private void GetHostEntryCallBack(IAsyncResult ar)
{
GetHostEntryState state = ar.AsyncState as GetHostEntryState;
if (state != null)
{
try
{
state.resolvedIPs = Dns.EndGetHostEntry(ar);
state.resetEvent.Set();
}
catch (SocketException sex)
{
state.exception = sex;
state.resetEvent.Set();
}
}
else
{
state.exception = new SocketException((int)SocketError.HostNotFound);
state.resetEvent.Set();
}
}
private IPHostEntry GetHostEntry()
{
GetHostEntryState state = new GetHostEntryState();
IPHostEntry hostEntry = null;
try
{
Dns.BeginGetHostEntry(Host, getHostEntryCallBack, state);
if (!state.resetEvent.WaitOne(2000, false))
{
state.resetEvent.Reset();
throw new SocketException((int)SocketError.HostNotFound);
}
else
{
if (state.exception != null)
{
//done this way because the CallBack is on another thread,
//so any exceptions it throws will not be caught by calling code
throw state.exception;
}
else
{
state.resetEvent.Reset();
}
hostEntry = state.resolvedIPs;
}
}
catch (Exception ex)
{
if (RelayNodeMapping.log.IsErrorEnabled)
{
RelayNodeMapping.log.ErrorFormat("Error getting IP address for host '{0}': {1}", Host, ex.Message);
}
}
return(hostEntry);
}