gcc/testsuite/gnat.dg/sync1.adb

   1 --  { dg-do compile }
   2 package body sync1 is
   3    protected body Chopstick is
   4
   5      entry Pick_Up when not Busy is
   6      begin
   7         Busy := True;
   8      end Pick_Up;
   9
  10      procedure Put_Down is
  11      begin
  12         Busy := False;
  13      end Put_Down;
  14    end Chopstick;
  15 end sync1;