//Receives messages from the Mailbox. Note that the state parameter is ignored; we're already
//carrying our state in the AsyncState property of the base class. However, Receive() has to
//take a single parameter of type Object in order to be a valid WaitCallback delegate.
private void doReceive( object state )
{
Pop3 pop3 = null;
bool bCaughtException = false;
//This part does the work of connecting to the POP3 account, logging in, and
//checking for new messages. If any messages were found, they will be downloaded
//and stored in this.Messages
try
{
Mailbox box = this.AsyncState as Mailbox;
string server = box.Options.MailServer;
string username = box.Address;
string password = box.Options.MailServerPassword;
pop3 = new Pop3( );
pop3.User = username;
pop3.Password = password;
pop3.Connect( server );
if ( pop3.HasTimeStamp )
pop3.APOPLogin( );
else
pop3.Login( );
pop3.GetAccountStat( );
this.Messages = new SimpleMailMessage[ pop3.MessageCount ];
log.Debug(string.Format("pop3 check -- {0} - mail count:{1}", username, pop3.MessageCount));
//If we don't have any messages, go to sleep for a little while and try again.
//We'll keep doing this sleep/retry loop until a message shows up. That way, SoapTransport
//never has to pay any attention to us until we actually have work for it to do.
if ( pop3.MessageCount == 0 )
{
pop3.Close( );
pop3 = null;
SleepAndRetry( box.Options.RetrySeconds );
return;
}
for ( int i = 1; i <= pop3.MessageCount; i++ )
{
try
{
string message = pop3.GetMessage( i );
this.Messages[ i - 1 ] = SimpleMailMessage.Parse( message );
}
finally
{
pop3.DeleteMessage( i );
}
}
}
catch ( Exception e )
{
//This part's very important. Since we're running on a ThreadPool thread right now, any exceptions
//thrown on this thread will be swallowed by the ThreadPool. If an exception happens, we need to
//somehow marshal it back to the thread that initiated the async operation and rethrow it there.
//Forutnately, the AsyncResult base class lets us do that. We'll catch the exception here and
//pass it to Complete(). When the originating thread calls AsyncResult.End() on us, the AsyncResult base
//class will rethrow the exception on the right thread so it can be handled by the application.
bCaughtException = true;
base.Complete( false, e );
}
finally
{
if ( pop3 != null )
pop3.Close( true );
}
if ( !bCaughtException )
base.Complete( false );
}
