Merge TinyOS 2.1.1 into master.

[tinyos-2.x.git] / tos / chips / rf2xx / layers / SoftwareAckLayerP.nc

diff --git a/tos/chips/rf2xx/layers/SoftwareAckLayerP.nc b/tos/chips/rf2xx/layers/SoftwareAckLayerP.nc
new file mode 100644 (file)
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+++ b/tos/chips/rf2xx/layers/SoftwareAckLayerP.nc
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+/*
+ * Copyright (c) 2007, Vanderbilt University
+ * 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 VANDERBILT UNIVERSITY 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 VANDERBILT
+ * UNIVERSITY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * 
+ * THE VANDERBILT UNIVERSITY 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 VANDERBILT UNIVERSITY HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ * Author: Miklos Maroti
+ */
+
+#include <Tasklet.h>
+#include <RadioAssert.h>
+
+module SoftwareAckLayerP
+{
+       provides
+       {
+               interface RadioSend;
+               interface RadioReceive;
+               interface PacketAcknowledgements;
+       }
+
+       uses
+       {
+               interface RadioSend as SubSend;
+               interface RadioReceive as SubReceive;
+               interface RadioAlarm;
+
+               interface SoftwareAckConfig;
+               interface PacketFlag as AckReceivedFlag;
+       }
+}
+
+implementation
+{
+       tasklet_norace uint8_t state;
+       enum
+       {
+               STATE_READY = 0,
+               STATE_DATA_SEND = 1,
+               STATE_ACK_WAIT = 2,
+               STATE_ACK_SEND = 3,
+       };
+
+       tasklet_norace message_t *txMsg;
+       tasklet_norace message_t ackMsg;
+
+       tasklet_async event void SubSend.ready()
+       {
+               if( state == STATE_READY )
+                       signal RadioSend.ready();
+       }
+
+       tasklet_async command error_t RadioSend.send(message_t* msg)
+       {
+               error_t error;
+
+               if( state == STATE_READY )
+               {
+                       if( (error = call SubSend.send(msg)) == SUCCESS )
+                       {
+                               call AckReceivedFlag.clear(msg);
+                               state = STATE_DATA_SEND;
+                               txMsg = msg;
+                       }
+               }
+               else
+                       error = EBUSY;
+
+               return error;
+       }
+
+       tasklet_async event void SubSend.sendDone(error_t error)
+       {
+               if( state == STATE_ACK_SEND )
+               {
+                       // TODO: what if error != SUCCESS
+                       ASSERT( error == SUCCESS );
+
+                       state = STATE_READY;
+               }
+               else
+               {
+                       ASSERT( state == STATE_DATA_SEND );
+                       ASSERT( call RadioAlarm.isFree() );
+
+                       if( error == SUCCESS && call SoftwareAckConfig.requiresAckWait(txMsg) && call RadioAlarm.isFree() )
+                       {
+                               call RadioAlarm.wait(call SoftwareAckConfig.getAckTimeout());
+                               state = STATE_ACK_WAIT;
+                       }
+                       else
+                       {
+                               state = STATE_READY;
+                               signal RadioSend.sendDone(error);
+                       }
+               }
+       }
+
+       tasklet_async event void RadioAlarm.fired()
+       {
+               ASSERT( state == STATE_ACK_WAIT );
+
+               call SoftwareAckConfig.reportChannelError();
+
+               state = STATE_READY;
+               signal RadioSend.sendDone(SUCCESS);     // we have sent it, but not acked
+       }
+
+       tasklet_async event bool SubReceive.header(message_t* msg)
+       {
+               if( call SoftwareAckConfig.isAckPacket(msg) )
+                       return state == STATE_ACK_WAIT && call SoftwareAckConfig.verifyAckPacket(txMsg, msg);
+               else
+                       return signal RadioReceive.header(msg);
+       }
+
+       tasklet_async event message_t* SubReceive.receive(message_t* msg)
+       {
+               bool ack = call SoftwareAckConfig.isAckPacket(msg);
+
+               ASSERT( state == STATE_ACK_WAIT || state == STATE_READY );
+
+               if( state == STATE_ACK_WAIT )
+               {
+                       ASSERT( !ack || call SoftwareAckConfig.verifyAckPacket(txMsg, msg) );
+
+                       call RadioAlarm.cancel();
+                       call AckReceivedFlag.setValue(txMsg, ack);
+
+                       state = STATE_READY;
+                       signal RadioSend.sendDone(SUCCESS);
+               }
+
+               if( ack )
+                       return msg;
+
+               if( call SoftwareAckConfig.requiresAckReply(msg) )
+               {
+                       call SoftwareAckConfig.createAckPacket(msg, &ackMsg);
+
+                       // TODO: what to do if we are busy and cannot send an ack
+                       if( call SubSend.send(&ackMsg) == SUCCESS )
+                               state = STATE_ACK_SEND;
+                       else
+                               ASSERT(FALSE);
+               }
+
+               return signal RadioReceive.receive(msg);
+       }
+
+/*----------------- PacketAcknowledgements -----------------*/
+
+       async command error_t PacketAcknowledgements.requestAck(message_t* msg)
+       {
+               call SoftwareAckConfig.setAckRequired(msg, TRUE);
+
+               return SUCCESS;
+       }
+
+       async command error_t PacketAcknowledgements.noAck(message_t* msg)
+       {
+               call SoftwareAckConfig.setAckRequired(msg, FALSE);
+
+               return SUCCESS;
+       }
+
+       async command bool PacketAcknowledgements.wasAcked(message_t* msg)
+       {
+               return call AckReceivedFlag.get(msg);
+       }
+
+
+}