+/*
+ * "Copyright (c) 2008 The Regents of the University of California.
+ * All rights reserved."
+ *
+ * Permission to use, copy, modify, and distribute this software and its
+ * documentation for any purpose, without fee, and without written agreement is
+ * hereby granted, provided that the above copyright notice, the following
+ * two paragraphs and the author appear in all copies of this software.
+ *
+ * IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
+ * OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF
+ * CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS."
+ *
+ */
+/*
+ * Copyright (c) 2005-2006 Rincon Research Corporation
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ * - Neither the name of the Rincon Research Corporation nor the names of
+ * its contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * RINCON RESEARCH OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE
+ */
+
+/**
+ * Reliable Packet Link Functionality
+ * @author David Moss
+ * @author Jon Wyant
+ * @author Miklos Maroti
+ */
+
+#include <PacketLinkLayer.h>
+
+module PacketLinkLayerP {
+ provides {
+ interface Send;
+ interface PacketLink;
+ }
+
+ uses {
+ interface Send as SubSend;
+ interface PacketAcknowledgements;
+ interface Timer<TMilli> as DelayTimer;
+ interface PacketData<packet_link_metadata_t>;
+ }
+}
+
+implementation {
+
+ /** The message currently being sent */
+ message_t *currentSendMsg;
+
+ /** Length of the current send message */
+ uint8_t currentSendLen;
+
+ /** The length of the current send message */
+ uint16_t totalRetries;
+
+ /***************** Prototypes ***************/
+
+ task void send();
+ void signalDone(error_t error);
+
+
+ /***************** PacketLink Commands ***************/
+ /**
+ * Set the maximum number of times attempt message delivery
+ * Default is 0
+ * @param msg
+ * @param maxRetries the maximum number of attempts to deliver
+ * the message
+ */
+ command void PacketLink.setRetries(message_t *msg, uint16_t maxRetries) {
+ (call PacketData.getData(msg))->maxRetries = maxRetries;
+ }
+
+ /**
+ * Set a delay between each retry attempt
+ * @param msg
+ * @param retryDelay the delay betweeen retry attempts, in milliseconds
+ */
+ command void PacketLink.setRetryDelay(message_t *msg, uint16_t retryDelay) {
+ (call PacketData.getData(msg))->retryDelay = retryDelay;
+ }
+
+ /**
+ * @return the maximum number of retry attempts for this message
+ */
+ command uint16_t PacketLink.getRetries(message_t *msg) {
+ return (call PacketData.getData(msg))->maxRetries;
+ }
+
+ /**
+ * @return the delay between retry attempts in ms for this message
+ */
+ command uint16_t PacketLink.getRetryDelay(message_t *msg) {
+ return (call PacketData.getData(msg))->retryDelay;
+ }
+
+ /**
+ * @return TRUE if the message was delivered.
+ */
+ command bool PacketLink.wasDelivered(message_t *msg) {
+ return call PacketAcknowledgements.wasAcked(msg);
+ }
+
+ async event void PacketData.clear(packet_link_metadata_t* data) {
+ data->maxRetries = 0;
+ }
+
+ /***************** Send Commands ***************/
+ /**
+ * Each call to this send command gives the message a single
+ * DSN that does not change for every copy of the message
+ * sent out. For messages that are not acknowledged, such as
+ * a broadcast address message, the receiving end does not
+ * signal receive() more than once for that message.
+ */
+ command error_t Send.send(message_t *msg, uint8_t len) {
+ error_t error = EBUSY;
+ if(currentSendMsg == NULL) {
+
+ if(call PacketLink.getRetries(msg) > 0) {
+ call PacketAcknowledgements.requestAck(msg);
+ }
+
+ if((error = call SubSend.send(msg, len)) == SUCCESS) {
+ currentSendMsg = msg;
+ currentSendLen = len;
+ totalRetries = 0;
+ }
+ }
+ return error;
+ }
+
+ command error_t Send.cancel(message_t *msg) {
+ if(currentSendMsg == msg) {
+ currentSendMsg = NULL;
+ return call SubSend.cancel(msg);
+ }
+
+ return FAIL;
+ }
+
+
+ command uint8_t Send.maxPayloadLength() {
+ return call SubSend.maxPayloadLength();
+ }
+
+ command void *Send.getPayload(message_t* msg, uint8_t len) {
+ return call SubSend.getPayload(msg, len);
+ }
+
+ /***************** SubSend Events ***************/
+ event void SubSend.sendDone(message_t* msg, error_t error) {
+ totalRetries++;
+
+ if(call PacketAcknowledgements.wasAcked(msg)) {
+ signalDone(SUCCESS);
+ return;
+
+ } else if(totalRetries < call PacketLink.getRetries(currentSendMsg)) {
+
+ if(call PacketLink.getRetryDelay(currentSendMsg) > 0) {
+ // Resend after some delay
+ call DelayTimer.startOneShot(call PacketLink.getRetryDelay(currentSendMsg));
+ } else {
+ // Resend immediately
+ post send();
+ }
+
+ return;
+ }
+
+ signalDone(error);
+ }
+
+ /***************** Timer Events ****************/
+ /**
+ * When this timer is running, that means we're sending repeating messages
+ * to a node that is receive check duty cycling.
+ */
+ event void DelayTimer.fired() {
+ if(currentSendMsg != NULL) {
+ post send();
+ }
+ }
+
+ /***************** Tasks ***************/
+ task void send() {
+ if(call PacketLink.getRetries(currentSendMsg) > 0) {
+ call PacketAcknowledgements.requestAck(currentSendMsg);
+ }
+
+ if(call SubSend.send(currentSendMsg, currentSendLen) != SUCCESS) {
+ post send();
+ }
+ }
+
+ /***************** Functions ***************/
+ void signalDone(error_t error) {
+ message_t* msg = currentSendMsg;
+ currentSendMsg = NULL;
+
+ // AT: A bit of a hack to be able to keep track of the number of retries
+ // printfUART("Signaling done with total retries at 0x%x\n", totalRetries);
+
+ call DelayTimer.stop();
+ call PacketLink.setRetries(msg, totalRetries);
+ signal Send.sendDone(msg, error);
+ }
+}