SIPSorcery.SIP.SIPTransaction.FireTransactionRemoved C# (CSharp) Method

        public void FireTransactionRemoved()
        {
            try
            {
                if (TransactionRemoved != null)
                {
                    TransactionRemoved(this);
                }
            }
            catch (Exception excp)
            {
                logger.Error("Exception FireTransactionRemoved. " + excp.Message);
            }
        }

        public void RemoveExpiredTransactions()
        {
            try
            {
                lock (m_transactions)
                {
                    List <string> expiredTransactionIds = new List <string>();

                    foreach (SIPTransaction transaction in m_transactions.Values)
                    {
                        if (transaction.TransactionType == SIPTransactionTypesEnum.Invite)
                        {
                            if (transaction.TransactionState == SIPTransactionStatesEnum.Confirmed)
                            {
                                // Need to wait until the transaction timeout period is reached in case any ACK re-transmits are received.
                                if (DateTime.Now.Subtract(transaction.CompletedAt).TotalMilliseconds >= m_t6)
                                {
                                    expiredTransactionIds.Add(transaction.TransactionId);
                                }
                            }
                            else if (transaction.TransactionState == SIPTransactionStatesEnum.Completed)
                            {
                                if (DateTime.Now.Subtract(transaction.CompletedAt).TotalMilliseconds >= m_t6)
                                {
                                    expiredTransactionIds.Add(transaction.TransactionId);
                                }
                            }
                            else if (transaction.HasTimedOut)
                            {
                                // For INVITES need to give timed out transactions time to send the reliable repsonses and receive the ACKs.
                                if (DateTime.Now.Subtract(transaction.TimedOutAt).TotalSeconds >= m_t6)
                                {
                                    expiredTransactionIds.Add(transaction.TransactionId);
                                }
                            }
                            else if (transaction.TransactionState == SIPTransactionStatesEnum.Proceeding)
                            {
                                if (DateTime.Now.Subtract(transaction.Created).TotalMilliseconds >= m_maxRingTime)
                                {
                                    // INVITE requests that have been ringing too long.
                                    transaction.HasTimedOut     = true;
                                    transaction.TimedOutAt      = DateTime.Now;
                                    transaction.DeliveryPending = false;
                                    transaction.DeliveryFailed  = true;
                                    transaction.FireTransactionTimedOut();
                                }
                            }
                            else if (DateTime.Now.Subtract(transaction.Created).TotalMilliseconds >= m_t6)
                            {
                                //logger.LogDebug("INVITE transaction (" + transaction.TransactionId + ") " + transaction.TransactionRequestURI.ToString() + " in " + transaction.TransactionState + " has been alive for " + DateTime.Now.Subtract(transaction.Created).TotalSeconds.ToString("0") + ".");

                                if (transaction.TransactionState == SIPTransactionStatesEnum.Calling ||
                                    transaction.TransactionState == SIPTransactionStatesEnum.Trying)
                                {
                                    transaction.HasTimedOut     = true;
                                    transaction.TimedOutAt      = DateTime.Now;
                                    transaction.DeliveryPending = false;
                                    transaction.DeliveryFailed  = true;
                                    transaction.FireTransactionTimedOut();
                                }
                            }
                        }
                        else if (transaction.HasTimedOut)
                        {
                            expiredTransactionIds.Add(transaction.TransactionId);
                        }
                        else if (DateTime.Now.Subtract(transaction.Created).TotalMilliseconds >= m_t6)
                        {
                            if (transaction.TransactionState == SIPTransactionStatesEnum.Calling ||
                                transaction.TransactionState == SIPTransactionStatesEnum.Trying ||
                                transaction.TransactionState == SIPTransactionStatesEnum.Proceeding)
                            {
                                //logger.LogWarning("Timed out transaction in SIPTransactionEngine, should have been timed out in the SIP Transport layer. " + transaction.TransactionRequest.Method + ".");
                                transaction.DeliveryPending = false;
                                transaction.DeliveryFailed  = true;
                                transaction.TimedOutAt      = DateTime.Now;
                                transaction.HasTimedOut     = true;
                                transaction.FireTransactionTimedOut();
                            }

                            expiredTransactionIds.Add(transaction.TransactionId);
                        }
                    }

                    foreach (string transactionId in expiredTransactionIds)
                    {
                        if (m_transactions.ContainsKey(transactionId))
                        {
                            SIPTransaction expiredTransaction = m_transactions[transactionId];
                            expiredTransaction.FireTransactionRemoved();
                            RemoveTransaction(expiredTransaction);
                        }
                    }
                }

                //PrintPendingTransactions();
            }
            catch (Exception excp)
            {
                logger.LogError("Exception RemoveExpiredTransaction. " + excp.Message);
            }
        }