task and add it to the list of tasks that are ready to run. Internally, within the FreeRTOS implementation, tasks use two blocks of memory. The first block is used to hold the task's data structures. The second block is used by the task as its stack. If a task is created using xTaskCreate() then both blocks of memory are automatically dynamically allocated inside the xTaskCreate() function. (see https://www.FreeRTOS.org/a00111.html). If a task is created using xTaskCreateStatic() then the application writer must provide the required memory. xTaskCreateStatic() therefore allows a task to be created without using any dynamic memory allocation. Example usage:
{c}
// Dimensions the buffer that the task being created will use as its stack.
// NOTE: This is the number of bytes the stack will hold, not the number of
// words as found in vanilla FreeRTOS.
#define STACK_SIZE 200
// Structure that will hold the TCB of the task being created.
StaticTask_t xTaskBuffer;
// Buffer that the task being created will use as its stack. Note this is
// an array of StackType_t variables. The size of StackType_t is dependent on
// the RTOS port.
StackType_t xStack[ STACK_SIZE ];
// Function that implements the task being created.
void vTaskCode( void * pvParameters )
{
// The parameter value is expected to be 1 as 1 is passed in the
// pvParameters value in the call to xTaskCreateStatic().
configASSERT( ( uint32_t ) pvParameters == 1UL );
for( ;; )
{
// Task code goes here.
}
}
// Function that creates a task.
void vOtherFunction( void )
{
TaskHandle_t xHandle = NULL;
// Create the task without using any dynamic memory allocation.
xHandle = xTaskCreateStatic(
vTaskCode, // Function that implements the task.
"NAME", // Text name for the task.
STACK_SIZE, // Stack size in bytes.
( void * ) 1, // Parameter passed into the task.
tskIDLE_PRIORITY,// Priority at which the task is created.
xStack, // Array to use as the task's stack.
&xTaskBuffer ); // Variable to hold the task's data structure.
// puxStackBuffer and pxTaskBuffer were not NULL, so the task will have
// been created, and xHandle will be the task's handle. Use the handle
// to suspend the task.
vTaskSuspend( xHandle );
}