private void UpdateAckCounter(Ack ack)
{
if (ack.Message.GetType().IsSubclassOf(typeof(Request)))
{
Request request = (Request)ack.Message;
AcksReceivedPerRequest.TryRemove(request.SeqNum, out var oldCounter);
AcksReceivedPerRequest.TryAdd(request.SeqNum, ++oldCounter);
}
if (ack.Message.GetType() == typeof(TakeRemove))
{
TakeRemove takeRemove = (TakeRemove)ack.Message;
AcksReceivedPerRequest.TryRemove(takeRemove.TakeRequestSeqNumber, out var oldCounter);
AcksReceivedPerRequest.TryAdd(takeRemove.TakeRequestSeqNumber, ++oldCounter);
}
}
public override Tuple Take(Tuple tuple)
{
int timeStep = 250; // ms
List <Message> messages = null;
Message resultMessage = null;
List <Tuple> intersection = new List <Tuple>();
Tuple selectedTuple = new Tuple(new List <object>());
// PHASE 1
var takeRequest = new TakeRequest(ClientRequestSeqNumber, EndpointURL, tuple);
// wait for all responses
MulticastMessageWaitAll(View.Nodes, takeRequest);
WaitMessage(takeRequest, View.Nodes);
ClientRequestSeqNumber++;
lock (ReplyResultQueue)
{
ReplyResultQueue.TryGetValue(takeRequest, out var replyResult);
messages = new List <Message>(replyResult?.GetAllResults());
}
// get the intersection
Response response;
intersection = ((Response)messages.First()).Tuples;
foreach (Message msg in messages)
{
response = (Response)msg;
intersection = new List <Tuple>(intersection.Intersect(response.Tuples));
}
// choose random tuple from intersection
selectedTuple = intersection.ElementAt((new Random()).Next(0, intersection.Count));
// phase 2, issue a take remove and wait for all acks
Message takeRemove = new TakeRemove(EndpointURL, selectedTuple, takeRequest.SeqNum);
MulticastMessageWaitAll(View.Nodes, takeRemove);
WaitMessage(takeRemove, View.Nodes);
return(selectedTuple);
}
/**
* Remove the selected tuple and add the remaining locked tuples back to the tuplespace
*/
private Message ProcessTakeRemove(Message message)
{
TakeRemove takeRemove = (TakeRemove)message;
LockedTuples.TryRemove(takeRemove.TakeRequestSeqNumber, out List <Tuple> lockedTuples);
// remove the selected tuple specified in the request
if (lockedTuples != null && takeRemove.SelectedTuple != null)
{
lockedTuples.Remove(takeRemove.SelectedTuple);
// add back the remaining tuples to the tuple space
foreach (Tuple tuple in lockedTuples)
{
TupleSpace.Write(tuple);
}
}
// Send back an Ack of the remove
Ack ack = new Ack(EndpointURL, takeRemove);
SendMessageToRemoteURL(takeRemove.SrcRemoteURL, ack);
return(ack);
}
