public async Task <bool> ConnectAsync(IEnumerable <string> hostnames, int port)
{
foreach (var hostname in hostnames)
{
IPAddress[] ipAddresses;
try
{
ipAddresses = await Dns.GetHostAddressesAsync(hostname).ConfigureAwait(false);
}
catch (SocketException)
{
// name couldn't be resolved
continue;
}
// need to try IP Addresses one at a time: https://github.com/dotnet/corefx/issues/5829
foreach (var ipAddress in ipAddresses)
{
Socket socket = null;
try
{
socket = new Socket(SocketType.Stream, ProtocolType.Tcp);
#if NETSTANDARD1_3
await socket.ConnectAsync(ipAddress, port).ConfigureAwait(false);
#else
await Task.Factory.FromAsync(socket.BeginConnect, socket.EndConnect, hostname, port, null).ConfigureAwait(false);
#endif
}
catch (SocketException)
{
Utility.Dispose(ref socket);
continue;
}
m_socket = socket;
m_transmitter = new PacketTransmitter(m_socket);
m_state = State.Connected;
return(true);
}
}
return(false);
}
private async Task <bool> OpenSocketAsync(IEnumerable <string> hostnames, int port, IOBehavior ioBehavior, CancellationToken cancellationToken)
{
foreach (var hostname in hostnames)
{
IPAddress[] ipAddresses;
try
{
#if NETSTANDARD1_3
// Dns.GetHostAddresses isn't available until netstandard 2.0: https://github.com/dotnet/corefx/pull/11950
ipAddresses = await Dns.GetHostAddressesAsync(hostname).ConfigureAwait(false);
#else
if (ioBehavior == IOBehavior.Asynchronous)
{
ipAddresses = await Dns.GetHostAddressesAsync(hostname).ConfigureAwait(false);
}
else
{
ipAddresses = Dns.GetHostAddresses(hostname);
}
#endif
}
catch (SocketException)
{
// name couldn't be resolved
continue;
}
// need to try IP Addresses one at a time: https://github.com/dotnet/corefx/issues/5829
foreach (var ipAddress in ipAddresses)
{
Socket socket = null;
try
{
socket = new Socket(ipAddress.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
using (cancellationToken.Register(() => socket.Dispose()))
{
try
{
if (ioBehavior == IOBehavior.Asynchronous)
{
#if NETSTANDARD1_3
await socket.ConnectAsync(ipAddress, port).ConfigureAwait(false);
#else
await Task.Factory.FromAsync(socket.BeginConnect, socket.EndConnect, ipAddress, port, null).ConfigureAwait(false);
#endif
}
else
{
#if NETSTANDARD1_3
await socket.ConnectAsync(ipAddress, port).ConfigureAwait(false);
#else
socket.Connect(ipAddress, port);
#endif
}
}
catch (ObjectDisposedException ex) when(cancellationToken.IsCancellationRequested)
{
throw new MySqlException("Connect Timeout expired.", ex);
}
}
}
catch (SocketException)
{
Utility.Dispose(ref socket);
continue;
}
m_socket = socket;
m_transmitter = new PacketTransmitter(m_socket);
m_state = State.Connected;
return(true);
}
}
return(false);
}
