test_back_and_forth Subroutine

   subroutine test_back_and_forth(this)
      use pFIO_ArrayReferenceMod
      class (MpiTestMethod), intent(inout) :: this

      integer :: comm
      type (MpiSocket) :: s1, s2
      class (AbstractMessage), allocatable :: message
      type (ProtocolParser), target :: parser

      integer :: rank

      type (ArrayReference) :: ref
      integer, target :: fake_data

      enum, bind(c)
         enumerator :: collection1, collection2
      end enum
      enum, bind(c)
         enumerator :: request_A, request_B, request_C
      end enum
      
      comm = this%getMpiCommunicator()
      parser = ProtocolParser()

      rank = this%getProcessRank()

      ref = ArrayReference(fake_data)
      
      select case (rank)
      case (0) ! server
         s1 = MpiSocket(comm, 2, parser)
         s2 = MpiSocket(comm, 3, parser)

         allocate(message, source=s1%receive())
         @assertEqual(PrefetchData_ID, message%get_type_id())
         select type (message)
         type is (PrefetchDataMessage)
            @assertEqual(collection1,  message%collection_id)
         end select
         call s1%send(IdMessage(request_B))

         deallocate(message)
         allocate(message, source=s2%receive())
         @assertEqual(PrefetchData_ID, message%get_type_id())
         select type (message)
         type is (PrefetchDataMessage)
            @assertEqual(collection2,  message%collection_id)
         end select
         call s2%send(IdMessage(REQUEST_C))

         deallocate(message)
         allocate(message, source=s1%receive())
         @assertEqual(TERMINATE_ID, message%get_type_id())
         deallocate(message)
         allocate(message, source=s2%receive())
         @assertEqual(TERMINATE_ID, message%get_type_id())

      case (1)
         s1 = MpiSocket(comm, 4, parser)
         allocate(message, source=s1%receive())
         @assertEqual(PrefetchData_ID, message%get_type_id())
         select type (message)
         type is (PrefetchDataMessage)
            @assertEqual(collection1,  message%collection_id)
         end select
         call s1%send(IdMessage(request_A))

         deallocate(message)
         allocate(message, source=s1%receive())
         @assertEqual(TERMINATE_ID, message%get_type_id())

      case (2)
         s1 = MpiSocket(comm, 0, parser)
         !call s1%send(PrefetchDataMessage(1, collection1,'foo','u', ref, start=[]))
         call s1%send(PrefetchDataMessage(1, collection1,'foo','u', ref))
         allocate(message, source=s1%receive())
         @assertEqual(ID_ID, message%get_type_id())
         select type (message)
         type is (IdMessage)
            @assertEqual(request_B, message%id)
         end select
         call s1%send(TerminateMessage())

      case (3)
         s1 = MpiSocket(comm, 0, parser)
         !call s1%send(PrefetchDataMessage(2, collection2,'foo','v', ref, start=[]))
         call s1%send(PrefetchDataMessage(2, collection2,'foo','v', ref))
         allocate(message, source=s1%receive())
         @assertEqual(ID_ID, message%get_type_id())
         select type (message)
         type is (IdMessage)
            @assertEqual(request_C, message%id)
         end select
         call s1%send(TerminateMessage())

      case (4)
         s1 = MpiSocket(comm, 1, parser)
         !call s1%send(PrefetchDataMessage(3, collection1,'foo','w', ref, start=[]))
         call s1%send(PrefetchDataMessage(3, collection1,'foo','w', ref))
         allocate(message, source=s1%receive())
         @assertEqual(ID_ID, message%get_type_id())
         select type (message)
         type is (IdMessage)
            @assertEqual(request_A, message%id)
         end select
         call s1%send(TerminateMessage())
      end select

   end subroutine test_back_and_forth