anchor.diff:  %     ,t_sendfile_hdtl
        ,t_sendfile_partial
        ,t_sendfile_offset
  +     ,t_sendfile_sendafter
  +     ,t_sendfile_recvafter
  +     ,t_sendfile_sendduring
  +     ,t_sendfile_recvduring
       ].
   %    [t_sendfile_big].
   %    [t_sendfile_small].
  
positive.code: 	 t_fdopen/1, t_implicit_inet6/1,
  	 t_sendfile_small/1, t_sendfile_big/1,
  	 t_sendfile_hdtl/1, t_sendfile_partial/1,
  	 t_sendfile_offset/1]).
  
  -export([sendfile_server/2]).
  
  
negative.code: 	       end,
      ok = sendfile_send(SendTl).
  
  t_sendfile_sendafter(Config) ->
      Filename = proplists:get_value(small_file, Config),
  
      Send = fun(Sock) ->
  		   {Size, Data} = sendfile_file_info(Filename),
  		   {ok, Size} = gen_tcp:sendfile(Filename, Sock),
  		   ok = gen_tcp:send(Sock, <<2>>),
  		   <<Data/binary,2>>
  	   end,
  
      ok = sendfile_send(Send).
  
  t_sendfile_recvafter(Config) ->
      Filename = proplists:get_value(small_file, Config),
  
      Send = fun(Sock) ->
  		   {Size, Data} = sendfile_file_info(Filename),
  		   {ok, Size} = gen_tcp:sendfile(Filename, Sock),
  		   ok = gen_tcp:send(Sock, <<1>>),
  		   {ok,<<1>>} = gen_tcp:recv(Sock, 1),
  		   <<Data/binary,1>>
  	   end,
  
      ok = sendfile_send(Send).
  
  t_sendfile_sendduring(Config) ->
      Filename = proplists:get_value(big_file, Config),
  
      Send = fun(Sock) ->
  		   {ok, #file_info{size = Size}} =
  		       file:read_file_info(Filename),
  		   spawn_link(fun() ->
  				      timer:sleep(10),
  				      ok = gen_tcp:send(Sock, <<2>>)
  			      end),
  		   {ok, Size} = gen_tcp:sendfile(Filename, Sock),
  		   Size+1
  	   end,
  
      ok = sendfile_send("localhost", Send, 0).
  
  t_sendfile_recvduring(Config) ->
      Filename = proplists:get_value(big_file, Config),
  
      Send = fun(Sock) ->
  		   {ok, #file_info{size = Size}} =
  		       file:read_file_info(Filename),
  		   spawn_link(fun() ->
  				      timer:sleep(10),
  				      ok = gen_tcp:send(Sock, <<1>>),
  				      {ok,<<1>>} = gen_tcp:recv(Sock, 1)
  			      end),
  		   {ok, Size} = gen_tcp:sendfile(Filename, Sock),
  		   timer:sleep(1000),
  		   Size+1
  	   end,
  
      ok = sendfile_send("localhost", Send, 0).
  
  %% TODO: consolidate tests and reduce code
  sendfile_send(Send) ->
  