internal void MarkASDUAsConfirmed(int index, long timestamp)
{
if (asduQueue != null)
{
asduQueue.MarkASDUAsConfirmed(index, timestamp);
}
}
private bool CheckSequenceNumber(int seqNo)
{
lock (sentASDUs)
{
/* check if received sequence number is valid */
bool seqNoIsValid = false;
bool counterOverflowDetected = false;
int oldestValidSeqNo = -1;
if (oldestSentASDU == -1)
{ /* if k-Buffer is empty */
if (seqNo == sendCount)
{
seqNoIsValid = true;
}
}
else
{
// Two cases are required to reflect sequence number overflow
if (sentASDUs[oldestSentASDU].seqNo <= sentASDUs[newestSentASDU].seqNo)
{
if ((seqNo >= sentASDUs[oldestSentASDU].seqNo) &&
(seqNo <= sentASDUs[newestSentASDU].seqNo))
{
seqNoIsValid = true;
}
}
else
{
if ((seqNo >= sentASDUs[oldestSentASDU].seqNo) ||
(seqNo <= sentASDUs[newestSentASDU].seqNo))
{
seqNoIsValid = true;
}
counterOverflowDetected = true;
}
if (sentASDUs[oldestSentASDU].seqNo == 0)
{
oldestValidSeqNo = 32767;
}
else
{
oldestValidSeqNo = sentASDUs[oldestSentASDU].seqNo - 1;
}
if (oldestValidSeqNo == seqNo)
{
seqNoIsValid = true;
}
}
if (seqNoIsValid == false)
{
DebugLog("Received sequence number out of range");
return(false);
}
if (oldestSentASDU != -1)
{
/* remove confirmed messages from list */
do
{
/* skip removing messages if confirmed message was already removed */
if (counterOverflowDetected == false)
{
if (seqNo < sentASDUs[oldestSentASDU].seqNo)
{
break;
}
}
if (seqNo == oldestValidSeqNo)
{
break;
}
/* remove from server (low-priority) queue if required */
if (sentASDUs[oldestSentASDU].queueIndex != -1)
{
asduQueue.MarkASDUAsConfirmed(sentASDUs[oldestSentASDU].queueIndex,
sentASDUs[oldestSentASDU].entryTime);
}
if (sentASDUs[oldestSentASDU].seqNo == seqNo)
{
/* we arrived at the seq# that has been confirmed */
if (oldestSentASDU == newestSentASDU)
{
oldestSentASDU = -1;
}
else
{
oldestSentASDU = (oldestSentASDU + 1) % maxSentASDUs;
}
break;
}
oldestSentASDU = (oldestSentASDU + 1) % maxSentASDUs;
int checkIndex = (newestSentASDU + 1) % maxSentASDUs;
if (oldestSentASDU == checkIndex)
{
oldestSentASDU = -1;
break;
}
} while (true);
}
}
return(true);
}