--- /dev/null
+/*
+ * Copyright (c) 2008, Technische Universitaet Berlin
+ * 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 Technische Universitaet Berlin 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 COPYRIGHT
+ * OWNER OR 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.
+ *
+ * - Revision -------------------------------------------------------------
+ * $Revision$
+ * $Date$
+ * @author Jan Hauer <hauer@tkn.tu-berlin.de>
+ * ========================================================================
+ */
+
+#include "TKN154_PHY.h"
+#include "TKN154_MAC.h"
+
+/**
+ * This module implements the slotted and unslotted CSMA-CA algorithm.
+ * Unslotted CSMA-CA is used in nonbeacon-enabled PANs, slotted CSMA-CA is used
+ * in beacon-enabled PANs. In a beacon-enabled PAN this module is responsible
+ * for channel access during the contention access period (CAP). It does
+ * slightly different things depending on whether it is the CAP for an outgoing
+ * superframe (superframeDirection = OUTGOING_SUPERFRAME), i.e. the CAP from
+ * the perspective of a coordinator after it has transmitted its own beacon; or
+ * for an incoming superframe (superframeDirection = INCOMING_SUPERFRAME), i.e.
+ * the CAP from the perspective of a device after it has received a beacon from
+ * its coordinator; for example, in the CAP a coordinator will usually listen for
+ * incoming frames from the devices, and a device will usually switch the radio
+ * off unless it has a frame to transmit. In nonbeacon-enabled PANs the
+ * superframeDirection parameter is ignored.
+ */
+
+generic module CsmaP(uint8_t superframeDirection)
+{
+ provides
+ {
+ interface Init as Reset;
+ interface FrameTx as FrameTx;
+ interface FrameRx as FrameRx[uint8_t frameType];
+ interface FrameExtracted as FrameExtracted[uint8_t frameType];
+ interface FrameTxNow as BroadcastTx;
+ interface Notify<bool> as WasRxEnabled;
+ interface Notify<bool> as FindBeacon;
+ }
+ uses
+ {
+ interface Random;
+ interface Alarm<TSymbolIEEE802154,uint32_t> as CapEndAlarm;
+ interface Alarm<TSymbolIEEE802154,uint32_t> as BLEAlarm;
+ interface Alarm<TSymbolIEEE802154,uint32_t> as IndirectTxWaitAlarm;
+ interface Alarm<TSymbolIEEE802154,uint32_t> as BroadcastAlarm;
+ interface Resource as Token;
+ interface ResourceTransfer as TokenToCfp;
+ interface ResourceTransferred as TokenTransferred;
+ interface ResourceRequested as TokenRequested;
+ interface GetNow<bool> as IsTokenRequested;
+ interface GetNow<uint32_t> as CapStart;
+ interface GetNow<ieee154_reftime_t*> as CapStartRefTime;
+ interface GetNow<uint32_t> as CapLen;
+ interface GetNow<bool> as IsBLEActive;
+ interface GetNow<uint16_t> as BLELen;
+ interface GetNow<bool> as IsRxBroadcastPending;
+ interface GetNow<bool> as IsRxEnableActive;
+ interface Notify<bool> as RxEnableStateChange;
+ interface GetNow<bool> as IsTrackingBeacons;
+ interface FrameUtility;
+ interface RadioTx;
+ interface RadioRx;
+ interface RadioOff;
+ interface Get<bool> as IsBeaconEnabledPAN;
+ interface MLME_GET;
+ interface MLME_SET;
+ interface Ieee802154Debug as Debug;
+ interface TimeCalc;
+ interface Leds;
+ interface SetNow<ieee154_cap_frame_backup_t*> as FrameBackup;
+ interface GetNow<ieee154_cap_frame_backup_t*> as FrameRestore;
+ }
+}
+implementation
+{
+ typedef enum {
+ SWITCH_OFF,
+ LOAD_TX,
+ PREPARE_RX,
+ DO_NOTHING,
+ WAIT_FOR_TXDONE,
+ } next_state_t;
+
+ typedef enum {
+ INDIRECT_TX_ALARM,
+ BROADCAST_ALARM,
+ NO_ALARM,
+ } rx_alarm_t;
+
+ enum {
+ COORD_ROLE = (superframeDirection == OUTGOING_SUPERFRAME),
+ DEVICE_ROLE = !COORD_ROLE,
+ };
+
+ norace bool m_lock;
+ norace ieee154_txframe_t *m_currentFrame;
+ norace ieee154_txframe_t *m_bcastFrame;
+ norace ieee154_txframe_t *m_lastFrame;
+ norace ieee154_macMaxBE_t m_BE;
+ norace ieee154_macMaxBE_t m_NB;
+ norace ieee154_macMaxBE_t m_numCCA;
+ norace ieee154_macMaxCSMABackoffs_t m_macMaxCSMABackoffs;
+ norace ieee154_macMaxFrameRetries_t m_macMaxFrameRetries;
+ norace ieee154_macMaxBE_t m_macMaxBE;
+ norace ieee154_macMinBE_t m_macMinBE;
+ norace uint16_t m_backoff;
+ norace uint16_t m_backoffElapsed;
+ norace ieee154_status_t m_result;
+ norace uint32_t m_transactionTime;
+ norace bool m_indirectTxPending = FALSE;
+ norace bool m_broadcastRxPending;
+ norace ieee154_macMaxFrameTotalWaitTime_t m_macMaxFrameTotalWaitTime;
+ norace bool m_isBeaconEnabledPAN;
+
+ uint16_t generateRandomBackoff(uint8_t BE);
+ void stopAllAlarms();
+ next_state_t tryReceive(rx_alarm_t alarmType);
+ next_state_t tryTransmit();
+ next_state_t trySwitchOff();
+ void backupCurrentFrame();
+ void restoreFrameFromBackup();
+ void updateState();
+ void setCurrentFrame(ieee154_txframe_t *frame);
+ void signalTxBroadcastDone(ieee154_txframe_t *frame, ieee154_status_t error);
+ task void signalTxDoneTask();
+ task void setupTxBroadcastTask();
+ task void wasRxEnabledTask();
+
+ command error_t Reset.init()
+ {
+ if (call Token.isOwner()){
+ call Leds.led0On(); // internal error
+ return FAIL;
+ }
+ if (m_currentFrame)
+ signal FrameTx.transmitDone(m_currentFrame, IEEE154_TRANSACTION_OVERFLOW);
+ if (m_lastFrame)
+ signal FrameTx.transmitDone(m_lastFrame, IEEE154_TRANSACTION_OVERFLOW);
+ if (m_bcastFrame)
+ signalTxBroadcastDone(m_bcastFrame, IEEE154_TRANSACTION_OVERFLOW);
+ m_currentFrame = m_lastFrame = m_bcastFrame = NULL;
+ m_macMaxFrameTotalWaitTime = call MLME_GET.macMaxFrameTotalWaitTime();
+ m_isBeaconEnabledPAN = call IsBeaconEnabledPAN.get();
+ stopAllAlarms();
+ return SUCCESS;
+ }
+
+ event void TokenTransferred.transferred()
+ {
+ // we got the token, i.e. CAP has just started
+ uint32_t actualCapLen = call CapLen.getNow();
+ if (m_isBeaconEnabledPAN && (DEVICE_ROLE && !call IsTrackingBeacons.getNow())){
+ // rare case: we're on a beacon-enabled PAN, not tracking beacons, searched
+ // and didn't find a beacon for aBaseSuperframeDuration*(2n+1) symbols
+ // -> transmit current frame using unslotted CSMA-CA
+ m_numCCA = 1;
+ signal Token.granted();
+ return;
+ }
+ else if (actualCapLen < IEEE154_RADIO_GUARD_TIME){
+ call Debug.log(LEVEL_IMPORTANT, CapP_TOO_SHORT, superframeDirection, actualCapLen, IEEE154_RADIO_GUARD_TIME);
+ call TokenToCfp.transfer();
+ return;
+ } else {
+ actualCapLen -= IEEE154_RADIO_GUARD_TIME;
+ if (DEVICE_ROLE)
+ m_broadcastRxPending = call IsRxBroadcastPending.getNow();
+ else {
+ // COORD_ROLE
+ if (m_bcastFrame != NULL) {
+ // we have to transmit a broadcast frame immediately; this
+ // (possibly) requires a backup of the previously active frame
+ // and a reinitializing the CSMA parameters -> will do it
+ // in task context and then continue
+ m_lock = TRUE;
+ post setupTxBroadcastTask();
+ }
+ }
+ call CapEndAlarm.startAt(call CapStart.getNow(), actualCapLen);
+ if (call IsBLEActive.getNow())
+ call BLEAlarm.startAt(call CapStart.getNow(), call BLELen.getNow());
+ call Debug.log(LEVEL_IMPORTANT, CapP_SET_CAP_END, call CapStart.getNow(),
+ actualCapLen, call CapStart.getNow()+ actualCapLen);
+ }
+ updateState();
+ call Debug.flush();
+ }
+
+ command ieee154_status_t FrameTx.transmit(ieee154_txframe_t *frame)
+ {
+ if (m_currentFrame != NULL)
+ return IEEE154_TRANSACTION_OVERFLOW;
+ else {
+ setCurrentFrame(frame);
+ if (!m_isBeaconEnabledPAN){
+ call Token.request(); // prepare for unslotted CSMA-CA
+ } else {
+ // a beacon must be found before transmitting in a beacon-enabled PAN
+ if (DEVICE_ROLE && !call IsTrackingBeacons.getNow()){
+ signal FindBeacon.notify(TRUE);
+ // we'll receive the Token at latest after aBaseSuperframeDuration*(2n+1) symbols;
+ // if the beacon was not found, then we'll send the frame using unslotted CSMA-CA
+ }
+ updateState();
+ }
+ return IEEE154_SUCCESS;
+ }
+ }
+
+ task void setupTxBroadcastTask()
+ {
+ ieee154_macDSN_t tmp;
+ ieee154_txframe_t *oldFrame = m_currentFrame;
+ if (COORD_ROLE){
+ if (m_bcastFrame != NULL){
+ // broadcasts should be transmitted *immediately* after the beacon,
+ // which may interrupt a pending transmit operation from the previous
+ // CAP; back up the last active frame configuration (may be none)
+ // and restore it after the broadcast frame has been transmitted;
+ // do this through interfaces and don't wire them for DEVICE_ROLE,
+ // so we don't waste the RAM of devices
+ backupCurrentFrame();
+ setCurrentFrame(m_bcastFrame);
+ if (oldFrame){
+ // now the sequence number are out of order... swap them back
+ tmp = m_bcastFrame->header->mhr[MHR_INDEX_SEQNO];
+ m_bcastFrame->header->mhr[MHR_INDEX_SEQNO] =
+ oldFrame->header->mhr[MHR_INDEX_SEQNO];
+ oldFrame->header->mhr[MHR_INDEX_SEQNO] = tmp;
+ }
+ }
+ }
+ m_lock = FALSE;
+ updateState();
+ }
+
+ void setCurrentFrame(ieee154_txframe_t *frame)
+ {
+ ieee154_macDSN_t dsn = call MLME_GET.macDSN();
+ frame->header->mhr[MHR_INDEX_SEQNO] = dsn++;
+ call MLME_SET.macDSN(dsn);
+ m_macMaxCSMABackoffs = call MLME_GET.macMaxCSMABackoffs();
+ m_macMaxFrameRetries = call MLME_GET.macMaxFrameRetries();
+ m_macMaxBE = call MLME_GET.macMaxBE();
+ m_macMinBE = call MLME_GET.macMinBE();
+ if (call MLME_GET.macBattLifeExt() && m_macMinBE > 2)
+ m_macMinBE = 2;
+ m_BE = m_macMinBE;
+ if (m_isBeaconEnabledPAN)
+ m_numCCA = 2;
+ else
+ m_numCCA = 1;
+ m_NB = 0;
+ m_transactionTime = IEEE154_SHR_DURATION +
+ (frame->headerLen + frame->payloadLen) * IEEE154_SYMBOLS_PER_OCTET;
+ if (frame->header->mhr[MHR_INDEX_FC1] & FC1_ACK_REQUEST)
+ m_transactionTime += (IEEE154_aTurnaroundTime + IEEE154_aUnitBackoffPeriod +
+ 11 * IEEE154_SYMBOLS_PER_OCTET);
+ if (frame->headerLen + frame->payloadLen > IEEE154_aMaxSIFSFrameSize)
+ m_transactionTime += call MLME_GET.macMinLIFSPeriod();
+ else
+ m_transactionTime += call MLME_GET.macMinSIFSPeriod();
+ m_backoff = generateRandomBackoff(m_BE) * IEEE154_aUnitBackoffPeriod; // initial backoff
+ m_macMaxFrameTotalWaitTime = call MLME_GET.macMaxFrameTotalWaitTime();
+ m_backoffElapsed = 0;
+ m_currentFrame = frame;
+ }
+
+ uint16_t generateRandomBackoff(uint8_t BE)
+ {
+ // return random number from [0,(2^BE) - 1] (uniform distr.)
+ uint16_t res = call Random.rand16();
+ uint16_t mask = 0xFFFF;
+ mask <<= BE;
+ mask = ~mask;
+ res &= mask;
+ return res;
+ }
+
+ void stopAllAlarms()
+ {
+ call CapEndAlarm.stop();
+ if (DEVICE_ROLE){
+ call IndirectTxWaitAlarm.stop();
+ call BroadcastAlarm.stop();
+ }
+ call BLEAlarm.stop();
+ }
+
+ /**
+ * The updateState() function is called whenever some event happened that
+ * might require a state change; it implements a lock mechanism (m_lock) to
+ * prevent race conditions. Whenever the lock is set a "done"-event (from a
+ * RadioTx/RadioRx/RadioOff interface) is pending and will "soon" unset the
+ * lock (and then updateState() will called again). The updateState()
+ * function decides about the next state by checking a list of possible
+ * current states ordered by priority, e.g. it first always checks whether
+ * the CAP is still active. Calling this function more than necessary can do
+ * no harm, but it SHOULD be called whenever an event happened that might
+ * lead to a state change.
+ */
+
+ void updateState()
+ {
+ error_t result = SUCCESS;
+ next_state_t next;
+ atomic {
+ // long atomics are bad... but in this block, once the
+ // current state has been determined only one branch will
+ // be taken (no loops, etc.)
+ if (m_lock || !call Token.isOwner())
+ return;
+ m_lock = TRUE; // lock
+
+ // Check 1: for beacon-enabled PANs, has the CAP finished?
+ if (m_isBeaconEnabledPAN
+ && (COORD_ROLE || call IsTrackingBeacons.getNow()) // FALSE only if device could't find a beacon
+ && (call TimeCalc.hasExpired(call CapStart.getNow(), call CapLen.getNow()-IEEE154_RADIO_GUARD_TIME) ||
+ !call CapEndAlarm.isRunning())){
+ if (call RadioOff.isOff()) {
+ stopAllAlarms(); // may still fire, locked through isOwner()
+ if (DEVICE_ROLE && m_indirectTxPending)
+ signal IndirectTxWaitAlarm.fired();
+ m_broadcastRxPending = FALSE;
+ if (COORD_ROLE && m_bcastFrame){
+ // didn't manage to transmit a broadcast
+ restoreFrameFromBackup();
+ signalTxBroadcastDone(m_bcastFrame, IEEE154_CHANNEL_ACCESS_FAILURE);
+ m_bcastFrame = NULL;
+ }
+ m_lock = FALSE; // unlock
+ call TokenToCfp.transfer();
+ return;
+ } else
+ next = SWITCH_OFF;
+ }
+
+ // Check 2: should a broadcast frame be received/transmitted immediately
+ // at the start of CAP?
+ else if (DEVICE_ROLE && m_broadcastRxPending){
+ // receive a broadcast from coordinator
+ next = tryReceive(BROADCAST_ALARM);
+ } else if (COORD_ROLE && m_bcastFrame){
+ next = tryTransmit();
+ }
+
+ // Check 3: was an indirect transmission successfully started
+ // and are we now waiting for a frame from the coordinator?
+ else if (DEVICE_ROLE && m_indirectTxPending) {
+ next = tryReceive(INDIRECT_TX_ALARM);
+ }
+
+ // Check 4: is some other operation (like MLME-SCAN or MLME-RESET) pending?
+ else if (call IsTokenRequested.getNow()) {
+ if (call RadioOff.isOff()) {
+ stopAllAlarms(); // may still fire, locked through isOwner()
+ call Token.release();
+ next = DO_NOTHING;
+ } else
+ next = SWITCH_OFF;
+ }
+
+ // Check 5: is battery life extension (BLE) active and
+ // has the BLE period expired?
+ else if (call IsBLEActive.getNow() &&
+ call TimeCalc.hasExpired(call CapStart.getNow(), call BLELen.getNow()) &&
+ !call IsRxEnableActive.getNow()) {
+ next = trySwitchOff();
+ }
+
+ // Check 6: is there a frame ready to transmit?
+ else if (m_currentFrame != NULL) {
+ next = tryTransmit();
+ }
+
+ // Check 7: should we be in receive mode?
+ else if (COORD_ROLE || call IsRxEnableActive.getNow()) {
+ next = tryReceive(NO_ALARM);
+ if (next == DO_NOTHING && call IsRxEnableActive.getNow()){
+ // this means there is an active MLME_RX_ENABLE.request
+ // and the radio was just switched to Rx mode - signal
+ // a notify event to inform the next higher layer
+ post wasRxEnabledTask();
+ }
+ }
+
+ // Check 8: just make sure the radio is switched off
+ else {
+ next = trySwitchOff();
+ if (next == DO_NOTHING && (!m_isBeaconEnabledPAN || (DEVICE_ROLE && !call IsTrackingBeacons.getNow()))){
+ // nothing more to do... just release the Token
+ m_lock = FALSE; // unlock
+ call TokenToCfp.transfer();
+ return;
+ }
+ }
+
+ // if there is nothing to do, then we must clear the lock
+ if (next == DO_NOTHING)
+ m_lock = FALSE;
+ } // atomic
+ // put next state in operation (possibly keeping the lock)
+ switch (next)
+ {
+ case SWITCH_OFF: result = call RadioOff.off(); break;
+ case LOAD_TX: result = call RadioTx.load(m_currentFrame); break;
+ case PREPARE_RX: result = call RadioRx.prepare(); break;
+ case WAIT_FOR_TXDONE: break;
+ case DO_NOTHING: break;
+ }
+ if (result != SUCCESS)
+ call Leds.led0On(); // internal error: could not update state !!!
+ }
+
+ next_state_t tryTransmit()
+ {
+ // tries to transmit m_currentFrame using the configuration stored
+ // in other module variables (m_backoff, etc.)
+ next_state_t next;
+ if (call RadioTx.getLoadedFrame() == m_currentFrame){
+ // the frame is already loaded -> transmit it now
+ if (m_numCCA == 1){
+ // unslotted CSMA-CA
+ call RadioTx.transmit(NULL, m_backoff, m_numCCA, m_currentFrame->header->mhr[MHR_INDEX_FC1] & FC1_ACK_REQUEST ? TRUE : FALSE);
+ next = WAIT_FOR_TXDONE; // this will NOT clear the lock
+ } else {
+ // slotted CSMA-CA
+ uint32_t capLen = call CapLen.getNow(), capStart = call CapStart.getNow();
+ uint32_t elapsed, totalTime;
+ totalTime = IEEE154_RADIO_TX_SEND_DELAY +
+ m_backoff - m_backoffElapsed + m_transactionTime + IEEE154_RADIO_GUARD_TIME;
+ if (totalTime > capLen)
+ totalTime = capLen; // CAP is too short
+ elapsed = call TimeCalc.timeElapsed(capStart, call CapEndAlarm.getNow());
+ elapsed += (20 - (elapsed % 20)); // round to backoff boundary
+ if (!call TimeCalc.hasExpired(capStart, capLen - totalTime)){
+ call RadioTx.transmit(call CapStartRefTime.getNow(),
+ elapsed + IEEE154_RADIO_TX_SEND_DELAY + m_backoff - m_backoffElapsed,
+ m_numCCA,
+ m_currentFrame->header->mhr[MHR_INDEX_FC1] & FC1_ACK_REQUEST ? TRUE : FALSE);
+ next = WAIT_FOR_TXDONE; // this will NOT clear the lock
+ } else {
+ // frame does not fit in remaing portion of the CAP
+ if (elapsed < call CapLen.getNow()){
+ m_backoffElapsed += call CapLen.getNow() - elapsed;
+ if (m_backoffElapsed > m_backoff)
+ m_backoffElapsed = m_backoff;
+ }
+ next = SWITCH_OFF;
+ }
+ }
+ } else {
+ // the frame to transmit has not yet been loaded -> load it now
+ if (!call RadioOff.isOff())
+ next = SWITCH_OFF;
+ else {
+ if (m_lastFrame){
+ // the done event for the previous frame has not yet been
+ // signalled to the upper layer -> wait
+ next = DO_NOTHING;
+ } else
+ next = LOAD_TX;
+ }
+ }
+ return next;
+ }
+
+ next_state_t tryReceive(rx_alarm_t alarmType)
+ {
+ next_state_t next;
+ if (call RadioRx.isReceiving()){
+ next = DO_NOTHING;
+ } else if (call RadioRx.isPrepared()){
+ call RadioRx.receive(NULL, 0);
+ switch (alarmType)
+ {
+ case INDIRECT_TX_ALARM: call IndirectTxWaitAlarm.start(m_macMaxFrameTotalWaitTime); break;
+ case BROADCAST_ALARM: call BroadcastAlarm.start(m_macMaxFrameTotalWaitTime); break;
+ case NO_ALARM: break;
+ }
+ next = DO_NOTHING;
+ } else if (call RadioOff.isOff())
+ next = PREPARE_RX;
+ else
+ next = SWITCH_OFF;
+ return next;
+ }
+
+ next_state_t trySwitchOff()
+ {
+ next_state_t next;
+ if (call RadioOff.isOff())
+ next = DO_NOTHING;
+ else
+ next = SWITCH_OFF;
+ return next;
+ }
+
+ async event void RadioTx.loadDone(){ m_lock = FALSE; updateState();}
+ async event void RadioOff.offDone(){ m_lock = FALSE; updateState();}
+ async event void RadioRx.prepareDone(){ m_lock = FALSE; updateState();}
+
+ async event void CapEndAlarm.fired(){
+ call Debug.log(LEVEL_IMPORTANT, CapP_CAP_END_FIRED, superframeDirection, 0, 0);
+ updateState();
+ }
+ async event void BLEAlarm.fired(){ updateState();}
+ event void RxEnableStateChange.notify(bool whatever){ updateState();}
+ async event void BroadcastAlarm.fired(){ m_broadcastRxPending = FALSE; updateState();}
+
+ async event void IndirectTxWaitAlarm.fired()
+ {
+ atomic {
+ if (m_indirectTxPending){
+ m_indirectTxPending = FALSE;
+ post signalTxDoneTask();
+ }
+ }
+ }
+
+ async event void RadioTx.transmitDone(ieee154_txframe_t *frame,
+ ieee154_reftime_t *referenceTime, bool ackPendingFlag, error_t error)
+ {
+ bool retry = FALSE;
+ switch (error)
+ {
+ case SUCCESS:
+ m_result = IEEE154_SUCCESS;
+ if (DEVICE_ROLE && frame->payload[0] == CMD_FRAME_DATA_REQUEST &&
+ ((frame->header->mhr[MHR_INDEX_FC1]) & FC1_FRAMETYPE_MASK) == FC1_FRAMETYPE_CMD){
+ // just transmitted a data request frame
+ m_result = IEEE154_NO_DATA; // pessimistic
+ if (ackPendingFlag){
+ // the coordinator has data for us; switch to Rx
+ // to complete the indirect transmission
+ m_indirectTxPending = TRUE;
+ m_lastFrame = m_currentFrame;
+ m_currentFrame = NULL;
+ if (call RadioRx.prepare() != SUCCESS) // SHOULD succeed
+ call RadioOff.off();
+ return;
+ }
+ }
+ break;
+ case EBUSY:
+ // we're following the SDL Spec in IEEE 802.15.4-2003 Annex D
+ m_result = IEEE154_CHANNEL_ACCESS_FAILURE;
+ m_NB += 1;
+ if (m_NB < m_macMaxCSMABackoffs){
+ m_BE += 1;
+ if (m_BE > m_macMaxBE)
+ m_BE = m_macMaxBE;
+ retry = TRUE;
+ }
+ break;
+ case ENOACK:
+ // we're following the SDL Spec in IEEE 802.15.4-2003 Annex D
+ m_result = IEEE154_NO_ACK;
+ m_NB += 1;
+ // shouldn't the next check be (m_NB-1 < m_macMaxFrameRetries)? but
+ // on the other hand, NB is used for CHANNEL_ACCESS_FAILURE and NO_ACK,
+ // i.e. m_NB does not tell us much about past retransmissions anyway...
+ if (m_NB < m_macMaxFrameRetries){
+ m_BE = m_macMinBE;
+ retry = TRUE;
+ }
+ break;
+ default: break;
+ }
+ if (retry){
+ m_backoff = generateRandomBackoff(m_BE) * IEEE154_aUnitBackoffPeriod; // next backoff
+ m_backoffElapsed = 0;
+ } else if (COORD_ROLE && frame == m_bcastFrame){
+ // signal result of broadcast transmissions immediately
+ restoreFrameFromBackup();
+ signalTxBroadcastDone(m_bcastFrame, m_result);
+ m_bcastFrame = NULL;
+ } else {
+ m_lastFrame = m_currentFrame;
+ m_currentFrame = NULL;
+ post signalTxDoneTask();
+ }
+ m_lock = FALSE;
+ updateState();
+ }
+
+ task void signalTxDoneTask()
+ {
+ ieee154_txframe_t *lastFrame = m_lastFrame;
+ m_lastFrame = NULL; // only now can a next transmission begin
+ m_indirectTxPending = FALSE;
+ if (lastFrame)
+ signal FrameTx.transmitDone(lastFrame, m_result);
+ updateState();
+ }
+
+ event message_t* RadioRx.received(message_t* frame, ieee154_reftime_t *timestamp)
+ {
+ // received a frame during CAP - find out frame type and
+ // signal it to corresponding client component
+ uint8_t *payload = (uint8_t *) frame->data;
+ uint8_t *mhr = MHR(frame);
+ uint8_t frameType = mhr[MHR_INDEX_FC1] & FC1_FRAMETYPE_MASK;
+ if (frameType == FC1_FRAMETYPE_CMD)
+ frameType += payload[0];
+ atomic {
+ if (DEVICE_ROLE && m_indirectTxPending){
+ message_t* frameBuf;
+ call IndirectTxWaitAlarm.stop();
+ // TODO: check!
+ //if (frame->payloadLen)
+ // is this frame from our coordinator? hmm... we cannot say
+ // with certainty, because we might only know either the
+ // coordinator extended or short address (and the frame could
+ // have been sent with the other addressing mode) ??
+ m_result = IEEE154_SUCCESS;
+ frameBuf = signal FrameExtracted.received[frameType](frame, m_lastFrame);
+ signal IndirectTxWaitAlarm.fired();
+ return frameBuf;
+ } else
+ return signal FrameRx.received[frameType](frame);
+ }
+ }
+
+ void backupCurrentFrame()
+ {
+ ieee154_cap_frame_backup_t backup = {m_currentFrame, m_BE, m_macMaxCSMABackoffs,
+ m_macMaxBE, m_macMinBE, m_NB, m_backoff, m_backoffElapsed, m_transactionTime};
+ call FrameBackup.setNow(&backup);
+ }
+
+ void restoreFrameFromBackup()
+ {
+ ieee154_cap_frame_backup_t *backup = call FrameRestore.getNow();
+ if (backup != NULL){
+ m_currentFrame = backup->frame;
+ m_BE = backup->BE;
+ m_macMaxCSMABackoffs = backup->allowedBackoffs;
+ m_macMaxBE = backup->macMaxBE;
+ m_macMinBE = backup->macMinBE;
+ m_NB = backup->NB;
+ m_backoff = backup->backoff;
+ m_backoffElapsed = backup->backoffElapsed;
+ m_transactionTime = backup->transactionTime;
+ }
+ }
+
+ async command ieee154_status_t BroadcastTx.transmitNow(ieee154_txframe_t *frame)
+ {
+ // if this command is called then it is (MUST be) called
+ // only just before the token is transferred to this component
+ // and it is then be called only once per CAP (max. one broadcast
+ // is allowed after a beacon transmission)
+ atomic {
+ if (!call Token.isOwner() && m_bcastFrame == NULL){
+ m_bcastFrame = frame;
+ return IEEE154_SUCCESS;
+ } else {
+ call Leds.led0On();
+ return IEEE154_TRANSACTION_OVERFLOW;
+ }
+ }
+ }
+
+ void signalTxBroadcastDone(ieee154_txframe_t *frame, ieee154_status_t error)
+ {
+ signal BroadcastTx.transmitNowDone(frame, error);
+ }
+
+ task void wasRxEnabledTask()
+ {
+ signal WasRxEnabled.notify(TRUE);
+ }
+
+ bool isUnslottedCSMA_CA()
+ {
+ return (m_numCCA == 1);
+ }
+
+ event void Token.granted()
+ {
+ // the current frame should be transmitted using unslotted CSMA-CA
+ updateState();
+ }
+
+ task void tokenRequestedTask()
+ {
+ signal TokenRequested.requested();
+ }
+
+ async event void TokenRequested.requested()
+ {
+ atomic {
+ if (call Token.isOwner()){
+ if (!m_lock && !(DEVICE_ROLE && m_indirectTxPending) && !(COORD_ROLE && m_bcastFrame))
+ call Token.release();
+ else
+ post tokenRequestedTask();
+ }
+ }
+ }
+
+ async event void TokenRequested.immediateRequested() {}
+
+ default event void FrameTx.transmitDone(ieee154_txframe_t *data, ieee154_status_t status){}
+ default event message_t* FrameRx.received[uint8_t client](message_t* data){return data;}
+ default async command bool IsRxEnableActive.getNow(){return FALSE;}
+
+ default async command void IndirectTxWaitAlarm.start(uint32_t dt){call Leds.led0On();}
+ default async command void IndirectTxWaitAlarm.stop(){call Leds.led0On();}
+ default async command void IndirectTxWaitAlarm.startAt(uint32_t t0, uint32_t dt){call Leds.led0On();}
+
+ default async command void BroadcastAlarm.start(uint32_t dt){call Leds.led0On();}
+ default async command void BroadcastAlarm.stop(){call Leds.led0On();}
+ default async command void BroadcastAlarm.startAt(uint32_t t0, uint32_t dt){call Leds.led0On();}
+
+ default async command bool IsRxBroadcastPending.getNow(){ return FALSE;}
+ default async event void BroadcastTx.transmitNowDone(ieee154_txframe_t *frame, ieee154_status_t status){}
+ default event message_t* FrameExtracted.received[uint8_t client](message_t* msg, ieee154_txframe_t *txFrame){return msg;}
+ default async command error_t FrameBackup.setNow(ieee154_cap_frame_backup_t* val ){return FAIL;}
+ default async command ieee154_cap_frame_backup_t* FrameRestore.getNow(){return NULL;}
+
+ command error_t WasRxEnabled.enable(){return FAIL;}
+ command error_t WasRxEnabled.disable(){return FAIL;}
+ command error_t FindBeacon.enable(){return FAIL;}
+ command error_t FindBeacon.disable(){return FAIL;}
+}
projects / tinyos-2.x.git / blobdiff