1. -- 
  2. -- Uwe R. Zimmer, Australia, 2013 
  3. -- 
  4.  
  5. package body Queue_Pack_Protected is 
  6.  
  7.    protected body Protected_Queue is 
  8.  
  9.       entry Enqueue (Item : Element) when not Is_Full is 
  10.  
  11.       begin 
  12.          Queue.Elements (Queue.Free) := Item; 
  13.          Queue.Free     := Queue.Free + 1; 
  14.          Queue.Is_Empty := False; 
  15.       end Enqueue; 
  16.  
  17.       entry Dequeue (Item : out Element) when not Is_Empty is 
  18.  
  19.       begin 
  20.          Item      := Queue.Elements (Queue.Top); 
  21.          Queue.Top := Queue.Top + 1; 
  22.          Queue.Is_Empty := Queue.Top = Queue.Free; 
  23.       end Dequeue; 
  24.  
  25.       function Is_Empty return Boolean is 
  26.         (Queue.Is_Empty); 
  27.  
  28.       function Is_Full return Boolean is 
  29.         (not Queue.Is_Empty and then Queue.Top = Queue.Free); 
  30.  
  31.    end Protected_Queue; 
  32. end Queue_Pack_Protected;