* masked by the given mask and added to the given offset.
*/
static void startRetxmitTimer(uint16_t mask, uint16_t offset);
+ void clearState(uint8_t state);
+ bool hasState(uint8_t state);
+ void setState(uint8_t state);
- /* Indicates whether our client is congested */
- bool clientCongested = FALSE;
-
- /* Tracks our parent's congestion state. */
- bool parentCongested = FALSE;
-
- /* Threshold for congestion */
- uint8_t congestionThreshold;
-
- /* Keeps track of whether the routing layer is running; if not,
- * it will not send packets. */
- bool running = FALSE;
-
- /* Keeps track of whether the radio is on; no sense sending packets
- * if the radio is off. */
- bool radioOn = FALSE;
-
- /* Keeps track of whether an ack is pending on an outgoing packet,
- * so that the engine can work unreliably when the data-link layer
- * does not support acks. */
- bool ackPending = FALSE;
-
- /* Keeps track of whether the packet on the head of the queue
- * is being used, and control access to the data-link layer. Note
- * that CTP may be busy sending but there might be no transmission
- * scheduled to the link layer, because CTP is using its own layer 3
- * timers to prevent self-interference.*/
- bool sending = FALSE;
+ // CTP state variables.
+ enum {
+ QUEUE_CONGESTED = 0x1, // Need to set C bit?
+ ROUTING_ON = 0x2, // Forwarding running?
+ RADIO_ON = 0x4, // Radio is on?
+ ACK_PENDING = 0x8, // Have an ACK pending?
+ SENDING = 0x10 // Am sending a packet?
+ };
+ // Start with all states false
+ uint8_t forwardingState = 0;
+
/* Keep track of the last parent address we sent to, so that
unacked packets to an old parent are not incorrectly attributed
to a new parent. */
clientPtrs[i] = clientEntries + i;
dbg("Forwarder", "clientPtrs[%hhu] = %p\n", i, clientPtrs[i]);
}
- congestionThreshold = (call SendQueue.maxSize()) >> 1;
loopbackMsgPtr = &loopbackMsg;
lastParent = call AMPacket.address();
seqno = 0;
}
command error_t StdControl.start() {
- running = TRUE;
+ setState(ROUTING_ON);
return SUCCESS;
}
command error_t StdControl.stop() {
- running = FALSE;
+ clearState(ROUTING_ON);
return SUCCESS;
}
when it turns on, it then starts sending packets. */
event void RadioControl.startDone(error_t err) {
if (err == SUCCESS) {
- radioOn = TRUE;
+ setState(RADIO_ON);
if (!call SendQueue.empty()) {
+ dbg("FHangBug", "%s posted sendTask.\n", __FUNCTION__);
post sendTask();
}
}
* sending packets.
*/
event void UnicastNameFreeRouting.routeFound() {
+ dbg("FHangBug", "%s posted sendTask.\n", __FUNCTION__);
post sendTask();
}
event void RadioControl.stopDone(error_t err) {
if (err == SUCCESS) {
- radioOn = FALSE;
+ clearState(RADIO_ON);
}
}
ctp_data_header_t* hdr;
fe_queue_entry_t *qe;
dbg("Forwarder", "%s: sending packet from client %hhu: %x, len %hhu\n", __FUNCTION__, client, msg, len);
- if (!running) {return EOFF;}
+ if (!hasState(ROUTING_ON)) {return EOFF;}
if (len > call Send.maxPayloadLength[client]()) {return ESIZE;}
call Packet.setPayloadLength(msg, len);
qe->retries = MAX_RETRIES;
dbg("Forwarder", "%s: queue entry for %hhu is %hhu deep\n", __FUNCTION__, client, call SendQueue.size());
if (call SendQueue.enqueue(qe) == SUCCESS) {
- if (radioOn && !call RetxmitTimer.isRunning()) {
+ if (hasState(RADIO_ON) && !hasState(SENDING)) {
+ dbg("FHangBug", "%s posted sendTask.\n", __FUNCTION__);
post sendTask();
}
clientPtrs[client] = NULL;
*/
task void sendTask() {
+ uint16_t gradient;
dbg("Forwarder", "%s: Trying to send a packet. Queue size is %hhu.\n", __FUNCTION__, call SendQueue.size());
- if (sending) {
- dbg("Forwarder", "%s: busy, don't send.\n", __FUNCTION__);
- call CollectionDebug.logEvent(NET_C_FE_SEND_BUSY);
- return;
- }
- else if (call SendQueue.empty()) {
- dbg("Forwarder", "%s: queue empty, nothing to send.\n", __FUNCTION__);
+ if (hasState(SENDING) || call SendQueue.empty()) {
call CollectionDebug.logEvent(NET_C_FE_SENDQUEUE_EMPTY);
return;
}
- else if (!call RootControl.isRoot() &&
- !call UnicastNameFreeRouting.hasRoute()) {
- // Technically, this retry isn't necessary, as if a route
- // is found we'll get an event. But just in case such an event
- // is lost (e.g., a bug in the routing engine), we retry.
- // Otherwise the forwarder might hang indefinitely. As this test
- // doesn't require radio activity, the energy cost is minimal.
+ else if ((!call RootControl.isRoot() &&
+ !call UnicastNameFreeRouting.hasRoute()) ||
+ (call CtpInfo.getEtx(&gradient) != SUCCESS)) {
+ /* This code path is for when we don't have a valid next
+ * hop. We set a retry timer.
+ *
+ * Technically, this timer isn't necessary, as if a route
+ * is found we'll get an event. But just in case such an event
+ * is lost (e.g., a bug in the routing engine), we retry.
+ * Otherwise the forwarder might hang indefinitely. As this test
+ * doesn't require radio activity, the energy cost is minimal. */
dbg("Forwarder", "%s: no route, don't send, try again in %i.\n", __FUNCTION__, NO_ROUTE_RETRY);
call RetxmitTimer.startOneShot(NO_ROUTE_RETRY);
call CollectionDebug.logEvent(NET_C_FE_NO_ROUTE);
return;
}
else {
- // We can send a packet.
+ /* We can send a packet.
+ First check if it's a duplicate;
+ if not, try to send/forward. */
error_t subsendResult;
fe_queue_entry_t* qe = call SendQueue.head();
uint8_t payloadLen = call SubPacket.payloadLength(qe->msg);
am_addr_t dest = call UnicastNameFreeRouting.nextHop();
- uint16_t gradient;
- // Make sure we haven't sent this packet before with the same THL.
- // Note that this implies it's a forwarded packet, so we can
- // circumvent the client or forwarded branch for freeing
- // the buffer.
if (call SentCache.lookup(qe->msg)) {
+ /* This packet is a duplicate, so suppress it: free memory and
+ * send next packet. Duplicates are only possible for
+ * forwarded packets, so we can circumvent the client or
+ * forwarded branch for freeing the buffer. */
call CollectionDebug.logEvent(NET_C_FE_DUPLICATE_CACHE_AT_SEND);
call SendQueue.dequeue();
- if (call MessagePool.put(qe->msg) != SUCCESS)
- call CollectionDebug.logEvent(NET_C_FE_PUT_MSGPOOL_ERR);
- if (call QEntryPool.put(qe) != SUCCESS)
- call CollectionDebug.logEvent(NET_C_FE_PUT_QEPOOL_ERR);
+ if (call MessagePool.put(qe->msg) != SUCCESS)
+ call CollectionDebug.logEvent(NET_C_FE_PUT_MSGPOOL_ERR);
+ if (call QEntryPool.put(qe) != SUCCESS)
+ call CollectionDebug.logEvent(NET_C_FE_PUT_QEPOOL_ERR);
+
post sendTask();
return;
}
- /* If our current parent is not the same as the last parent
- we sent do, then reset the count of unacked packets: don't
- penalize a new parent for the failures of a prior one.*/
- // Give the high retry count, keeping this seems like a bad idea.
- // If you've reached MAX_RETRIES, you've cycled through a bunch of
- // parents. -pal
- /*
- if (dest != lastParent) {
- qe->retries = MAX_RETRIES;
- lastParent = dest;
- }
- */
-
- // We've decided we're going to send.
+
+ // Not a duplicate: we've decided we're going to send.
dbg("Forwarder", "Sending queue entry %p\n", qe);
- // If we're a root, copy the packet to a receive buffer and signal
- // receive. We have to copy because send expects the buffer back,
- // but receive might do a buffer swap.
+
if (call RootControl.isRoot()) {
+ /* Code path for roots: copy the packet and signal receive. */
collection_id_t collectid = getHeader(qe->msg)->type;
+ uint8_t* payload;
+ uint8_t payloadLength;
+
memcpy(loopbackMsgPtr, qe->msg, sizeof(message_t));
- ackPending = FALSE;
-
+
+ payload = call Packet.getPayload(loopbackMsgPtr, call Packet.payloadLength(loopbackMsgPtr));
+ payloadLength = call Packet.payloadLength(loopbackMsgPtr);
dbg("Forwarder", "%s: I'm a root, so loopback and signal receive.\n", __FUNCTION__);
loopbackMsgPtr = signal Receive.receive[collectid](loopbackMsgPtr,
- call Packet.getPayload(loopbackMsgPtr, call Packet.payloadLength(loopbackMsgPtr)),
- call Packet.payloadLength(loopbackMsgPtr));
+ payload,
+ payloadLength);
signal SubSend.sendDone(qe->msg, SUCCESS);
- return;
- }
-
- // Loop-detection functionality:
- if (call CtpInfo.getEtx(&gradient) != SUCCESS) {
- // If we have no metric, set our gradient conservatively so
- // that other nodes don't automatically drop our packets.
- gradient = 0;
- }
- call CtpPacket.setEtx(qe->msg, gradient);
-
- ackPending = (call PacketAcknowledgements.requestAck(qe->msg) == SUCCESS);
-
- // Make sure the ECN bit is not set.
- call CtpPacket.clearOption(qe->msg, CTP_OPT_ECN);
-
- subsendResult = call SubSend.send(dest, qe->msg, payloadLen);
- if (subsendResult == SUCCESS) {
- // Successfully submitted to the data-link layer.
- sending = TRUE;
- dbg("Forwarder", "%s: subsend succeeded with %p.\n", __FUNCTION__, qe->msg);
- if (qe->client < CLIENT_COUNT) {
- dbg("Forwarder", "%s: client packet.\n", __FUNCTION__);
- }
- else {
- dbg("Forwarder", "%s: forwarded packet.\n", __FUNCTION__);
- }
- return;
- }
- else if (subsendResult == EOFF) {
- // The radio has been turned off underneath us. Assume that
- // this is for the best. When the radio is turned back on, we'll
- // handle a startDone event and resume sending.
- radioOn = FALSE;
- dbg("Forwarder", "%s: subsend failed from EOFF.\n", __FUNCTION__);
- // send a debug message to the uart
- call CollectionDebug.logEvent(NET_C_FE_SUBSEND_OFF);
- }
- else if (subsendResult == EBUSY) {
- // This shouldn't happen, as we sit on top of a client and
- // control our own output; it means we're trying to
- // double-send (bug). This means we expect a sendDone, so just
- // wait for that: when the sendDone comes in, we'll try
- // sending this packet again.
- dbg("Forwarder", "%s: subsend failed from EBUSY.\n", __FUNCTION__);
- // send a debug message to the uart
- call CollectionDebug.logEvent(NET_C_FE_SUBSEND_BUSY);
}
- // The packet is too big: truncate it and retry.
- else if (subsendResult == ESIZE) {
- dbg("Forwarder", "%s: subsend failed from ESIZE: truncate packet.\n", __FUNCTION__);
- call Packet.setPayloadLength(qe->msg, call Packet.maxPayloadLength());
- post sendTask();
- call CollectionDebug.logEvent(NET_C_FE_SUBSEND_SIZE);
+ else {
+ /* The basic forwarding/sending case. */
+ call CtpPacket.setEtx(qe->msg, gradient);
+ call CtpPacket.clearOption(qe->msg, CTP_OPT_ECN | CTP_OPT_PULL);
+ if (call PacketAcknowledgements.requestAck(qe->msg) == SUCCESS) {
+ setState(ACK_PENDING);
+ }
+ if (hasState(QUEUE_CONGESTED)) {
+ call CtpPacket.setOption(qe->msg, CTP_OPT_ECN);
+ clearState(QUEUE_CONGESTED);
+ }
+
+ subsendResult = call SubSend.send(dest, qe->msg, payloadLen);
+ if (subsendResult == SUCCESS) {
+ // Successfully submitted to the data-link layer.
+ setState(SENDING);
+ dbg("Forwarder", "%s: subsend succeeded with %p.\n", __FUNCTION__, qe->msg);
+ return;
+ }
+ // The packet is too big: truncate it and retry.
+ else if (subsendResult == ESIZE) {
+ dbg("Forwarder", "%s: subsend failed from ESIZE: truncate packet.\n", __FUNCTION__);
+ call Packet.setPayloadLength(qe->msg, call Packet.maxPayloadLength());
+ post sendTask();
+ call CollectionDebug.logEvent(NET_C_FE_SUBSEND_SIZE);
+ }
+ else {
+ dbg("Forwarder", "%s: subsend failed from %i\n", __FUNCTION__, (int)subsendResult);
+ }
}
}
}
- void sendDoneBug() {
- // send a debug message to the uart
- call CollectionDebug.logEvent(NET_C_FE_BAD_SENDDONE);
- }
/*
* The second phase of a send operation; based on whether the transmission was
event void SubSend.sendDone(message_t* msg, error_t error) {
fe_queue_entry_t *qe = call SendQueue.head();
dbg("Forwarder", "%s to %hu and %hhu\n", __FUNCTION__, call AMPacket.destination(msg), error);
- if (qe == NULL || qe->msg != msg) {
- dbg("Forwarder", "%s: BUG: not our packet (%p != %p)!\n", __FUNCTION__, msg, qe->msg);
- sendDoneBug(); // Not our packet, something is very wrong...
- return;
- }
- else if (error != SUCCESS) {
- // Immediate retransmission is the worst thing to do.
+
+ if (error != SUCCESS) {
+ /* The radio wasn't able to send the packet: retransmit it. */
dbg("Forwarder", "%s: send failed\n", __FUNCTION__);
call CollectionDebug.logEventMsg(NET_C_FE_SENDDONE_FAIL,
call CollectionPacket.getSequenceNumber(msg),
call AMPacket.destination(msg));
startRetxmitTimer(SENDDONE_FAIL_WINDOW, SENDDONE_FAIL_OFFSET);
}
- else if (ackPending && !call PacketAcknowledgements.wasAcked(msg)) {
- // AckPending is for case when DL cannot support acks.
+ else if (hasState(ACK_PENDING) && !call PacketAcknowledgements.wasAcked(msg)) {
+ /* Retransmission for unacked packet. Might drop the packet. */
call LinkEstimator.txNoAck(call AMPacket.destination(msg));
call CtpInfo.recomputeRoutes();
if (--qe->retries) {
call AMPacket.destination(msg));
}
call SendQueue.dequeue();
- sending = FALSE;
+ clearState(SENDING);
startRetxmitTimer(SENDDONE_OK_WINDOW, SENDDONE_OK_OFFSET);
}
}
- else if (qe->client < CLIENT_COUNT) {
- ctp_data_header_t* hdr;
- uint8_t client = qe->client;
- dbg("Forwarder", "%s: our packet for client %hhu, remove %p from queue\n",
- __FUNCTION__, client, qe);
- call CollectionDebug.logEventMsg(NET_C_FE_SENT_MSG,
+ else {
+ /* Packet was acknowledged. Updated the link estimator,
+ free the buffer (pool or sendDone), start timer to
+ send next packet. */
+ call SendQueue.dequeue();
+ clearState(SENDING);
+ startRetxmitTimer(SENDDONE_OK_WINDOW, SENDDONE_OK_OFFSET);
+ call LinkEstimator.txAck(call AMPacket.destination(msg));
+
+ if (qe->client < CLIENT_COUNT) {
+ call CollectionDebug.logEventMsg(NET_C_FE_SENT_MSG,
call CollectionPacket.getSequenceNumber(msg),
call CollectionPacket.getOrigin(msg),
call AMPacket.destination(msg));
- call LinkEstimator.txAck(call AMPacket.destination(msg));
- clientPtrs[client] = qe;
- hdr = getHeader(qe->msg);
- call SendQueue.dequeue();
- signal Send.sendDone[client](msg, SUCCESS);
- sending = FALSE;
- startRetxmitTimer(SENDDONE_OK_WINDOW, SENDDONE_OK_OFFSET);
- }
- else if (call MessagePool.size() < call MessagePool.maxSize()) {
- // A successfully forwarded packet.
- dbg("Forwarder,Route", "%s: successfully forwarded packet (client: %hhu), message pool is %hhu/%hhu.\n", __FUNCTION__, qe->client, call MessagePool.size(), call MessagePool.maxSize());
- call CollectionDebug.logEventMsg(NET_C_FE_FWD_MSG,
+ signal Send.sendDone[qe->client](msg, SUCCESS);
+ dbg("Forwarder", "%s: our packet for client %hhu, remove %p from queue\n",
+ __FUNCTION__, client, qe);
+ clientPtrs[qe->client] = qe;
+ }
+ else if (call MessagePool.size() < call MessagePool.maxSize()) {
+ // A successfully forwarded packet.
+ dbg("Forwarder,Route", "%s: successfully forwarded packet (client: %hhu), message pool is %hhu/%hhu.\n", __FUNCTION__, qe->client, call MessagePool.size(), call MessagePool.maxSize());
+ call CollectionDebug.logEventMsg(NET_C_FE_FWD_MSG,
call CollectionPacket.getSequenceNumber(msg),
call CollectionPacket.getOrigin(msg),
call AMPacket.destination(msg));
- call LinkEstimator.txAck(call AMPacket.destination(msg));
- call SentCache.insert(qe->msg);
- call SendQueue.dequeue();
- if (call MessagePool.put(qe->msg) != SUCCESS)
- call CollectionDebug.logEvent(NET_C_FE_PUT_MSGPOOL_ERR);
- if (call QEntryPool.put(qe) != SUCCESS)
- call CollectionDebug.logEvent(NET_C_FE_PUT_QEPOOL_ERR);
- sending = FALSE;
- startRetxmitTimer(SENDDONE_OK_WINDOW, SENDDONE_OK_OFFSET);
- }
- else {
- dbg("Forwarder", "%s: BUG: we have a pool entry, but the pool is full, client is %hhu.\n", __FUNCTION__, qe->client);
- sendDoneBug(); // It's a forwarded packet, but there's no room the pool;
- // someone has double-stored a pointer somewhere and we have nowhere
- // to put this, so we have to leak it...
+ call SentCache.insert(qe->msg);
+ if (call MessagePool.put(qe->msg) != SUCCESS)
+ call CollectionDebug.logEvent(NET_C_FE_PUT_MSGPOOL_ERR);
+ if (call QEntryPool.put(qe) != SUCCESS)
+ call CollectionDebug.logEvent(NET_C_FE_PUT_QEPOOL_ERR);
+ }
+ else {
+ dbg("Forwarder", "%s: BUG: we have a pool entry, but the pool is full, client is %hhu.\n", __FUNCTION__, qe->client);
+ }
}
}
if (!call RetxmitTimer.isRunning()) {
// sendTask is only immediately posted if we don't detect a
// loop.
+ dbg("FHangBug", "%s: posted sendTask.\n", __FUNCTION__);
post sendTask();
}
}
event void RetxmitTimer.fired() {
- sending = FALSE;
+ clearState(SENDING);
+ dbg("FHangBug", "%s posted sendTask.\n", __FUNCTION__);
post sendTask();
}
}
+ void clearState(uint8_t state) {
+ forwardingState = forwardingState & ~state;
+ }
+ bool hasState(uint8_t state) {
+ return forwardingState & state;
+ }
+ void setState(uint8_t state) {
+ forwardingState = forwardingState | state;
+ }
+
/******** Defaults. **************/
default event void
projects / tinyos-2.x.git / commitdiff