/// <summary>
/// Opens a database connection with the property settings specified by the
/// <see cref="NpgsqlConnection.ConnectionString">ConnectionString</see>.
/// </summary>
public override void Open()
{
// If we're postponing a close (see doc on this variable), the connection is already
// open and can be silently reused
if (_postponingClose)
{
return;
}
CheckConnectionClosed();
NpgsqlEventLog.LogMethodEnter(LogLevel.Debug, CLASSNAME, "Open");
// Check if there is any missing argument.
if (!settings.ContainsKey(Keywords.Host))
{
throw new ArgumentException("Exception_MissingConnStrArg: " + Keywords.Host);
}
if (!settings.ContainsKey(Keywords.UserName) && !settings.ContainsKey(Keywords.IntegratedSecurity))
{
throw new ArgumentException("Exception_MissingConnStrArg: " + Keywords.UserName);
}
// Get a Connector, either from the pool or creating one ourselves.
if (Pooling)
{
connector = NpgsqlConnectorPool.ConnectorPoolMgr.RequestConnector(this);
}
else
{
connector = new NpgsqlConnector(this);
connector.Open();
}
connector.Notice += NoticeDelegate;
connector.Notification += NotificationDelegate;
if (SyncNotification)
{
connector.AddNotificationThread();
}
if (Enlist)
{
Promotable.Enlist(Transaction.Current);
}
OpenCounter++;
this.OnStateChange(new StateChangeEventArgs(ConnectionState.Closed, ConnectionState.Open));
}
/// <summary>
/// Find an available pooled connector in the non-shared pool, or create
/// a new one if none found.
/// </summary>
private NpgsqlConnector GetPooledConnector(NpgsqlConnection Connection)
{
ConnectorQueue Queue = null;
NpgsqlConnector Connector = null;
do
{
if (Connector != null)
{
//This means Connector was found to be invalid at the end of the loop
lock (Queue)
{
Queue.Busy.Remove(Connector);
}
Connector.Close();
Connector = null;
}
// We only need to lock all pools when trying to get one pool or create one.
lock (locker)
{
// Try to find a queue.
if (!PooledConnectors.TryGetValue(Connection.ConnectionString, out Queue))
{
Queue = new ConnectorQueue();
Queue.ConnectionLifeTime = Connection.ConnectionLifeTime;
Queue.MinPoolSize = Connection.MinPoolSize;
PooledConnectors[Connection.ConnectionString] = Queue;
}
}
// Now we can simply lock on the pool itself.
lock (Queue)
{
if (Queue.Available.Count > 0)
{
// Found a queue with connectors. Grab the top one.
// Check if the connector is still valid.
Connector = Queue.Available.Dequeue();
Queue.Busy.Add(Connector, null);
}
}
} while (Connector != null && !Connector.IsValid());
if (Connector != null)
{
return(Connector);
}
lock (Queue)
{
if (Queue.Available.Count + Queue.Busy.Count < Connection.MaxPoolSize)
{
Connector = new NpgsqlConnector(Connection);
Queue.Busy.Add(Connector, null);
}
}
if (Connector != null)
{
try
{
Connector.Open();
}
catch
{
lock (Queue)
{
Queue.Busy.Remove(Connector);
}
Connector.Close();
throw;
}
// Meet the MinPoolSize requirement if needed.
if (Connection.MinPoolSize > 1)
{
lock (Queue)
{
while (Queue.Available.Count + Queue.Busy.Count < Connection.MinPoolSize)
{
NpgsqlConnector Spare = new NpgsqlConnector(Connection);
Spare.Open();
Queue.Available.Enqueue(Spare);
}
}
}
}
return(Connector);
}
