/// <summary>
/// Adds a tuple to the distributed tuple space.
/// </summary>
/// <param name="tuple">Tuple to be added.</param>
public void Add(ITuple tuple)
{
if (View.Count == 0)
{
Console.WriteLine("No tuple space servers available.");
return;
}
// Create request message
TSpaceMsg message = new TSpaceMsg();
message.Code = "add";
message.Tuple = tuple;
message.RequestID = ClientID + "_" + (++SequenceNumber);
message.MsgView = GetCurrentView();
//Clear acks
ActiveOperations.Add(message.RequestID);
AcksCounter = 0;
// Create local callback
AsyncCallback remoteCallback = new AsyncCallback(AddCallback);
// Repeat request until all replicas have acknowledged receipt
while (AcksCounter < Quorum())
{
//Send multicast message to all members of the view
this.Multicast(message, remoteCallback);
}
ActiveOperations.Remove(message.RequestID);
Console.WriteLine("Add " + (++AddCounter) + ": OK");
}
/// <summary>
/// Returns a tuple from the distributed tuple space, deleting it.
/// </summary>
/// <param name="template">Template of the requested tuple.</param>
/// <returns></returns>
public ITuple Take(ITuple template)
{
if (View.Count == 0)
{
Console.WriteLine("No tuple space servers available.");
return(null);
}
/*------------------------------------------------
* Phase 1: Selecting the tuple to be removed
* ------------------------------------------------*/
ITuple selectedTuple = null;
// Repeat phase 1 until all replicas return at least
// one common matching tuple
while (selectedTuple == null)
{
Console.WriteLine("Take 1: " + SequenceNumber);
selectedTuple = this.Take1(template);
}
Console.WriteLine("Take: Phase 1 completed");
/*------------------------------------------------
* Phase 2: Removing the selected tuple
* ------------------------------------------------*/
TSpaceMsg message = new TSpaceMsg();
message.Code = "take2";
message.Tuple = selectedTuple;
message.ProcessID = ClientID.ToString();
message.RequestID = ClientID + "_" + (++SequenceNumber);
message.MsgView = GetCurrentView();
// Create local callback.
AsyncCallback remoteCallback = new AsyncCallback(AddCallback);
//Clear acks
ActiveOperations.Add(message.RequestID);
AcksCounter = 0;
//Repeat until all replicas have acknowledged deletion
while (AcksCounter < Quorum())
{
// Send multicast request to remove tuples to all members of the view
this.Multicast(message, remoteCallback);
}
ActiveOperations.Remove(message.RequestID);
Console.WriteLine("Take: Phase 2 completed");
Console.WriteLine("Take " + (++TakeCounter) + ": OK");
return(message.Tuple);
}
public async void BeginOperation(string operationName)
{
if (CurrentDocument == null)
{
return;
}
_oldObjects.Clear();
_oldObjects.AddRange(CurrentDocument.ObjectsDictionary.Values);
CurrentDocument.ObjectsDictionary.StartAccessList();
//call operation
if (OperationsDictionary.ContainsKey(operationName))
{
var operation = (UserOperation)Activator.CreateInstance(OperationsDictionary[operationName]);
operation.OwnerDocument = CurrentDocument;
ActiveOperations.Add(operation);
OperationReturnValue result = OperationReturnValue.CancelOperation;
Task <OperationReturnValue> task = new Task <OperationReturnValue>(operation.Execute);
try
{
task.Start();
result = await task;
}
catch (Exception e)
{
Log.Error(e.Message);
}
if (result == OperationReturnValue.EndOperation)
{
ActiveOperations.Remove(operation);
foreach (var o in new Dictionary <int, CADObject>(operation.TemporaryObjectsDictionary))
{
CurrentDocument.PostCreateCADObject(o.Value);
o.Value.LockOperation = null;
}
EndOperation(operation);
}
else
{
ActiveOperations.Remove(operation);
operation.TemporaryObjectsDictionary.Clear();
}
}
}
/****************************************************************
* AUX FUNCTIONS / CLASSES
****************************************************************/
/// <summary>
/// Determines the agreed sequence number of a message
/// </summary>
/// <param name="id">Message OperationID</param>
/// <returns>Agreed sequence number</returns>
private int GetSequenceNumber(string id)
{
//Console.WriteLine("Message " + id + " : request proposed sequence number");
// Create request message
TSpaceMsg message = new TSpaceMsg();
message.Code = "proposeSeq";
message.OperationID = id;
message.ProcessID = ClientID.ToString();
message.RequestID = ClientID + "_" + (RequestCounter++);
ActiveOperations.Add(message.RequestID);
message.SequenceNumber = -1;
message.MsgView = GetCurrentView();
// Create local callback
AsyncCallback asyncCallback = new AsyncCallback(PropesedSeqCallback);
// Clear proposed sequence number for previous messages
lock (ProposedSeq)
{
AcksCounter = 0;
ProposedSeq.Clear();
}
// Send message to all replicas until all have proposed a sequence number
while (AcksCounter < Quorum())
{
this.Multicast(message, asyncCallback);
}
int agreedSeq;
lock (ProposedSeq)
{
// Agreed sequence number = highest proposed sequence number
agreedSeq = ProposedSeq.Max();
}
Console.WriteLine("Message " + message.OperationID + " (agreedSeq = " + agreedSeq + ")");
// Remove operation from active operations
ActiveOperations.Remove(message.RequestID);
return(agreedSeq);
}
/// <summary>
/// Adds a tuple to the distributed tuple space.
/// </summary>
/// <param name="tuple">Tuple to be added.</param>
public void Add(ITuple tuple)
{
if (View.Count == 0)
{
Console.WriteLine("No tuple space servers available.");
return;
}
// Create message
TSpaceMsg request = new TSpaceMsg();
request.Code = "add";
request.Tuple = tuple;
// Create unique message identifier
request.OperationID = ClientID + "_" + (OperationCounter++);
// Get the sequence number of the request in the view
request.SequenceNumber = GetSequenceNumber(request.OperationID);
request.RequestID = ClientID + "_" + (RequestCounter++);
ActiveOperations.Add(request.RequestID);
request.MsgView = GetCurrentView();
AsyncCallback remoteCallback = new AsyncCallback(AcksCallback);
// Clear acks count
AcksCounter = 0;
// Repeat until all replicas have acknowledged receipt
while (AcksCounter < Quorum())
{
// Send request to all replicas in the view
this.Multicast(request, remoteCallback);
}
ActiveOperations.Remove(request.RequestID);
Console.WriteLine("Add " + (++AddCounter) + ": OK");
}
/// <summary>
/// Returns a tuple from the distributed tuple space, whithout deleting it.
/// </summary>
/// <param name="template">Template of the requested tuple.</param>
/// <returns></returns>
public ITuple Read(ITuple template)
{
if (View.Count == 0)
{
Console.WriteLine("No tuple space servers available.");
return(null);
}
// Create message
TSpaceMsg request = new TSpaceMsg();
request.Code = "read";
request.Tuple = template;
AsyncCallback remoteCallback = new AsyncCallback(ReadCallback);
// Clear responses to previous request
// Clear previous answers
lock (LockRef)
{
Tuple = null;
}
bool matchFound = false;
while (!matchFound)
{
// Create unique id of the request
request.RequestID = ClientID + "_" + (RequestCounter++);
ActiveOperations.Add(request.RequestID);
// Create unique message identifier
request.OperationID = ClientID + "_" + (OperationCounter++);
// Get the sequence number of the request in the view
request.SequenceNumber = this.GetSequenceNumber(request.OperationID);
request.MsgView = GetCurrentView();
AcksCounter = 0;
// Waits until one replica returns a tuple or
// all replicas answered that they dont have a match
while (AcksCounter < Quorum())
{
// Send multicast request to all members of the view
this.Multicast(request, remoteCallback);
lock (LockRef)
{
if (Tuple != null)
{
matchFound = true;
break;
}
}
}
lock (LockRef)
{
if (Tuple != null)
{
matchFound = true;
}
}
ActiveOperations.Remove(request.RequestID);
}
Console.WriteLine("Read " + (++ReadCounter) + ": OK");
// Return after the first replica answers
return(Tuple);
}
/// <summary>
/// Returns a tuple from the distributed tuple space, deleting it.
/// </summary>
/// <param name="template">Template of the tuple requested</param>
/// <returns>Tuple matching the template</returns>
public ITuple Take(ITuple template)
{
if (View.Count == 0)
{
Console.WriteLine("No tuple space servers available.");
return(null);
}
// Create message
TSpaceMsg request = new TSpaceMsg();
request.Code = "take1";
request.Tuple = template;
// Create remote callback
AsyncCallback remoteCallback = new AsyncCallback(ReadCallback);
// Clear response from last request
lock (LockRef)
{
Tuple = null;
}
// Repeat until one matching tuple is found
while (true)
{
// Create unique message identifier
request.OperationID = ClientID + "_" + (OperationCounter++);
// Get the sequence number of the request in the view
request.SequenceNumber = this.GetSequenceNumber(request.OperationID);
// Create unique identifier for the round
request.RequestID = ClientID + "_" + (RequestCounter++);
ActiveOperations.Add(request.RequestID);
request.MsgView = GetCurrentView();
//Clear acks from last request
AcksCounter = 0;
// Repeat untill all replicas have answered
while (AcksCounter < Quorum())
{
// Send take request to all members of the view
this.Multicast(request, remoteCallback);
}
// Return if there is a match
// Repeat otherwise
lock (LockRef)
{
if (Tuple != null)
{
break;
}
}
ActiveOperations.Remove(request.RequestID);
}
Console.WriteLine("Take " + (++TakeCounter) + ": OK");
return(Tuple);
}
/// <summary>
/// Returns a tuple from the distributed tuple space, whithout deleting it.
/// </summary>
/// <param name="template">Template of the requested tuple.</param>
/// <returns></returns>
public ITuple Read(ITuple template)
{
if (View.Count == 0)
{
Console.WriteLine("No tuple space servers available.");
return(null);
}
// Create request message.
TSpaceMsg message = new TSpaceMsg();
message.Code = "read";
message.Tuple = template;
message.MsgView = GetCurrentView();
// Create local callback.
AsyncCallback remoteCallback = new AsyncCallback(ReadCallback);
// Clear previous answers
lock (LockRef)
{
Tuple = null;
}
bool matchFound = false;
while (!matchFound)
{
if (message.RequestID != null && ActiveOperations.Contains(message.RequestID))
{
ActiveOperations.Remove(message.RequestID);
}
message.RequestID = ClientID + "_" + (++SequenceNumber);
ActiveOperations.Add(message.RequestID);
AcksCounter = 0;
// Waits until one replica returns a tuple or
// all replicas answered that they dont have a match
while (AcksCounter < Quorum())
{
// Send multicast message to all members of the view.
this.Multicast(message, remoteCallback);
// Return after first response
lock (LockRef)
{
if (Tuple != null)
{
matchFound = true;
break;
}
}
}
lock (LockRef)
{
if (Tuple != null)
{
matchFound = true;
}
}
}
ActiveOperations.Remove(message.RequestID);
// Return first response.
Console.WriteLine("Read " + (++ReadCounter) + ": OK");
return(Tuple);
}
/// <summary>
/// Executes the phase 1 of the take operation.
/// </summary>
/// <param name="template">Template of the requested tuple.</param>
/// <returns></returns>
private ITuple Take1(ITuple template)
{
// Create request message.
TSpaceMsg message = new TSpaceMsg();
message.Code = "take1";
message.Tuple = template;
message.ProcessID = ClientID.ToString();
message.RequestID = ClientID + "_" + (++SequenceNumber);
message.MsgView = GetCurrentView();
ActiveOperations.Add(message.RequestID);
// Clear responses from previour requests
lock (MatchingTuples)
{
AcksCounter = 0;
MatchingTuples.Clear();
}
// Create local callback.
AsyncCallback remoteCallback = new AsyncCallback(Take1Callback);
// Repeat until all replicas have responded
while (AcksCounter < Quorum())
{
//Send multicast take request to all members of the view
this.Multicast(message, remoteCallback);
}
ActiveOperations.Remove(message.RequestID);
List <ITuple> intersection;
lock (MatchingTuples)
{
// Select one tuple from the intersection of all matching tuples lists
intersection = MatchingTuples[0];
foreach (List <ITuple> tupleList in MatchingTuples)
{
intersection.Intersect(tupleList, new TupleComparator());
}
}
// If intersection = {}
// Send release locks to all replicas
if (intersection.Count == 0)
{
//Create message
message.Code = "releaseLocks";
message.RequestID = ClientID + "_" + (++SequenceNumber);
// Clear acks
ActiveOperations.Add(message.RequestID);
AcksCounter = 0;
// Create remote callback
remoteCallback = new AsyncCallback(AddCallback);
// Repeat until all replicas have acknowledged release
while (AcksCounter < Quorum())
{
//Send multicast take request to all members of the view
this.Multicast(message, remoteCallback);
}
ActiveOperations.Remove(message.RequestID);
Console.WriteLine("Take 1: intersection = {}");
return(null);
}
return(intersection[0]);
}