/// <summary>
/// Checks if server at the given location is alive
/// </summary>
/// <param name="serverUrl">Server URL</param>
/// <returns>True if the server is alive; false otherwise.</returns>
public bool TryConnection(string serverUrl, bool tryRemove)
{
TSMan.CheckFreeze();
TSMan.CheckDelay();
if (serverUrl.Equals(TSMan.URL))
{
return(true);
}
// Get the reference for the tuple space server
ITSpaceServer server = (ITSpaceServer)Activator.GetObject(typeof(ITSpaceServer), serverUrl);
PingDelegate del = new PingDelegate(server.Ping);
IAsyncResult asyncResult = del.BeginInvoke(TSMan.URL, null, null);
asyncResult.AsyncWaitHandle.WaitOne(5000, false);
if (asyncResult.IsCompleted)
{
try
{
del.EndInvoke(asyncResult);
return(true);
}
catch (Exception)
{
if (tryRemove)
{
TryRemoveFromView(serverUrl);
}
return(false);
}
}
if (tryRemove)
{
TryRemoveFromView(serverUrl);
}
return(false);
}
public TSpaceMsg SMRProcessRequest(TSpaceMsg msg)
{
TSMan.CheckFreeze();
TSMan.CheckDelay();
lock (AggredOperations)
{
if (msg.Code != "proposeSeq")
{
AggredOperations[msg.OperationID] = msg.SequenceNumber;
}
else
{
//Console.WriteLine("Not Agreed: " + msg.OperationID);
}
}
TSpaceMsg response = new TSpaceMsg
{
ProcessID = TSMan.URL,
OperationID = msg.OperationID,
RequestID = msg.RequestID,
MsgView = TSMan.GetTotalView()
};
// Verifying View! Wrong view sends updated view
if (!TSMan.ValidView(msg))
{
Console.WriteLine("Wrong View ( s = " + TSMan.ServerView.ID + "; c = " + msg.MsgView.ID + " )");
return(TSMan.CreateBadViewReply(msg));
}
lock (TSpaceAdvManager.ProcessedRequests)
{
// Check if request as already been processed
if (TSpaceAdvManager.ProcessedRequests.Contains(msg.RequestID))
{
// Check if it was processed in a previous viwew
if (TSpaceAdvManager.ProcessedRequests.GetByKey(msg.RequestID).Request.MsgView.ID < TSMan.ServerView.ID)
{
//Console.WriteLine(TSMan.ServerView.ID);
TSpaceAdvManager.ProcessedRequests.UpdateView(msg.RequestID, TSMan.ServerView);
TSpaceMsg resp = TSpaceAdvManager.ProcessedRequests.GetByKey(msg.RequestID).Response;
if (resp == null)
{
Console.WriteLine("NULL RESPONSE SAVED");
return(null);
}
return(resp);
}
else
{
response.Code = "Repeated";
return(response);
}
}
Console.WriteLine("Starting processing of request " + msg.RequestID);
// Add sequence number of request to processed requests
TSpaceAdvManager.ProcessedRequests.Add(msg);
}
string command = msg.Code;
Message update = null;
// Sequence number proposal request
if (command.Equals("proposeSeq"))
{
lock (AggredOperations)
{
//Already was executed corresponsing operation
if (AggredOperations.ContainsKey(msg.OperationID))
{
response.Code = "proposedSeq";
response.SequenceNumber = AggredOperations[msg.OperationID];
return(response);
}
lock (MessageQueue)
{
// Increment sequence number
Interlocked.Increment(ref SequenceNumber);
}
response.SequenceNumber = SequenceNumber;
response.Code = "proposedSeq";
AddMessageToQueue(msg);
}
Console.WriteLine("Proposing (id = " + msg.OperationID + "; seq = " + response.SequenceNumber + ")");
return(response);
}
// Message with agreed sequence number
else
{
//Update message queue with agreed seq number
update = UpdateMessage(msg.OperationID, msg.SequenceNumber);
if (update == null)
{
Console.WriteLine("Err: operation message not in queue");
//response.Code = "Err";
}
}
//Wait for the message head of queue
Monitor.Enter(MessageQueue);
while (MessageQueue.Count == 0 || !MessageQueue[0].MessageID.Equals(msg.OperationID))
{
TSMan.FinishedProcessing();
Monitor.Wait(MessageQueue, 500);
TSMan.Processing();
}
Monitor.Exit(MessageQueue);
Console.WriteLine("Execute operation " + msg.OperationID + ": code = " + command);
// Execute the operation
if (TSMan.Verbose)
{
Console.WriteLine(msg);
}
switch (command)
{
case "add":
lock (TakeLock)
{
if (msg.Tuple == null)
{
response.Code = "ERR";
break;
}
TSMan.TSpace.Add(msg.Tuple);
response.Code = "ACK";
break;
}
case "read":
if (msg.Tuple == null)
{
response.Code = "ERR";
break;
}
response.Tuple = TSMan.TSpace.Read(msg.Tuple);
response.Code = "OK";
if (response.Tuple == null)
{
Console.WriteLine("Match not Found");
}
break;
case "take1":
lock (TakeLock)
{
if (msg.Tuple == null)
{
response.Code = "ERR";
break;
}
// Get matching tuple
response.Tuple = TSMan.TSpace.Read(msg.Tuple);
response.Code = "OK";
if (response.Tuple != null)
{
// Delete it
TSMan.TSpace.Take2(response.Tuple);
}
}
response.Code = "OK";
break;
case "take2":
Console.WriteLine("Current Tuple Space not in XL mode");
response.Code = "ERR";
break;
// Operation exclusive of the XL Tuple Space
case "releaseLocks":
lock (TakeLock)
response.Code = "ERR";
Console.WriteLine("Current Tuple Space not in XL mode");
break;
default:
Console.WriteLine("Invalid command.");
break;
}
RemoveFromQueue(msg.OperationID);
return(response);
}