code: public boolean tryMarkSlotActive(JobID jobId, AllocationID allocationId) {
  		TaskSlot taskSlot = getTaskSlot(allocationId);
  
  		if (taskSlot != null && taskSlot.isAllocated(jobId, allocationId)) {
  			return taskSlot.markActive();
  		} else {
  			return false;
  		}
  	}
docs: Try to mark the specified slot as active if it has been allocated by the given job.
  
  @param jobId of the allocated slot
  @param allocationId identifying the allocation
  @return True if the task slot could be marked active.