(a)
java.lang.Object 
              javax.realtime.AsyncEvent 
                    javax.realtime.Timer 
                           javax.realtime.OneShotTimer 
                           javax.realtime.PeriodicTimer 
              javax.realtime.AsyncEventHandler 
                    javax.realtime.BoundAsyncEventHandler 
              javax.realtime.Clock 
              javax.realtime.GarbageCollector 
              javax.realtime.HiResTime 
                    javax.realtime.AbsoluteTime 
                    javax.realtime.RelativeTime 
              javax.realtime.MemoryArea 
                    javax.realtime.ImmortalMemory 
                    javax.realtime.ImmortalPhysicalMemory 
                    javax.realtime.ScopedMemory 
                           javax.realtime.CTMemory 
                           javax.realtime.ScopedPhysicalMemory 
                           javax.realtime.VTMemory 
              javax.realtime.MemoryParameters 
              javax.realtime.MonitorControl 
                    javax.realtime.PriorityCeilingEmulation 
                    javax.realtime.PriorityInheritance 
              javax.realtime.PhysicalMemoryFactory 
              javax.realtime.PosixSignalHandler 
              javax.realtime.RawMemoryAccess 
              javax.realtime.RealtimeSystem 
              javax.realtime.Scheduler 
              javax.realtime.SchedulingParameters 
                    javax.realtime.DDMParameters 
                    javax.realtime.DDMSubtaskParameters 
                    javax.realtime.PeriodicParameters 
                    javax.realtime.PriorityParameters 
              java.lang.Thread 
                    javax.realtime.RealtimeThread 
                           javax.realtime.NoHeapRealtimeThread 
              java.lang.Throwable 
                    java.lang.Error 
                           javax.realtime.MemoryAccessError 
                           javax.realtime.ThrowBoundaryError 
                    java.lang.Exception 
                           java.lang.InterruptedException 
                                  javax.realtime.AsynchronouslyInterruptedException 
                                        javax.realtime.Timed 
                           javax.realtime.MemoryScopeException 
                           javax.realtime.OffsetOutOfBoundsException 
                           javax.realtime.ResourceLimitException 
                                  javax.realtime.AdmissionControlException 
                           java.lang.RuntimeException 
                                  javax.realtime.ThrowBoundaryException 
                           javax.realtime.SizeOutOfBoundsException 
              javax.realtime.WaitFreeDequeue 
              javax.realtime.WaitFreeReadQueue 
              javax.realtime.WaitFreeWriteQueue 

(b)
       javax.realtime.Interruptible 
       javax.realtime.Schedulable 

Figure 1: (a) Class hierarchy; (b) interface hierarchy.