private void handleFirstTX(SinkData channel, Time currentTime)
throws NoRoomException, IllegalActionException {
// Method to handle the third stage, transmitting the first packet to a sink
IntToken token = new IntToken(currentChannel); // Create a token to send
output.send(0, token); // Send the token
if (channel.n
!= null) { // If we have already calculated n in a previous stage (if n is 1) we can skip
// straight to the next transmission period
setNextFireTime(channel, currentTime.getDoubleValue() + (channel.t.getDoubleValue() * 12));
channel.state = states.SECONDTX;
} else { // If we do not know n then we need to next fire at the beginning of the next
// synchronisation phase so we can receive the first pulse and find n
setNextFireTime(
channel, currentTime.getDoubleValue() + (channel.t.getDoubleValue() * 11) - 0.02);
channel.state = states.NCALC;
}
System.out.println(
"FIRSTTX on channel "
+ currentChannel
+ ". t is "
+ channel.t
+ ". nextFireTime is "
+ channel.nextFireTime
+ " currentTime is "
+ currentTime);
}
private void handleNCalc(SinkData channel, Time currentTime)
throws NoTokenException, IllegalActionException {
// Method to handle the fourth stage, where we listen to the first synchronisation pulse to find
// the value of n
System.out.println(channel.nextFireTime.getDoubleValue() >= currentTime.getDoubleValue() + 0.4);
if (channel.nextFireTime.getDoubleValue() >= currentTime.getDoubleValue()) {
input.get(0);
return;
} else if (channel
.secondRun) { // If we are on the second run through, we have already transmitted twice so
// we can stop here
channel.state = states.FINISHED;
return;
} else if (currentTime.subtract(channel.nextFireTime).getDoubleValue()
> 2) { // There is a large delta between when we were supposed to fire and when we fired, so
// we probably have a collision with another channel
channel.secondRun = true; // Store that we will need to go around again for this channel
channel.state = states.FIRSTRX; // Set the stage back to the beginning so we can restart
System.out.println(
"NCALC on channel "
+ currentChannel
+ " n is: "
+ channel.n
+ ". t is "
+ channel.t
+ ". nextFireTime is "
+ channel.nextFireTime
+ " currentTime is "
+ currentTime);
nextChannel(currentChannel, currentTime);
} else {
channel.n = ((IntToken) input.get(0)).intValue();
setNextFireTime(
channel, currentTime.getDoubleValue() + (channel.t.getDoubleValue() * channel.n));
channel.state = states.SECONDTX;
System.out.println(
"NCALC on channel "
+ currentChannel
+ " n is: "
+ channel.n
+ ". t is "
+ channel.t
+ ". nextFireTime is "
+ channel.nextFireTime
+ " currentTime is "
+ currentTime);
nextChannel(currentChannel, currentTime);
removeFromQueue(currentChannel);
}
}
private void handleFirstRX(SinkData channel, Time currentTime)
throws NoTokenException, IllegalActionException {
// Method to handle the first stage, receiving the first synchronisation pulse
IntToken token = (IntToken) input.get(0); // Retrieve the token from the input
Time timeDelta =
currentTime.subtract(
waitTime); // Calculate a delta between the current time and when the channel was
// changed, to find the waiting time
if (timeDelta.getDoubleValue() <= 1.5
&& token.equals(
1)) { // Token is 1, and we have been waiting for longer than 1.5s. So we will not have
// a follow-up token, so can't be used for determining t
channelQueue
.remove(); // Send the current channel to the back of the queue so we can do something
// useful while it is in its sleep state
channelQueue.add(currentChannel);
return;
}
if (!channel
.secondRun) { // If this is the first time we have received packets on the channel we will
// need the current time to calculate a t
channel.t = currentTime;
}
channel.state = states.SECONDRX; // Set the channel state to the next stage
channel.firstValue = token.intValue(); // Store the value we have received
System.out.println("FIRSTRX on channel " + currentChannel + " currentTime is " + currentTime);
}
private void handleSecondTX(SinkData channel, Time currentTime) throws IllegalActionException {
IntToken token = new IntToken(currentChannel);
output.send(0, token);
channel.state = states.FINISHED;
System.out.println(
"SECONDTX on channel "
+ currentChannel
+ ". t is "
+ channel.t
+ " currentTime is "
+ currentTime);
System.out.println(channelQueue.toString());
}
private void handleSecondRX(SinkData channel, Time currentTime)
throws NoTokenException, IllegalActionException {
// Method to handle the second stage, receiving the second synchronisation pulse
if (!channel
.secondRun) { // If this is the second time we have received packets on the channel we
// already have t so no need to calculate it
channel.t = currentTime.subtract(channel.t);
}
int currentValue = ((IntToken) input.get(0)).intValue(); // Retrieve the value from the input
if (channel.firstValue == 1 && currentValue == 1) { // If the first two values are 1 then n is 1
channel.n = 1;
channel.t =
new Time(getDirector())
.add(
channel.t.getDoubleValue()
/ 12); // Calculate t given that n is 1, i.e divide the period by 12 as per
// the protocol
}
setNextFireTime(
channel,
currentTime.getDoubleValue()
+ (channel.t.getDoubleValue()
* currentValue)); // Manually set the next fire time for this channel
channel.state = states.FIRSTTX; // Set the channel state to the next stage
System.out.println(
"SECONDRX on channel "
+ currentChannel
+ ". Current value is "
+ currentValue
+ ". t is "
+ channel.t
+ ". nextFireTime is "
+ channel.nextFireTime
+ " currentTime is "
+ currentTime);
nextChannel(currentChannel, currentTime);
removeFromQueue(currentChannel); // We can now move onto listening on the next channel
}
