/**********************************************************************
* 2PC protocol section
* TODO: Maybe it could be in another section (like a different class)
**********************************************************************/
/**********************************************************************
* COORDINATOR part
**********************************************************************/
// This method is only called by the coordinator
// URLs is the list of participants of transaction txID
internal static bool Commit(int txID, List <String> URLs)
{
try
{
Console.WriteLine("Datastore.Commit: Commit do Datastore");
TentativeTx tx = _tentativeTransactions[txID];
tx.COORDINATOR = new CoordinatorManager(tx, URLs);
tx.COORDINATOR.prepare();
if (tx.COORDINATOR.MY_DECISION.Equals(TransactionDecision.ABORT))
{
return(false);
}
addValues(tx.WRITTENOBJECTS);
// Send an update to the replica if there is one
if (Replica.updateSucessor(tx.WRITTENOBJECTS).Equals(UpdateState.COMMIT))
{
return(true);
}
return(false);
}
catch (Exception)
{
Console.WriteLine("CATCH IN COMMIT");
return(false);
}
}
// Only for participants
internal void doCommit(int txID, string coordURL)
{
_myCoordinatorDecision = TransactionDecision.COMMIT;
Replica.updateSucessor(TX.WRITTENOBJECTS);
// writePermanentLog();
endTimer();
}
// TODO: should run a separate thread to receive replies
// only the coordinator should call this
internal void prepare()
{
lock (_participantURLs)
{
Console.WriteLine("I'm the coordinator: " + MY_URL);
if (_participantURLs.Count > 0)
{
foreach (String url in _participantURLs.Keys)
{
// TODO: A thread per participant
// after all thread are sent, create one main thread responsible
// for receiving votes (yes or no) - Assync callback (ver exemplo da aula 4)
// and another one to run the timer
Console.WriteLine("URL: " + url);
IParticipant participant = (IParticipant)Activator.GetObject(typeof(IParticipant), url);
//participant.canCommit(TX.TXID, MY_URL);
// Create delegate to remote method
RemoteAsyncDelegate RemoteDel = new RemoteAsyncDelegate(participant.canCommit);
// Call delegate to remote method
IAsyncResult RemAr = RemoteDel.BeginInvoke(TX.TXID, MY_URL, null, null);
// Wait for the end of the call and then explictly call EndInvoke
//RemAr.AsyncWaitHandle.WaitOne();
//Console.WriteLine(RemoteDel.EndInvoke(RemAr));
}
timer(10000);
MY_DECISION = waitParticipantsResponse();
evaluateMyDecision();
}
else
{
// Coordinator decision
// Default commit
MY_DECISION = TransactionDecision.COMMIT;
Console.WriteLine("AFTER MY_DECISION is commit and there are no participants");
// Send an update to the replica if there is one
Replica.updateSucessor(TX.WRITTENOBJECTS);
}
// First phase of commit, temporary write to disk
//writeAheadLog();
// if (MY_DECISION.Equals(TransactionDecision.COMMIT))
//writePermanentLog();
}
}
internal static void doCommit(int txID, string coordURL)
{
TentativeTx tx = _tentativeTransactions[txID];
tx.PARTICIPANT.doCommit(txID, coordURL);
// Send an update to the replica if there is one
Console.WriteLine("MY OBJECTS ARE : ");
//replaceValue(tx.WRITTENOBJECTS);
addValues(tx.WRITTENOBJECTS);
/*
* foreach (ServerObject o in SERVEROBJECTS)
* {
* Console.WriteLine("\t UID= " + o.UID + " VALUE=" + o.VALUE);
* }
*/
Replica.updateSucessor(tx.WRITTENOBJECTS);
}
