[Tinyos-devel] value of error for Send.sendDone from CtpForwardingEngineP.nc

[Omprakash Gnawali]

An excerpt from Send.nc:

  /**
    * Signaled in response to an accepted send request. <tt>msg</tt>
    * is the sent buffer, and <tt>error</tt> indicates whether the
    * send was succesful, and if not, the cause of the failure.
    *
    * @param 'message_t* ONE msg'   the message which was requested to send
    * @param error SUCCESS if it was transmitted successfully, FAIL if
    *              it was not, ECANCEL if it was cancelled via <tt>cancel</tt>
    */
  event void sendDone(message_t* msg, error_t error);

This comment and what CTP forwarding engine does do not agree. CTP
forwarding engine will return FAIL if it exhausts the number of
retransmissions before receiving an ack:

        // <Max retries reached, dropping packet: first case is a client packet,
        // second case is a forwarded packet. Memory management for the
        // two is different.
...
          signal Send.sendDone[qe->client](msg, FAIL);

It is possible that the packet was transmitted successfully. Should
SUCCESS/FAIL value be tied to the acks? I think not.

- om_p