public void ruN(int index1)
{
StringBuilder result = new StringBuilder("");
List<Client> clientList = Server.getInstance().getShallowCopyClients();
Client[] clients = clientList.ToArray();
Client[] clientsOtherThanThis = Server.getInstance()
.getClientsArrayOtherThan(clients[index1]);
//set the state of this client to wanted, because
//it wants to access critical section
clients[index1].setWanted(true);
//and before submitting request, the client must update its
//logical clock, so
//update clock, which will increment default timestamp
//basically Ricart&Agrawala is using extended Lamport clock
//in extended lamport clock, for each send event, the node
//has to update its clock (increment timestamp)
clients[index1].updateClock();
Client clienT = new Client(Server.getInstance().getSocketAddress(), Utils.getDefaultSocketAddress());
object reply = null;
node = clienT.nodeList.Values.Last();
foreach( Client client in clientsOtherThanThis)
{
bool isRequestSendingOK = false;
try
{
Console.WriteLine("Client " + clients[index1].getIP()
+ " with timeStamp " + clients[index1].getClock()
+ " sending \"request\" to client " + client.getIP()
+ "\n");
result.Append("Client " + clients[index1].getIP()
+ " with timeStamp " + clients[index1].getClock()
+ " sending \"request\" to client " + client.getIP()
+ "\n");
reply = node.sendmessage("request", clients[index1].getIP(), clients[index1].getClock(), client.getIP());
//if we have reached here request sending has been successful
isRequestSendingOK = true;
}
catch(Exception e)
{
Console.WriteLine("Exception while executing the "
+ "RequestProcessor.sendMessage method for"
+ " each client other than this client");
result.Append("Exception while executing the "
+ "RequestProcessor.sendMessage method for"
+ " each client other than this client\n");
}
if (isRequestSendingOK)
{
//cast reply to string
string replyString = (string)reply;
if (replyString.Contains(","))
{
//now split and get OK sender's timestamp
string[] splitComponents = replyString.Split(',');
if (splitComponents[0].Equals("OK", StringComparison.InvariantCultureIgnoreCase))
{
//update the logical clock, when received OK
//from the other node, because it is receive event
clients[index1].updateClock(int.Parse(splitComponents[1]));
//increment the OK count for this client
clients[index1].incrementOKCount();
}
}
}
}
//so, number of OKCount is the same as number of clients
//other than this. In other words, if received "OK" from
//all clients that this client has sent the request to
while (clients[index1].getOKCount() != clientsOtherThanThis.Length)
{
//wait
}
if (clients[index1].getOKCount() == clientsOtherThanThis.Length)
{
//now this client can enter the critical section
//set the using flag for this client
clients[index1].setUsing(true);
Server.getInstance().assignToCriticalSection(clients[index1].getIP());
// get the random English word
string randomEnglishWord = Server.getInstance().generateRandomEnglishWord();
// method to write this generated word to
// client's
// buffer to check it later whether or not
// written
// word exists in the resulting master string
clients[index1].rememberWord(randomEnglishWord);
// now enter the critical section where the word
// will be written
// to the coordinator's master string
// boolean variable to hold whether
// criticalSection entrance was OK
bool isCriticalSectionSuccess = false;
try
{
// params will contain the client's ip who
// will enter
// the critical section and and the
// randomEnglishWord
reply = node.enterCS(clients[index1].getIP(), randomEnglishWord);
// reply could be like
// "Node with ip has written some word"
Console.WriteLine((string)reply);
result.Append((string)reply);
//if we have reached here critical section completed successfully
isCriticalSectionSuccess = true;
}
catch (Exception e)
{
Console.WriteLine("Exception while calling method"
+ " RequestProcessor.enterCS\n");
}
if (isCriticalSectionSuccess)
{
// update clock when sending OK
clients[index1].updateClock();
int oksSent = 0;
int numberOfNodesOkToBeSent = clients[index1].getRequestQueue().Count();
//get the queue, send OK to all processes in own queue
//and empty queue.
foreach (string IP in clients[index1].getRequestQueue())
{
try
{
result.Append("Client " + clients[index1].getIP()
+ " with timeStamp " + clients[index1].getClock()
+ " sending \"OK\" to client " + IP
+ "\n");
node.sendmessage("OK", clients[index1].getIP(), clients[index1].getClock(), IP);
oksSent++;
}
catch (Exception e)
{
Console.WriteLine("Exception while executing the "
+ "RequestProcessor.sendMessage method for"
+ " each client other than this client");
}
}
//if all oks sent successfully
if (oksSent == numberOfNodesOkToBeSent)
{
Server.getInstance().removeFromCriticalSection(clients[index1].getIP());
//now empty queue, set using and wanted flags to false
//and resetOKCount to 0.
clients[index1].emptyRequestQueue();
clients[index1].setUsing(false);
clients[index1].setWanted(false);
clients[index1].resetOKCount();
}
}
}
}
public string receiveMessage(string message, string requesterIP)
{
// if the received message is "request"
if (message.Equals("request", StringComparison.InvariantCultureIgnoreCase))
{
//if critical section is empty, access has to be granted
if (Server.getInstance().isCriticalSectionEmpty())
{
// so send "GRANTED"
Server.getInstance().assignToCriticalSection(requesterIP);
return "GRANTED";
}
else // someone is in the critical section
{
// queue the request, return DENIED
Server.getInstance().queueRequest(requesterIP);
return "DENIED";
}
}
else if (message.Equals("release", StringComparison.InvariantCultureIgnoreCase))
{
// requester is done with critical section
// remove the requesterIP from critical section
Server.getInstance().removeFromCriticalSection(requesterIP);
// if queue is not empty, dequeue first and reply "GRANTED"
if (!Server.getInstance().isQueueEmpty())
{
string newRequesterIP = Server.getInstance().dequeue();
//assign critical section new enterer ip
Server.getInstance().assignToCriticalSection(newRequesterIP);
//print out who is the new enterer
Console.WriteLine("New Critical Section Enterer IP: " + newRequesterIP);
Client client = Server.getInstance().getClientByIP(newRequesterIP);
// get the random English word
string randomEnglishWord = Server.getInstance()
.generateRandomEnglishWord();
// method to write this generated word to
// client's
// buffer to check it later whether or not
// written
// word exists in the resulting master string
client.rememberWord(randomEnglishWord);
try
{
node = client.nodeList.Values.Last();
object reply = node.enterCS(client.getIP(),randomEnglishWord);
Console.WriteLine((string)reply);
}
catch (Exception e)
{
Console.WriteLine("Exception while calling method"
+ " RequestProcessor.enterCS\n");
}
//to prevent deadlock, because the same thread can
//access the sendMessage again
ThreadStart threadDelegate = new ThreadStart(run);
Thread tempThread = new Thread(threadDelegate);
tempThread.Start();
return "GRANTED";
}
else // queue is already empty, so reply GRANTED
{
return "GRANTED";
}
}
else
{
return "GRANTED";
}
}
public void ruN(int index1)
{
StringBuilder result = new StringBuilder("");
List <Client> clientList = Server.getInstance().getShallowCopyClients();
Client[] clients = clientList.ToArray();
Client[] clientsOtherThanThis = Server.getInstance()
.getClientsArrayOtherThan(clients[index1]);
//set the state of this client to wanted, because
//it wants to access critical section
clients[index1].setWanted(true);
//and before submitting request, the client must update its
//logical clock, so
//update clock, which will increment default timestamp
//basically Ricart&Agrawala is using extended Lamport clock
//in extended lamport clock, for each send event, the node
//has to update its clock (increment timestamp)
clients[index1].updateClock();
Client clienT = new Client(Server.getInstance().getSocketAddress(), Utils.getDefaultSocketAddress());
object reply = null;
node = clienT.nodeList.Values.Last();
foreach (Client client in clientsOtherThanThis)
{
bool isRequestSendingOK = false;
try
{
Console.WriteLine("Client " + clients[index1].getIP()
+ " with timeStamp " + clients[index1].getClock()
+ " sending \"request\" to client " + client.getIP()
+ "\n");
result.Append("Client " + clients[index1].getIP()
+ " with timeStamp " + clients[index1].getClock()
+ " sending \"request\" to client " + client.getIP()
+ "\n");
reply = node.sendmessage("request", clients[index1].getIP(), clients[index1].getClock(), client.getIP());
//if we have reached here request sending has been successful
isRequestSendingOK = true;
}
catch (Exception e)
{
Console.WriteLine("Exception while executing the "
+ "RequestProcessor.sendMessage method for"
+ " each client other than this client");
result.Append("Exception while executing the "
+ "RequestProcessor.sendMessage method for"
+ " each client other than this client\n");
}
if (isRequestSendingOK)
{
//cast reply to string
string replyString = (string)reply;
if (replyString.Contains(","))
{
//now split and get OK sender's timestamp
string[] splitComponents = replyString.Split(',');
if (splitComponents[0].Equals("OK", StringComparison.InvariantCultureIgnoreCase))
{
//update the logical clock, when received OK
//from the other node, because it is receive event
clients[index1].updateClock(int.Parse(splitComponents[1]));
//increment the OK count for this client
clients[index1].incrementOKCount();
}
}
}
}
//so, number of OKCount is the same as number of clients
//other than this. In other words, if received "OK" from
//all clients that this client has sent the request to
while (clients[index1].getOKCount() != clientsOtherThanThis.Length)
{
//wait
}
if (clients[index1].getOKCount() == clientsOtherThanThis.Length)
{
//now this client can enter the critical section
//set the using flag for this client
clients[index1].setUsing(true);
Server.getInstance().assignToCriticalSection(clients[index1].getIP());
// get the random English word
string randomEnglishWord = Server.getInstance().generateRandomEnglishWord();
// method to write this generated word to
// client's
// buffer to check it later whether or not
// written
// word exists in the resulting master string
clients[index1].rememberWord(randomEnglishWord);
// now enter the critical section where the word
// will be written
// to the coordinator's master string
// boolean variable to hold whether
// criticalSection entrance was OK
bool isCriticalSectionSuccess = false;
try
{
// params will contain the client's ip who
// will enter
// the critical section and and the
// randomEnglishWord
reply = node.enterCS(clients[index1].getIP(), randomEnglishWord);
// reply could be like
// "Node with ip has written some word"
Console.WriteLine((string)reply);
result.Append((string)reply);
//if we have reached here critical section completed successfully
isCriticalSectionSuccess = true;
}
catch (Exception e)
{
Console.WriteLine("Exception while calling method"
+ " RequestProcessor.enterCS\n");
}
if (isCriticalSectionSuccess)
{
// update clock when sending OK
clients[index1].updateClock();
int oksSent = 0;
int numberOfNodesOkToBeSent = clients[index1].getRequestQueue().Count();
//get the queue, send OK to all processes in own queue
//and empty queue.
foreach (string IP in clients[index1].getRequestQueue())
{
try
{
result.Append("Client " + clients[index1].getIP()
+ " with timeStamp " + clients[index1].getClock()
+ " sending \"OK\" to client " + IP
+ "\n");
node.sendmessage("OK", clients[index1].getIP(), clients[index1].getClock(), IP);
oksSent++;
}
catch (Exception e)
{
Console.WriteLine("Exception while executing the "
+ "RequestProcessor.sendMessage method for"
+ " each client other than this client");
}
}
//if all oks sent successfully
if (oksSent == numberOfNodesOkToBeSent)
{
Server.getInstance().removeFromCriticalSection(clients[index1].getIP());
//now empty queue, set using and wanted flags to false
//and resetOKCount to 0.
clients[index1].emptyRequestQueue();
clients[index1].setUsing(false);
clients[index1].setWanted(false);
clients[index1].resetOKCount();
}
}
}
}
public string receiveMessage(string message, string requesterIP)
{
// if the received message is "request"
if (message.Equals("request", StringComparison.InvariantCultureIgnoreCase))
{
//if critical section is empty, access has to be granted
if (Server.getInstance().isCriticalSectionEmpty())
{
// so send "GRANTED"
Server.getInstance().assignToCriticalSection(requesterIP);
return("GRANTED");
}
else // someone is in the critical section
{
// queue the request, return DENIED
Server.getInstance().queueRequest(requesterIP);
return("DENIED");
}
}
else if (message.Equals("release", StringComparison.InvariantCultureIgnoreCase))
{
// requester is done with critical section
// remove the requesterIP from critical section
Server.getInstance().removeFromCriticalSection(requesterIP);
// if queue is not empty, dequeue first and reply "GRANTED"
if (!Server.getInstance().isQueueEmpty())
{
string newRequesterIP = Server.getInstance().dequeue();
//assign critical section new enterer ip
Server.getInstance().assignToCriticalSection(newRequesterIP);
//print out who is the new enterer
Console.WriteLine("New Critical Section Enterer IP: " + newRequesterIP);
Client client = Server.getInstance().getClientByIP(newRequesterIP);
// get the random English word
string randomEnglishWord = Server.getInstance()
.generateRandomEnglishWord();
// method to write this generated word to
// client's
// buffer to check it later whether or not
// written
// word exists in the resulting master string
client.rememberWord(randomEnglishWord);
try
{
node = client.nodeList.Values.Last();
object reply = node.enterCS(client.getIP(), randomEnglishWord);
Console.WriteLine((string)reply);
}
catch (Exception e)
{
Console.WriteLine("Exception while calling method"
+ " RequestProcessor.enterCS\n");
}
//to prevent deadlock, because the same thread can
//access the sendMessage again
ThreadStart threadDelegate = new ThreadStart(run);
Thread tempThread = new Thread(threadDelegate);
tempThread.Start();
return("GRANTED");
}
else // queue is already empty, so reply GRANTED
{
return("GRANTED");
}
}
else
{
return("GRANTED");
}
}
