A Question About Execution Schedule

[MaGuoWei]

Hi,guysThere are some codes in scheduleForExecution Function in Execution.java:
   1.  SlotAllocationFuture future = scheduler.scheduleQueued(toSchedule);   2. 
         future.setFutureAction(new SlotAllocationFutureAction() {......})
When scheduler  finds some slot between line1 and line 2 the scheduler can't 
get the future action.
Please let me know If I am wrong .
Thanks.