int rtos_AddThreads (void(*task0)(void),void(*task1)(void),void(*task2)(void))
{
	//Using Circular Linked-List for chaining Threads
    tcbs[0].nextThread = &tcbs[1]; //Thread 0 points to Thread 1
    tcbs[1].nextThread = &tcbs[2]; //Thread 1 points to Thread 2
    tcbs[2].nextThread = &tcbs[0]; //Thread 2 points to Thread 0
    setInitialStack(0);//Set Software Stack for Thread 0
    stacks[0][STACKSIZE-2] = (uint32_t)(task0);//PC for Thread 0
    setInitialStack(1);//Set Software Stack for Thread 1
    stacks[1][STACKSIZE-2] = (uint32_t)(task1);//PC for Thread 1
    setInitialStack(2);//Set Software Stack for Thread 2
    stacks[2][STACKSIZE-2] = (uint32_t)(task2);//PC for Thread 2
    currentThread = &tcbs[0];//Thread 0 will run first
    return 1;
}
Exemple #2
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int OS_AddThread(void(*task)(void), unsigned long stackSize, unsigned long priority) {

  long status;
  int i;
  int index;

  status = StartCritical();

  if(NumThreads == 0) {
    // First thread no TCBs yet
    tcbs[0].next = &tcbs[0];
    tcbs[0].prev = &tcbs[0];
    Head = &tcbs[0];
    Tail = &tcbs[0];
    index = 0;
  } else {

    // Look for open spot in tcbs array
    for(i = 0; i < MAXTHREADS; i++) {
      if(tcbs[i].valid == INVALID) {
        index = i;
        i = MAXTHREADS; // Exit loop
      } else {
        index = -1; // Sentinel to detect no invalid spots
      }
    }

    if(index == -1) {
      EndCritical(status);
      return FAILURE; // No space in tcbs
    }

    tcbs[index].next = Head; // New tcb points to head
    tcbs[index].prev = Tail; // Point back to current tail
    (*Tail).next = &tcbs[index]; // Tail now points to new tcb
    Tail = &tcbs[index]; // New tcb becomes the tail
    (*Head).prev = &tcbs[index]; // Head now points backwards to new tcb
  }

  // Initilizing the stack for debugging
  setInitialStack(index);

  // Set PC for stack to point to function to run
  tcbs[index].stack[STACKSIZE - 2] = (long) (task);

  // Set inital values for sleep status and id
  tcbs[index].sleepState = 0;
  tcbs[index].priority = priority;
  tcbs[index].blockedState = '\0';
  tcbs[index].id = index;
  tcbs[index].valid = VALID;
  NumThreads++;

  EndCritical(status);

  return SUCCESS;
}