[Tinyos-devel] Tossim - node receives packet althought sending other

[Philip Levis]

On Feb 12, 2009, at 8:05 AM, Lumir Honus wrote:

> I'm sending a patch, I think it fix the problem. Node is now not able
> to receive packet while sending.
> I don't know whether is possible to send attachments directly to
> mailing list, so I dump patch also here.
>
> -----------------------------------------
>
> *** /opt/tinyos-2.1.0/tos/lib/tossim/CpmModelC.nc	2009-02-12
> 16:54:15.000000000 +0100
> --- Desktop/cvstos/tinyos-2.x/tos/lib/tossim/CpmModelC.nc	2007-09-04
> 19:19:22.000000000 +0200
> ***************
> *** 50,56 ****
>     message_t* outgoing; // If I'm sending, this is my outgoing packet
>     bool requestAck;
>     bool receiving = 0;  // Whether or not I think I'm receiving a  
> packet
> -   bool sending = 0;    // Whether or not I think I'm sending a  
> packet
>     struct receive_message;
>     typedef struct receive_message receive_message_t;
>
> --- 50,55 ----
> ***************
> *** 72,78 ****
>     receive_message_t* allocate_receive_message();
>     void free_receive_message(receive_message_t* msg);
>     sim_event_t* allocate_receive_event(sim_time_t t,  
> receive_message_t* m);
> -   sim_event_t* allocate_sending_finished_event(sim_time_t endTime);
>
>     bool shouldReceive(double SNR);
>     bool checkReceive(receive_message_t* msg);
> --- 71,76 ----
> ***************
> *** 383,391 ****
>       if (!sim_mote_is_on(sim_node())) {
>         dbg("CpmModelC", "Lost packet from %i due to %i being off\n",
> source, sim_node());
>         rcv->lost = 1;
> -     }else if (sending){
> -       dbg("CpmModelC", "Node can not receive it sends another  
> packet.\n");
> -       rcv->lost = 1;
>       }
>       else if (!shouldReceive(power - noiseStr)) {
>         dbg("CpmModelC,SNRLoss", "Lost packet from %i to %i due to SNR
> being too low (%i)\n", source, sim_node(), (int)(power - noiseStr));
> --- 381,386 ----
> ***************
> *** 414,424 ****
>       sim_queue_insert(evt);
>
>     }
> -
> -   // Node finished sending packet
> -   void sim_sending_finished_handle(sim_event_t* evt) {
> -       sending = 0;
> -   }
>
>     void sim_gain_put(int dest, message_t* msg, sim_time_t endTime,
> bool receive, double power, double reversePower) {
>       int prevNode = sim_node();
> --- 409,414 ----
> ***************
> *** 430,443 ****
>
>     command void Model.putOnAirTo(int dest, message_t* msg, bool ack,
> sim_time_t endTime, double power, double reversePower) {
>       gain_entry_t* neighborEntry = sim_gain_first(sim_node());
> -     sim_event_t* evt;
>       requestAck = ack;
>       outgoing = msg;
> -     // Node is busy until does not send the whole packet
> -     evt = allocate_sending_finished_event(endTime);
> -     sim_queue_insert(evt);
> -     sending = 1;
> -
>       dbg("CpmModelC", "Node %i transmitting to %i, finishes at
> %llu.\n", sim_node(), dest, endTime);
>
>       while (neighborEntry != NULL) {
> --- 420,427 ----
> ***************
> *** 464,479 ****
>      return evt;
>    }
>
> -  sim_event_t* allocate_sending_finished_event(sim_time_t endTime)
> -  {
> -    sim_event_t* evt = (sim_event_t*)malloc(sizeof(sim_event_t));
> -    evt->mote = sim_node();
> -    evt->time = endTime;
> -    evt->handle = sim_sending_finished_handle;
> -    evt->cleanup = sim_queue_cleanup_event;
> -    return evt;
> -  }
> -
>    receive_message_t* allocate_receive_message() {
>      return (receive_message_t*)malloc(sizeof(receive_message_t));
>    }
> --- 448,453 ----

Sorry it took so long, but this bug has now been fixed in the tree.  
It turns out correctly catching all the cases was a little more  
complex than the above patch. There is no longer a case where a node  
can receive a packet while transmitting.

Phil