RTOS/TMS320F28035: State Machine and background loop with cpu timers

Tool/software: TI-RTOS

Hi,

In FOC example I know that we run mainISR in RAM which is interrupted with ADC but,
My questions :
what is background loop?
Why are 3 cpu timers (0/1/2) runed in this example? Do they count to special values?
What is “STATE-MACHINE SEQUENCING AND SYNCRONIZATION FOR SLOW BACKGROUND TASKS” ?
What is duty of these functions and pointers during mainISR execution ?

// State Machine function prototypes
//------------------------------------
// Alpha states
void A0(void);    //state A0
void B0(void);    //state B0
void C0(void);    //state C0

// A branch states
void A1(void);    //state A1
void A2(void);    //state A2
void A3(void);    //state A3

// B branch states
void B1(void);    //state B1
void B2(void);    //state B2
void B3(void);    //state B3

// C branch states
void C1(void);    //state C1
void C2(void);    //state C2
void C3(void);    //state C3

// Variable declarations
void (*Alpha_State_Ptr)(void);    // Base States pointer
void (*A_Task_Ptr)(void);        // State pointer A branch
void (*B_Task_Ptr)(void);        // State pointer B branch
void (*C_Task_Ptr)(void);        // State pointer C branch

just i found this pic in white paper about this topic :


Best Wishes,
Ali Karimi