void IClientMonitor.MonitorReservation(Reservation res)
{
//Lock here
res.ClientStubs = LookupUsers(res);
//Unlock here
_monitoredReservations[res.ReservationID] = res;
}
private void PrepareCommitOrBookNextSlot(Reservation res, int slotID)
{
Monitor.Enter(_calendar[slotID]);
CalendarSlot calendarSlot = _calendar[slotID];
ReservationSlot slot = GetSlot(res, slotID);
if (calendarSlot.Locked || calendarSlot.State == CalendarSlotState.ASSIGNED || (calendarSlot.State == CalendarSlotState.BOOKED && res.ReservationID > calendarSlot.ReservationID))
{
Log.Show(_userName, "Booking of slot " + slotID + " of reservation " + res.ReservationID + " failed. Trying to book next slot.");
AbortReservationSlot(slot, true);
Monitor.Exit(_calendar[slotID]);
BookNextSlot(res);
}
else
{
Log.Show(_userName, "Slot " + slotID + " of reservation " + res.ReservationID + " was booked successfully. Starting commit process.");
LockCalendarSlot(res, slot);
Monitor.Exit(_calendar[slotID]);
foreach (string participantID in res.Participants)
{
if (!participantID.Equals(_userName))
{
_msgDispatcher.SendMessage(MessageType.PRE_COMMIT, res.ReservationID, participantID, slot.SlotID);
}
}
}
}
/*
* CALENDAR SHOULD BE LOCKED BEFORE CALLING THIS METHOD
*/
private void LockCalendarSlot(Reservation res, ReservationSlot resSlot)
{
//Change calendar and reservation slot states
CalendarSlot calendarSlot = _calendar[resSlot.SlotID];
calendarSlot.Locked = true;
resSlot.State = ReservationSlotState.COMMITTED;
}
private ReservationSlot GetSlotAndAbortPredecessors(Reservation res, int slotID)
{
foreach (ReservationSlot slot in res.Slots)
{
if (slot.SlotID == slotID)
{
return slot;
}
else if (slot.State != ReservationSlotState.ABORTED)
{
AbortReservationSlot(slot, false);
}
}
return null;
}
private Reservation CreateReservation(ReservationRequest req, int resID, string initiatorID, string initiatorIP, int initiatorPort)
{
Reservation thisRes = new Reservation();
thisRes.ReservationID = resID;
thisRes.Description = req.Description;
thisRes.Participants = req.Users;
thisRes.InitiatorID = initiatorID;
thisRes.InitiatorIP = initiatorIP;
thisRes.InitiatorPort = initiatorPort;
return thisRes;
}
private void CommitSlot(Reservation res, int slotID)
{
ReservationSlot slot = GetSlot(res, slotID);
Log.Show(_userName, "Slot " + slotID + " of reservation " + res.ReservationID + " was pre-committed successfully. Assigning calendar slot.");
Monitor.Enter(_calendar[slotID]);
AssignCalendarSlot(res, slot, false);
Monitor.Exit(_calendar[slotID]);
foreach (string participantID in res.Participants)
{
if (!participantID.Equals(_userName))
{
_msgDispatcher.SendMessage(MessageType.DO_COMMIT, res.ReservationID, participantID, slot.SlotID);
}
}
}
private bool CollectReply(int resID, int slotID, string userID, bool ack, out Reservation res)
{
if (!_activeReservations.TryGetValue(resID, out res))
{
Log.Show(_userName, "WARN: Received reply from unknown reservation " + resID);
return false;
}
if (res.CurrentSlot == slotID)
{
ReservationSlot slot = GetSlot(res, slotID);
Monitor.Enter(slot);
if (ack)
{
Monitor.Exit(slot);
res.Replied.Add(userID);
if (res.Replied.Count == (res.Participants.Count - 1))
{
res.Replied.Clear();
return true;
}
}
else if (slot.State != ReservationSlotState.ABORTED)
{
AbortReservationSlot(slot, false);
Monitor.Exit(slot);
_msgDispatcher.ClearMessages(res.Participants, resID);
res.Replied.Clear();
BookNextSlot(res);
}
else
{
Monitor.Exit(slot);
}
return false;
}
return false;
}
private void CleanReservation(Reservation res)
{
//Remove from list of active reservations
_activeReservations.Remove(res.ReservationID);
_committedReservations[res.ReservationID] = res;
}
/*
* AUX METHODS
*/
private void BookNextSlot(Reservation res)
{
bool booked = false;
//LOCK HERE
foreach (ReservationSlot slot in res.Slots)
{
Monitor.Enter(_calendar[slot.SlotID]);
CalendarSlot cSlot = _calendar[slot.SlotID];
if (slot.State != ReservationSlotState.ABORTED && !cSlot.Locked && (cSlot.State == CalendarSlotState.ACKNOWLEDGED || (cSlot.State == CalendarSlotState.BOOKED && res.ReservationID < cSlot.ReservationID)))
{
booked = true;
BookCalendarSlot(res, slot);
Monitor.Exit(_calendar[slot.SlotID]);
Log.Show(_userName, "Starting book process of slot " + slot.SlotID + " from reservation " + res.ReservationID);
foreach (string participantID in res.Participants)
{
if (!participantID.Equals(_userName))
{
_msgDispatcher.SendMessage(MessageType.BOOK_SLOT, res.ReservationID, participantID, slot.SlotID);
}
}
break;
}
else
{
Monitor.Exit(_calendar[slot.SlotID]);
}
}
if (!booked)
{
Log.Show(_userName, "No available slots. Aborting reservation " + res.ReservationID);
foreach (IBookingService client in res.ClientStubs.Values)
{
try
{
Log.Show(_userName, "Sending abort to client...");
AbortDelegate bookSlot = new AbortDelegate(client.AbortReservation);
IAsyncResult RemAr = bookSlot.BeginInvoke(res.ReservationID, null, null);
}
catch (SocketException e)
{
Log.Show(_userName, "ERROR: Could not connect to client. Exception: " + e);
}
}
AbortReservation(res.ReservationID);
}
}
/*
* CALENDAR SHOULD BE LOCKED BEFORE CALLING THIS METHOD
*/
private void BookCalendarSlot(Reservation res, ReservationSlot resSlot)
{
CalendarSlot calendarSlot = _calendar[resSlot.SlotID];
calendarSlot.WaitingBook.Remove(resSlot.ReservationID);
res.CurrentSlot = resSlot.SlotID;
calendarSlot.State = CalendarSlotState.BOOKED;
calendarSlot.ReservationID = resSlot.ReservationID;
resSlot.State = ReservationSlotState.TENTATIVELY_BOOKED;
}
/*
* CALENDAR SHOULD BE LOCKED BEFORE CALLING THIS METHOD
*/
private void AssignCalendarSlot(Reservation res, ReservationSlot resSlot, bool clean)
{
//Change calendar and reservation slot states
CalendarSlot calendarSlot = _calendar[resSlot.SlotID];
calendarSlot.State = CalendarSlotState.ASSIGNED;
calendarSlot.ReservationID = res.ReservationID;
calendarSlot.Participants = res.Participants;
calendarSlot.Description = res.Description;
foreach (ReservationSlot slot in res.Slots)
{
if (slot != resSlot && slot.State != ReservationSlotState.ABORTED)
{
AbortReservationSlot(slot, true);
}
}
if (clean)
{
CleanReservation(res);
}
}
private static ReservationSlot GetSlot(Reservation res, int slotID)
{
foreach (ReservationSlot slot in res.Slots)
{
if (slot.SlotID == slotID)
{
return slot;
}
}
return null;
}
private Dictionary<string, IBookingService> LookupUsers(Reservation res)
{
Dictionary<string, IBookingService> onlineUsers = new Dictionary<string, IBookingService>();
foreach (string userID in res.Participants)
{
if (!userID.Equals(_userName))
{
IBookingService client = LookupClientStub(userID);
if (client != null)
{
_msgDispatch.ClientConnected(userID, client);
onlineUsers[userID] = client;
}
}
}
return onlineUsers;
}