internal override ReplyData HandleRequest(RequestData requestData, int requestNum)
{
Random random = new Random();
int delayValue = random.Next(minDelay, maxDelay);
Thread.Sleep(delayValue);
while (freezed || requestNum < currentReq)
{
Thread.Sleep(200);
}
Utils.Print("[*] SMRServer: Handle Request.");
if (CheckOldMsg(requestData))
{
return(new DiscardedMsgReply(requestData.RequestId));
}
if (CheckOldView(requestData))
{
return(new ViewProposal(viewManager.GetView(), ServerData));
}
holdbackQueue.Add(requestData.RequestId, requestData);
Utils.Print(" [*] SMR Server: Added to Holdback Queue.", verbose: Verbose);
Utils.Print($" [*] SMR Server: Request ID: {requestData.RequestId}.", verbose: Verbose);
View view = viewManager.GetView();
string leaderUId = view.ManagerUId;
ServerData leaderData = view.Find(leaderUId);
if (leaderData.Equals(ServerData)) // As the View Leader.
{
int requestId = requestData.RequestId;
Utils.Print($" [*] SMR Server Sequencer: Request ID: {requestId}.", verbose: Verbose);
//If the message received is not the following message of the previously received
//from the same Client, the message is added to the hold back list, to ensure FIFO
//ordering.
int lastClientMessageId = mIdTable[requestData.ClientId];
Utils.Print($" [*] SMR Server Sequencer: Last Client Request ID: {lastClientMessageId}.", verbose: Verbose);
if (requestId > lastClientMessageId + 1)
{
holdbackQueueSequencer.Add(requestId, requestData);
return(null);
}
SendTotalOrder(requestData.ClientId, requestId);
return(null);
}
CheckDeliveryQueue();
return(null);
}
internal ReplyData Take(RequestData requestData)
{
ViewManager viewM = viewManager;
View view = viewM.GetView();
ServerData leaderData = view.Find(view.ManagerUId);
if (leaderData.Equals(ServerData)) // As the View Leader.
{
receiveTakeTupleFromLeader.Reset();
List <List <DIDATuple> > serversMatchingTuples = new List <List <DIDATuple> >();
List <ServerData> replicasList = viewManager.GetKnownReplicas();
Utils.Print($" [*] SMR Server Leader: Calling {replicasList.Count()} servers.", verbose: Verbose);
foreach (ServerData serverData in replicasList)
{
if (!serverData.Equals(leaderData))
{
string serverProxyURL = $"tcp://{serverData.ServerURL}/{serverData.ServerName}";
ISMRServerService serverProxy = (ISMRServerService)Activator.GetObject(typeof(ISMRServerService), serverProxyURL);
try
{
List <DIDATuple> matchingTuples = serverProxy.SendMatchingTuples(requestData.TupleData);
serversMatchingTuples.Add(matchingTuples);
}
catch (SocketException)
{
viewManager.TryViewChange(viewManager.GetKnownReplicas());
}
}
}
serversMatchingTuples.Add(GetMatchingTuples(requestData.TupleData));
PrintTuplesListsList(serversMatchingTuples);
DIDATuple takeTuple = GetRandomIntersectedTuple(serversMatchingTuples);
if (takeTuple == null)
{
return(new NoTupleFoundReply(requestData.RequestId));
}
Utils.Print($" [*] SMR Server Leader: Taking {takeTuple}.", verbose: Verbose);
// Removed tuple from all replicas.
foreach (ServerData serverData in replicasList)
{
string serverProxyURL = $"tcp://{serverData.ServerURL}/{serverData.ServerName}";
ISMRServerService serverProxy = (ISMRServerService)Activator.GetObject(typeof(ISMRServerService), serverProxyURL);
RequestData leaderTakeRequestData = new RequestData(0, 0, "", "", takeTuple, EOperationType.Take);
try
{
serverProxy.ReceiveTakeTuple(leaderTakeRequestData);
}
catch (SocketException)
{
viewManager.TryViewChange(viewManager.GetKnownReplicas());
}
}
object toRemove = takeTuple;
if (tupleSpace.TryTake(out toRemove))
{
return(new TupleReply(requestData.RequestId, takeTuple));
}
else
{
return(new NoTupleFoundReply(requestData.RequestId)); // Should be impossible to execute this else.
}
}
// As a follower.
else
{
receiveTakeTupleFromLeader.WaitOne(); // Waits for the signal of when the Take Tuple arrives.
// After receiving the Tuple from the Leader, for the Take Operation.
DIDATuple takeTuple = takeTupleFromLeader.TupleData;
Utils.Print($" [*] SMR Server: Taking {takeTuple}.", verbose: Verbose);
if (takeTuple == null)
{
return(new NoTupleFoundReply(requestData.RequestId));
}
object toRemove = takeTuple;
if (tupleSpace.TryTake(out toRemove))
{
return(new TupleReply(requestData.RequestId, takeTuple));
}
else
{
return(new NoTupleFoundReply(requestData.RequestId)); // Should be impossible to execute this else.
}
// Add send Leader an Ack.
}
}