internal Task ValidateAndReconnect(Action beforeDisconnect, int timeout)
{
Task runningReconnect = _currentReconnectionTask;
// This loop in the end will return not completed reconnect task or null
while (runningReconnect != null && runningReconnect.IsCompleted)
{
// clean current reconnect task (if it is the same one we checked
Interlocked.CompareExchange <Task>(ref _currentReconnectionTask, null, runningReconnect);
// make sure nobody started new task (if which case we did not clean it)
runningReconnect = _currentReconnectionTask;
}
if (runningReconnect == null)
{
if (_connectRetryCount > 0)
{
SqlInternalConnectionTds tdsConn = GetOpenTdsConnection();
if (tdsConn._sessionRecoveryAcknowledged)
{
TdsParserStateObject stateObj = tdsConn.Parser._physicalStateObj;
if (!stateObj.ValidateSNIConnection())
{
if (tdsConn.Parser._sessionPool != null)
{
if (tdsConn.Parser._sessionPool.ActiveSessionsCount > 0)
{
// >1 MARS session
if (beforeDisconnect != null)
{
beforeDisconnect();
}
OnError(SQL.CR_UnrecoverableClient(ClientConnectionId), true, null);
}
}
SessionData cData = tdsConn.CurrentSessionData;
cData.AssertUnrecoverableStateCountIsCorrect();
if (cData._unrecoverableStatesCount == 0)
{
bool callDisconnect = false;
lock (_reconnectLock)
{
runningReconnect = _currentReconnectionTask; // double check after obtaining the lock
if (runningReconnect == null)
{
if (cData._unrecoverableStatesCount == 0)
{ // could change since the first check, but now is stable since connection is know to be broken
_originalConnectionId = ClientConnectionId;
_recoverySessionData = cData;
if (beforeDisconnect != null)
{
beforeDisconnect();
}
try
{
_supressStateChangeForReconnection = true;
tdsConn.DoomThisConnection();
}
catch (SqlException)
{
}
runningReconnect = Task.Run(() => ReconnectAsync(timeout));
// if current reconnect is not null, somebody already started reconnection task - some kind of race condition
Debug.Assert(_currentReconnectionTask == null, "Duplicate reconnection tasks detected");
_currentReconnectionTask = runningReconnect;
}
}
else
{
callDisconnect = true;
}
}
if (callDisconnect && beforeDisconnect != null)
{
beforeDisconnect();
}
}
else
{
if (beforeDisconnect != null)
{
beforeDisconnect();
}
OnError(SQL.CR_UnrecoverableServer(ClientConnectionId), true, null);
}
} // ValidateSNIConnection
} // sessionRecoverySupported
} // connectRetryCount>0
}
else
{ // runningReconnect = null
if (beforeDisconnect != null)
{
beforeDisconnect();
}
}
return(runningReconnect);
}
internal Task ValidateAndReconnect(Action beforeDisconnect, int timeout)
{
Task runningReconnect = _currentReconnectionTask;
// This loop in the end will return not completed reconnect task or null
while (runningReconnect != null && runningReconnect.IsCompleted)
{
// clean current reconnect task (if it is the same one we checked
Interlocked.CompareExchange <Task>(ref _currentReconnectionTask, null, runningReconnect);
// make sure nobody started new task (if which case we did not clean it)
runningReconnect = _currentReconnectionTask;
}
if (runningReconnect == null)
{
if (_connectRetryCount > 0)
{
SqlInternalConnectionTds tdsConn = GetOpenTdsConnection();
if (tdsConn._sessionRecoveryAcknowledged)
{
TdsParser tdsParser = tdsConn.Parser;
if (!tdsParser._physicalStateObj.ValidateSNIConnection())
{
if ((tdsParser._sessionPool != null) && (tdsParser._sessionPool.ActiveSessionsCount > 0))
{
// >1 MARS session
beforeDisconnect?.Invoke();
OnError(SQL.CR_UnrecoverableClient(ClientConnectionId), true, null);
}
SessionData cData = tdsConn.CurrentSessionData;
cData.AssertUnrecoverableStateCountIsCorrect();
if (cData._unrecoverableStatesCount == 0)
{
TaskCompletionSource <object> reconnectCompletionSource = new TaskCompletionSource <object>();
runningReconnect = Interlocked.CompareExchange(ref _currentReconnectionTask, reconnectCompletionSource.Task, null);
if (runningReconnect == null)
{
if (cData._unrecoverableStatesCount == 0)
{ // could change since the first check, but now is stable since connection is know to be broken
_originalConnectionId = ClientConnectionId;
_recoverySessionData = cData;
beforeDisconnect?.Invoke();
try
{
_supressStateChangeForReconnection = true;
tdsConn.DoomThisConnection();
}
catch (SqlException)
{
}
Task.Run(() => ReconnectAsync(timeout).ContinueWith(t => {
if (t.IsFaulted)
{
reconnectCompletionSource.SetException(t.Exception);
}
else if (t.IsCanceled)
{
reconnectCompletionSource.SetCanceled();
}
else
{
reconnectCompletionSource.SetResult(null);
}
}));
runningReconnect = reconnectCompletionSource.Task;
}
}
else
{
beforeDisconnect?.Invoke();
}
}
else
{
beforeDisconnect?.Invoke();
OnError(SQL.CR_UnrecoverableServer(ClientConnectionId), true, null);
}
} // ValidateSNIConnection
} // sessionRecoverySupported
} // connectRetryCount>0
}
else
{ // runningReconnect = null
beforeDisconnect?.Invoke();
}
return(runningReconnect);
}
